Sample records for matter power spectrum

  1. REVISING THE HALOFIT MODEL FOR THE NONLINEAR MATTER POWER SPECTRUM

    SciTech Connect (OSTI)

    Takahashi, Ryuichi [Faculty of Science and Technology, Hirosaki University, 3 bunkyo-cho, Hirosaki, Aomori 036-8561 (Japan); Sato, Masanori [Department of Physics, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Nishimichi, Takahiro; Taruya, Atsushi; Oguri, Masamune [Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa, Chiba 277-8583 (Japan)

    2012-12-20T23:59:59.000Z

    Based on a suite of state-of-the-art high-resolution N-body simulations, we revisit the so-called halofit model as an accurate fitting formula for the nonlinear matter power spectrum. While the halofit model has frequently been used as a standard cosmological tool to predict the nonlinear matter power spectrum in a universe dominated by cold dark matter, its precision has been limited by the low resolution of N-body simulations used to determine the fitting parameters, suggesting the necessity of an improved fitting formula at small scales for future cosmological studies. We run high-resolution N-body simulations for 16 cosmological models around the Wilkinson Microwave Anisotropy Probe best-fit cosmological parameters (one-, three-, five-, and seven-year results), including dark energy models with a constant equation of state. The simulation results are used to re-calibrate the fitting parameters of the halofit model so as to reproduce small-scale power spectra of the N-body simulations, while keeping the precision at large scales. The revised fitting formula provides an accurate prediction of the nonlinear matter power spectrum in a wide range of wavenumbers (k {<=} 30 h Mpc{sup -1}) at redshifts 0 {<=} z {<=} 10, with 5% precision for k {<=} 1 h Mpc{sup -1} at 0 {<=} z {<=} 10 and 10% for 1 {<=} k {<=} 10 h Mpc{sup -1} at 0 {<=} z {<=} 3. We discuss the impact of the improved halofit model on weak-lensing power spectra and correlation functions, and show that the improved model better reproduces ray-tracing simulation results.

  2. PkANN: Non-Linear Matter Power Spectrum Interpolation through Artificial Neural Networks

    E-Print Network [OSTI]

    Agarwal, Shankar

    2012-12-31T23:59:59.000Z

    We investigate the interpolation of power spectra of matter fluctuations using artificial neural networks (ANNs). We present a new approach to confront small-scale non-linearities in the matter power spectrum. This ...

  3. Unscreening modified gravity in the matter power spectrum

    E-Print Network [OSTI]

    Lucas Lombriser; Fergus Simpson; Alexander Mead

    2015-01-20T23:59:59.000Z

    Viable modifications of gravity that may produce cosmic acceleration need to be screened in high-density regions such as the Solar System, where general relativity is well tested. Screening mechanisms also prevent strong anomalies in the large-scale structure and limit the constraints that can be inferred on these gravity models from cosmology. We find that by suppressing the contribution of the screened high-density regions in the matter power spectrum, allowing a greater contribution of unscreened low densities, modified gravity models can be more readily discriminated from the concordance cosmology. Moreover, by variation of density thresholds, degeneracies with other effects may be dealt with more adequately. Specializing to chameleon gravity as a worked example for screening in modified gravity, employing N-body simulations of f(R) models and the halo model of chameleon theories, we demonstrate the effectiveness of this method. We find that a percent-level measurement of the clipped power at k Solar System tests or distance indicators in unscreened dwarf galaxies.

  4. Unscreening modified gravity in the matter power spectrum

    E-Print Network [OSTI]

    Lombriser, Lucas; Mead, Alexander

    2015-01-01T23:59:59.000Z

    Viable modifications of gravity that may produce cosmic acceleration need to be screened in high-density regions such as the Solar System, where general relativity is well tested. Screening mechanisms also prevent strong anomalies in the large-scale structure and limit the constraints that can be inferred on these gravity models from cosmology. We find that by suppressing the contribution of the screened high-density regions in the matter power spectrum, allowing a greater contribution of unscreened low densities, modified gravity models can be more readily discriminated from the concordance cosmology. Moreover, by variation of density thresholds, degeneracies with other effects may be dealt with more adequately. Specializing to chameleon gravity as a worked example for screening in modified gravity, employing N-body simulations of f(R) models and the halo model of chameleon theories, we demonstrate the effectiveness of this method. We find that a percent-level measurement of the clipped power at k < 0.3 h...

  5. EFFECTS OF THE NEUTRINO MASS SPLITTING ON THE NONLINEAR MATTER POWER SPECTRUM

    SciTech Connect (OSTI)

    Wagner, Christian; Verde, Licia; Jimenez, Raul [Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Marti i Franques 1, E08028 Barcelona (Spain)

    2012-06-20T23:59:59.000Z

    We have performed cosmological N-body simulations which include the effect of the masses of the individual neutrino species. The simulations were aimed at studying the effect of different neutrino hierarchies on the matter power spectrum. Compared to the linear theory predictions, we find that nonlinearities enhance the effect of hierarchy on the matter power spectrum at mildly nonlinear scales. The maximum difference between the different hierarchies is about 0.5% for a sum of neutrino masses of 0.1 eV. Albeit this is a small effect, it is potentially measurable from upcoming surveys. In combination with neutrinoless double-{beta} decay experiments, this opens up the possibility of using the sky to determine if neutrinos are Majorana or Dirac fermions.

  6. The Space Density of Galaxy Peaks and the Linear Matter Power Spectrum

    E-Print Network [OSTI]

    Rupert A. C. Croft; Enrique Gaztanaga

    1997-01-22T23:59:59.000Z

    One way of recovering information about the initial conditions of the Universe is by measuring features of the cosmological density field which are preserved during gravitational evolution and galaxy formation. In this paper we study the total number density of peaks in a (galaxy) point distribution smoothed with a filter, evaluating its usefulness as a means of inferring the shape of the initial (matter) power spectrum. We find that in numerical simulations which start from Gaussian initial conditions, the peak density follows well that predicted by the theory of Gaussian density fields, even on scales where the clustering is mildly non-linear. For smaller filter scales, $r \\simlt 4-6 \\hmpc$, we see evidence of merging as the peak density decreases with time. On larger scales, the peak density is independent of time. One might also expect it to be fairly robust with respect to variations in biasing, i.e. the way galaxies trace mass fluctuations. We find that this is the case when we apply various biasing prescriptions to the matter distribution in simulations. If the initial conditions are Gaussian, it is possible to use the peak density measured from the evolved field to reconstruct the shape of the initial power spectrum. We describe a stable method for doing this and apply it to several biased and unbiased non-linear simulations. We are able to recover the slope of the linear matter power spectrum on scales $k \\simlt 0.4 \\hmpc^{-1}$. The reconstruction has the advantage of being independent of the cosmological parameters ($\\Omega$, $\\Lambda$, $H_0$) and of the clustering normalisation ($\\sigma_8$). The peak density and reconstructed power spectrum slope therefore promise to be powerful discriminators between popular cosmological scenarios.

  7. PkANN - II. A non-linear matter power spectrum interpolator developed using artificial neural networks

    E-Print Network [OSTI]

    Agarwal, Shankar; Feldman, Hume A; Lahav, Ofer; Thomas, Shaun A

    2013-01-01T23:59:59.000Z

    In this paper we introduce PkANN, a freely available software package for interpolating the non-linear matter power spectrum, constructed using Artificial Neural Networks (ANNs). Previously, using Halofit to calculate matter power spectrum, we demonstrated that ANNs can make extremely quick and accurate predictions of the power spectrum. Now, using a suite of 6380 N-body simulations spanning 580 cosmologies, we train ANNs to predict the power spectrum over the cosmological parameter space spanning $3\\sigma$ confidence level (CL) around the concordance cosmology. When presented with a set of cosmological parameters ($\\Omega_{\\rm m} h^2, \\Omega_{\\rm b} h^2, n_s, w, \\sigma_8, \\sum m_\

  8. MODELING THE NONLINEAR CLUSTERING IN MODIFIED GRAVITY MODELS. I. A FITTING FORMULA FOR THE MATTER POWER SPECTRUM OF f(R) GRAVITY

    SciTech Connect (OSTI)

    Zhao, Gong-Bo, E-mail: gongbo@icosmology.info [National Astronomy Observatories, Chinese Academy of Science, Beijing 100012, ChinaAND (China); Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX (United Kingdom)

    2014-04-01T23:59:59.000Z

    Based on a suite of N-body simulations of the Hu-Sawicki model of f(R) gravity with different sets of model and cosmological parameters, we develop a new fitting formula with a numeric code, MGHalofit, to calculate the nonlinear matter power spectrum P(k) for the Hu-Sawicki model. We compare the MGHalofit predictions at various redshifts (z ? 1) to the f(R) simulations and find that the relative error of the MGHalofit fitting formula of P(k) is no larger than 6% at k ? 1 h Mpc{sup –1} and 12% at k in (1, 10] h Mpc{sup –1}, respectively. Based on a sensitivity study of an ongoing and a future spectroscopic survey, we estimate the detectability of a signal of modified gravity described by the Hu-Sawicki model using the power spectrum up to quasi-nonlinear scales.

  9. Atick-Witten Hagedorn Conjecture, near scale-invariant matter and blue-tilted gravity power spectrum

    E-Print Network [OSTI]

    Tirthabir Biswas; Tomi Koivisto; Anupam Mazumdar

    2014-05-03T23:59:59.000Z

    We will provide an interesting new mechanism to generate almost scale invariant seed density perturbations with a red spectrum, while keeping the gravitational wave spectrum blue-tilted in a stringy thermal contracting phase at temperatures beyond the Hagedorn temperature. This phase is often referred to as the Hagedorn phase where the free energy has been conjectured by Atick and Witten to grow more slowly than ordinary radiation. The primordial fluctuations are created by the statistical thermal fluctuations determined by the partition function, rather than quantum vacuum driven fluid dynamical fluctuations. In order for our mechanism to work we require a non-singular bouncing cosmology.

  10. Causality and the Power Spectrum

    E-Print Network [OSTI]

    James Robinson; Benjamin D. Wandelt

    1995-07-12T23:59:59.000Z

    We find constraints on the generation of super-causal-horizon energy perturbations from a smooth initial state, under a simple physical scheme. We quantify these constraints by placing the upper limit $\\lambda_c = 3.0 d_H$ on the wavelength at which the power spectrum turns over to $k^4$ behavior. This means that sub-horizon processes can generate significant power on scales further outside the horizon than one might naively expect. The existence of this limit may have important implications for the interpretation of the small scale power spectrum of the Cosmic Microwave Background.

  11. Effective dark matter power spectra in $f(R)$ gravity

    E-Print Network [OSTI]

    He, Jian-hua; Hawken, Adam J

    2015-01-01T23:59:59.000Z

    Using N-body simulations, we measure the power spectrum of the effective dark matter density field, which is defined through the modified Poisson equation in $f(R)$ cosmologies. We find that when compared to the conventional dark matter power spectrum, the effective power spectrum deviates more significantly from the $\\Lambda$CDM model. For models with $f_{R0}=-10^{-4}$, the deviation can exceed 150\\% while the deviation of the conventional matter power spectrum is less than 50\\%. Even for models with $f_{R0}=-10^{-6}$, for which the conventional matter power spectrum is very close to the $\\Lambda$CDM prediction, the effective power spectrum shows sizeable deviations. Our results indicate that traditional analyses based on the dark matter density field may seriously underestimate the impact of $f(R)$ gravity on galaxy clustering. We therefore suggest the use of the effective density field in such studies.

  12. A ROBUST MEASURE OF COSMIC STRUCTURE BEYOND THE POWER SPECTRUM: COSMIC FILAMENTS AND THE TEMPERATURE OF DARK MATTER

    SciTech Connect (OSTI)

    Obreschkow, D.; Power, C. [International Centre for Radio Astronomy Research (ICRAR), M468, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia)] [International Centre for Radio Astronomy Research (ICRAR), M468, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia); Bruderer, M. [Institut fuer Theoretische Physik, Albert-Einstein Allee 11, Universitaet Ulm, D-89069 Ulm (Germany)] [Institut fuer Theoretische Physik, Albert-Einstein Allee 11, Universitaet Ulm, D-89069 Ulm (Germany); Bonvin, C. [Kavli Institute for Cosmology Cambridge and Institute of Astronomy, Madingley Road, Cambridge CB3 OHA (United Kingdom)] [Kavli Institute for Cosmology Cambridge and Institute of Astronomy, Madingley Road, Cambridge CB3 OHA (United Kingdom)

    2013-01-10T23:59:59.000Z

    We discover that the mass of dark matter particles m {sub DM} is imprinted in phase correlations of the cosmic density field more significantly than in the two-point correlation. In particular, phase correlations trace m {sub DM} out to scales about five times larger than the two-point correlation. This result relies on a new estimator l(r) of pure phase information in Fourier space, which can be interpreted as a parameter-free and scale-invariant tracer of filament-like structure. Based on simulated density fields, we show how m {sub DM} can, in principle, be measured using l(r), given a suitably reconstructed density field.

  13. Power Spectrum of Inflationary Attractors

    E-Print Network [OSTI]

    Benedict J. Broy; Diederik Roest; Alexander Westphal

    2015-01-20T23:59:59.000Z

    Inflationary attractors predict the spectral index and tensor-to-scalar ratio to take specific values that are consistent with Planck. An example is the universal attractor for models with a generalised non-minimal coupling, leading to Starobinsky inflation. In this paper we demonstrate that it also predicts a specific relation between the amplitude of the power spectrum and the number of e-folds. The length and height of the inflationary plateau are related via the non-minimal coupling: in a wide variety of examples, the observed power normalisation leads to at least 55 flat e-foldings. Prior to this phase, the inflationary predictions vary and can account for the observational indications of power loss at large angular scales.

  14. Dark energy and non-linear power spectrum

    E-Print Network [OSTI]

    Sang Gyu Biern; Jinn-Ouk Gong

    2015-06-29T23:59:59.000Z

    We investigate the effects of homogeneous general dark energy on the non-linear matter perturbation in fully general relativistic context. The equation for the density contrast contains even at linear order new contributions which are non-zero for general dark energy. Taking into account the next-leading-order corrections, we derive the total power spectrum in real and redshift spaces. We find that the observable galaxy power spectrum deviates from the LambdaCDM spectrum, which is nearly identical to that in the Einstein-de Sitter universe, and the relative difference is about 10% on a scale of the baryon acoustic oscillations.

  15. A Narrower Spectrum for a Wider View of Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Wider View of Matter July 9, 2014 Bookmark and Share Ultra-high-resolution dispersive optics of the new inelastic x-ray scattering (IXS) spectrometer (top) and IXS spectrum of...

  16. Tilting the Primordial Power Spectrum with Bulk Viscosity

    E-Print Network [OSTI]

    James E. Lidsey

    1993-12-16T23:59:59.000Z

    Within the context of the cold dark matter model, current observations suggest that inflationary models which generate a tilted primordial power spectrum with negligible gravitational waves provide the most promising mechanism for explaining large scale clustering. The general form of the inflationary potential which produces such a spectrum is a hyperbolic function and is interpreted physically as a bulk viscous stress contribution to the energy-momentum of a perfect baryotropic fluid. This is equivalent to expanding the equation of state as a truncated Taylor series. Particle physics models which lead to such a potential are discussed.

  17. Constraining the Power Spectrum Using the Column Density Distribution: a Status Report

    E-Print Network [OSTI]

    Lam Hui

    1997-12-04T23:59:59.000Z

    We review the arguments for how the slope of the column density distribution of the Lyman-alpha forest should depend on the matter power spectrum. The latest progress, presented by various groups in this conference and elsewhere, is summarized.

  18. Smoothing spline primordial power spectrum reconstruction

    E-Print Network [OSTI]

    Carolyn Sealfon; Licia Verde; Raul Jimenez

    2005-11-01T23:59:59.000Z

    We reconstruct the shape of the primordial power spectrum (PPS) using a smoothing spline. Our adapted smoothing spline technique provides a complementary method to existing efforts to search for smooth features in the PPS, such as a running spectral index. With this technique we find no significant indication with WMAP first-year data that the PPS deviates from Harrison-Zeldovich and no evidence for loss of power on large scales. We also examine the effect on the cosmological parameters of the additional PPS freedom. Smooth variations in the PPS are not significantly degenerate with other cosmological parameters, but the spline reconstruction greatly increases the errors on the optical depth and baryon fraction.

  19. Bayesian power spectrum analysis of interferometric data

    E-Print Network [OSTI]

    Sutter, P M; Malu, Siddarth

    2011-01-01T23:59:59.000Z

    We present a Bayesian power spectrum and signal map inference engine which can be adapted to interferometric observations of anisotropies in the cosmic microwave background, 21 cm emission line mapping of galactic brightness fluctuations, or 21 cm absorption line mapping of neutral hydrogen in the dark ages. The method uses Gibbs sampling to generate a sampled representation of the power spectrum posterior and the posterior of signal maps given a set of measured visibilities in the uv-plane. We use a mock interferometric CMB observation to demonstrate the validity of this method in the flat-sky approximation when adapted to take into account arbitrary coverage of the uv-plane, mode-mode correlations due to observations on a finite patch, and heteroschedastic visibility errors. The computational requirements scale as O(n_p log n_p) where n_p measures the ratio of the size of the detector array to the inter-detector spacing, meaning that Gibbs sampling is a viable technique for meeting the data analysis require...

  20. Power spectrum of the fluctuation of Chebyshev's prime counting function

    E-Print Network [OSTI]

    Boon Leong Lan; Shaohen Yong

    2005-06-20T23:59:59.000Z

    The one-sided power spectrum of the fluctuation of Chebyshev's weighted prime counting function is numerically estimated based on samples of the fluctuating function of different sizes. The power spectrum is also estimated analytically for large frequency based on Riemann hypothesis and the exact formula for the fluctuating function in terms of all the non-trivial Riemann zeroes. Our analytical estimate is consistent with our numerical estimate of a 1/f^2 power spectrum.

  1. Just enough inflation: power spectrum modifications at large scales

    E-Print Network [OSTI]

    Michele Cicoli; Sean Downes; Bhaskar Dutta; Francisco G. Pedro; Alexander Westphal

    2014-07-03T23:59:59.000Z

    We show that models of `just enough' inflation, where the slow-roll evolution lasted only $50-60$ e-foldings, feature modifications of the CMB power spectrum at large angular scales. We perform a systematic and model-independent analysis of any possible non-slow-roll background evolution prior to the final stage of slow-roll inflation. We find a high degree of universality since most common backgrounds like fast-roll evolution, matter or radiation-dominance give rise to a power loss at large angular scales and a peak together with an oscillatory behaviour at scales around the value of the Hubble parameter at the beginning of slow-roll inflation. Depending on the value of the equation of state parameter, different pre-inflationary epochs lead instead to an enhancement of power at low-$\\ell$, and so seem disfavoured by recent observational hints for a lack of CMB power at $\\ell\\lesssim 40$. We also comment on the importance of initial conditions and the possibility to have multiple pre-inflationary stages.

  2. Lyman Alpha Flux Power Spectrum and Its Covariance

    E-Print Network [OSTI]

    Hu Zhan; Romeel Dave; Daniel Eisenstein; Neal Katz

    2005-08-10T23:59:59.000Z

    We analyze the flux power spectrum and its covariance using simulated Lyman alpha forests. We find that pseudo-hydro techniques are good approximations of hydrodynamical simulations at high redshift. However, the pseudo-hydro techniques fail at low redshift because they are insufficient for characterizing some components of the low-redshift intergalactic medium, notably the warm-hot intergalactic medium. Hence, to use the low-redshift Lyman alpha flux power spectrum to constrain cosmology, one would need realistic hydrodynamical simulations. By comparing one-dimensional mass statistics with flux statistics, we show that the nonlinear transform between density and flux quenches the fluctuations so that the flux power spectrum is much less sensitive to cosmological parameters than the one-dimensional mass power spectrum. The covariance of the flux power spectrum is nearly Gaussian. As such, the uncertainties of the underlying mass power spectrum could still be large, even though the flux power spectrum can be precisely determined from a small number of lines of sight.

  3. Power spectrum of electron number density perturbations at cosmological recombination epoch

    E-Print Network [OSTI]

    B. Venhlovska; B. Novosyadlyj

    2009-02-19T23:59:59.000Z

    The power spectrum of number density perturbations of free electrons is obtained for the epoch of cosmological recombination of hydrogen. It is shown that amplitude of the electron perturbations power spectrum of scales larger than acoustic horizon exceeds by factor of 17 the amplitude of baryon matter density ones (atoms and ions of hydrogen and helium). In the range of the first and second acoustic peaks such relation is 18, in the range of the third one 16. The dependence of such relations on cosmological parameters is analysed too.

  4. Power Control and Capacity of Spread Spectrum Wireless Networks

    E-Print Network [OSTI]

    Tse, David

    Power Control and Capacity of Spread Spectrum Wireless Networks S.V. Hanly a;1 , and D.N. Tse b;2, there has been signif­ icant research in the area in recent years. While power control has been considered questions about optimal power control as well as the problem of charac­ terizing the resulting network

  5. Sequential Bandwidth and Power Auctions for Spectrum Sharing

    E-Print Network [OSTI]

    Kuzmanovic, Aleksandar

    user's power). Although the worst-case efficiency loss can be significant, numerical results1 Sequential Bandwidth and Power Auctions for Spectrum Sharing Junjik Bae, Eyal Beigman, Randall resource (bandwidth or power) among compet- ing transmitters. The resource is assumed to be managed

  6. Cosmology Constraints from the Weak Lensing Peak Counts and the Power Spectrum in CFHTLenS

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Jia [Department of Astronomy and Astrophysics, Columbia University, New York, NY, (United States); May, Morgan [Physics Department, Brookhaven National Laboratory, Upton, NY, (United States); Petri, Andrea [Department of Physics, Columbia University, New York, NY, (United States); Haiman, Zoltan [Department of Astronomy and Astrophysics, Columbia University, New York, NY, (United States); Institute for Strings, Cosmology, and Astroparticle Physics (ISCAP), Columbia University, New York, (United States); Hui, Lam [Department of Physics, Columbia University, New York, NY, (United States); Institute for Strings, Cosmology, and Astroparticle Physics (ISCAP), Columbia University, New York, (United States); Kratochvil, Jan M. [Astrophysics and Cosmology Research Unit, University of KwaZulu-Natal, Westville, Durban, (South Africa)

    2015-03-01T23:59:59.000Z

    Lensing peaks have been proposed as a useful statistic, containing cosmological information from non-Gaussianities that is inaccessible from traditional two-point statistics such as the power spectrum or two-point correlation functions. Here we examine constraints on cosmological parameters from weak lensing peak counts, using the publicly available data from the 154 deg2 CFHTLenS survey. We utilize a new suite of ray-tracing N-body simulations on a grid of 91 cosmological models, covering broad ranges of the three parameters ?m, ?8, and w, and replicating the galaxy sky positions, redshifts, and shape noise in the CFHTLenS observations. We then build an emulator that interpolates the power spectrum and the peak counts to an accuracy of ? 5%, and compute the likelihood in the three-dimensional parameter space (?m, ?8, w) from both observables. We find that constraints from peak counts are comparable to those from the power spectrum, and somewhat tighter when different smoothing scales are combined. Neither observable can constrain w without external data. When the power spectrum and peak counts are combined, the area of the error “banana” in the (?m, ?8) plane reduces by a factor of ? two, compared to using the power spectrum alone. For a flat ? cold dark matter model, combining both statistics, we obtain the constraint ?8(?m/0.27)0.63 = 0.85+0.03-0.03.

  7. Cosmology Constraints from the Weak Lensing Peak Counts and the Power Spectrum in CFHTLenS

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Jia; May, Morgan; Petri, Andrea; Haiman, Zoltan; Hui, Lam; Kratochvil, Jan M.

    2015-03-01T23:59:59.000Z

    Lensing peaks have been proposed as a useful statistic, containing cosmological information from non-Gaussianities that is inaccessible from traditional two-point statistics such as the power spectrum or two-point correlation functions. Here we examine constraints on cosmological parameters from weak lensing peak counts, using the publicly available data from the 154 deg2 CFHTLenS survey. We utilize a new suite of ray-tracing N-body simulations on a grid of 91 cosmological models, covering broad ranges of the three parameters ?m, ?8, and w, and replicating the galaxy sky positions, redshifts, and shape noise in the CFHTLenS observations. We then build an emulator thatmore »interpolates the power spectrum and the peak counts to an accuracy of ? 5%, and compute the likelihood in the three-dimensional parameter space (?m, ?8, w) from both observables. We find that constraints from peak counts are comparable to those from the power spectrum, and somewhat tighter when different smoothing scales are combined. Neither observable can constrain w without external data. When the power spectrum and peak counts are combined, the area of the error “banana” in the (?m, ?8) plane reduces by a factor of ? two, compared to using the power spectrum alone. For a flat ? cold dark matter model, combining both statistics, we obtain the constraint ?8(?m/0.27)0.63 = 0.85+0.03-0.03.« less

  8. An ideal mass assignment scheme for measuring the Power Spectrum with FFTs

    E-Print Network [OSTI]

    Weiguang Cui; Lei Liu; Xiaohu Yang; Yu Wang; Longlong Feng; Volker Springel

    2008-07-20T23:59:59.000Z

    In measuring the power spectrum of the distribution of large numbers of dark matter particles in simulations, or galaxies in observations, one has to use Fast Fourier Transforms (FFT) for calculational efficiency. However, because of the required mass assignment onto grid points in this method, the measured power spectrum $\\la |\\delta^f(k)|^2\\ra$ obtained with an FFT is not the true power spectrum $P(k)$ but instead one that is convolved with a window function $|W(\\vec k)|^2$ in Fourier space. In a recent paper, Jing (2005) proposed an elegant algorithm to deconvolve the sampling effects of the window function and to extract the true power spectrum, and tests using N-body simulations show that this algorithm works very well for the three most commonly used mass assignment functions, i.e., the Nearest Grid Point (NGP), the Cloud In Cell (CIC) and the Triangular Shaped Cloud (TSC) methods. In this paper, rather than trying to deconvolve the sampling effects of the window function, we propose to select a particular function in performing the mass assignment that can minimize these effects. An ideal window function should fulfill the following criteria: (i) compact top-hat like support in Fourier space to minimize the sampling effects; (ii) compact support in real space to allow a fast and computationally feasible mass assignment onto grids. We find that the scale functions of Daubechies wavelet transformations are good candidates for such a purpose. Our tests using data from the Millennium Simulation show that the true power spectrum of dark matter can be accurately measured at a level better than 2% up to $k=0.7k_N$, without applying any deconvolution processes. The new scheme is especially valuable for measurements of higher order statistics, e.g. the bi-spectrum,........

  9. On the Power Spectrum Density of Gamma Ray Bursts

    E-Print Network [OSTI]

    Motoko Suzuki; Masahiro Morikawa; Izumi Joichi

    2001-04-13T23:59:59.000Z

    Gamma ray bursts (GRBs) are known to have short-time variability and power-law behavior with the index -1.67 in the power spectrum density. Reanalyzing the expanded data, we have found a) the power-law comes from the global profile of the burst and not from the self-similar shots nor rapid fluctuations in the luminosity profile. b) The power indices vary from burst to burst and the value -1.67 is given simply as the mean value of the distribution; there is no systematic correlation among GRBs to yield the power law.

  10. Quantifying galactic propagation uncertainty in WIMP dark matter search with AMS01 Z=-1 spectrum

    E-Print Network [OSTI]

    Xiao, Sa, Ph. D. Massachusetts Institute of Technology

    2009-01-01T23:59:59.000Z

    A search for a WIMP dark matter annihilation signal is carried out in the AMS01 negatively charged (Z=-I) particle spectrum, following a set of supersymmetric benchmark scenarios in the mSUGRA framework. The result is ...

  11. Constraints on power spectrum of density fluctuations from PBH evaporations

    E-Print Network [OSTI]

    Edgar Bugaev; Peter Klimai

    2006-12-21T23:59:59.000Z

    We calculate neutrino and photon energy spectra in extragalactic space from evaporation of primordial black holes, assuming that the power spectrum of primordial density fluctuations has a strong bump in the region of small scales. The constraints on the parameters of this bump based on neutrino and photon cosmic background data are obtained.

  12. Computing Fourier Series and Power Spectrum with MATLAB

    E-Print Network [OSTI]

    Storey, Brian D.

    Computing Fourier Series and Power Spectrum with MATLAB By Brian D. Storey 1. Introduction Fourier. If you ever watched the blink- ing lights on a stereo equalizer then you have seen Fourier analysis Fourier, a French Mathematician who once served as a scientific adviser to Napoleon, is credited

  13. SIC (MUltiple SIgnal Classification) CSP (Cross-power Spectrum Phase)

    E-Print Network [OSTI]

    Takiguchi, Tetsuya

    2ch CSP ( ) 1 MU- SIC (MUltiple SIgnal Classification) CSP (Cross- power Spectrum Phase) [1, 2, 3, 4] [5, 6] [7, 8, 9, 10] [7] CSP CSP [8] [9] CSP [10] Estimation of talker's head orientation based (Kobe univ.) [11] 2ch CSP CSP CSP CSP 2 CSP GCC-PHAT (Generalized Cross- Correlation PHAse Transform

  14. Isocurvature and curvaton perturbations with red power spectrum and large hemispherical asymmetry

    SciTech Connect (OSTI)

    McDonald, John, E-mail: j.mcdonald@lancaster.ac.uk [Lancaster-Manchester-Sheffield Consortium for Fundamental Physics, Cosmology and Astroparticle Physics Group, Dept. of Physics, University of Lancaster, Lancaster LA1 4YB (United Kingdom)

    2013-07-01T23:59:59.000Z

    We calculate the power spectrum and hemispherical asymmetry of isocurvature and curvaton perturbations due to a complex field ? which is evolving along the tachyonic part of its potential. Using a semi-classical evolution of initially sub-horizon quantum fluctuations, we compute the power spectrum, mean field and hemispherical asymmetry as a function of the number of e-foldings of tachyonic growth ?N and the tachyonic mass term cH{sup 2}. We find that a large hemispherical asymmetry due to the modulation of |?| can easily be generated via the spatial modulation of |?| across the horizon, with ?|?|/|?| > 0.5 when the observed Universe exits the horizon within 10-40 e-foldings of the beginning of tachyonic evolution and c is in the range 0.1-1. The spectral index of the isocurvature and curvaton perturbations is generally negative, corresponding to a red power spectrum. Dark matter isocurvature perturbations due to an axion-like curvaton with a large hemispherical asymmetry may be able to explain the hemispherical asymmetry observed by WMAP and Planck. In this case, the red spectrum can additionally suppress the hemispherical asymmetry at small scales, which should make it easier to satisfy scale-dependence requirements on the asymmetry from quasar number counts.

  15. THE TURBULENCE POWER SPECTRUM IN OPTICALLY THICK INTERSTELLAR CLOUDS

    SciTech Connect (OSTI)

    Burkhart, Blakesley; Lazarian, A. [Astronomy Department, University of Wisconsin, Madison, 475 North Charter Street, WI 53711 (United States); Ossenkopf, V.; Stutzki, J. [Physikalisches Institut der Universitaet zu Koeln, Zuelpicher Strasse 77, D-50937 Koeln (Germany)

    2013-07-10T23:59:59.000Z

    The Fourier power spectrum is one of the most widely used statistical tools to analyze the nature of magnetohydrodynamic (MHD) turbulence in the interstellar medium. Lazarian and Pogosyan predicted that the spectral slope should saturate to -3 for an optically thick medium and many observations exist in support of their prediction. However, there have not been any numerical studies to date for testing these results. We analyze the spatial power spectrum of MHD simulations with a wide range of sonic and Alfvenic Mach numbers, which include radiative transfer effects of the {sup 13}CO transition. We numerically confirm the predictions of Lazarian and Pogosyan that the spectral slope of line intensity maps of an optically thick medium saturates to -3. Furthermore, for very optically thin supersonic CO gas, where the density or CO abundance values are too low to excite emission in all but the densest shock compressed gas, we find that the spectral slope is shallower than expected from the column density. Finally, we find that mixed optically thin/thick CO gas, which has average optical depths on the order of unity, shows mixed behavior: for super-Alfvenic turbulence, the integrated intensity power spectral slopes generally follow the same trend with sonic Mach number as the true column density power spectrum slopes. However, for sub-Alfvenic turbulence the spectral slopes are steeper with values near -3 which are similar to the very optically thick regime.

  16. Density Power Spectrum of Compressible Hydrodynamic Turbulent Flows

    E-Print Network [OSTI]

    Jongsoo Kim; Dongsu Ryu

    2005-07-26T23:59:59.000Z

    Turbulent flows are ubiquitous in astrophysical environments, and understanding density structures and their statistics in turbulent media is of great importance in astrophysics. In this paper, we study the density power spectra, $P_{\\rho}$, of transonic and supersonic turbulent flows through one and three-dimensional simulations of driven, isothermal hydrodynamic turbulence with root-mean-square Mach number in the range of $1 \\la M_{\\rm rms} \\la 10$. From one-dimensional experiments we find that the slope of the density power spectra becomes gradually shallower as the rms Mach number increases. It is because the density distribution transforms from the profile with {\\it discontinuities} having $P_{\\rho} \\propto k^{-2}$ for $M_{\\rm rms} \\sim 1$ to the profile with {\\it peaks} having $P_{\\rho} \\propto k^0$ for $M_{\\rm rms} \\gg 1$. We also find that the same trend is carried to three-dimension; that is, the density power spectrum flattens as the Mach number increases. But the density power spectrum of the flow with $M_{\\rm rms} \\sim 1$ has the Kolmogorov slope. The flattening is the consequence of the dominant density structures of {\\it filaments} and {\\it sheets}. Observations have claimed different slopes of density power spectra for electron density and cold H I gas in the interstellar medium. We argue that while the Kolmogorov spectrum for electron density reflects the {\\it transonic} turbulence of $M_{\\rm rms} \\sim 1$ in the warm ionized medium, the shallower spectrum of cold H I gas reflects the {\\it supersonic} turbulence of $M_{\\rm rms} \\sim$ a few in the cold neutral medium.

  17. Single-Particle Spectrum of Pure Neutron Matter

    E-Print Network [OSTI]

    Khalaf Gad; Hesham Mansour

    2015-02-06T23:59:59.000Z

    We have calculated the self-consistent auxiliary potential effects on the binding energy of neutron matter using the Brueckner Hartree Fock approach by adopting the Argonne V18 and CD-Bonn potentials. The binding energy with the four different choices for the self-consistent auxiliary potential is discussed. Also, the binding energy of neutron matter has been computed within the framework of the self-consistent Green s function approach. We also compare the binding energies obtained in this study with those obtained by various microscopic approaches.

  18. Fast optimal CMB power spectrum estimation with Hamiltonian sampling

    E-Print Network [OSTI]

    J. F. Taylor; M. A. J. Ashdown; M. P. Hobson

    2008-05-14T23:59:59.000Z

    We present a method for fast optimal estimation of the temperature angular power spectrum from observations of the cosmic microwave background. We employ a Hamiltonian Monte Carlo (HMC) sampler to obtain samples from the posterior probability distribution of all the power spectrum coefficients given a set of observations. We compare the properties of the HMC and the related Gibbs sampling approach on low-resolution simulations and find that the HMC method performs favourably even in the regime of relatively low signal-to-noise. We also demonstrate the method on high-resolution data by applying it to simulated WMAP data. Analysis of a WMAP-sized data set is possible in a around eighty hours on a high-end desktop computer. HMC imposes few conditions on the distribution to be sampled and provides us with an extremely flexible approach upon which to build.

  19. Nonisotropy in the CMB power spectrum in single field inflation

    SciTech Connect (OSTI)

    Donoghue, John F. [Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Dutta, Koushik [Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, D-80805 Muenchen (Germany); Ross, Andreas [Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Department of Physics, Yale University, New Haven, Connecticut 06520 (United States)

    2009-07-15T23:59:59.000Z

    Contaldi et al.[C. R. Contaldi, M. Peloso, L. Kofman, and A. Linde, J. Cosmol. Astropart. Phys. 07 (2003) 002] have suggested that an initial period of kinetic energy domination in single field inflation may explain the lack of CMB power at large angular scales. We note that in this situation it is natural that there also be a spatial gradient in the initial value of the inflaton field, and that this can provide a spatial asymmetry in the observed CMB power spectrum, manifest at low values of l. We investigate the nature of this asymmetry and comment on its relation to possible anomalies at low l.

  20. Nuclear stopping power in warm and hot dense matter

    SciTech Connect (OSTI)

    Faussurier, Gerald; Blancard, Christophe [CEA, DAM, DIF, F-91 297 Arpajon (France); Gauthier, Maxence [CEA, DAM, DIF, F-91 297 Arpajon (France); LULI, Ecole Polytechnique, CNRS, CEA, UPMC, Route de Saclay, 91128 Palaiseau (France)

    2013-01-15T23:59:59.000Z

    We present a method to estimate the nuclear component of the stopping power of ions propagating in dense matter. Three kinds of effective pair potentials are proposed. Results from the warm dense matter regime and the domain of high energy density physics are presented and discussed for proton and helium. The role of ionic temperature is examined. The nuclear stopping power can play a noticeable role in hot dense matter.

  1. CMB anisotropy power spectrum using linear combinations of WMAP maps Rajib Saha,1,2,3

    E-Print Network [OSTI]

    Souradeep, Tarun

    CMB anisotropy power spectrum using linear combinations of WMAP maps Rajib Saha,1,2,3 Simon Prunet year WMAP data by Saha et al. 2006. All previous estimates of the power spectrum of the CMB are based

  2. Fractal power spectra plotted upside-down Comment on ``Scaling of power spectrum of extinction events

    E-Print Network [OSTI]

    Kirchner, James W.

    Discussion Fractal power spectra plotted upside-down Comment on ``Scaling of power spectrum. Dimri and Pra- kash interpret their results as demonstrating a fractal pattern in the fossil record or not the underlying data are fractal. Similarly, their use of interpolated time series (in their ¢gures 1b,d, 2a,b, 3a

  3. Higher derivatives and power spectrum in effective single field inflation

    E-Print Network [OSTI]

    Jinn-Ouk Gong; Min-Seok Seo; Spyros Sypsas

    2015-03-10T23:59:59.000Z

    We study next-to-leading corrections to the effective action of the curvature perturbation obtained by integrating out the coupled heavy isocurvature perturbation. These corrections result from including higher order derivative operators, weighted by the mass scale of the heavy physics, in the effective theory expansion. We find that the correction terms are suppressed by the ratio of the Hubble parameter to the heavy mass scale. The corresponding corrections to the power spectrum of the curvature perturbation are presented for a simple illustrative example.

  4. Cosmic string formation and the power spectrum of field configurations

    E-Print Network [OSTI]

    James Robinson; Andrew Yates

    1996-06-12T23:59:59.000Z

    We examine the statistical properties of defects formed by the breaking of a U(1) symmetry when the Higgs field has a power spectrum $P(k) \\propto k^n$. We find a marked dependence of the amount of infinite string on the spectral index $n$ and empirically identify an analytic form for this quantity. We also confirm that this result is robust to changes in the definition of infinite string. It is possible that this result could account for the apparent absence of infinite string in recent lattice-free simulations.

  5. The Power Spectrum, Bias Evolution, and the Spatial Three-Point Correlation Function

    E-Print Network [OSTI]

    Ari Buchalter; Marc Kamionkowski

    1999-03-30T23:59:59.000Z

    We calculate perturbatively the normalized spatial skewness, $S_3$, and full three-point correlation function (3PCF), $\\zeta$, induced by gravitational instability of Gaussian primordial fluctuations for a biased tracer-mass distribution in flat and open cold-dark-matter (CDM) models. We take into account the dependence on the shape and evolution of the CDM power spectrum, and allow the bias to be nonlinear and/or evolving in time, using an extension of Fry's (1996) bias-evolution model. We derive a scale-dependent, leading-order correction to the standard perturbative expression for $S_3$ in the case of nonlinear biasing, as defined for the unsmoothed galaxy and dark-matter fields, and find that this correction becomes large when probing positive effective power-spectrum indices. This term implies that the inferred nonlinear-bias parameter, as usually defined in terms of the smoothed density fields, might depend on the chosen smoothing scale. In general, we find that the dependence of $S_3$ on the biasing scheme can substantially outweigh that on the adopted cosmology. We demonstrate that the normalized 3PCF, $Q$, is an ill-behaved quantity, and instead investigate $Q_V$, the variance-normalized 3PCF. The configuration dependence of $Q_V$ shows similarly strong sensitivities to the bias scheme as $S_3$, but also exhibits significant dependence on the form of the CDM power spectrum. Though the degeneracy of $S_3$ with respect to the cosmological parameters and constant linear- and nonlinear-bias parameters can be broken by the full configuration dependence of $Q_V$, neither statistic can distinguish well between evolving and non-evolving bias scenarios. We show that this can be resolved, in principle, by considering the redshift dependence of $\\zeta$.

  6. The Power Spectrum of Galaxy Density Fluctuations: Current Results and Improved Techniques

    E-Print Network [OSTI]

    Michael S. Vogeley

    1995-08-17T23:59:59.000Z

    The power spectrum of density fluctuations measured from galaxy redshift surveys provides important constraints on models for the formation of large-scale structure. I review current results for the 3-D power spectrum and examine the limitations of current measurements and estimation techniques. To span the decade of wavelength between the scales probed by galaxy surveys and COBE, measure the detailed shape of the power spectrum, and accurately examine the dependence of clustering on galaxy species, we require deeper samples with carefully controlled selection criteria and improved techniques for power spectrum estimation. I describe a new method for estimating the power spectrum that optimally treats survey data with arbitrary geometry and sampling.

  7. Imprints of deviations from the gravitational inverse-square law on the power spectrum of mass fluctuations

    E-Print Network [OSTI]

    M. Sereno; J. A. Peacock

    2006-05-19T23:59:59.000Z

    Deviations from the gravitational inverse-square law would imprint scale-dependent features on the power spectrum of mass density fluctuations. We model such deviations as a Yukawa-like contribution to the gravitational potential and discuss the growth function in a mixed dark matter model with adiabatic initial conditions. Evolution of perturbations is considered in general non-flat cosmological models with a cosmological constant, and an analytical approximation for the growth function is provided. The coupling between baryons and cold dark matter across recombination is negligibly affected by modified gravity physics if the proper cutoff length of the long-range Yukawa-like force is > 10 h^{-1} Mpc. Enhancement of gravity affects the subsequent evolution, boosting large-scale power in a way that resembles the effect of a lower matter density. This phenomenon is almost perfectly degenerate in power-spectrum shape with the effect of a background of massive neutrinos. Back-reaction on density growth from a modified cosmic expansion rate should however also affect the normalization of the power spectrum, with a shape distortion similar to the case of a non-modified background.

  8. Using the Comoving Maximum of the Galaxy Power Spectrum to Measure Cosmological Curvature

    E-Print Network [OSTI]

    Tom Broadhurst; Andrew H. Jaffe

    1999-04-26T23:59:59.000Z

    The large-scale maximum at k~0.05 identified in the power-spectrum of galaxy fluctuations provides a co-moving scale for measuring cosmological curvature. In shallow 3D surveys the peak is broad, but appears to be well resolved in 1D, at ~130 Mpc (k=0.048), comprising evenly spaced peaks and troughs. Surprisingly similar behaviour is evident at z=3 in the distribution of Lyman-break galaxies, for which we find a 5 sigma excess of pairs separated by Delta z=0.22pm0.02, equivalent to 85Mpc for Omega=1, increasing to 170 Mpc for Omega=0, with a number density contrast of 30% averaged over 5 independent fields. The combination, 3.2\\Omega_m -\\Omega_{\\Lambda}=0.7, matches the local scale of 130 Mpc, i.e. Omega=0.2\\pm0.1 or Omega_{m}=0.4\\pm0.1 for the matter-dominated and flat models respectively, with an uncertainty given by the width of the excess correlation. The consistency here of the flat model with SNIa based claims is encouraging, but overshadowed by the high degree of coherence observed in 1D compared with conventional Gaussian models of structure formation. The appearance of this scale at high redshift and its local prominence in the distribution of Abell clusters lends support to claims that the high-z `spikes' represent young clusters. Finally we show that a spike in the primordial power spectrum of delta\\rho/\\rho=0.3 at k=0.05 has little effect on the CMB, except to exaggerate the first Doppler peak in flat matter-dominated models, consistent with recent observations. \\\\effect on the CMB, except to exaggerate the first Doppler peak in flat matter-dominated models, consistent with recent observations.

  9. What Does The PAMELA Antiproton Spectrum Tell Us About Dark Matter?

    E-Print Network [OSTI]

    Dan Hooper; Tim Linden; Philipp Mertsch

    2014-10-06T23:59:59.000Z

    Measurements of the cosmic ray antiproton spectrum can be used to search for contributions from annihilating dark matter and to constrain the dark matter annihilation cross section. Depending on the assumptions made regarding cosmic ray propagation in the Galaxy, such constraints can be quite stringent. We revisit this topic, utilizing a set of propagation models fit to the cosmic ray boron, carbon, oxygen and beryllium data. We derive upper limits on the dark matter annihilation cross section and find that when the cosmic ray propagation parameters are treated as nuisance parameters (as we argue is appropriate), the resulting limits are significantly less stringent than have been previously reported. We also note (as have several previous groups) that simple GALPROP-like diffusion-reacceleration models predict a spectrum of cosmic ray antiprotons that is in good agreement with PAMELA's observations above ~5 GeV, but that significantly underpredict the flux at lower energies. Although the complexity of modeling cosmic ray propagation at GeV-scale energies makes it difficult to determine the origin of this discrepancy, we consider the possibility that the excess antiprotons are the result of annihilating dark matter. Suggestively, we find that this excess is best fit for a dark matter mass of approximately 35 GeV and annihilation cross section of approximately 1e-26 cm^3/s (to b-bbar), in good agreement with the mass and cross section previously shown to be required to generate the gamma-ray excess observed from the Galactic Center.

  10. The linear power spectrum of observed source number counts

    E-Print Network [OSTI]

    Challinor, Anthony

    2011-01-01T23:59:59.000Z

    We relate the observable number of sources per solid angle and redshift to the underlying proper source density and velocity, background evolution and line-of-sight potentials. We give an exact result in the case of linearized perturbations assuming general relativity. This consistently includes contributions of the source density perturbations and redshift distortions, magnification, radial displacement, and various additional linear terms that are small on sub-horizon scales. In addition we calculate the effect on observed luminosities, and hence the result for sources observed as a function of flux, including magnification bias and radial-displacement effects. We give the corresponding linear result for a magnitude-limited survey at low redshift, and discuss the angular power spectrum of the total count distribution. We also calculate the cross-correlation with the CMB polarization and temperature including Doppler source terms, magnification, redshift distortions and other velocity effects for the sources...

  11. A Non-parametric Analysis of the CMB Power Spectrum

    E-Print Network [OSTI]

    Christopher J. Miller; Robert C. Nichol; Christopher Genovese; Larry Wasserman

    2001-12-03T23:59:59.000Z

    We examine Cosmic Microwave Background (CMB) temperature power spectra from the BOOMERANG, MAXIMA, and DASI experiments. We non-parametrically estimate the true power spectrum with no model assumptions. This is a significant departure from previous research which used either cosmological models or some other parameterized form (e.g. parabolic fits). Our non-parametric estimate is practically indistinguishable from the best fit cosmological model, thus lending independent support to the underlying physics that governs these models. We also generate a confidence set for the non-parametric fit and extract confidence intervals for the numbers, locations, and heights of peaks and the successive peak-to-peak height ratios. At the 95%, 68%, and 40% confidence levels, we find functions that fit the data with one, two, and three peaks respectively (0 8 sigma level. If we assume that there are three peaks in the data, we find their locations to be within l_1 = (118,300), l_2 = (377,650), and l_3 = (597,900). We find the ratio of the first peak-height to the second (Delta T_1)/(Delta T_2)^2= (1.06, 4.27) and the second to the third (Delta T_2)/(Delta T_3)^2= (0.41, 2.5). All measurements are for 95% confidence. If the standard errors on the temperature measurements were reduced to a third of what they are currently, as we expect to be achieved by the MAP and Planck CMB experiments, we could eliminate two-peak models at the 95% confidence limit. The non-parametric methodology discussed in this paper has many astrophysical applications.

  12. The Density Perturbation Power Spectrum to Second-Order Corrections in the Slow-Roll Expansion

    E-Print Network [OSTI]

    Ewan D. Stewart; Jin-Ook Gong

    2001-02-17T23:59:59.000Z

    We set up a formalism that can be used to calculate the power spectrum of the curvature perturbations produced during inflation up to arbitrary order in the slow-roll expansion, and explicitly calculate the power spectrum and spectral index up to second-order corrections.

  13. CONSTRAINTS ON THE HIGH-l POWER SPECTRUM OF MILLIMETER-WAVE ANISOTROPIES FROM APEX-SZ

    SciTech Connect (OSTI)

    Reichardt, C. L.; Zahn, O.; Ferrusca, D.; Holzapfel, W. L.; Johnson, B. R.; Lee, A. T.; Lueker, M. [Department of Physics, University of California, Berkeley, CA 94720 (United States); Ade, P. A. R.; Lanting, T. [School of Physics and Astronomy, Cardiff University, CF24 3YB (United Kingdom); Basu, K.; Chon, G.; Kneissl, R. [Max Planck Institute for Radioastronomy, 53121 Bonn (Germany); Bender, A. N.; Halverson, N. W. [Center for Astrophysics and Space Astronomy, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Bertoldi, F. [Argelander Institute for Astronomy, Bonn University, Bonn (Germany); Cho, H.-M. [National Institute of Standards and Technology, Boulder, CO 80305 (United States); Dobbs, M.; Kennedy, J. [Department of Physics, McGill University, Montreal, H3A 2T8 (Canada); Horellou, C.; Johansson, D. [Onsala Space Observatory, Chalmers University of Technology, SE-439 92 Onsala (Sweden)] (and others)

    2009-08-20T23:59:59.000Z

    We present measurements of the angular power spectrum of millimeter wave anisotropies with the APEX-SZ instrument. APEX-SZ has mapped 0.8 deg{sup 2} of sky at a frequency of 150 GHz with an angular resolution of 1'. These new measurements significantly improve the constraints on anisotropy power at 150 GHz over the range of angular multipoles 3000 < l < 10, 000, limiting the total astronomical signal in a flat band power to be less than 105 {mu}K{sup 2} at 95% CL. We expect both submillimeter-bright, dusty galaxies and to a lesser extent secondary cosmic microwave background anisotropies from the Sunyaev-Zel'dovich effect (SZE) to significantly contribute to the observed power. Subtracting the SZE power spectrum expected for {sigma}{sub 8} = 0.8 and masking bright sources, the best-fit value for the remaining power is C {sub l} = 1.1{sup +0.9} {sub -0.8} x 10{sup -5} {mu}K{sup 2} (1.7{sup +1.4} {sub -1.3} Jy{sup 2} sr{sup -1}). This agrees well with model predictions for power due to submillimeter-bright, dusty galaxies. Comparing this power to the power detected by BLAST at 600 GHz, we find the frequency dependence of the source fluxes to be S{sub {nu}}{proportional_to}{nu}{sup 2.6+0.4}{sub -0.2}} if both experiments measure the same population of sources. Simultaneously fitting for the amplitude of the SZE power spectrum and a Poisson-distributed point source population, we place an upper limit on the matter fluctuation amplitude of {sigma}{sub 8} < 1.18 at 95% confidence.

  14. EECE 595: SPREAD SPECTRUM COMMUNICATIONS 1 Distributed Power Control in CDMA Cellular

    E-Print Network [OSTI]

    EECE 595: SPREAD SPECTRUM COMMUNICATIONS 1 Distributed Power Control in CDMA Cellular System Aly El-Osery Abstract In wireless cellular communication, it is essential to #12;nd e#11;ective means of power control power control will heavily impact the system capacity. Distributed power control (DPC) is a natural

  15. PROBING THE INFLATON: SMALL-SCALE POWER SPECTRUM CONSTRAINTS FROM MEASUREMENTS OF THE COSMIC MICROWAVE BACKGROUND ENERGY SPECTRUM

    SciTech Connect (OSTI)

    Chluba, Jens; Erickcek, Adrienne L.; Ben-Dayan, Ido, E-mail: jchluba@cita.utoronto.ca [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, Ontario M5S 3H8 (Canada)

    2012-10-20T23:59:59.000Z

    In the early universe, energy stored in small-scale density perturbations is quickly dissipated by Silk damping, a process that inevitably generates {mu}- and y-type spectral distortions of the cosmic microwave background (CMB). These spectral distortions depend on the shape and amplitude of the primordial power spectrum at wavenumbers k {approx}< 10{sup 4} Mpc{sup -1}. Here, we study constraints on the primordial power spectrum derived from COBE/FIRAS and forecasted for PIXIE. We show that measurements of {mu} and y impose strong bounds on the integrated small-scale power, and we demonstrate how to compute these constraints using k-space window functions that account for the effects of thermalization and dissipation physics. We show that COBE/FIRAS places a robust upper limit on the amplitude of the small-scale power spectrum. This limit is about three orders of magnitude stronger than the one derived from primordial black holes in the same scale range. Furthermore, this limit could be improved by another three orders of magnitude with PIXIE, potentially opening up a new window to early universe physics. To illustrate the power of these constraints, we consider several generic models for the small-scale power spectrum predicted by different inflation scenarios, including running-mass inflation models and inflation scenarios with episodes of particle production. PIXIE could place very tight constraints on these scenarios, potentially even ruling out running-mass inflation models if no distortion is detected. We also show that inflation models with sub-Planckian field excursion that generate detectable tensor perturbations should simultaneously produce a large CMB spectral distortion, a link that could potentially be established with PIXIE.

  16. Power Control in Spectrum Overlay Networks: How to Cross a Multi-Lane Highway

    E-Print Network [OSTI]

    Islam, M. Saif

    Power Control in Spectrum Overlay Networks: How to Cross a Multi-Lane Highway Wei Ren, Qing Zhao Research Laboratory, Adelphi, MD 20783 Email: aswami@arl.army.mil Abstract--We consider power control interference to primary users. We quantify the impact of the transmission power of secondary users

  17. EECE 595: SPREAD SPECTRUM COMMUNICATIONS 1 Distributed Power Control in CDMA Cellular

    E-Print Network [OSTI]

    EECE 595: SPREAD SPECTRUM COMMUNICATIONS 1 Distributed Power Control in CDMA Cellular System Aly El-Osery Abstract In wireless cellular communication, it is essential to #12;nd e#11;ective means of power control control will heavily impact the system capacity. Distributed power control (DPC) is a natural choice

  18. Modeling the affect of dark matter distributions in the Milky Way on the component of the cosmic rays energy spectrum as incident on Earth

    E-Print Network [OSTI]

    Kamenetska, Masha

    2005-01-01T23:59:59.000Z

    In this thesis, we investigate the effect of dark matter distribution in the galaxy on the positron spectrum on earth. We wrote code to simulate two district dark matter distribution functions as well as the annihilations ...

  19. Power-laws and Non-Power-laws in Dark Matter Halos

    E-Print Network [OSTI]

    R. N. Henriksen

    2006-09-05T23:59:59.000Z

    Simulated dark matter profiles are often modelled as a `NFW' density profile rather than a single power law. Recently, attention has turned to the rather rigorous power-law behaviour exhibited by the `pseudo phase-space density' of the dark matter halo, which is defined dimensionally in terms of the local density and velocity dispersion of the dark matter particles. The non-power-law behaviour of the density profile is generally taken to exclude simple scale-free, in-fall models; however the power-law behaviour of the `pseudo-density' is a counter indication. We argue in this paper that both behaviours may be at least qualitatively understood in terms of a dynamically evolving self-similarity, rather than the form for self-similar infall that is fixed by cosmological initial conditions. The evolution is likely due to collective relaxation such as that provided by the radial-orbit instability on large scales. We deduce, from a distribution function given by first order coarse-graining, both the NFW-type density profile and the power-law pseudo-density profile. The results are not greatly sensitive to variation about 3 in the power of the velocity dispersion used in the definition of the phase space pseudo-density. We suggest that the power 2 may create the more physical quantity, whose deviations from a power-law are a diagnostic of incomplete relaxation.

  20. Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters

    SciTech Connect (OSTI)

    Robert J. Goldston

    2010-03-03T23:59:59.000Z

    Integrated energy, environment and economics modeling suggests electrical energy use will increase from 2.4 TWe today to 12 TWe in 2100. It will be challenging to provide 40% of this electrical power from combustion with carbon sequestration, as it will be challenging to provide 30% from renewable energy sources. Thus nuclear power may be needed to provide ~30% by 2100. Calculations of the associated stocks and flows of uranium, plutonium and minor actinides indicate that the proliferation risks at mid-century, using current light-water reactor technology, are daunting. There are institutional arrangements that may be able to provide an acceptable level of risk mitigation, but they will be difficult to implement. If a transition is begun to fast-spectrum reactors at mid-century, without a dramatic change in the proliferation risks of such systems, at the end of the century proliferation risks are much greater, and more resistant to mitigation. The risks of nuclear power should be compared with the risks of the estimated 0.64oC long-term global surface-average temperature rise predicted if nuclear power were replaced with coal-fired power plants without carbon sequestration. Fusion energy, if developed, would provide a source of nuclear power with much lower proliferation risks than fission.

  1. Solar Gamma Rays Powered by Secluded Dark Matter

    E-Print Network [OSTI]

    Brian Batell; Maxim Pospelov; Adam Ritz; Yanwen Shang

    2009-10-08T23:59:59.000Z

    Secluded dark matter models, in which WIMPs annihilate first into metastable mediators, can present novel indirect detection signatures in the form of gamma rays and fluxes of charged particles arriving from directions correlated with the centers of large astrophysical bodies within the solar system, such as the Sun and larger planets. This naturally occurs if the mean free path of the mediator is in excess of the solar (or planetary) radius. We show that existing constraints from water Cerenkov detectors already provide a novel probe of the parameter space of these models, complementary to other sources, with significant scope for future improvement from high angular resolution gamma-ray telescopes such as Fermi-LAT. Fluxes of charged particles produced in mediator decays are also capable of contributing a significant solar system component to the spectrum of energetic electrons and positrons, a possibility which can be tested with the directional and timing information of PAMELA and Fermi.

  2. Increased Photovoltaic Power Output via Diffractive Spectrum Separation

    E-Print Network [OSTI]

    Kim, Ganghun

    In this Letter, we report the preliminary demonstration of a new paradigm for photovoltaic power generation that utilizes a broadband diffractive-optical element (BDOE) to efficiently separate sunlight into laterally spaced ...

  3. Model independent foreground power spectrum estimation using WMAP 5-year data

    SciTech Connect (OSTI)

    Ghosh, Tuhin; Souradeep, Tarun [IUCAA, Post Bag 4, Ganeshkhind, Pune-411007 (India); Saha, Rajib [IUCAA, Post Bag 4, Ganeshkhind, Pune-411007 (India); Jet Propulsion Laboratory, M/S 169-327, 4800 Oak Grove Drive, Pasadena, California 91109 (United States); California Institute of Technology, Pasadena, California 91125 (United States); Department of Physics, Indian Institute of Technology, Kanpur, U.P, 208016 (India); Jain, Pankaj [Department of Physics, Indian Institute of Technology, Kanpur, U.P, 208016 (India)

    2009-06-15T23:59:59.000Z

    In this paper, we propose and implement on WMAP 5 yr data a model independent approach of foreground power spectrum estimation for multifrequency observations of the CMB experiments. Recently, a model independent approach of CMB power spectrum estimation was proposed by Saha et al. 2006. This methodology demonstrates that the CMB power spectrum can be reliably estimated solely from WMAP data without assuming any template models for the foreground components. In the current paper, we extend this work to estimate the galactic foreground power spectrum using the WMAP 5 yr maps following a self-contained analysis. We apply the model independent method in harmonic basis to estimate the foreground power spectrum and frequency dependence of combined foregrounds. We also study the behavior of synchrotron spectral index variation over different regions of the sky. We use the full sky Haslam map as an external template to increase the degrees of freedom, while computing the synchrotron spectral index over the frequency range from 408 MHz to 94 GHz. We compare our results with those obtained from maximum entropy method foreground maps, which are formed in pixel space. We find that relative to our model independent estimates maximum entropy method maps overestimate the foreground power close to galactic plane and underestimates it at high latitudes.

  4. Power density spectrum of NGC 5548 and the nature of its variability

    E-Print Network [OSTI]

    B. Czerny; A. Schwarzenberg-Czerny; Z. Loska

    1998-10-14T23:59:59.000Z

    We derive power density spectra in the optical and X-ray band in the timescale range from several years down to $\\sim $ a day. We suggest that the optical power density spectrum consists of two separate components: long timescale variations and short timescale variations, with the dividing timescale around 100 days. The shape of the short timescale component is similar to X-ray power density spectrum which is consistent with the interpretation of short timescale optical variations being caused by X-ray reprocessing. We show that the observed optical long timescale variability is consistent with thermal pulsations of the accretion disc.

  5. Cosmic microwave background constraints on dark energy dynamics: analysis beyond the power spectrum

    E-Print Network [OSTI]

    Fabio Giovi; Carlo Baccigalupi; Francesca Perrotta

    2005-05-18T23:59:59.000Z

    We consider the distribution of the non-Gaussian signal induced by weak lensing on the primary total intensity cosmic microwave background (CMB) anisotropies. Our study focuses on the three point statistics exploiting an harmonic analysis based on the CMB bispectrum. By considering the three multipoles as independent variables, we reveal a complex structure of peaks and valleys determined by the re-projection of the primordial acoustic oscillations through the lensing mechanism. We study the dependence of this system on the expansion rate at the epoch in which the weak lensing power injection is relevant, probing the dark energy equation of state at redshift corresponding to the equivalence with matter or higher ($w_\\infty$). We evaluate the impact of the bispectrum observable on the CMB capability of constraining the dark energy dynamics. We perform a maximum likelihood analysis by varying the dark energy abundance, the present equation of state $w_0$ and $w_\\infty$. We show that the projection degeneracy affecting a pure power spectrum analysis in total intensity is broken if the bispectrum is taken into account. For a Planck-like experiment, assuming nominal performance, no foregrounds or systematics, and fixing all the parameters except $w_0$, $w_\\infty$ and the dark energy abundance, a percent and ten percent precision measure of $w_0$ and $w_\\infty$ is achievable from CMB data only. These results indicate that the detection of the weak lensing signal by the forthcoming CMB probes may be relevant to gain insight into the dark energy dynamics at the onset of cosmic acceleration.

  6. No evidence for the blue-tilted power spectrum of relic gravitational waves

    E-Print Network [OSTI]

    Huang, Qing-Guo

    2015-01-01T23:59:59.000Z

    In this paper, we constrain the tilt of the power spectrum of relic gravitational waves by combining the data from BICEP2/Keck array and Planck (BKP) and the Laser Interferometer Gravitational-Waves Observatory (LIGO). From the data of BKP B-modes, the constraint on the tensor tilt is $n_t=0.66^{+1.83}_{-1.44}$ at the $68%$ confidence level. By further adding the LIGO upper limit on the energy density of gravitational waves, the constraint becomes $n_t=-0.76^{+1.37}_{-0.52}$ at the $68%$ confidence level. We conclude that there is no evidence for a blue-tilted power spectrum of relic gravitational waves and either sign of the index of tensor power spectrum is compatible with the data.

  7. No evidence for the blue-tilted power spectrum of relic gravitational waves

    E-Print Network [OSTI]

    Qing-Guo Huang; Sai Wang

    2015-02-09T23:59:59.000Z

    In this paper, we constrain the tilt of the power spectrum of relic gravitational waves by combining the data from BICEP2/Keck array and Planck (BKP) and the Laser Interferometer Gravitational-Waves Observatory (LIGO). From the data of BKP B-modes, the constraint on the tensor tilt is $n_t=0.66^{+1.83}_{-1.44}$ at the $68%$ confidence level. By further adding the LIGO upper limit on the energy density of gravitational waves, the constraint becomes $n_t=-0.76^{+1.37}_{-0.52}$ at the $68%$ confidence level. We conclude that there is no evidence for a blue-tilted power spectrum of relic gravitational waves and either sign of the index of tensor power spectrum is compatible with the data.

  8. Reliable self-powered highly spectrum-selective ZnO ultraviolet photodetectors

    SciTech Connect (OSTI)

    Shen, H. [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China) [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Shan, C. X., E-mail: shancx@ciomp.ac.cn, E-mail: binghuili@163.com; Li, B. H., E-mail: shancx@ciomp.ac.cn, E-mail: binghuili@163.com; Shen, D. Z. [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)] [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Xuan, B. [Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)] [Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)

    2013-12-02T23:59:59.000Z

    Ultraviolet photodetectors (PDs) have been fabricated from p-ZnO:(Li,N)/n-ZnO structures in this Letter. The PDs can operate without any external power supply and show response only to a very narrow spectrum range. The self-power character of the devices is due to the built-in electric field in the p-n junctions that can separate the photogenerated electrons and holes while the high spectrum-selectivity has been attributed to the filter effect of the neutral region in the ZnO:(Li,N) layer. The performance of the self-powered highly spectrum-selective PDs degrades little after five months, indicating their good reliability.

  9. Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters

    SciTech Connect (OSTI)

    Robert J. Goldston

    2011-04-28T23:59:59.000Z

    Integrated energy, environment and economics modeling suggests that worldwide electrical energy use will increase from 2.4 TWe today to ~12 TWe in 2100. It will be challenging to provide 40% of this electrical power from combustion with carbon sequestration, as it will be challenging to provide 30% from renewable energy sources derived from natural energy flows. Thus nuclear power may be needed to provide ~30%, 3600 GWe, by 2100. Calculations of the associated stocks and flows of uranium, plutonium and minor actinides indicate that the proliferation risks at mid-century, using current light-water reactor technology, are daunting. There are institutional arrangements that may be able to provide an acceptable level of risk mitigation, but they will be difficult to implement. If a transition is begun to fast-spectrum reactors at mid-century, without a dramatic change in the proliferation risks of such systems, at the end of the century global nuclear proliferation risks are much greater, and more resistant to mitigation. Fusion energy, if successfully demonstrated to be economically competitive, would provide a source of nuclear power with much lower proliferation risks than fission.

  10. Shrinking and the True Power Spectrum at Decoupling

    E-Print Network [OSTI]

    B. A. C. C. Bassett; P. K. S. Dunsby; G. F. R. Ellis

    1994-10-19T23:59:59.000Z

    In this paper we examine the change in the estimated spatial power spectra at decoupling due to the effects of our clumpy universe which modify observational distances. We find that scales at decoupling can be significantly underestmated in our approximation of neglecting the shear of the ray bundle. We compare our results with other work on lensing and speculate on the implications for structure formation. In particular we examine a proposal to use the position of the first Doppler peak to determine $\\Omega$, and find that shrinking will modify the esimated curvature, so that it must be included to obtain an accurate estimate of $\\Omega$. Finally we consider future applications and improvements of our results.

  11. Effect of turbulent velocity on the \\HI intensity fluctuation power spectrum from spiral galaxies

    E-Print Network [OSTI]

    Dutta, Prasun

    2015-01-01T23:59:59.000Z

    We use numerical simulations to investigate effect of turbulent velocity on the power spectrum of \\HI intensity from external galaxies when (a) all emission is considered, (b) emission with velocity range smaller than the turbulent velocity dispersion is considered. We found that for case (a) the intensity fluctuation depends directly only on the power spectrum of the column density, whereas for case (b) it depends only on the turbulent velocity fluctuation. We discuss the implications of this result in real observations of \\HI fluctuations.

  12. Mass spectrum of diquarks and mesons in the color--flavor locked phase of dense quark matter

    E-Print Network [OSTI]

    Ebert, D; Yudichev, V L

    2007-01-01T23:59:59.000Z

    The spectrum of meson and diquark excitations of dense quark matter is considered in the framework of the Nambu -- Jona-Lasinio model with three types of massless quarks in the presense of a quark number chemical potential $\\mu$. We investigate the effective action of meson- and diquark fields both at sufficiently large values of $\\mu>\\mu_c\\approx 330$ MeV, where the color--flavor locked (CFL) phase is realized, and in the chirally broken phase of quark matter ($\\mu\\mu_c$.

  13. Effect of Compressing the Dynamic Range of the Power Spectrum in Modulation Filtering Based Speech Enhancement

    E-Print Network [OSTI]

    .paliwal@griffith.edu.au Abstract In the modulation-filtering based speech enhancement method, noise suppression is achieved systematically different dynamic range compression functions applied to the power spectrum for speech enhancement- gibility of the enhanced speech. The quality is measured objec- tively in terms of the Perceptual

  14. Minimal modifications of the primordial power spectrum from an adiabatic short distance cutoff

    E-Print Network [OSTI]

    J. C. Niemeyer; R. Parentani; D. Campo

    2002-09-03T23:59:59.000Z

    As a simple model for unknown Planck scale physics, we assume that the quantum modes responsible for producing primordial curvature perturbations during inflation are placed in their instantaneous adiabatic vacuum when their proper momentum reaches a fixed high energy scale M. The resulting power spectrum is derived and presented in a form that exhibits the amplitude and frequency of the superimposed oscillations in terms of H/M and the slow roll parameter epsilon. The amplitude of the oscillations is proportional to the third power of H/M. We argue that these small oscillations give the lower bound of the modifications of the power spectrum if the notion of free mode propagation ceases to exist above the critical energy scale M.

  15. Minimal modifications of the primordial power spectrum from an adiabatic short distance cutoff

    E-Print Network [OSTI]

    Niemeyer, J C; Campo, D

    2002-01-01T23:59:59.000Z

    As a simple model for unknown Planck scale physics, we assume that the quantum modes responsible for producing primordial curvature perturbations during inflation are placed in their instantaneous adiabatic vacuum when their proper momentum reaches a fixed high energy scale M. The resulting power spectrum is derived and presented in a form that exhibits the amplitude and frequency of the superimposed oscillations in terms of H/M and the slow roll parameter epsilon. The amplitude of the oscillations is proportional to the third power of H/M. We argue that these small oscillations give the lower bound of the modifications of the power spectrum if the notion of free mode propagation ceases to exist above the critical energy scale M.

  16. The number density of quasars as a probe of initial power spectrum on small scale

    E-Print Network [OSTI]

    B. Novosyadlyj; Yu. Chornij

    1998-12-15T23:59:59.000Z

    The dependence of the number density of the bright QSOs at different redshifts ($n_{QSO}(z)$) on initial power spectrum is studied. It is assumed that QSO phenomenon is an early short term stage of evolution of massive galaxies with $M\\geq 2\\times 10^{11}h^{-1}M_{\\odot}$. The duration of such QSO stage which is passed through by fraction $\\alpha$ of galaxies is determined by means of minimization of the divergence of the theoretical number density of QSOs at different redshifts for specified initial spectrum from observable one \\cite{sc91}. It is shown that the nearest number densities of QSOs at $0.7\\le z\\le 3.5$ to observable ones are obtained for the tilted CDM model ($\\Omega_{b}=0.1$, $n=0.7$). The QSO stage lasts $\\sim 7\\times 10^{7}/\\alpha$ years and begins soon after the moment of rise of the first counterflow in collisionless component and shock wave in gas. The possibility of the reconstruction of initial power spectrum on small scale on the base of the observable data on number density of QSOs at different $z$ is considered too. Such reconstructed spectrum in comparison with standard CDM has steep reducing of power at $k\\ge 0.5 h Mpc^{-1}$.

  17. A Bayesian approach to power-spectrum significance estimation, with application to solar neutrino data

    E-Print Network [OSTI]

    P. A. Sturrock

    2008-09-01T23:59:59.000Z

    The usual procedure for estimating the significance of a peak in a power spectrum is to calculate the probability of obtaining that value or a larger value by chance, on the assumption that the time series contains only noise (e.g. that the measurements were derived from random samplings of a Gaussian distribution). However, it is known that one should regard this P-Value approach with caution. As an alternative, we here examine a Bayesian approach to estimating the significance of a peak in a power spectrum. This approach requires that we consider explicitly the hypothesis that the time series contains a periodic signal as well as noise. The challenge is to identify a probability distribution function for the power that is appropriate for this hypothesis. We propose what seem to be reasonable conditions to require of this function, and then propose a simple function that meets these requirements. We also propose a consistency condition, and check to see that our function satisfies this condition. We find that the Bayesian significance estimates are considerably more conservative than the conventional estimates. We apply this procedure to three recent analyses of solar neutrino data: (a) bimodality of GALLEX data; (b) power spectrum analysis of Super-Kamiokande data; and (c) the combined analysis of radiochemical neutrino data and irradiance data.

  18. An alternative power spectrum of the resonance fluorescence of atomic systems

    E-Print Network [OSTI]

    Adam Stokes; Almut Beige

    2014-08-31T23:59:59.000Z

    We adopt an open quantum systems perspective to calculate the power spectrum associated with the electric field generated by an atomic dipole moment undergoing resonant laser-driving. This spectrum has a similar shape to the usual Mollow spectrum, but also has some distinct features. For sufficiently strong laser driving, both spectra have a symmetric triplet structure with a large central peak and two sidebands. However, the relative height of the sidebands to the central peak differs in each case. The two spectra also behave quite differently when the laser Rabi frequency is varied. Both spectra may be of interest in high-precision experiments into the quantum physics of atomic systems, especially artificial atoms.

  19. Peaks and Troughs in Helioseismology: The Power Spectrum of Solar Oscillations

    E-Print Network [OSTI]

    Colin S. Rosenthal

    1998-04-15T23:59:59.000Z

    I present a matched-wave asymptotic analysis of the driving of solar oscillations by a general localised source. The analysis provides a simple mathematical description of the asymmetric peaks in the power spectrum in terms of the relative locations of eigenmodes and troughs in the spectral response. It is suggested that the difference in measured phase function between the modes and the troughs in the spectrum will provide a key diagnostic of the source of the oscillations. I also suggest a form for the asymmetric line profiles to be used in the fitting of solar power spectra. Finally I present a comparison between the numerical and asymptotic descriptions of the oscillations. The numerical results bear out the qualitative features suggested by the asymptotic analysis but suggest that numerical calculations of the locations of the troughs will be necessary for a quantitative comparison with the observations.

  20. Revisiting a pre-inflationary radiation era and its effect on the CMB power spectrum

    E-Print Network [OSTI]

    Suratna Das; Gaurav Goswami; Jayanti Prasad; Raghavan Rangarajan

    2014-12-22T23:59:59.000Z

    We revisit the scenario where inflation is preceded by a radiation era by considering that the inflaton too could have been in thermal equilibrium early in the radiation era. Hence we take into account not only the effect of a pre-inflationary era on the inflaton mode functions but also that of a frozen thermal distribution of inflaton quanta. We initially discuss in detail the issues relevant to our scenario of a pre-inflationary radiation dominated era and then obtain the scalar power spectrum for this scenario. We find that the power spectrum is free from infrared divergences. We then use the WMAP and Planck data to determine the constraints on the inflaton comoving `temperature' and on the duration of inflation. We find that the best fit value of the duration of inflation is less than 1 e-folding more than what is required to solve cosmological problems, while only an upper bound on the inflaton temperature can be obtained.

  1. Effect of noise on the power spectrum of passively mode-locked lasers

    SciTech Connect (OSTI)

    Eliyahu, D.; Salvatore, R.A.; Yariv, A. [California Institute of Technology, M/S 128-95, Pasadena, California 91125 (United States)

    1997-01-01T23:59:59.000Z

    We analyze the effects of noise on the power spectrum of pulse trains generated by a continuously operating passively mode-locked laser. The shape of the different harmonics of the power spectrum is calculated in the presence of correlated timing fluctuations between neighboring pulses and in the presence of amplitude fluctuations. The spectra at the different harmonics are influenced mainly by the nonstationary timing-jitter fluctuations; amplitude fluctuations slightly modify the spectral tails. Estimation of the coupling term between the longitudinal cavity modes or the effective saturable absorber coefficient is made from the timing-jitter correlation time. Experimental results from an external cavity two-section semiconductor laser are given. The results show timing-jitter fluctuations having a relaxation time much longer than the repetition period. {copyright} 1997 Optical Society of America.

  2. Nonlinear relativistic single-electron Thomson scattering power spectrum for incoming laser of arbitrary intensity

    SciTech Connect (OSTI)

    Alvarez-Estrada, R. F. [Departamento de Fisica Teorica I, Facultad de Ciencias Fisicas, Universidad Complutense, 28040 Madrid (Spain); Pastor, I.; Guasp, J.; Castejon, F. [Asociacion Euratom/Ciemat para Fusion, Avenida Complutense 22, 28040 Madrid (Spain)

    2012-06-15T23:59:59.000Z

    The classical nonlinear incoherent Thomson scattering power spectrum from a single relativistic electron with incoming laser radiation of any intensity, investigated numerically by the present authors in a previous publication, displayed both an approximate quadratic behavior in frequency and a redshift of the power spectrum for high intensity incoming radiation. The present work is devoted to justify, in a more general setup, those numerical findings. Those justifications are reinforced by extending suitably analytical approaches, as developed by other authors. Moreover, our analytical treatment exhibits differences between the Doppler-like frequencies for linear and circular polarization of the incoming radiation. Those differences depend nonlinearly on the laser intensity and on the electron initial velocity and do not appear to have been displayed by previous authors. Those Doppler-like frequencies and their differences are validated by new Monte Carlo computations beyond our previuos ones and reported here.

  3. The Power of Efficiency: Why Momentum Savings Really Do Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Efficiency: Why Momentum Savings Really Do Matter It's easy to dismiss Momentum Savings. After all, they can be difficult to understand and quantify in comparison to the direct...

  4. Power spectrum sensitivity of raster-scanned CMB experiments in the presence of 1/f noise

    E-Print Network [OSTI]

    Tom Crawford

    2007-09-24T23:59:59.000Z

    We investigate the effects of 1/f noise on the ability of a particular class of Cosmic Microwave Background experiments to measure the angular power spectrum of temperature anisotropy. We concentrate on experiments that operate primarily in raster-scan mode and develop formalism that allows us to calculate analytically the effect of 1/f noise on power spectrum sensitivity for this class of experiments and determine the benefits of raster-scanning at different angles relative to the sky field versus scanning at only a single angle (cross-linking versus not cross-linking). We find that the sensitivity of such experiments in the presence of 1/f noise is not significantly degraded at moderate spatial scales (l ~ 100) for reasonable values of scan speed and 1/f knee. We further find that the difference between cross-linked and non-cross-linked experiments is small in all cases and that the non-cross-linked experiments are preferred from a raw sensitivity standpoint in the noise-dominated regime -- i.e., in experiments in which the instrument noise is greater than the sample variance of the target power spectrum at the scales of interest. This analysis does not take into account systematic effects.

  5. A search for signatures of dark matter in the AMS-01 electron and antiproton spectrum

    E-Print Network [OSTI]

    Carosi, Gianpaolo Patrick

    2006-01-01T23:59:59.000Z

    If dark matter consists of Weakly Interacting Massive Particles (WIMPs), such as the supersymmetric neutralino, various theories predict that their annihilation in the galaxy can give rise to anomalous features in the ...

  6. The Turbulence Velocity Power Spectrum of Neutral Hydrogen in the Small Magellanic Cloud

    E-Print Network [OSTI]

    Chepurnov, Alexey; Lazarian, Alex; Stanimirovic, Snezana

    2015-01-01T23:59:59.000Z

    We present the results of the Velocity Coordinate Spectrum (VCS) technique to calculate the velocity power spectrum of turbulence in the Small Magellanic Cloud (SMC) in 21cm emission. We have obtained a velocity spectral index of -3.85 and an injection scale of 2.3 kpc. The spectral index is steeper than the Kolmogorov index which is expected for shock-dominated turbulence which is in agreement with past works on the SMC gas dynamics. The injection scale of 2.3 kpc suggests that tidal interactions with the Large Magellanic Cloud are the dominate driver of turbulence in this dwarf galaxy. This implies turbulence maybe driven by multiple mechanisms in galaxies in addition to supernova injection and that galaxy-galaxy interactions may play an important role.

  7. The constraints on power spectrum of relic gravitational waves from current observations of large-scale structure of the Universe

    E-Print Network [OSTI]

    B. Novosyadlyj; S. Apunevych

    2004-12-02T23:59:59.000Z

    We carry out the determination of the amplitude of relic gravitational waves power spectrum. Indirect best-fit technique was applied to compare observational data and theory predictions. As observations we have used data on large-scale structure (LSS) of the Universe and anisotropy of cosmic microwave background (CMB) temperature. The conventional inflationary model with 11 parameters has been investigated, all of them evaluated jointly. This approach gave us a possibility to find parameters of power spectrum of gravitational waves along with statistical errors. The main result consists in following: WMAP data on power spectrum of CMB temperature fluctuations along with LSS data prefer model with small amplitude of tensor mode power spectrum, close to zero. The upper limit for its amplitude at quadupole harmonics T/S=0.6 at 95% C.L.

  8. Angular Signatures of Dark Matter in the Diffuse Gamma Ray Spectrum

    SciTech Connect (OSTI)

    Hooper, Dan; Serpico, Pasquale D.; /Fermilab

    2007-02-01T23:59:59.000Z

    Dark matter annihilating in our Galaxy's halo and elsewhere in the universe is expected to generate a diffuse flux of gamma rays, potentially observable with next generation satellite-based experiments, such as GLAST. In this article, we study the signatures of dark matter in the angular distribution of this radiation. Pertaining to the extragalactic contribution, we discuss the effect of the motion of the solar system with respect to the cosmological rest frame, and anisotropies due to the structure of our local universe. For the gamma ray flux from dark matter in our own Galactic halo, we discuss the effects of the offset position of the solar system, the Compton-Getting effect, the asphericity of the Milky Way halo, and the signatures of nearby substructure. We explore the prospects for the detection of these features by the GLAST satellite and find that, if {approx} 10% or more of the diffuse gamma ray background observed by EGRET is the result of dark matter annihilations, then GLAST should be sensitive to anisotropies down to the 0.1% level. Such precision would be sufficient to detect many, if not all, of the signatures discussed in this paper.

  9. Energy Spectrum of the Electrons Accelerated by a Reconnection Electric Field: Exponential or Power Law?

    E-Print Network [OSTI]

    W. J. Liu; P. F. Chen; M. D. Ding; C. Fang

    2009-01-10T23:59:59.000Z

    The direct current (DC) electric field near the reconnection region has been proposed as an effective mechanism to accelerate protons and electrons in solar flares. A power-law energy spectrum was generally claimed in the simulations of electron acceleration by the reconnection electric field. However in most of the literature, the electric and magnetic fields were chosen independently. In this paper, we perform test-particle simulations of electron acceleration in a reconnecting magnetic field, where both the electric and magnetic fields are adopted from numerical simulations of the MHD equations. It is found that the accelerated electrons present a truncated power-law energy spectrum with an exponential tail at high energies, which is analogous to the case of diffusive shock acceleration. The influences of reconnection parameters on the spectral feature are also investigated, such as the longitudinal and transverse components of the magnetic field and the size of the current sheet. It is suggested that the DC electric field alone might not be able to reproduce the observed single or double power-law distributions.

  10. VES-0071- In the Matter of Mississippi Power Company

    Broader source: Energy.gov [DOE]

    On May 1, 2000, the Mississippi Power Company, of Gulfport, Mississippi (Mississippi Power), filed with the Office of Hearings and Appeals (OHA) of the Department of Energy an Application for...

  11. Short distance physics and initial state effects on the CMB power spectrum

    SciTech Connect (OSTI)

    Zarei, M. [Department of Physics, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2008-12-15T23:59:59.000Z

    We investigate a modification in the action of inflaton due to noncommutativity leads to a nonstandard initial vacuum and oscillatory corrections in the initial power spectrum. We show that the presence of these oscillations causes a drop in the WMAP {chi}{sup 2} about {delta}{chi}{sup 2}{approx}8.5. As a bonus, from the parameter estimation done in this work, we show that the noncommutative parameters can be precisely bound to 10{sup 16} GeV or 10{sup 4} GeV depending on the inflation scale.

  12. SECOND SEASON QUIET OBSERVATIONS: MEASUREMENTS OF THE COSMIC MICROWAVE BACKGROUND POLARIZATION POWER SPECTRUM AT 95 GHz

    SciTech Connect (OSTI)

    Araujo, D.; Dumoulin, R. N.; Newburgh, L. B.; Zwart, J. T. L. [Department of Physics and Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Bischoff, C.; Brizius, A.; Buder, I.; Kusaka, A. [Kavli Institute for Cosmological Physics, Department of Physics, Enrico Fermi Institute, The University of Chicago, Chicago, IL 60637 (United States); Chinone, Y. [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Cleary, K.; Reeves, R. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, 1200 E. California Blvd M/C 249-17, Pasadena, CA 91125 (United States); Monsalve, R.; Bustos, R. [Department of Physics, University of Miami, 1320 Campo Sano Drive, Coral Gables, FL 33146 (United States); Naess, S. K.; Eriksen, H. K. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway); Wehus, I. K. [Department of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Bronfman, L. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Church, S. E. [Kavli Institute for Particle Astrophysics and Cosmology and Department of Physics, Stanford University, Varian Physics Building, 382 Via Pueblo Mall, Stanford, CA 94305 (United States); Dickinson, C. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Gaier, T., E-mail: ibuder@uchicago.edu [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Collaboration: QUIET Collaboration; and others

    2012-12-01T23:59:59.000Z

    The Q/U Imaging ExperimenT (QUIET) has observed the cosmic microwave background (CMB) at 43 and 95 GHz. The 43 GHz results have been published in a previous paper, and here we report the measurement of CMB polarization power spectra using the 95 GHz data. This data set comprises 5337 hr of observations recorded by an array of 84 polarized coherent receivers with a total array sensitivity of 87 {mu}K{radical}s. Four low-foreground fields were observed, covering a total of {approx}1000 deg{sup 2} with an effective angular resolution of 12.'8, allowing for constraints on primordial gravitational waves and high signal-to-noise measurements of the E-modes across three acoustic peaks. The data reduction was performed using two independent analysis pipelines, one based on a pseudo-C {sub l} (PCL) cross-correlation approach, and the other on a maximum-likelihood (ML) approach. All data selection criteria and filters were modified until a predefined set of null tests had been satisfied before inspecting any non-null power spectrum. The results derived by the two pipelines are in good agreement. We characterize the EE, EB, and BB power spectra between l = 25 and 975 and find that the EE spectrum is consistent with {Lambda}CDM, while the BB power spectrum is consistent with zero. Based on these measurements, we constrain the tensor-to-scalar ratio to r = 1.1{sup +0.9} {sub -0.8} (r < 2.8 at 95% C.L.) as derived by the ML pipeline, and r = 1.2{sup +0.9} {sub -0.8} (r < 2.7 at 95% C.L.) as derived by the PCL pipeline. In one of the fields, we find a correlation with the dust component of the Planck Sky Model, though the corresponding excess power is small compared to statistical errors. Finally, we derive limits on all known systematic errors, and demonstrate that these correspond to a tensor-to-scalar ratio smaller than r = 0.01, the lowest level yet reported in the literature.

  13. Anisotropic power spectrum and bispectrum in the f(?)F² mechanism

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bartolo, Nicola; Matarrese, Sabino; Peloso, Marco; Ricciardone, Angelo

    2013-01-01T23:59:59.000Z

    A suitable coupling of the inflaton ? to a vector kinetic term F² gives frozen and scale invariant vector perturbations. We compute the cosmological perturbations ? that result from such coupling by taking into account the classical vector field that unavoidably gets generated at large scales during inflation. This generically results in a too-anisotropic power spectrum of ?. Specifically, the anisotropy exceeds the 1% level (10% level) if inflation lasts ~5 e-folds (~50 e-folds) more than the minimal amount required to produce the cosmic microwave background modes. This conclusion applies, among others, to the application of this mechanism for magnetogenesis, for anisotropic inflation, and for the generation of anisotropic perturbations at the end of inflation through a waterfall field coupled to the vector (in this case, the unavoidable contribution that we obtain is effective all throughout inflation, and it is independent of the waterfall field). For a tuned duration of inflation, a 1% (10%) anisotropy in the power spectrum corresponds to an anisotropic bispectrum which is enhanced like the local one in the squeezed limit, and with an effective local fNL~3(~30). More in general, a significant anisotropy of the perturbations may be a natural outcome of all models that sustain higher than 0 spin fields during inflation.

  14. Power Spectrum of Out-of-equilibrium Forces in Living Cells : Amplitude and Frequency Dependence

    E-Print Network [OSTI]

    Francois Gallet; Delphine Arcizet; Pierre Bohec; Alain Richert

    2009-01-20T23:59:59.000Z

    Living cells exhibit an important out-of-equilibrium mechanical activity, mainly due to the forces generated by molecular motors. These motor proteins, acting individually or collectively on the cytoskeleton, contribute to the violation of the fluctuation-dissipation theorem in living systems. In this work we probe the cytoskeletal out-of-equilibrium dynamics by performing simultaneous active and passive microrheology experiments, using the same micron-sized probe specifically bound to the actin cortex. The free motion of the probe exhibits a constrained, subdiffusive behavior at short time scales (t power law dependence with time. Combining the results of both experiments, we precisely measure for the first time the power spectrum of the force fluctuations exerted on this probe, which lies more than one order of magnitude above the spectrum expected at equilibrium, and greatly depends on frequency. We retrieve an effective temperature Teff of the system, as an estimate of the departure from thermal equilibrium. This departure is especially pronounced on long time scales, where Teff bears the footprint of the cooperative activity of motors pulling on the actin network. ATP depletion reduces the fluctuating force amplitude and results in a sharp decrease of Teff towards equilibrium.

  15. On the detection of Lorentzian profiles in a power spectrum: A Bayesian approach using ignorance priors

    E-Print Network [OSTI]

    M. Gruberbauer; T. Kallinger; W. W. Weiss; D. B. Guenther

    2009-08-23T23:59:59.000Z

    Aims. Deriving accurate frequencies, amplitudes, and mode lifetimes from stochastically driven pulsation is challenging, more so, if one demands that realistic error estimates be given for all model fitting parameters. As has been shown by other authors, the traditional method of fitting Lorentzian profiles to the power spectrum of time-resolved photometric or spectroscopic data via the Maximum Likelihood Estimation (MLE) procedure delivers good approximations for these quantities. We, however, show that a conservative Bayesian approach allows one to treat the detection of modes with minimal assumptions (i.e., about the existence and identity of the modes). Methods. We derive a conservative Bayesian treatment for the probability of Lorentzian profiles being present in a power spectrum and describe an efficient implementation that evaluates the probability density distribution of parameters by using a Markov-Chain Monte Carlo (MCMC) technique. Results. Potentially superior to "best-fit" procedure like MLE, which only provides formal uncertainties, our method samples and approximates the actual probability distributions for all parameters involved. Moreover, it avoids shortcomings that make the MLE treatment susceptible to the built-in assumptions of a model that is fitted to the data. This is especially relevant when analyzing solar-type pulsation in stars other than the Sun where the observations are of lower quality and can be over-interpreted. As an example, we apply our technique to CoRoT observations of the solar-type pulsator HD 49933.

  16. Early structure formation from primordial density fluctuations with a blue-tilted power spectrum

    E-Print Network [OSTI]

    Hirano, Shingo; Yoshida, Naoki; Spergel, David; Yorke, Harold W

    2015-01-01T23:59:59.000Z

    While observations of large-scale structure and the cosmic microwave background (CMB) provide strong constraints on the amplitude of the primordial power spectrum (PPS) on scales larger than 10 Mpc, the amplitude of the power spectrum on sub-galactic length scales is much more poorly constrained. We study early structure formation in a cosmological model with a blue-tilted PPS. We assume that the standard scale-invariant PPS is modified at small length scales as $P(k) \\sim k^{m_{\\rm s}}$ with $m_{\\rm s} > 1$. We run a series of cosmological hydrodynamic simulations to examine the dependence of the formation epoch and the characteristic mass of primordial stars on the tilt of the PPS. In models with $m_{\\rm s} > 1$, star-forming gas clouds are formed at $z > 100$, when formation of hydrogen molecules is inefficient because the intense CMB radiation destroys chemical intermediates. Without efficient coolant, the gas clouds gravitationally contract while keeping a high temperature. The protostars formed in such ...

  17. The power spectrum of the Milky Way: Velocity fluctuations in the Galactic disk

    E-Print Network [OSTI]

    Bovy, Jo; Pérez, Ana E García; Zasowski, Gail

    2014-01-01T23:59:59.000Z

    We investigate the kinematics of stars in the mid-plane of the Milky Way on scales between 25 pc and 10 kpc with data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE), the Radial Velocity Experiment (RAVE), and the Geneva-Copenhagen Survey (GCS). Using red-clump stars in APOGEE, we determine the large-scale line-of-sight velocity field out to 5 kpc from the Sun in (0.75 kpc)^2 bins. The solar motion is the largest contribution to the power on large scales after subtracting an axisymmetric rotation field; we determine the solar motion by minimizing the large-scale power to be V_sun = 24+/-1 (ran.)+/-2 (syst [V_c])+/-5 (syst. [large-scale]) km/s, where the systematic uncertainty is due to (a) a conservative 20 km/s uncertainty in V_c and (b) the estimated power on unobserved larger scales. Combining the APOGEE peculiar-velocity field with red-clump stars in RAVE out to 2 kpc from the Sun and with local GCS stars, we determine the power spectrum of residual velocity fluctuations in the Mi...

  18. PARAMETRIC TENSION BETWEEN EVEN AND ODD MULTIPOLE DATA OF THE WMAP POWER SPECTRUM: UNACCOUNTED CONTAMINATION OR MISSING PARAMETERS?

    SciTech Connect (OSTI)

    Kim, Jaiseung; Naselsky, Pavel, E-mail: jkim@nbi.d [Niels Bohr Institute and Discovery Center, Blegdamsvej 17, DK-2100 Copenhagen (Denmark)

    2010-12-01T23:59:59.000Z

    There exists power contrast in even and odd multipoles of the WMAP power spectrum at low and intermediate multipole ranges. This anomaly is explicitly associated with the angular power spectrum, which is heavily used for cosmological model fitting. Having noted this, we have investigated whether even (odd) multipole data set is individually consistent with the WMAP concordance model. Our investigation shows that the WMAP concordance model does not make a good fit for even (odd) multipole data set, which indicates parametric tension between even and odd multipole data set. Noting that tension is highest in primordial power spectrum parameters, we have additionally considered a running spectral index, but found that tension increases to even a higher level. We believe these parametric tensions may be indications of unaccounted contamination or imperfection of the model.

  19. Mass spectrum of diquarks and mesons in the color--flavor locked phase of dense quark matter

    E-Print Network [OSTI]

    D. Ebert; K. G. Klimenko; V. L. Yudichev

    2007-09-25T23:59:59.000Z

    The spectrum of meson and diquark excitations of dense quark matter is considered in the framework of the Nambu -- Jona-Lasinio model with three types of massless quarks in the presense of a quark number chemical potential $\\mu$. We investigate the effective action of meson- and diquark fields both at sufficiently large values of $\\mu>\\mu_c\\approx 330$ MeV, where the color--flavor locked (CFL) phase is realized, and in the chirally broken phase of quark matter ($\\muphase the pseudoscalar diquarks are not allowed to exist as stable particles, but the scalar diquarks might be stable only at a rather strong interaction in the diquark channel. In the case of the CFL phase, all NG bosons of the model are realized as scalar and pseudoscalar diquarks. Moreover, it turns out that massive diquark excitations are unstable for this phase. In particular, for the scalar and pseudoscalar octets of diquark resonances a mass value around 230 MeV was found numerically. In contrast, mesons are stable particles in the CFL phase. Their masses lie in the interval 400$\\div$500 MeV for not too large values of $\\mu>\\mu_c$.

  20. Time Variations of the Superkamiokande Solar Neutrino Flux Data by Rayleigh Power Spectrum Analysis

    E-Print Network [OSTI]

    Koushik Ghosh; Probhas Raychaudhuri

    2006-06-05T23:59:59.000Z

    We have used the Rayleigh Power Spectrum Analysis of the solar neutrino flux data from 1) 5-day-long samples from Super-Kamiokande-I detector during the period from June, 1996 to July, 2001; 2) 10 -day-long samples from the same detector during the same period and (3) 45-day long from the same detector during the same period. According to our analysis (1) gives periodicities around 0.25, 23.33, 33.75 and 42.75 months; (2) exhibits periodicities around 0.5, 1.0, 28.17, 40.67 and 52.5 months and (3) shows periodicities around 16.5 and 28.5 months. We have found almost similar periods in the solar flares, sunspot data, solar proton data.

  1. Studying accreting black holes and neutron stars with time series: beyond the power spectrum

    E-Print Network [OSTI]

    S. Vaughan; P. Uttley

    2008-02-04T23:59:59.000Z

    The fluctuating brightness of cosmic X-ray sources, particularly accreting black holes and neutron star systems, has enabled enormous progress in understanding the physics of turbulent accretion flows, the behaviour of matter on the surfaces of neutron stars and improving the evidence for black holes. Most of this progress has been made by analysing and modelling time series data in terms of their power and cross spectra, as will be discussed in other articles in this volume. Recently, attempts have been made to make use of other aspects of the data, by testing for non-linearity, non-Gaussianity, time asymmetry and by examination of higher order Fourier spectra. These projects, which have been made possible by the vast increase in data quality and quantity over the past decade, are the subject of this article.

  2. A pulsed power hydrodynamics approach to exploring properties of warm dense matter

    SciTech Connect (OSTI)

    Reinovsky, Robert Emil [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    Pulsed Power Hydrodynamics, as an application of low-impedance, pulsed power, and high magnetic field technology developed over the last decade to study advanced hydrodynamic problems, instabilities, turbulence, and material properties, can potentially be applied to the study of the behavior and properties of warm dense matter (WDM) as well. Exploration of the properties, such as equation of state and conductivity, of warm dense matter is an emerging area of study focused on the behavior of matter at density near solid density (from 10% of solid density to a few times solid density) and modest temperatures ({approx}1-10 eV). Warm dense matter conditions can be achieved by laser or particle beam heating of very small quantities of matter on timescales short compared to the subsequent hydrodynamic expansion timescales (isochoric heating) and a vigorous community of researchers is applying these techniques using petawatt scale laser systems, but the microscopic size scale of the WDM produced in this way limits access to some physics phenomena. Pulsed power hydrodynamics techniques, either through high convergence liner compression of a large volume, modest density, low temperature plasma to densities approaching solid density or through the explosion and subsequent expansion of a conductor (wire) against a high pressure (density) gas background (isobaric expansion) techniques both offer the prospect for producing warm dense matter in macroscopic quantities. However, both techniques demand substantial energy, proper power conditioning and delivery, and an understanding of the hydrodynamic and instability processes that limit each technique. Similarly, liner compression of normal density material, perhaps using multiple reflected shocks can provide access to the challenging region above normal density -- again with the requirement of very large amounts of driving energy. In this paper we will provide an introduction to techniques that might be applied to explore this interesting new application of the energy-rich technology of pulse power and high magnetic fields.

  3. arXiv:1302.6994v1[astro-ph.CO]27Feb2013 Power Spectrum Super-Sample Covariance

    E-Print Network [OSTI]

    Hu, Wayne

    that underlies them. Its two-point correlation function or the Fourier-transformed counterpart, the power from the large-scale structure probes. The statistical precision of power spectrum measurementsarXiv:1302.6994v1[astro-ph.CO]27Feb2013 Power Spectrum Super-Sample Covariance Masahiro Takada

  4. POWER SPECTRUM ANALYSIS OF MTNEURONS FROM AWAKE MONKEY W. Bair, C. Koch, W. Newsome 1 , K. Britten 1 ,

    E-Print Network [OSTI]

    Bair, Wyeth

    POWER SPECTRUM ANALYSIS OF MTNEURONS FROM AWAKE MONKEY W. Bair, C. Koch, W. Newsome 1 , K. Britten 1 , E. Niebur \\Lambda . Computation and Neural Systems, Caltech, Pasadena, CA 91125; Dept­related 30--70 Hz oscillations observed in cat V1. We investi­ gated temporal fine structure of single cell

  5. Power spectrum analysis of ionospheric fluctuations with the Murchison Widefield Array

    E-Print Network [OSTI]

    Loi, Shyeh Tjing; Murphy, Tara; Cairns, Iver H; Bell, Martin; Hurley-Walker, Natasha; Morgan, John; Lenc, Emil; Offringa, A R; Feng, L; Hancock, P J; Kaplan, D L; Kudryavtseva, N; Bernardi, G; Bowman, J D; Briggs, F; Cappallo, R J; Corey, B E; Deshpande, A A; Emrich, D; Gaensler, B M; Goeke, R; Greenhill, L J; Hazelton, B J; Johnston-Hollitt, M; Kasper, J C; Kratzenberg, E; Lonsdale, C J; Lynch, M J; McWhirter, S R; Mitchell, D A; Morales, M F; Morgan, E; Oberoi, D; Ord, S M; Prabu, T; Rogers, A E E; Roshi, A; Shankar, N Udaya; Srivani, K S; Subrahmanyan, R; Tingay, S J; Waterson, M; Wayth, R B; Webster, R L; Whitney, A R; Williams, A; Williams, C L

    2015-01-01T23:59:59.000Z

    Low-frequency, wide field-of-view (FoV) radio telescopes such as the Murchison Widefield Array (MWA) enable the ionosphere to be sampled at high spatial completeness. We present the results of the first power spectrum analysis of ionospheric fluctuations in MWA data, where we examined the position offsets of radio sources appearing in two datasets. The refractive shifts in the positions of celestial sources are proportional to spatial gradients in the electron column density transverse to the line of sight. These can be used to probe plasma structures and waves in the ionosphere. The regional (10-100 km) scales probed by the MWA, determined by the size of its FoV and the spatial density of radio sources (typically thousands in a single FoV), complement the global (100-1000 km) scales of GPS studies and local (0.01-1 km) scales of radar scattering measurements. Our data exhibit a range of complex structures and waves. Some fluctuations have the characteristics of travelling ionospheric disturbances (TIDs), whi...

  6. Power-spectrum analysis of Super-Kamiokande solar neutrino data, taking into account asymmetry in the error estimates

    E-Print Network [OSTI]

    P. A. Sturrock; J. D. Scargle

    2006-06-20T23:59:59.000Z

    The purpose of this article is to carry out a power-spectrum analysis (based on likelihood methods) of the Super-Kamiokande 5-day dataset that takes account of the asymmetry in the error estimates. Whereas the likelihood analysis involves a linear optimization procedure for symmetrical error estimates, it involves a nonlinear optimization procedure for asymmetrical error estimates. We find that for most frequencies there is little difference between the power spectra derived from analyses of symmetrized error estimates and from asymmetrical error estimates. However, this proves not to be the case for the principal peak in the power spectra, which is found at 9.43 yr-1. A likelihood analysis which allows for a "floating offset" and takes account of the start time and end time of each bin and of the flux estimate and the symmetrized error estimate leads to a power of 11.24 for this peak. A Monte Carlo analysis shows that there is a chance of only 1% of finding a peak this big or bigger in the frequency band 1 - 36 yr-1 (the widest band that avoids artificial peaks). On the other hand, an analysis that takes account of the error asymmetry leads to a peak with power 13.24 at that frequency. A Monte Carlo analysis shows that there is a chance of only 0.1% of finding a peak this big or bigger in that frequency band 1 - 36 yr-1. From this perspective, power spectrum analysis that takes account of asymmetry of the error estimates gives evidence for variability that is significant at the 99.9% level. We comment briefly on an apparent discrepancy between power spectrum analyses of the Super-Kamiokande and SNO solar neutrino experiments.

  7. A power line impedance spectrum analyzer using real-time digital signal processing

    E-Print Network [OSTI]

    Margolis, Michael G

    1993-01-01T23:59:59.000Z

    Power distribution system impedance as seen by power converters and other non-linear loads is important for the determination of harmonic current injection and propagation caused by these loads. This thesis presents a real-time power line impedance...

  8. Advanced Condenser Boosts Geothermal Power Plant Output (Fact Sheet), The Spectrum of Clean Energy Innovation

    SciTech Connect (OSTI)

    Not Available

    2010-12-01T23:59:59.000Z

    When power production at The Geysers geothermal power complex began to falter, the National Renewable Energy Laboratory (NREL) stepped in, developing advanced condensing technology that dramatically boosted production efficiency - and making a major contribution to the effective use of geothermal power. NREL developed advanced direct-contact condenser (ADCC) technology to condense spent steam more effectively, improving power production efficiency in Unit 11 by 5%.

  9. Figure 5. Wavelet time series analysis for yearly LBM outbreaks. a) The normalized time-series. b) Temporally-local wavelet power spectrum (dark red indicates the strongest

    E-Print Network [OSTI]

    SUPPLEMENT Figure 5. Wavelet time series analysis for yearly LBM outbreaks. a) The normalized time-series. b) Temporally-local wavelet power spectrum (dark red indicates the strongest periodicity while white indicates the weakest periodicity). c) Spatiotemporally-global wavelet spectrum. d) Time-series plot

  10. Model independent foreground power spectrum estimation using WMAP 5-year data Tuhin Ghosh,1,* Rajib Saha,1,2,3,4,

    E-Print Network [OSTI]

    Souradeep, Tarun

    Saha,1,2,3,4, Pankaj Jain,4, and Tarun Souradeep1,x 1 IUCAA, Post Bag 4, Ganeshkhind, Pune-411007 of CMB power spectrum estimation was proposed by Saha et al. 2006. This methodology demonstrates

  11. Review of Methods of Power-Spectrum Analysis as Applied to Super-Kamiokande Solar Neutrino Data

    E-Print Network [OSTI]

    P. A. Sturrock

    2004-08-02T23:59:59.000Z

    To help understand why different published analyses of the Super-Kamiokande solar neutrino data arrive at different conclusions, we have applied six different methods to a standardized problem. The key difference between the various methods rests in the amount of information that each processes. A Lomb-Scargle analysis that uses the mid times of the time bins and ignores experimental error estimates uses the least information. A likelihood analysis that uses the start times, end times, and mean live times, and takes account of the experimental error estimates, makes the greatest use of the available information. We carry out power-spectrum analyses of the Super-Kamiokande 5-day solar neutrino data, using each method in turn, for a standard search band (0 to 50 yr-1). For each method, we also carry out a fixed number (10,000) of Monte-Carlo simulations for the purpose of estimating the significance of the leading peak in each power spectrum. We find that, with one exception, the results of these calculations are compatible with those of previously published analyses. (We are unable to replicate Koshio's recent results.) We find that the significance of the peaks at 9.43 yr-1 and at 43.72 yr-1 increases progressively as one incorporates more information into the analysis procedure.

  12. Detection of periodic signatures in the solar power spectrum. On the track of l=1 gravity modes

    E-Print Network [OSTI]

    R. A. Garcia; S. Turck-Chieze; S. J. Jimenez-Reyes; J. Ballot; P. L. Palle; A. Eff-Darwich; S. Mathur; J. Provost

    2006-11-27T23:59:59.000Z

    In the present work we show robust indications of the existence of g modes in the Sun using 10 years of GOLF data. The present analysis is based on the exploitation of the collective properties of the predicted low-frequency (25 to 140 microHz) g modes: their asymptotic nature, which implies a quasi equidistant separation of their periods for a given angular degree (l). The Power Spectrum (PS) of the Power Spectrum Density (PSD), reveals a significant structure indicating the presence of features (peaks) in the PSD with near equidistant periods corresponding to l=1 modes in the range n=-4 to n=-26. The study of its statistical significance of this feature was fully undertaken and complemented with Monte Carlo simulations. This structure has a confidence level better than 99.86% not to be due to pure noise. Furthermore, a detailed study of this structure suggests that the gravity modes have a much more complex structure than the one initially expected (line-widths, magnetic splittings...). Compared to the latest solar models, the obtained results tend to favor a solar core rotating significantly faster than the rest of the radiative zone. In the framework of the Phoebus group, we have also applied the same methodology to other helioseismology instruments on board SoHO and ground based networks.

  13. A Gamma-Ray Burst/Pulsar for Cosmic-Ray Positrons with a Dark Matter-like Spectrum

    E-Print Network [OSTI]

    Kunihito Ioka

    2010-06-15T23:59:59.000Z

    We propose that a nearby gamma-ray burst (GRB) or GRB-like (old, single and short-lived) pulsar/supernova remnant/microquasar about 10^{5-6} years ago may be responsible for the excesses of cosmic-ray positrons and electrons recently observed by the PAMELA, ATIC/PPB-BETS, Fermi and HESS experiments. We can reproduce the smooth Fermi/HESS spectra as well as the spiky ATIC/PPB-BETS spectra. The spectra have a sharp cutoff that is similar to the dark matter predictions, sometimes together with a line (not similar), since higher energy cosmic-rays cool faster where the cutoff/line energy marks the source age. A GRB-like astrophysical source is expected to have a small but finite spread in the cutoff/line as well as anisotropy in the cosmic-ray and diffuse gamma-ray flux, providing a method for the Fermi and future CALET experiments to discriminate between dark matter and astrophysical origins.

  14. Gaussian random field power spectrum and the S\\'ersic law

    E-Print Network [OSTI]

    Nipoti, Carlo

    2015-01-01T23:59:59.000Z

    The surface-brightness profiles of galaxies are well described by the S\\'ersic law: systems with high S\\'ersic index m have steep central profiles and shallow outer profiles, while systems with low m have shallow central profiles and steep outer profiles. R. Cen (2014, ApJL, 790, L24) has conjectured that these profiles arise naturally in the standard cosmological model with initial density fluctuations represented by a Gaussian random field (GRF). We explore and confirm this hypothesis with N-body simulations of dissipationless collapses in which the initial conditions are generated from GRFs with different power spectra. The numerical results show that GRFs with more power on small scales lead to systems with higher m. In our purely dissipationless simulations the S\\'ersic index is in the range 2

  15. Design of a Low Power, Fast-Spectrum, Liquid-Metal Cooled Surface Reactor System

    SciTech Connect (OSTI)

    Marcille, T. F.; Poston, D. I.; Kapernick, R. J. [Nuclear Systems Design Group, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Dixon, D. D. [Nuclear Systems Design Group, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Fischer, G. A. [Nuclear Systems Design Group, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Doherty, S. P. [Nuclear Systems Design Group, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Department of Engineering, Trinity College, Hartford, CT 06106 (United States)

    2006-01-20T23:59:59.000Z

    In the current 2005 US budget environment, competition for fiscal resources make funding for comprehensive space reactor development programs difficult to justify and accommodate. Simultaneously, the need to develop these systems to provide planetary and deep space-enabling power systems is increasing. Given that environment, designs intended to satisfy reasonable near-term surface missions, using affordable technology-ready materials and processes warrant serious consideration. An initial lunar application design incorporating a stainless structure, 880 K pumped NaK coolant system and a stainless/UO2 fuel system can be designed, fabricated and tested for a fraction of the cost of recent high-profile reactor programs (JIMO, SP-100). Along with the cost reductions associated with the use of qualified materials and processes, this design offers a low-risk, high-reliability implementation associated with mission specific low temperature, low burnup, five year operating lifetime requirements.

  16. Power Spectrum Analysis of Physikalisch-Technische Bundesanstalt Decay-Rate Data: Evidence for Solar Rotational Modulation

    E-Print Network [OSTI]

    P. A. Sturrock; J. B. Buncher; E. Fischbach; J. T. Gruenwald; D. Javorsek II; J. H. Jenkins; R. H. Lee; J. J. Mattes; J. R. Newport

    2010-10-11T23:59:59.000Z

    Evidence for an anomalous annual periodicity in certain nuclear decay data has led to speculation concerning a possible solar influence on nuclear processes. We have recently analyzed data concerning the decay rates of Cl-36 and Si-32, acquired at the Brookhaven National Laboratory (BNL), to search for evidence that might be indicative of a process involving solar rotation. Smoothing of the power spectrum by weighted-running-mean analysis leads to a significant peak at frequency 11.18/yr, which is lower than the equatorial synodic rotation rates of the convection and radiative zones. This article concerns measurements of the decay rates of Ra-226 acquired at the Physikalisch-Technische Bundesanstalt (PTB) in Germany. We find that a similar (but not identical) analysis yields a significant peak in the PTB dataset at frequency 11.21/yr, and a peak in the BNL dataset at 11.25/yr. The change in the BNL result is not significant since the uncertainties in the BNL and PTB analyses are estimated to be 0.13/yr and 0.07/yr, respectively. Combining the two running means by forming the joint power statistic leads to a highly significant peak at frequency 11.23/yr. We comment briefly on the possible implications of these results for solar physics and for particle physics.

  17. Practitioner Perspectives Matter: Public Policy and Private Investment in the U.S. Electric Power Sector

    E-Print Network [OSTI]

    Barradale, Merrill Jones

    2010-01-01T23:59:59.000Z

    Renewable Energy Power Purchase Agreements. ” Journal ofit is the dynamic of power purchase agreement negotiationsbuy and sell sides of power purchase agreements (PPA), and

  18. The Journal of Neuroscience, May 1994, 14(5): 2870-2892 Power Spectrum Analysis of Bursting Cells in Area MT in the

    E-Print Network [OSTI]

    Koch, Christof

    The Journal of Neuroscience, May 1994, 14(5): 2870-2892 Power Spectrum Analysis of Bursting Cells Computation and Neural Systems Program, California Institute of Technology, Pasadena, California 91125 and 2 proposals, however, emphasize the information potentially available in the temporal structure of spike

  19. The Journal of Neuroscience, May 1994, 74(5): 2870-2892 Power Spectrum Analysis of Bursting Cells in Area MT in the

    E-Print Network [OSTI]

    Newsome, William

    The Journal of Neuroscience, May 1994, 74(5): 2870-2892 Power Spectrum Analysis of Bursting Cells* `Computation and Neural Systems Program, California Institute of Technology, Pasadena, California 91125 proposals, however, emphasize the information potentially available in the temporal structure of spike

  20. Power-Spectrum Analyses of Super-Kamiokande Solar Neutrino Data: Variability and its Implications for Solar Physics and Neutrino Physics

    E-Print Network [OSTI]

    P. A. Sturrock; D. O. Caldwell; J. D. Scargle; M. S. Wheatland

    2005-08-08T23:59:59.000Z

    There have been conflicting claims as to whether or not power-spectrum analysis of the Super-Kamiokande solar neutrino data yields evidence of variability. Comparison of these claims is complicated by the fact that the relevant articles may use different datasets, different methods of analysis, and different procedures for significance estimation. The purpose of this article is to clarify the role of power spectrum analysis. To this end, we analyze only the Super-Kamiokande 5-day dataset, and we use a standard procedure for significance estimation proposed by the Super-Kamiokande collaboration. We then analyze this dataset, with this method of significance estimation, using six methods of power spectrum analysis. We find that the significance of the principal peak in the power spectrum (that at 9.43 yr-1with a depth of modulation of 7%) shows a clear correlation with the amount and relevance of the information being processed, as would be expected if there were a real signal in the data. The significance level reaches 99.3% for one method of analysis. We discuss, in terms of sub-dominant processes, possible neutrino-physics interpretations of the apparent variability of the Super-Kamiokande measurements, and we suggest steps that could be taken to resolve the question of variability of the solar neutrino flux.

  1. Generation of primordial cosmological density inhomogeneities with scale invariant power spectrum during the standard radiation dominated expansion of the universe

    E-Print Network [OSTI]

    Oaknin, David H

    2007-01-01T23:59:59.000Z

    The expansion/contraction of a bubble of gas of radius $R_0(t)$ immersed in an incompressible fluid that fills the infinite 3D space around it, $r \\ge R_0(t)$, generates a radial flow, ${\\vec v}(r,t) = \\frac{R^2_0(t)}{r^2}\\ \\dot{R}_0(t) {\\hat r}$, which is set by the velocity of the bubble surface, $\\dot{R}_0(t)$. The kinetic energy that the expanding/contracting bubble pumps, at the expense of its own internal energy, into each unit volume of the flowing incompressible fluid is ${\\it e}(r,t) = \\frac{\\rho_0}{2} |{\\vec v}(r,t)|^2 = \\frac{\\rho_0}{2} \\dot{R}^2_0(t) R^4_0(t) r^{-4}$, where $\\rho_0$ is the mass density of the fluid. This incompressible flow generates equal time energy density (anti)correlations over infinitely long distances. They are imposed by global conservation laws and, therefore, do not violate causality. We notice that energy density inhomogeneities that are (anti)correlated as $f(r) \\sim - r^{-4}$ as $r \\to \\infty$ have scale invariant power spectrum in the range of very small wavenumbers,...

  2. Practitioner Perspectives Matter: Public Policy and Private Investment in the U.S. Electric Power Sector

    E-Print Network [OSTI]

    Barradale, Merrill Jones

    2010-01-01T23:59:59.000Z

    a boom-bust cycle in wind power plant investment in the U.S.tax credit for wind turbine power plants is an ineffectivewind power and became comfortable with turbine technology and plant

  3. Practitioner Perspectives Matter: Public Policy and Private Investment in the U.S. Electric Power Sector

    E-Print Network [OSTI]

    Barradale, Merrill Jones

    2010-01-01T23:59:59.000Z

    on U.S. Wind Power Installation, Cost, and Performanceon U.S. Wind Power Installation, Cost, and Performancenot returned). Higher wind supply costs; Greater reliance on

  4. Dark matter, a new proof of the predictive power of general relativity

    E-Print Network [OSTI]

    Stéphane Le Corre

    2015-04-07T23:59:59.000Z

    Without observational or theoretical modifications, Newtonian and general relativity seem to be unable to explain gravitational behavior of large structure of the universe. The assumption of dark matter solves this problem without modifying theories. But it implies that most of the matter in the universe must be unobserved matter. Another solution is to modify gravitation laws. In this article, we study a third way that does not modify gravitation of general relativity and not modify the matter's distribution, by using gravitomagnetism in a new physical context. Compare with Newtonian gravitation, it leads to add a new component without changing the gravity field. As already known, we retrieve that this new component is generally small enough to be undetectable. But we will see that the galaxies clusters can generate a significant component and embed large structure of universe. We show that the magnitude of this embedding component is once again small enough to be in agreement with current experimental results, undetectable at the scale of our solar system, but detectable at the scale of the galaxies and explain dark matter. Mainly, it explains six unexplained phenomena, the rotation speed of galaxies, the rotation speed of dwarf satellite galaxies, the movement in a plane of dwarf satellite galaxies, the decreasing quantity of dark matter with the distance to the center of galaxies' cluster, the expected quantity of dark matter inside galaxies and the expected experimental values of parameters of dark matter measured in CMB. This solution implies consequences on the dwarf galaxies (distribution in planes) that just have been observed and differentiate it from dark matter solution. It could explain some others facts (galaxies with two portions of their disk that rotate in opposite directions, galaxies with a truly declining rotation curve, narrowness of galaxy's jets, precocity of organization of galaxies, ...).

  5. Dark matter, a new proof of the predictive power of general relativity

    E-Print Network [OSTI]

    Corre, Stéphane Le

    2015-01-01T23:59:59.000Z

    Without observational or theoretical modifications, Newtonian and general relativity seem to be unable to explain gravitational behavior of large structure of the universe. The assumption of dark matter solves this problem without modifying theories. But it implies that most of the matter in the universe must be unobserved matter. Another solution is to modify gravitation laws. In this article, we study a third way that does not modify gravitation of general relativity and not modify the matter's distribution, by using gravitomagnetism in a new physical context. Compare with Newtonian gravitation, it leads to add a new component without changing the gravity field. As already known, we retrieve that this new component is generally small enough to be undetectable. But we will see that the galaxies clusters can generate a significant component and embed large structure of universe. We show that the magnitude of this embedding component is once again small enough to be in agreement with current experimental resul...

  6. Power Spectrum Analysis of LMSU (Lomonosov Moscow State University) Nuclear Decay-Rate Data: Further Indication of r-Mode Oscillations in an Inner Solar Tachocline

    E-Print Network [OSTI]

    Peter A. Sturrock; Alexander G. Parkhomov; Ephraim Fischbach; Jere H. Jenkins

    2012-03-21T23:59:59.000Z

    This article presents a power-spectrum analysis of 2,350 measurements of the $^{90}$Sr/$^{90}$Y decay process acquired over the interval 4 August 2002 to 6 February 2009 at the Lomonosov Moscow State University (LMSU). As we have found for other long sequences of decay measurements, the power spectrum is dominated by a very strong annual oscillation. However, we also find a set of low-frequency peaks, ranging from 0.26 year$^{-1}$ to 3.98 year$^{-1}$, which are very similar to an array of peaks in a power spectrum formed from Mt Wilson solar diameter measurements. The Mt Wilson measurements have been interpreted in terms of r-mode oscillations in a region where the sidereal rotation frequency is 12.08 year$^{-1}$. We find that the LMSU measurements may also be attributed to the same type of r-mode oscillations in a solar region with the same sidereal rotation frequency. We propose that these oscillations occur in an inner tachocline that separates the radiative zone from a more slowly rotating solar core.

  7. Practitioner Perspectives Matter: Public Policy and Private Investment in the U.S. Electric Power Sector

    E-Print Network [OSTI]

    Barradale, Merrill Jones

    2010-01-01T23:59:59.000Z

    Costs of Regulatory Uncertainty for Coal-Fired Power Plants. ”cost options for retrofitting later. Significantly, enthusiasm for coal plant

  8. Condensed Matter Cluster Reactions in LENR Power Cells for a Radical New Type of Space Power Source

    SciTech Connect (OSTI)

    Yang Xiaoling; Miley, George H.; Hora, Heinz [University of Illinois Urbana-Champaign, NPL Associates, Urbana, IL 217-333-3772 (United States); Department of Theoretical Physics Univ. of New South Wales Sydney (Australia)

    2009-03-16T23:59:59.000Z

    This paper reviews previous theoretical and experimental study on the possibility of nuclear events in multilayer thin film electrodes (Lipson et al., 2004 and 2005; Miley et al., 2007), including the correlation between excess heat and transmutations (Miley and Shrestha, 2003) and the cluster theory that predicts it. As a result of this added understanding of cluster reactions, a new class of electrodes is under development at the University of Illinois. These electrodes are designed to enhance cluster formation and subsequent reactions. Two approaches are under development. The first employs improved loading-unloading techniques, intending to obtain a higher volumetric density of sites favoring cluster formation. The second is designed to create nanostructures on the electrode where the cluster state is formed by electroless deposition of palladium on nickel micro structures. Power units employing these electrodes should offer unique advantages for space applications. This is a fundamental new nuclear energy source that is environmentally compatible with a minimum of radiation involvement, high specific power, very long lifetime, and scalable from micro power to kilowatts.

  9. Practitioner Perspectives Matter: Public Policy and Private Investment in the U.S. Electric Power Sector

    E-Print Network [OSTI]

    Barradale, Merrill Jones

    2010-01-01T23:59:59.000Z

    L.T. and P. Kraske (2003). “Renewable Energy Power PurchaseInvestments in Renewable Energy: The Role of Policy Design47. Wiser, R. (1997). “Renewable energy finance and project

  10. Practitioner Perspectives Matter: Public Policy and Private Investment in the U.S. Electric Power Sector

    E-Print Network [OSTI]

    Barradale, Merrill Jones

    2010-01-01T23:59:59.000Z

    of these policies would give wind energy a boost relative toon the cost of wind power. ” Energy Policy 25(1): 15-27.of Policy Uncertainty on Renewable Energy Investment: Wind

  11. Practitioner Perspectives Matter: Public Policy and Private Investment in the U.S. Electric Power Sector

    E-Print Network [OSTI]

    Barradale, Merrill Jones

    2010-01-01T23:59:59.000Z

    risk associated with CO2 emissions under potential climateimpact in terms of CO2 emissions of these power plants,gas, or wind, annual CO2 emissions from these 5,000 plants

  12. Precision reconstruction of the dark matter-neutrino relative velocity from N-body simulations

    E-Print Network [OSTI]

    Inman, Derek; Pen, Ue-Li; Farchi, Alban; Yu, Hao-Ran; Harnois-Deraps, Joachim

    2015-01-01T23:59:59.000Z

    Discovering the mass of neutrinos is a principle goal in high energy physics and cosmology. In addition to cosmological measurements based on two-point statistics, the neutrino mass can also be estimated by observations of neutrino wakes resulting from the relative motion between dark matter and neutrinos. Such a detection relies on an accurate reconstruction of the dark matter-neutrino relative velocity which is affected by non-linear structure growth and galaxy bias. We investigate our ability to reconstruct this relative velocity using large N-body simulations where we evolve neutrinos as distinct particles alongside the dark matter. We find that the dark matter velocity power spectrum is overpredicted by linear theory whereas the neutrino velocity power spectrum is underpredicted. The magnitude of the relative velocity observed in the simulations is found to be lower than what is predicted in linear theory. Since neither the dark matter nor the neutrino velocity fields are directly observable from galaxy ...

  13. Dark Energy - Dark Matter Unification: Generalized Chaplygin Gas Model

    E-Print Network [OSTI]

    Orfeu Bertolami

    2005-04-14T23:59:59.000Z

    We review the main features of the generalized Chaplygin gas (GCG) proposal for unification of dark energy and dark matter and discuss how it admits an unique decomposition into dark energy and dark matter components once phantom-like dark energy is excluded. In the context of this approach we consider structure formation and show that unphysical oscillations or blow-up in the matter power spectrum are not present. Moreover, we demonstrate that the dominance of dark energy occurs about the time when energy density fluctuations start evolving away from the linear regime.

  14. Confirmation of the Copernican principle at Gpc radial scale and above from the kinetic Sunyaev Zel'dovich effect power spectrum

    SciTech Connect (OSTI)

    Zhang, Pengjie; Stebbins, Albert

    2010-09-01T23:59:59.000Z

    The Copernican principle, a cornerstone of modern cosmology, remains largely unproven at Gpc radial scale and above. Violations of this type will inevitably cause a first order anisotropic kinetic Sunyaev Zel'dovich (kSZ) effect. Here we show that, if large scale radial inhomogeneities have amplitude large enough to explain the 'dark energy' phenomena, the induced kSZ power spectrum will be orders of magnitude larger than the ACT/SPT upper limit. This single test rules out the void model as a viable alternative to dark energy to explain the apparent cosmic acceleration, confirms the Copernican principle on Gpc radial scale and above and closes a loophole in the standard cosmology.

  15. THE 1998 NOVEMBER 14 OCCULTATION OF GSC 0622-00345 BY SATURN. II. STRATOSPHERIC THERMAL PROFILE, POWER SPECTRUM, AND GRAVITY WAVES

    SciTech Connect (OSTI)

    Harrington, Joseph [Planetary Sciences Group, Department of Physics, University of Central Florida, Orlando, FL 32816-2385 (United States); French, Richard G. [Astronomy Department, Wellesley College, Wellesley, MA 02481 (United States); Matcheva, Katia, E-mail: jh@physics.ucf.ed, E-mail: rfrench@wellesley.ed, E-mail: katia@phys.ufl.ed [Department of Physics, University of Florida, P.O. Box 118440, Gainesville, FL 32611 (United States)

    2010-06-10T23:59:59.000Z

    On 1998 November 14, Saturn and its rings occulted the star GSC 0622-00345. The occultation latitude was 55.{sup 0}5 S. This paper analyzes the 2.3 {mu}m light curve derived by Harrington and French. A fixed-baseline isothermal fit to the light curve has a temperature of 140 {+-} 3 K, assuming a mean molecular mass of 2.35 AMU. The thermal profile obtained by numerical inversion is valid between 1 and 60 {mu}bar. The vertical temperature gradient is > 0.2 K km{sup -1} more stable than the adiabatic lapse rate, but it still shows the alternating-rounded-spiked features seen in many temperature gradient profiles from other atmospheric occultations and usually attributed to breaking gravity (buoyancy) waves. We conduct a wavelet analysis of the thermal profile, and show that, even with our low level of noise, scintillation due to turbulence in Earth's atmosphere can produce large temperature swings in light-curve inversions. Spurious periodic features in the 'reliable' region of a wavelet amplitude spectrum can exceed 0.3 K in our data. We also show that gravity-wave model fits to noisy isothermal light curves can lead to convincing wave 'detections'. We provide new significance tests for localized wavelet amplitudes, wave model fits, and global power spectra of inverted occultation light curves by assessing the effects of pre- and post-occultation noise on these parameters. Based on these tests, we detect several significant ridges and isolated peaks in wavelet amplitude, to which we fit a gravity wave model. We also strongly detect the global power spectrum of thermal fluctuations in Saturn's atmosphere, which resembles the 'universal' (modified Desaubies) curve associated with saturated spectra of propagating gravity waves on Earth and Jupiter.

  16. Power spectrum estimates of high frequency noise generated by high impedance arcing faults on distribution systems / by Thomas James Talley

    E-Print Network [OSTI]

    Talley, Thomas James

    1979-01-01T23:59:59.000Z

    faults, and to search for possible solutions, Pennsylvania Power and Light Company (PP&L) gathered data on instances of downed conductors. [ 4 ] In a breakdown of 390 cases of downed conductors on 12 KV overhead distribution lines in 1974...-75, they found that over- current protective devices did not operate for 23%%d of the cases where the feeder had bare wire conductors, and 727. of the cases where the feeder had XLP covered conductors. These figures indicate the severity of the problem...

  17. Geomagnetic Temporal Spectrum Catherine Constable 1 GEOMAGNETIC TEMPORAL SPECTRUM

    E-Print Network [OSTI]

    Constable, Catherine G.

    of geomagnetic variations. The power spectral density S(f) is a measure of the power in geomagnetic field. At a distance of about 3 earth radii, the magnetospheric ring current for Encyclopedia of Geomagnetism measurements of the geomagnetic field to estimate the power spectrum. Power spectral estimation is usually

  18. Planck intermediate results. XXX. The angular power spectrum of polarized dust emission at intermediate and high Galactic latitudes

    E-Print Network [OSTI]

    Adam, R; Aghanim, N; Arnaud, M; Aumont, J; Baccigalupi, C; Banday, A J; Barreiro, R B; Bartlett, J G; Bartolo, N; Battaner, E; Benabed, K; Benoit-Lévy, A; Bernard, J -P; Bersanelli, M; Bielewicz, P; Bonaldi, A; Bonavera, L; Bond, J R; Borrill, J; Bouchet, F R; Boulanger, F; Bracco, A; Bucher, M; Burigana, C; Butler, R C; Calabrese, E; Cardoso, J -F; Catalano, A; Challinor, A; Chamballu, A; Chary, R -R; Chiang, H C; Christensen, P R; Clements, D L; Colombi, S; Colombo, L P L; Combet, C; Couchot, F; Coulais, A; Curto, A; Cuttaia, F; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Zotti, G; Delabrouille, J; Delouis, J -M; Désert, F -X; Dickinson, C; Diego, J M; Dolag, K; Dole, H; Donzelli, S; Doré, O; Douspis, M; Ducout, A; Dunkley, J; Dupac, X; Efstathiou, G; Elsner, F; Enßlin, T A; Eriksen, H K; Falgarone, E; Finelli, F; Forni, O; Frailis, M; Fraisse, A A; Franceschi, E; Frejsel, A; Galeotta, S; Galli, S; Ganga, K; Ghosh, T; Giard, M; Giraud-Héraud, Y; Gjerløw, E; González-Nuevo, J; Górski, K M; Gratton, S; Gregorio, A; Gruppuso, A; Guillet, V; Hansen, F K; Hanson, D; Harrison, D L; Helou, G; Henrot-Versillé, S; Hernández-Monteagudo, C; Herranz, D; Hivon, E; Holmes, W A; Huffenberger, K M; Hurier, G; Jaffe, A H; Jaffe, T R; Jewell, J; Jones, W C; Juvela, M; Keihänen, E; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Knox, L; Krachmalnicoff, N; Kunz, M; Kurki-Suonio, H; Lagache, G; Lamarre, J -M; Lasenby, A; Lattanzi, M; Lawrence, C R; Leahy, J P; Leonardi, R; Lesgourgues, J; Levrier, F; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Macías-Pérez, J F; Maffei, B; Maino, D; Mandolesi, N; Mangilli, A; Maris, M; Martin, P G; Martínez-González, E; Masi, S; Matarrese, S; Mazzotta, P; Melchiorri, A; Mendes, L; Mennella, A; Migliaccio, M; Mitra, S; Miville-Deschênes, M -A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Moss, A; Munshi, D; Murphy, J A; Naselsky, P; Nati, F; Natoli, P; Netterfield, C B; Nørgaard-Nielsen, H U; Noviello, F; Novikov, D; Novikov, I; Pagano, L; Pajot, F; Paladini, R; Paoletti, D; Partridge, B; Pasian, F; Patanchon, G; Pearson, T J; Perdereau, O; Perotto, L; Perrotta, F; Pettorino, V; Piacentini, F; Piat, M; Pierpaoli, E; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polenta, G; Ponthieu, N; Popa, L; Pratt, G W; Prunet, S; Puget, J -L; Rachen, J P; Reach, W T; Rebolo, R; Remazeilles, M; Renault, C; Renzi, A; Ricciardi, S; Ristorcelli, I; Rocha, G; Rosset, C; Rossetti, M; Roudier, G; d'Orfeuil, B Rouillé; Rubiño-Martín, J A; Rusholme, B; Sandri, M; Santos, D; Savelainen, M; Savini, G; Scott, D; Soler, J D; Spencer, L D; Stolyarov, V; Stompor, R; Sudiwala, R; Sunyaev, R; Sutton, D; Suur-Uski, A -S; Sygnet, J -F; Tauber, J A; Terenzi, L; Tomasi, M; Tristram, M; Tucci, M; Tuovinen, J; Valenziano, L; Valiviita, J; Van Tent, B; Vibert, L; Vielva, P; Villa, F; Wade, L A; Wandelt, B D; Watson, R; Wehus, I K; White, M; White, S D M; Yvon, D; Zacchei, A; Zonca, A

    2014-01-01T23:59:59.000Z

    The polarized thermal emission from Galactic dust is the main foreground present in measurements of the polarization of the cosmic microwave background (CMB) at frequencies above 100GHz. We exploit the Planck HFI polarization data from 100 to 353GHz to measure the dust angular power spectra $C_\\ell^{EE,BB}$ over the range $40<\\ell<600$. These will bring new insights into interstellar dust physics and a precise determination of the level of contamination for CMB polarization experiments. We show that statistical properties of the emission can be characterized over large fractions of the sky using $C_\\ell$. For the dust, they are well described by power laws in $\\ell$ with exponents $\\alpha^{EE,BB}=-2.42\\pm0.02$. The amplitudes of the polarization $C_\\ell$ vary with the average brightness in a way similar to the intensity ones. The dust polarization frequency dependence is consistent with modified blackbody emission with $\\beta_d=1.59$ and $T_d=19.6$K. We find a systematic ratio between the amplitudes of ...

  19. An angular power spectrum analysis of the DRAO 1.4 GHz polarization survey: implications for CMB observations

    E-Print Network [OSTI]

    La Porta, L; Reich, W; Reich, P

    2006-01-01T23:59:59.000Z

    The aim of the present analysis is to improve the knowledge of the statistical properties of the Galactic diffuse synchrotron emission, which constrains sensitive CMB anisotropy measurements. We have analysed the new DRAO 1.4 GHz polarization survey together with the Stockert 1.4 GHz total intensity survey and derived the angular power spectra (APSs) of the total intensity, the polarized emission, and their cross-correlation for the entire surveys and for three low-intensity regions. The APSs of the diffuse synchrotron emission are modelled by power laws. For the $E$ and $B$ modes, a slope of $\\alpha \\sim [-3.0,-2.5]$ for the multipole range $\\sim [30,300]$ is found. By the extrapolation of these results to 70 GHz, we can estimate the Galactic synchrotron contamination of CMB anisotropies, and we find results that are compatible with the ones coming from WMAP 3-yr data. In the low-intensity regions, the cosmological primordial B~mode peak at $\\ell \\sim 100$ should be clearly observable for a tensor-to-scalar ...

  20. Predictions on the angular power spectrum of clustered extragalactic point sources at CMB frequencies from flat and all--sky 2D-simulations

    E-Print Network [OSTI]

    J. González-Nuevo; L. Toffolatti; F. Argüeso

    2004-11-12T23:59:59.000Z

    We present predictions on the angular power spectrum of CMB fluctuations due to extragalactic point sources (EPS) by using a method for simulating realistic 2D distributions of clustered EPS. Both radio and far--IR selected source populations are taken into account. To analyze different clustering scenarios, we exploit angular power spectra of EPS, $P(k)$, estimated either by data coming from currently available surveys or by means of theoretical predictions. By adopting the source number counts predicted by the Toffolatti et al. (1998) evolution model -- capable of accounting well for the available data at radio cm wavelengths -- we are able to reproduce current data on the two--point angular correlation functions, $w(\\theta)$, of radio sources. We can confirm that the detection of primordial CMB anisotropies is not hampered by undetected clustered sources at frequencies $\\leq 150-200$ GHz. On the other hand, our current findings show that at higher frequencies the clustering signal could severely reduce the detectability of intrinsic CMB anisotropies, thus confirming previous theoretical predictions. We also show that unsubtracted EPS can account for the excess signal at high multipoles detected by recent CMB anisotropy experiments. Moreover, the additional power due to the clustering of sources gives rise to a small but not negligible contribution to the same excess signal. As a final result, we also present an example of a currently feasible {\\it realistic map} of EPS at 70 GHz, by taking into account data on bright detected sources as well as the previously quoted model for number counts.

  1. The X-ray Power Density Spectrum of the Seyfert 2 Galaxy NGC 4945: Analysis and Application of the Method of Light Curve Simulations

    SciTech Connect (OSTI)

    Mueller, Martin; /SLAC

    2010-12-16T23:59:59.000Z

    The study of the power density spectrum (PDS) of fluctuations in the X-ray flux from active galactic nuclei (AGN) complements spectral studies in giving us a view into the processes operating in accreting compact objects. An important line of investigation is the comparison of the PDS from AGN with those from galactic black hole binaries; a related area of focus is the scaling relation between time scales for the variability and the black hole mass. The PDS of AGN is traditionally modeled using segments of power laws joined together at so-called break frequencies; associations of the break time scales, i.e., the inverses of the break frequencies, with time scales of physical processes thought to operate in these sources are then sought. I analyze the Method of Light Curve Simulations that is commonly used to characterize the PDS in AGN with a view to making the method as sensitive as possible to the shape of the PDS. I identify several weaknesses in the current implementation of the method and propose alternatives that can substitute for some of the key steps in the method. I focus on the complications introduced by uneven sampling in the light curve, the development of a fit statistic that is better matched to the distributions of power in the PDS, and the statistical evaluation of the fit between the observed data and the model for the PDS. Using archival data on one AGN, NGC 3516, I validate my changes against previously reported results. I also report new results on the PDS in NGC 4945, a Seyfert 2 galaxy with a well-determined black hole mass. This source provides an opportunity to investigate whether the PDS of Seyfert 1 and Seyfert 2 galaxies differ. It is also an attractive object for placement on the black hole mass-break time scale relation. Unfortunately, with the available data on NGC 4945, significant uncertainties on the break frequency in its PDS remain.

  2. Strong dark matter constraints on GMSB models

    E-Print Network [OSTI]

    F. Staub; W. Porod; J. Niemeyer

    2010-01-18T23:59:59.000Z

    We reconsider the dark matter problem in supersymmetric models with gauge mediated supersymmetry breaking, with and without R-parity breaking. In these classes of models, a light gravitino forms the dark matter.Consistency with the experimental data, in particular the dark matter abundance and the small-scale power spectrum, requires additional entropy production after the decoupling of the gravitino from the thermal bath. We demonstrate that the usual mechanism via messenger number violating interactions does not work in models where the messenger belongs to SU (5) representations. This is mainly a consequence of two facts: (i) there are at least two different types of lightest messenger particles and (ii) the lightest messenger particle with SU (2) quantum numbers decays dominantly into vector bosons once messenger number is broken, a feature which has been overlooked so far. In case of SO(10) messenger multiplets we find scenarios which work if the SM gauge singlet component is rather light.

  3. Strong dark matter constraints on GMSB models

    E-Print Network [OSTI]

    Staub, F; Niemeyer, J

    2009-01-01T23:59:59.000Z

    We reconsider the dark matter problem in supersymmetric models with gauge mediated supersymmetry breaking, with and without R-parity breaking. In these classes of models, a light gravitino forms the dark matter.Consistency with the experimental data, in particular the dark matter abundance and the small-scale power spectrum, requires additional entropy production after the decoupling of the gravitino from the thermal bath. We demonstrate that the usual mechanism via messenger number violating interactions does not work in models where the messenger belongs to SU (5) representations. This is mainly a consequence of two facts: (i) there are at least two different types of lightest messenger particles and (ii) the lightest messenger particle with SU (2) quantum numbers decays dominantly into vector bosons once messenger number is broken, a feature which has been overlooked so far. In case of SO(10) messenger multiplets we find scenarios which work if the SM gauge singlet component is rather light.

  4. Constraints on particle dark matter from cosmic-ray antiprotons

    E-Print Network [OSTI]

    N. Fornengo; L. Maccione; A. Vittino

    2015-01-30T23:59:59.000Z

    Cosmic-ray antiprotons represent an important channel for dark matter indirect-detection studies. Current measurements of the antiproton flux at the top of the atmosphere and theoretical determinations of the secondary antiproton production in the Galaxy are in good agreement, with no manifest deviation which could point to an exotic contribution in this channel. Therefore, antiprotons can be used as a powerful tool for constraining particle dark matter properties. By using the spectrum of PAMELA data from 50 MV to 180 GV in rigidity, we derive bounds on the dark matter annihilation cross section (or decay rate, for decaying dark matter) for the whole spectrum of dark matter annihilation (decay) channels and under different hypotheses of cosmic-rays transport in the Galaxy and in the heliosphere. For typical models of galactic propagation, the constraints are significantly strong, setting a lower bound on the dark matter mass of a "thermal" relic at about 50-90 GeV for hadronic annihilation channels. These bounds are enhanced to about 150 GeV on the dark matter mass, when large cosmic-rays confinement volumes in the Galaxy are considered, and are reduced to 4-5 GeV for annihilation to light quarks (no bound for heavy-quark production) when the confinement volume is small. Bounds for dark matter lighter than few tens of GeV are due to the low energy part of the PAMELA spectrum, an energy region where solar modulation is relevant: to this aim, we have implemented a detailed solution of the transport equation in the heliosphere, which allowed us not only to extend bounds to light dark matter, but also to determine the uncertainty on the constraints arising from solar modulation modeling. Finally, we estimate the impact of soon-to-come AMS-02 data on the antiproton constraints.

  5. An Ultimate Target for Dark Matter Searches

    E-Print Network [OSTI]

    Kfir Blum; Yanou Cui; Marc Kamionkowski

    2014-12-10T23:59:59.000Z

    The combination of S-matrix unitarity and the dynamics of thermal freeze-out for massive relic particles (denoted here simply by WIMPs) implies a lower limit on the density of such particles, that provide a (potentially sub-dominant) contribution to dark matter. This then translates to lower limits to the signal rates for a variety of techniques for direct and indirect detection of dark matter. For illustration, we focus on models where annihilation is s-wave dominated. We derive lower limits to the flux of gamma-rays from WIMP annihilation at the Galactic center; direct detection of WIMPs; energetic neutrinos from WIMP annihilation in the Sun; and the effects of WIMPs on the angular power spectrum and frequency spectrum of the cosmic microwave background radiation. The results suggest that a variety of dark-matter-search techniques may provide interesting avenues to seek new physics, even if WIMPs do not constitute all the dark matter. While the limits are quantitatively some distance from the reach of current measurements, they may be interesting for long-range planning exercises.

  6. Time Variations of the Solar Neutrino Flux Data from Sage and Gallex-Gno Detectors Obtained by Rayleigh Power Spectrum Analysis

    E-Print Network [OSTI]

    Koushik Ghosh; Probhas Raychaudhuri

    2006-06-05T23:59:59.000Z

    We have used Rayleigh power spectrum analysis of the monthly solar neutrino flux data from (1) SAGE detector during the period from 1st January 1990 to 31st December 2000; (2) SAGE detector during the period from April 1998 to December 2001; (3) GALLEX detector during the period from May 1991 to January 1997; (4) GNO detector during the period from May 1998 to December 2001; (5) GALLEX-GNO detector (combined data) from May 1991 to December 2001 and (6) average of the data from GNO and SAGE detectors during the period from May 1998 to December 2001. (1) exhibits periodicity around 1.3, 4.3, 5.5, 6.3, 7.9, 8.7, 15.9, 18.7, 23.9, 32.9 and 48.7 months. (2) shows periodicity around 1.5, 2.9, 4.5, 10.1 months. For (3) we observe periodicity around 1.7, 18.7 and 26.9 months. For (4) periodicity is seen around 3.5, 5.5, 7.7 and 10.5 months. (5) gives periodicity around 1.7, 18.5, 28.5 and 42.1 months while (6) shows periodicity around 4.3, 6.9, 10.3 and 18.1 months. We have found almost similar periods in the solar flares, sunspot data, solar proton data which indicates that the solar activity cycle may be due to the variable character of nuclear energy generation inside the sun.

  7. ALS Spectrum

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76) (See theDoctoral Fellowship inALSALS SpectrumSpectrum

  8. Changes in the halo formation rates due to features in the primordial spectrum

    E-Print Network [OSTI]

    Dhiraj Kumar Hazra

    2013-02-07T23:59:59.000Z

    Features in the primordial scalar power spectrum provide a possible roadway to describe the outliers at the low multipoles in the WMAP data. Apart from the CMB angular power spectrum, these features can also alter the matter power spectrum and, thereby, the formation of the large scale structure. Carrying out a complete numerical analysis, we investigate the effects of primordial features on the formation rates of the halos. We consider a few different inflationary models that lead to features in the scalar power spectrum and an improved fit to the CMB data, and analyze the corresponding imprints on the formation of halos. Performing a Markov Chain Monte Carlo analysis with the WMAP seven year data and the SDSS halo power spectrum from LRG DR7 for the models of our interest, we arrive at the parameter space of the models allowed by the data. We illustrate that, inflationary potentials, such as the quadratic potential with sinusoidal modulations and the axion monodromy model, which generate certain repeated, oscillatory features in the inflationary perturbation spectrum, do not induce a substantial difference in the number density of halos at their best fit values, when compared with, say, a nearly scale invariant spectrum as is generated by the standard quadratic potential. However, we find that the number density and the formation rates of halos change by about 13-22% for halo masses ranging over 10^4-10^14 solar mass, for potential parameters that lie within 2-sigma around the best fit values arrived at from the aforesaid joint constraints. We briefly discuss the implications of our results.

  9. Baryonic fraction in the cold plus hot dark matter universe

    E-Print Network [OSTI]

    Eunwoo Choi; Dongsu Ryu

    1997-10-08T23:59:59.000Z

    We report a study to constrain the fraction of baryonic matter in the cold plus hot dark matter (CHDM) universe by numerical simulations which include the hydrodynamics of baryonic matter as well as the particle dynamics of dark matter. Spatially flat, COBE-normalized CHDM models with the fraction of hot component $\\Omega_h\\leq0.2$ are considered. We show that the models with $h/n/\\Omega_h=0.5/0.9/0.1$ and $0.5/0.9/0.2$ give a linear power spectrum which agrees well with observations. Here, $h$ is the Hubble constant in unit of $100~km/s/Mpc$ and $n$ is the spectral index of the initial power spectrum. Then, for the models with $h/n/\\Omega_h=0.5/0.9/0.2$ and baryonic fraction $\\Omega_b=0.05$ and 0.1 we calculate the properties of X-ray clusters, such as luminosity function, temperature distribution function, luminosity-temperature relation, histogram of gas to total mass ratio, and change of average temperature with redshift $z$. Comparison with the observed data of X-ray clusters indicates that the model with $\\Omega_b=0.05$ is preferred. The COBE-normalized CHDM model with $\\Omega_b>0.1$ may be ruled out by the present work, since it produces too many X-ray bright clusters.

  10. ALS Spectrum

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76) (See theDoctoral Fellowship inALSALS Spectrum Print

  11. ALS Spectrum

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76) (See theDoctoral Fellowship inALSALS Spectrum PrintALS

  12. ALS Spectrum

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76) (See theDoctoral Fellowship inALSALS Spectrum

  13. EVALUATION OF THE EMISSION, TRANSPORT, AND DEPOSITION OF MERCURY, FINE PARTICULATE MATTER, AND ARSENIC FROM COAL-BASED POWER PLANTS IN THE OHIO RIVER VALLEY REGION

    SciTech Connect (OSTI)

    Kevin Crist

    2004-04-02T23:59:59.000Z

    Ohio University, in collaboration with CONSOL Energy, Advanced Technology Systems, Inc. (ATS) and Atmospheric and Environmental Research, Inc. (AER) as subcontractors, is evaluating the impact of emissions from coal-fired power plants in the Ohio River Valley region as they relate to the transport and deposition of mercury, arsenic, and associated fine particulate matter. This evaluation will involve two interrelated areas of effort: ambient air monitoring and regional-scale modeling analysis. The scope of work for the ambient air monitoring will include the deployment of a surface air monitoring (SAM) station in southeastern Ohio. The SAM station will contain sampling equipment to collect and measure mercury (including speciated forms of mercury and wet and dry deposited mercury), arsenic, particulate matter (PM) mass, PM composition, and gaseous criteria pollutants (CO, NOx, SO{sub 2}, O{sub 3}, etc.). Laboratory analysis of time-integrated samples will be used to obtain chemical speciation of ambient PM composition and mercury in precipitation. Near-real-time measurements will be used to measure the ambient concentrations of PM mass and all gaseous species including Hg{sup 0} and RGM. Approximately 18 months of field data will be collected at the SAM site to validate the proposed regional model simulations for episodic and seasonal model runs. The ambient air quality data will also provide mercury, arsenic, and fine particulate matter data that can be used by Ohio Valley industries to assess performance on multi-pollutant control systems. The scope of work for the modeling analysis will include (1) development of updated inventories of mercury and arsenic emissions from coal-fired power plants and other important sources in the modeled domain; (2) adapting an existing 3-D atmospheric chemical transport model to incorporate recent advancements in the understanding of mercury transformations in the atmosphere; (3) analyses of the flux of Hg{sup 0}, RGM, arsenic, and fine particulate matter in the different sectors of the study region to identify key transport mechanisms; (4) comparison of cross correlations between species from the model results to observations in order to evaluate characteristics of specific air masses associated with long-range transport from a specified source region; and (5) evaluation of the sensitivity of these correlations to emissions from regions along the transport path. This will be accomplished by multiple model runs with emissions simulations switched on and off from the various source regions. To the greatest extent possible, model results will also be compared to field data collected at other air monitoring sites in the Ohio Valley Region, operated independently of this project. These sites may include (1) the DOE National Energy Technology Laboratory's monitoring site at its suburban Pittsburgh, PA facility; (2) sites in Pittsburgh (Lawrenceville) PA and Holbrook, PA operated by ATS; (3) sites in Steubenville, OH and Pittsburgh, PA operated by U.S. EPA and/or its contractors; and (4) sites operated by State or local air regulatory agencies. Field verification of model results and predictions will provide critical information for the development of cost effective air pollution control strategies by the coal-fired power plants in the Ohio River Valley region.

  14. Dark matter annihilation and its effect on CMB and Hydrogen 21 cm observations

    E-Print Network [OSTI]

    Natarajan, Aravind

    2009-01-01T23:59:59.000Z

    If dark matter is made up of Weakly Interacting Massive Particles, the annihilation of these particles in halos results in energy being released, some of which is absorbed by gas, causing partial ionization and heating. It is shown that early ionization results in a transfer of power to higher multipoles in the large angle CMB polarization power spectra. Future CMB experiments may be able to detect this effect in the case of certain light dark matter models. We also investigate the effect of gas heating on the expected H21 cm power spectrum. Heating by particle annihilation results in a decrease in the amplitude of the H21 cm power spectrum as the gas temperature $T$ becomes comparable to the CMB temperature $T_\\gamma$, and then an increase as $T > T_\\gamma$. The result is a minimum in the power spectrum at the redshift for which $T \\approx T_\\gamma$. Only certain models (low particle masses $\\sim$ 10 GeV, or favorable halo parameters) show this effect. Within these models, observations of the H21 cm power sp...

  15. EVALUATION OF THE EMISSION, TRANSPORT, AND DEPOSITION OF MERCURY, FINE PARTICULATE MATTER, AND ARSENIC FROM COAL-BASED POWER PLANTS IN THE OHIO RIVER VALLEY REGION

    SciTech Connect (OSTI)

    Kevin Crist

    2005-04-02T23:59:59.000Z

    Ohio University, in collaboration with CONSOL Energy, Advanced Technology Systems, Inc (ATS) and Atmospheric and Environmental Research, Inc. (AER) as subcontractors, is evaluating the impact of emissions from coal-fired power plants in the Ohio River Valley region as they relate to the transport and deposition of mercury, arsenic, and associated fine particulate matter. This evaluation will involve two interrelated areas of effort: ambient air monitoring and regional-scale modeling analysis. The scope of work for the ambient air monitoring will include the deployment of a surface air monitoring (SAM) station in southeastern Ohio. The SAM station will contain sampling equipment to collect and measure mercury (including speciated forms of mercury and wet and dry deposited mercury), arsenic, particulate matter (PM) mass, PM composition, and gaseous criteria pollutants (CO, NO{sub x}, SO{sub 2}, O{sub 3}, etc.). Laboratory analysis of time-integrated samples will be used to obtain chemical speciation of ambient PM composition and mercury in precipitation. Near-real-time measurements will be used to measure the ambient concentrations of PM mass and all gaseous species including Hg{sup 0} and RGM. Approximately of 18 months of field data will be collected at the SAM site to validate the proposed regional model simulations for episodic and seasonal model runs. The ambient air quality data will also provide mercury, arsenic, and fine particulate matter data that can be used by Ohio Valley industries to assess performance on multi-pollutant control systems. The scope of work for the modeling analysis will include (1) development of updated inventories of mercury and arsenic emissions from coal plants and other important sources in the modeled domain; (2) adapting an existing 3-D atmospheric chemical transport model to incorporate recent advancements in the understanding of mercury transformations in the atmosphere; (3) analyses of the flux of Hg{sup 0}, RGM, arsenic, and fine particulate matter in the different sectors of the study region to identify key transport mechanisms; (4) comparison of cross correlations between species from the model results to observations in order to evaluate characteristics of specific air masses associated with long-range transport from a specified source region; and (5) evaluation of the sensitivity of these correlations to emissions from regions along the transport path. This will be accomplished by multiple model runs with emissions simulations switched on and off from the various source regions. To the greatest extent possible, model results will also be compared to field data collected at other air monitoring sites in the Ohio Valley region, operated independently of this project. These sites may include (1) the DOE National Energy Technologies Laboratory's monitoring site at its suburban Pittsburgh, PA facility; (2) sites in Pittsburgh (Lawrenceville) PA and Holbrook, PA operated by ATS; (3) sites in Steubenville, OH and Pittsburgh, PA operated by U.S. EPA and/or its contractors; and (4) sites operated by State or local air regulatory agencies. Field verification of model results and predictions will provide critical information for the development of cost effective air pollution control strategies by the coal-fired power plants in the Ohio River Valley region.

  16. EVALUATION OF THE EMISSION, TRANSPORT, AND DEPOSITION OF MERCURY, FINE PARTICULATE MATTER, AND ARSENIC FROM COAL-BASED POWER PLANTS IN THE OHIO RIVER VALLEY REGION

    SciTech Connect (OSTI)

    Kevin Crist

    2004-10-02T23:59:59.000Z

    Ohio University, in collaboration with CONSOL Energy, Advanced Technology Systems, Inc (ATS) and Atmospheric and Environmental Research, Inc. (AER) as subcontractors, is evaluating the impact of emissions from coal-fired power plants in the Ohio River Valley region as they relate to the transport and deposition of mercury, arsenic, and associated fine particulate matter. This evaluation will involve two interrelated areas of effort: ambient air monitoring and regional-scale modeling analysis. The scope of work for the ambient air monitoring will include the deployment of a surface air monitoring (SAM) station in southeastern Ohio. The SAM station will contain sampling equipment to collect and measure mercury (including speciated forms of mercury and wet and dry deposited mercury), arsenic, particulate matter (PM) mass, PM composition, and gaseous criteria pollutants (CO, NOx, SO{sub 2}, O{sub 3}, etc.). Laboratory analysis of time-integrated samples will be used to obtain chemical speciation of ambient PM composition and mercury in precipitation. Near-real-time measurements will be used to measure the ambient concentrations of PM mass and all gaseous species including Hg{sup 0} and RGM. Approximately of 18 months of field data will be collected at the SAM site to validate the proposed regional model simulations for episodic and seasonal model runs. The ambient air quality data will also provide mercury, arsenic, and fine particulate matter data that can be used by Ohio Valley industries to assess performance on multi-pollutant control systems. The scope of work for the modeling analysis will include (1) development of updated inventories of mercury and arsenic emissions from coal plants and other important sources in the modeled domain; (2) adapting an existing 3-D atmospheric chemical transport model to incorporate recent advancements in the understanding of mercury transformations in the atmosphere; (3) analyses of the flux of Hg{sup 0}, RGM, arsenic, and fine particulate matter in the different sectors of the study region to identify key transport mechanisms; (4) comparison of cross correlations between species from the model results to observations in order to evaluate characteristics of specific air masses associated with long-range transport from a specified source region; and (5) evaluation of the sensitivity of these correlations to emissions from regions along the transport path. This will be accomplished by multiple model runs with emissions simulations switched on and off from the various source regions. To the greatest extent possible, model results will also be compared to field data collected at other air monitoring sites in the Ohio Valley region, operated independently of this project. These sites may include (1) the DOE National Energy Technologies Laboratory's monitoring site at its suburban Pittsburgh, PA facility; (2) sites in Pittsburgh (Lawrenceville) PA and Holbrook, PA operated by ATS; (3) sites in Steubenville, OH and Pittsburgh, PA operated by U.S. EPA and/or its contractors; and (4) sites operated by State or local air regulatory agencies. Field verification of model results and predictions will provide critical information for the development of cost effective air pollution control strategies by the coal-fired power plants in the Ohio River Valley region.

  17. EVALUATION OF THE EMISSION, TRANSPORT, AND DEPOSITION OF MERCURY, FINE PARTICULATE MATTER, AND ARSENIC FROM COAL-BASED POWER PLANTS IN THE OHIO RIVER VALLEY REGION

    SciTech Connect (OSTI)

    Kevin Crist

    2003-10-02T23:59:59.000Z

    Ohio University, in collaboration with CONSOL Energy, Advanced Technology Systems, Inc (ATS) and Atmospheric and Environmental Research, Inc. (AER) as subcontractors, is evaluating the impact of emissions from coal-fired power plants in the Ohio River Valley region as they relate to the transport and deposition of mercury, arsenic, and associated fine particulate matter. This evaluation will involve two interrelated areas of effort: ambient air monitoring and regional-scale modeling analysis. The scope of work for the ambient air monitoring will include the deployment of a surface air monitoring (SAM) station in southeastern Ohio. The SAM station will contain sampling equipment to collect and measure mercury (including speciated forms of mercury and wet and dry deposited mercury), arsenic, particulate matter (PM) mass, PM composition, and gaseous criteria pollutants (CO, NO{sub x}, SO{sub 2}, O{sub 3}, etc.). Laboratory analysis of time-integrated samples will be used to obtain chemical speciation of ambient PM composition and mercury in precipitation. Near-real-time measurements will be used to measure the ambient concentrations of PM mass and all gaseous species including Hg{sup 0} and RGM. Approximately of 18 months of field data will be collected at the SAM site to validate the proposed regional model simulations for episodic and seasonal model runs. The ambient air quality data will also provide mercury, arsenic, and fine particulate matter data that can be used by Ohio Valley industries to assess performance on multi-pollutant control systems. The scope of work for the modeling analysis will include (1) development of updated inventories of mercury and arsenic emissions from coal plants and other important sources in the modeled domain; (2) adapting an existing 3-D atmospheric chemical transport model to incorporate recent advancements in the understanding of mercury transformations in the atmosphere; (3) analyses of the flux of Hg{sup 0}, RGM, arsenic, and fine particulate matter in the different sectors of the study region to identify key transport mechanisms; (4) comparison of cross correlations between species from the model results to observations in order to evaluate characteristics of specific air masses associated with long-range transport from a specified source region; and (5) evaluation of the sensitivity of these correlations to emissions from regions along the transport path. This will be accomplished by multiple model runs with emissions simulations switched on and off from the various source regions. To the greatest extent possible, model results will also be compared to field data collected at other air monitoring sites in the Ohio Valley Region, operated independently of this project. These sites may include (1) the DOE National Energy Technologies Laboratory's monitoring site at its suburban Pittsburgh, PA facility; (2) sites in Pittsburgh (Lawrenceville) PA and Holbrook, PA operated by ATS; (3) sites in Steubenville, OH and Pittsburgh, PA operated by U.S. EPA and/or its contractors; and (4) sites operated by State or local air regulatory agencies. Field verification of model results and predictions will provide critical information for the development of cost effective air pollution control strategies by the coal-fired power plants in the Ohio River Valley Region.

  18. Evaluation of the Emission, Transport, and Deposition of Mercury, Fine Particulate Matter, and Arsenic from Coal-Based Power Plants in the Ohio River Valley Region

    SciTech Connect (OSTI)

    Kevin Crist

    2006-04-02T23:59:59.000Z

    As stated in the proposal: Ohio University, in collaboration with CONSOL Energy, Advanced Technology Systems, Inc (ATS) and Atmospheric and Environmental Research, Inc. (AER) as subcontractors, is evaluating the impact of emissions from coal-fired power plants in the Ohio River Valley region as they relate to the transport and deposition of mercury, arsenic, and associated fine particulate matter. This evaluation will involve two interrelated areas of effort: ambient air monitoring and regional-scale modeling analysis. The scope of work for the ambient air monitoring will include the deployment of a surface air monitoring (SAM) station in southeastern Ohio. The SAM station will contain sampling equipment to collect and measure mercury (including speciated forms of mercury and wet and dry deposited mercury), arsenic, particulate matter (PM) mass, PM composition, and gaseous criteria pollutants (CO, NO{sub x}, SO{sub 2}, O{sub 3}, etc.). Laboratory analysis of time-integrated samples will be used to obtain chemical speciation of ambient PM composition and mercury in precipitation. Near-real-time measurements will be used to measure the ambient concentrations of PM mass and all gaseous species including Hg0 and RGM. Approximately 18 months of field data will be collected at the SAM site to validate the proposed regional model simulations for episodic and seasonal model runs. The ambient air quality data will also provide mercury, arsenic, and fine particulate matter data that can be used by Ohio Valley industries to assess performance on multi-pollutant control systems. The scope of work for the modeling analysis will include (1) development of updated inventories of mercury and arsenic emissions from coal plants and other important sources in the modeled domain; (2) adapting an existing 3-D atmospheric chemical transport model to incorporate recent advancements in the understanding of mercury transformations in the atmosphere; (3) analyses of the flux of Hg{sup 0}, RGM, arsenic, and fine particulate matter in the different sectors of the study region to identify key transport mechanisms; (4) comparison of cross correlations between species from the model results to observations in order to evaluate characteristics of specific air masses associated with long-range transport from a specified source region; and (5) evaluation of the sensitivity of these correlations to emissions from regions along the transport path. This will be accomplished by multiple model runs with emissions simulations switched on and off from the various source regions. To the greatest extent possible, model results will also be compared to field data collected at other air monitoring sites in the Ohio Valley region, operated independently of this project. These sites may include (1) the DOE National Energy Technologies Laboratory's monitoring site at its suburban Pittsburgh, PA facility; (2) sites in Pittsburgh (Lawrenceville) PA and Holbrook, PA operated by ATS; (3) sites in Steubenville, OH and Pittsburgh, PA operated by the USEPA and/or its contractors; and (4) sites operated by State or local air regulatory agencies. Field verification of model results and predictions will provide critical information for the development of cost effective air pollution control strategies by the coal-fired power plants in the Ohio River Valley region.

  19. Evaluation of the Emission, Transport, and Deposition of Mercury, Fine Particulate Matter, and Arsenic from Coal-Based Power Plants in the Ohio River Valley Region

    SciTech Connect (OSTI)

    Kevin Crist

    2005-10-02T23:59:59.000Z

    Ohio University, in collaboration with CONSOL Energy, Advanced Technology Systems, Inc (ATS) and Atmospheric and Environmental Research, Inc. (AER) as subcontractors, is evaluating the impact of emissions from coal-fired power plants in the Ohio River Valley region as they relate to the transport and deposition of mercury, arsenic, and associated fine particulate matter. This evaluation will involve two interrelated areas of effort: ambient air monitoring and regional-scale modeling analysis. The scope of work for the ambient air monitoring will include the deployment of a surface air monitoring (SAM) station in southeastern Ohio. The SAM station will contain sampling equipment to collect and measure mercury (including speciated forms of mercury and wet and dry deposited mercury), arsenic, particulate matter (PM) mass, PM composition, and gaseous criteria pollutants (CO, NOx, SO{sub 2}, O{sub 3}, etc.). Laboratory analysis of time-integrated samples will be used to obtain chemical speciation of ambient PM composition and mercury in precipitation. Near-real-time measurements will be used to measure the ambient concentrations of PM mass and all gaseous species including Hg{sup 0} and RGM. Approximately of 18 months of field data will be collected at the SAM site to validate the proposed regional model simulations for episodic and seasonal model runs. The ambient air quality data will also provide mercury, arsenic, and fine particulate matter data that can be used by Ohio Valley industries to assess performance on multi-pollutant control systems. The scope of work for the modeling analysis will include (1) development of updated inventories of mercury and arsenic emissions from coal plants and other important sources in the modeled domain; (2) adapting an existing 3-D atmospheric chemical transport model to incorporate recent advancements in the understanding of mercury transformations in the atmosphere; (3) analyses of the flux of Hg0, RGM, arsenic, and fine particulate matter in the different sectors of the study region to identify key transport mechanisms; (4) comparison of cross correlations between species from the model results to observations in order to evaluate characteristics of specific air masses associated with long-range transport from a specified source region; and (5) evaluation of the sensitivity of these correlations to emissions from regions along the transport path. This will be accomplished by multiple model runs with emissions simulations switched on and off from the various source regions. To the greatest extent possible, model results will also be compared to field data collected at other air monitoring sites in the Ohio Valley region, operated independently of this project. These sites may include (1) the DOE National Energy Technologies Laboratory's monitoring site at its suburban Pittsburgh, PA facility; (2) sites in Pittsburgh (Lawrenceville) PA and Holbrook, PA operated by ATS; (3) sites in Steubenville, OH and Pittsburgh, PA operated by U.S. EPA and/or its contractors; and (4) sites operated by State or local air regulatory agencies. Field verification of model results and predictions will provide critical information for the development of cost effective air pollution control strategies by the coal-fired power plants in the Ohio River Valley region.

  20. Evaluation of the Emission, Transport, and Deposition of Mercury and Fine Particulate Matter from Coal-Based Power Plants in the Ohio River Valley Region

    SciTech Connect (OSTI)

    Kevin Crist

    2008-12-31T23:59:59.000Z

    As stated in the proposal: Ohio University, in collaboration with CONSOL Energy, Advanced Technology Systems, Inc (ATS) and Atmospheric and Environmental Research, Inc. (AER) as subcontractors, evaluated the impact of emissions from coal-fired power plants in the Ohio River Valley region as they relate to the transport and deposition of mercury and associated fine particulate matter. This evaluation involved two interrelated areas of effort: ambient air monitoring and regional-scale modeling analysis. The scope of work for the ambient air monitoring included the deployment of a surface air monitoring (SAM) station in southeastern Ohio. The SAM station contains sampling equipment to collect and measure mercury (including speciated forms of mercury and wet and dry deposited mercury), particulate matter (PM) mass, PM composition, and gaseous criteria pollutants (CO, NOx, SO2, O3, etc.). Laboratory analyses of time-integrated samples were used to obtain chemical speciation of ambient PM composition and mercury in precipitation. Nearreal- time measurements were used to measure the ambient concentrations of PM mass and all gaseous species including Hg0 and RGM. Approximately 30 months of field data were collected at the SAM site to validate the proposed regional model simulations for episodic and seasonal model runs. The ambient air quality data provides mercury, and fine particulate matter data that can be used by Ohio Valley industries to assess performance on multi-pollutant control systems. The scope of work for the modeling analysis includes (1) development of updated inventories of mercury emissions from coal plants and other important sources in the modeled domain; (2) adapting an existing 3-D atmospheric chemical transport model to incorporate recent advancements in the understanding of mercury transformations in the atmosphere; (3) analyses of the flux of Hg0, RGM, and fine particulate matter in the different sectors of the study region to identify key transport mechanisms; (4) comparison of cross correlations between species from the model results to observations in order to evaluate characteristics of specific air masses associated with long-range transport from a specified source region; and (5) evaluation of the sensitivity of these correlations to emissions from regions along the transport path. This is accomplished by multiple model runs with emissions simulations switched on and off from the various source regions. To the greatest extent possible, model results were compared to field data collected at other air monitoring sites in the Ohio Valley region, operated independently of this project. These sites may include (1) the DOE National Energy Technologies Laboratory’s monitoring site at its suburban Pittsburgh, PA facility; (2) sites in Pittsburgh (Lawrenceville) PA and Holbrook, PA operated by ATS; (3) sites in Steubenville, OH and Pittsburgh, PA operated by the USEPA and/or its contractors; and (4) sites operated by State or local air regulatory agencies. Field verification of model results and predictions provides critical information for the development of cost effective air pollution control strategies by the coal-fired power plants in the Ohio River Valley region.

  1. Shapes of dark matter halos

    E-Print Network [OSTI]

    James S. Bullock

    2001-06-21T23:59:59.000Z

    I present an analysis of the density shapes of dark matter halos in LCDM and LWDM cosmologies. The main results are derived from a statistical sample of galaxy-mass halos drawn from a high resolution LCDM N-body simulation. Halo shapes show significant trends with mass and redshift: low-mass halos are rounder than high mass halos, and, for a fixed mass, halos are rounder at low z. Contrary to previous expectations, which were based on cluster-mass halos and non-COBE normalized simulations, LCDM galaxy-mass halos at z=0 are not strongly flattened, with short to long axis ratios of s = 0.70 +/- 0.17. I go on to study how the shapes of individual halos change when going from a LCDM simulation to a simulation with a warm dark matter power spectrum (LWDM). Four halos were compared, and, on average, the WDM halos are more spherical than their CDM counterparts (s =0.77 compared to s = 0.71). A larger sample of objects will be needed to test whether the trend is significant.

  2. Gamma-ray probes of dark matter substructure

    SciTech Connect (OSTI)

    Campbell, Sheldon [Department of Physics and Center for Cosmology and AstroParticle Physics (CCAPP), The Ohio State University, 191 W. Woodruff Ave., Columbus, OH 43210 (United States)

    2014-06-24T23:59:59.000Z

    The substructure content of dark matter halos is interesting because it can be affected by complex galaxy physics and dark matter particle physics. However, observing the small scale structure of dark matter is a challenge. The subhalo abundance (mass function, minimum mass) and morphology (density profile, subhalo shape, subsubstructure) contain information about complex astrophysics (halo formation processes) and new exotic fundamental physics (dark matter interactions). Indirect detection of dark matter annihilation radiation (DMAR) in gamma rays may be the most direct method for observing small scale structure. I outline the ways in which gamma rays may probe halo substructure. If substructure is bountiful, it may be responsible for the eventual discovery of DMAR, for instance in galaxy clusters or the diffuse gamma-ray background. Otherwise, the observation of DMAR in places without much substructure, such as the Galactic center, would lead to strict limits on the properties of small scale structure. Properties of the gamma-ray angular power spectrum will also provide information or constraints on Milky Way halo substructure.

  3. Inflation that runs naturally: Gravitational waves and suppression of power at large and small scales

    E-Print Network [OSTI]

    Quinn E. Minor; Manoj Kaplinghat

    2015-03-08T23:59:59.000Z

    We point out three correlated predictions of the axion monodromy inflation model: large amplitude of gravitational waves, suppression of power on horizon scales and on scales relevant for the formation of dwarf galaxies. While these predictions are likely generic to models with oscillations in the inflaton potential, the axion monodromy model naturally accommodates the required running spectral index through Planck-scale corrections to the inflaton potential. Applying this model to a combined data set of Planck, ACT, SPT, and WMAP low-$\\ell$ polarization cosmic microwave background (CMB) data, we find a best-fit tensor-to-scalar ratio $r_{0.05} = 0.07^{+0.05}_{-0.04}$ due to gravitational waves, which may have been observed by the BICEP2 experiment. Despite the contribution of gravitational waves, the total power on large scales (CMB power spectrum at low multipoles) is lower than the standard $\\Lambda$CDM cosmology with a power-law spectrum of initial perturbations and no gravitational waves, thus mitigating some of the tension on large scales. There is also a reduction in the matter power spectrum of 20-30\\% at scales corresponding to $k = 10~{\\rm Mpc}^{-1}$, which are relevant for dwarf galaxy formation. This will alleviate some of the unsolved small-scale structure problems in the standard $\\Lambda$CDM cosmology. The inferred matter power spectrum is also found to be consistent with recent Lyman-$\\alpha$ forest data, which is in tension with the Planck-favored $\\Lambda$CDM model with power-law primordial power spectrum.

  4. Dark Matters

    ScienceCinema (OSTI)

    Joseph Silk

    2010-01-08T23:59:59.000Z

    One of the greatest mysteries in the cosmos is that it is mostly dark.  Astronomers and particle physicists today are seeking to unravel the nature of this mysterious, but pervasive dark matter which has profoundly influenced the formation of structure in the universe.  I will describe the complex interplay between galaxy formation and dark matter detectability and review recent attempts to measure particle dark matter by direct and indirect means.

  5. Axion hot dark matter bounds after Planck

    SciTech Connect (OSTI)

    Archidiacono, Maria; Hannestad, Steen [Department of Physics and Astronomy, University of Aarhus DK-8000 Aarhus C (Denmark); Mirizzi, Alessandro [II. Institut für Theoretische Physik, Universität Hamburg Luruper Chaussee 149, D-22761 Hamburg (Germany); Raffelt, Georg [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut) Föhringer Ring 6, D-80805 München (Germany); Wong, Yvonne Y.Y., E-mail: archi@phys.au.dk, E-mail: sth@phys.au.dk, E-mail: alessandro.mirizzi@desy.de, E-mail: raffelt@mpp.mpg.de, E-mail: yvonne.y.wong@unsw.edu.au [School of Physics, The University of New South Wales Sydney NSW 2052 (Australia)

    2013-10-01T23:59:59.000Z

    We use cosmological observations in the post-Planck era to derive limits on thermally produced cosmological axions. In the early universe such axions contribute to the radiation density and later to the hot dark matter fraction. We find an upper limit m{sub a} < 0.67 eV at 95% C.L. after marginalising over the unknown neutrino masses, using CMB temperature and polarisation data from Planck and WMAP respectively, the halo matter power spectrum extracted from SDSS-DR7, and the local Hubble expansion rate H{sub 0} released by the Carnegie Hubble Program based on a recalibration of the Hubble Space Telescope Key Project sample. Leaving out the local H{sub 0} measurement relaxes the limit somewhat to 0.86 eV, while Planck+WMAP alone constrain the axion mass to 1.01 eV, the first time an upper limit on m{sub a} has been obtained from CMB data alone. Our axion limit is therefore not very sensitive to the tension between the Planck-inferred H{sub 0} and the locally measured value. This is in contrast with the upper limit on the neutrino mass sum, which we find here to range from ? m{sub ?} < 0.27 eV at 95% C.L. combining all of the aforementioned observations, to 0.84 eV from CMB data alone.

  6. Blue running of the primordial tensor spectrum

    E-Print Network [OSTI]

    Jinn-Ouk Gong

    2014-07-09T23:59:59.000Z

    We examine the possibility of positive spectral index of the power spectrum of the primordial tensor perturbation produced during inflation in the light of the detection of the B-mode polarization by the BICEP2 collaboration. We find a blue tilt is in general possible when the slow-roll parameter decays rapidly. We present two known examples in which a positive spectral index for the tensor power spectrum can be obtained. We also briefly discuss other consistency tests for further studies on inflationary dynamics.

  7. Radiation detector spectrum simulator

    DOE Patents [OSTI]

    Wolf, M.A.; Crowell, J.M.

    1985-04-09T23:59:59.000Z

    A small battery operated nuclear spectrum simulator having a noise source generates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith to generate several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

  8. Luminous Dark Matter

    E-Print Network [OSTI]

    Brian Feldstein; Peter W. Graham; Surjeet Rajendran

    2011-01-13T23:59:59.000Z

    We propose a dark matter model in which the signal in direct detection experiments arises from electromagnetic, not nuclear, energy deposition. This can provide a novel explanation for DAMA while avoiding many direct detection constraints. The dark matter state is taken nearly degenerate with another state. These states are naturally connected by a dipole moment operator, which can give both the dominant scattering and decay modes between the two states. The signal at DAMA then arises from dark matter scattering in the Earth into the excited state and decaying back to the ground state through emission of a single photon in the detector. This model has unique signatures in direct detection experiments. The density and chemical composition of the detector is irrelevant, only the total volume affects the event rate. In addition, the spectrum is a monoenergetic line, which can fit the DAMA signal well. This model is readily testable at experiments such as CDMS and XENON100 if they analyze their low-energy, electronic recoil events.

  9. Revenue Management for Cognitive Spectrum Underlay Networks: An Interference Elasticity

    E-Print Network [OSTI]

    Huang, Jianwei

    to the large body of work on uplink power control with pricing for CDMA networks (e.g., [5]­[10] and a recent a total received interference power constraint at the primary user's receiver. The transmission power1 Revenue Management for Cognitive Spectrum Underlay Networks: An Interference Elasticity

  10. Symmetry of Lyapunov spectrum

    SciTech Connect (OSTI)

    Gupalo, D.; Kaganovich, A.S.; Cohen, E.G.D. (Rockefeller Univ., New York, NY (United States))

    1994-03-01T23:59:59.000Z

    The symmetry of the spectrum of Lyapunov exponents provides a useful quantitative connection between properties of dynamical systems consisting of N interacting particles coupled to a thermostat, and nonequilibrium statistical mechanics. The authors obtain here sufficient conditions for this symmetry and analyze the structure of 1/N corrections ignored in previous studies. The relation of the Lyapunov spectrum symmetry with some other symmetries of dynamical systems is discussed.

  11. Two field matter bounce cosmology

    SciTech Connect (OSTI)

    Cai, Yi-Fu; McDonough, Evan; Duplessis, Francis; Brandenberger, Robert H., E-mail: yifucai@physics.mcgill.ca, E-mail: evanmc@physics.mcgill.ca, E-mail: francis.duplessis@mail.mcgill.ca, E-mail: rhb@hep.physics.mcgill.ca [Department of Physics, McGill University, Montréal, QC H3A 2T8 (Canada)

    2013-10-01T23:59:59.000Z

    We re-examine the non-singular Matter Bounce scenario first developed in [20], which starts with a matter-dominated period of contraction and transitions into an Ekpyrotic phase of contraction. We consider both matter fields, the first of which plays the role of regular matter, and the second of which is responsible for the non-singular bounce. Since the dominant matter field is massive, the induced curvature fluctuations are initially not scale-invariant, whereas the fluctuations of the second scalar field (which are initially entropy fluctuations) are scale-invariant. We study the transfer of the initial entropy perturbations into curvature fluctuations in the matter-dominated phase of contraction and show that the latter become nearly scale invariant on large scales but are blue tilted on small scales. We study the evolution of both curvature and entropy fluctuations through the bounce, and show that both have a scale-invariant spectrum which is blue-tilted on small scales. However, we find that the entropy fluctuations have an amplitude that is much smaller than that of the curvature perturbations, due to gravitational amplification of curvature perturbations during the bounce phase.

  12. Isocurvature constraints and anharmonic effects on QCD axion dark matter

    SciTech Connect (OSTI)

    Kobayashi, Takeshi [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, Ontario M5S 3H8 (Canada); Kurematsu, Ryosuke; Takahashi, Fuminobu, E-mail: takeshi@cita.utoronto.ca, E-mail: rkurematsu@tuhep.phys.tohoku.ac.jp, E-mail: fumi@tuhep.phys.tohoku.ac.jp [Department of Physics, Tohoku University, Sendai 980-8578 (Japan)

    2013-09-01T23:59:59.000Z

    We revisit the isocurvature density perturbations induced by quantum fluctuations of the axion field by extending a recently developed analytic method and approximations to a time-dependent scalar potential, which enables us to follow the evolution of the axion until it starts to oscillate. We find that, as the initial misalignment angle approaches the hilltop of the potential, the isocurvature perturbations become significantly enhanced, while the non-Gaussianity parameter increases slowly but surely. As a result, the isocurvature constraint on the inflation scale is tightened as H{sub inf}?matter window. We also derive useful formulae for the power spectrum and non-Gaussianity of the isocurvature perturbations.

  13. Lorentz-violating dark matter

    E-Print Network [OSTI]

    Mondragon, Antonio Richard

    2009-05-15T23:59:59.000Z

    a power spectrum analysis based on nearly a quarter million galaxies, resulting in ?m = 0.231?0.021. Upper bounds have also been placed on the vacuum energy density. The CNOC find [92] ?? < 1.5. Independent upper bounds have been determined...

  14. Matter Field, Dark Matter and Dark Energy

    E-Print Network [OSTI]

    Masayasu Tsuge

    2009-03-24T23:59:59.000Z

    A model concerning particle theory and cosmology is proposed. Matter field, dark matter and dark energy are created by an energy flow from space to primordial matter fields at the phase transition in the early universe.

  15. Two Emission Mechanisms in the Fermi Bubbles: A Possible Signal of Annihilating Dark Matter

    SciTech Connect (OSTI)

    Hooper, Dan; Slatyer, Tracy R.

    2013-09-01T23:59:59.000Z

    We study the variation of the spectrum of the Fermi Bubbles with Galactic latitude. Far from the Galactic plane (|b| > 30 degrees), the observed gamma-ray emission is nearly invariant with latitude, and is consistent with arising from inverse Compton scattering of the interstellar radiation field by cosmic-ray electrons with an approximately power-law spectrum. The same electrons in the presence of microgauss-scale magnetic fields can also generate the the observed microwave "haze". At lower latitudes (b < 20 degrees), in contrast, the spectrum of the emission correlated with the Bubbles possesses a pronounced spectral feature peaking at 1-4 GeV (in E^2 dN/dE) which cannot be generated by any realistic spectrum of electrons. Instead, we conclude that a second (non-inverse-Compton) emission mechanism must be responsible for the bulk of the low-energy, low-latitude emission. This second component is spectrally similar to the excess GeV emission previously reported from the Galactic Center (GC), and also appears spatially consistent with a luminosity per volume falling approximately as r^-2.4, where r is the distance from the GC. We argue that the spectral feature visible in the low-latitude Bubbles is the extended counterpart of the GC excess, now detected out to at least 2-3 kpc from the GC. The spectrum and angular distribution of the signal is consistent with that predicted from ~10 GeV dark matter particles annihilating to leptons, or from ~50 GeV dark matter particles annihilating to quarks, following a distribution similar to the canonical Navarro-Frenk-White (NFW) profile. We also consider millisecond pulsars as a possible astrophysical explanation for the signal, as observed millisecond pulsars possess a spectral cutoff at approximately the required energy. Any such scenario would require a large population of unresolved millisecond pulsars extending at least 2-3 kpc from the GC.

  16. Quantized black holes, their spectrum and radiation

    SciTech Connect (OSTI)

    Khriplovich, I. B. [Budker Institute of Nuclear Physics (Russian Federation)], E-mail: khriplovich@inp.nsk.su

    2008-04-15T23:59:59.000Z

    Under quite natural general assumptions, the following results are obtained. The maximum entropy of a quantized surface is demonstrated to be proportional to the surface area in the classical limit. The general structure of the horizon spectrum is found. In the special case of loop quantum gravity, the value of the Barbero-Immirzi parameter is found. The discrete spectrum of thermal radiation of a black hole fits the Wien profile. The natural widths of the lines are much smaller than the distances between them. The total intensity of the thermal radiation is estimated. If the density of quantized primordial black holes is close to the present upper limit on the dark-matter density in our Solar system, the sensitivity of modern detectors is close to that necessary for detecting this radiation.

  17. Broad spectrum solar cell

    DOE Patents [OSTI]

    Walukiewicz, Wladyslaw (Kensington, CA); Yu, Kin Man (Lafayette, CA); Wu, Junqiao (Richmond, CA); Schaff, William J. (Ithaca, NY)

    2007-05-15T23:59:59.000Z

    An alloy having a large band gap range is used in a multijunction solar cell to enhance utilization of the solar energy spectrum. In one embodiment, the alloy is In.sub.1-xGa.sub.xN having an energy bandgap range of approximately 0.7 eV to 3.4 eV, providing a good match to the solar energy spectrum. Multiple junctions having different bandgaps are stacked to form a solar cell. Each junction may have different bandgaps (realized by varying the alloy composition), and therefore be responsive to different parts of the spectrum. The junctions are stacked in such a manner that some bands of light pass through upper junctions to lower junctions that are responsive to such bands.

  18. 2012-2013 Keywords: Routing and spectrum allocation (RSA), flexible optical networks

    E-Print Network [OSTI]

    Varvarigo, Emmanouel "Manos"

    , "Conserving Transmission Power in Wireless Ad Hoc Networks" #12;), flexible optical networks WDM (FWDM) . (RSA) (RWA). FWDM Matlab. 2: Keywords: Routing and spectrum allocation (RSA), flexible optical networks

  19. On an open question about the complexity of a dynamic spectrum ...

    E-Print Network [OSTI]

    2014-12-02T23:59:59.000Z

    the users dynamically adjust their transmit power spectral densities over it. ... the performance of the whole system, a Dynamic Spectrum Management (DSM).

  20. NREL Spectrum of Innovation

    ScienceCinema (OSTI)

    None

    2013-05-29T23:59:59.000Z

    There are many voices calling for a future of abundant clean energy. The choices are difficult and the challenges daunting. How will we get there? The National Renewable Energy Laboratory integrates the entire spectrum of innovation including fundamental science, market relevant research, systems integration, testing and validation, commercialization and deployment. The innovation process at NREL is interdependent and iterative. Many scientific breakthroughs begin in our own laboratories, but new ideas and technologies come to NREL at any point along the innovation spectrum to be validated and refined for commercial use.

  1. Neutron Scattering: Condensed Matter and Magnetic Science, MPA...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Neutron Scattering Neutron Scattering Capability description: Neutron scattering is a powerful probe of structure and collective modes of condensed matter. We are focused on direct...

  2. Which Models Matter: Uncertainty and Sensitivity Analysis for

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Models Matter: Uncertainty and Sensitivity Analysis for Photovoltaic Power Systems Clifford W. Hansen and Andrew Pohl Sandia National Laboratories, Albuquerque, NM, 87185-1033, USA...

  3. Neutrino oscillations and dark matter

    E-Print Network [OSTI]

    K. Zuber

    1996-12-17T23:59:59.000Z

    The significance of light massive neutrinos as hot dark matter is outlined. The power of neutrino oscillation experiments with respect to detect such neutrinos in the eV-region is discussed. Present hints for neutrino oscillations in solar, atmospheric and LSND data are reviewed as well as future experiments and their potential.

  4. Chapter 9: Photovoltaic DevicesChapter 9: Photovoltaic Devices Solar energy spectrumSolar energy spectrum

    E-Print Network [OSTI]

    Wang, Jianfang

    Chapter 9: Photovoltaic DevicesChapter 9: Photovoltaic Devices Solar energy spectrumSolar energy Solar Energy? · Clean · Nearly unlimited PHYS5320 Chapter Nine 3 #12;S l ll l t PHYS5320 Chapter Nine 4 Solar cell plant #12;Cars powered by photovoltaic devices PHYS5320 Chapter Nine 5 #12;Solar Energy

  5. Dark Matter Theory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power Administration wouldDECOMPOSITION OFSupplemental TechnologySummaryDariuszDark Matter Theory

  6. Power Spectra for Deterministic Chaotic Dynamical Systems

    E-Print Network [OSTI]

    Power Spectra for Deterministic Chaotic Dynamical Systems Ian Melbourne #3; Georg A. Gottwald y 8 observables. For slowly mixing systems such as Pomeau-Manneville intermittency maps, where the power spectrum done for mixing Axiom A systems [19] where the power spectrum is analytic apart from isolated

  7. Power Spectra for Deterministic Chaotic Dynamical Systems

    E-Print Network [OSTI]

    Gottwald, Georg A.

    Power Spectra for Deterministic Chaotic Dynamical Systems Ian Melbourne Georg A. Gottwald 23 July observables. For slowly mixing systems such as Pomeau-Manneville intermittency maps, where the power spectrum done for mixing Axiom A systems [19] where the power spectrum is analytic apart from isolated

  8. FREQUENCY HOPPING SPREAD SPECTRUM DIRECT SEQUENCE SPREAD SPECTRUM

    E-Print Network [OSTI]

    Westall, James M.

    FREQUENCY HOPPING SPREAD SPECTRUM VS. DIRECT SEQUENCE SPREAD SPECTRUM RAYLINK AND RAYTHEON local-area network products, such as Raytheon's RaylinkTM products, use the frequency hopping method

  9. Dark Matter vs. Neutrinos: The effect of astrophysical uncertainties and timing information on the neutrino floor

    E-Print Network [OSTI]

    Jonathan H. Davis

    2015-03-09T23:59:59.000Z

    Future multi-tonne Direct Detection experiments will be sensitive to solar neutrino induced nuclear recoils which form an irreducible background to light Dark Matter searches. Indeed for masses around 6 GeV the spectra of neutrinos and Dark Matter are so similar that experiments will run into a neutrino floor, for which sensitivity increases only marginally with exposure past a certain cross section. In this work we show that this floor can be overcome using the different annual modulation expected from solar neutrinos and Dark Matter. Specifically for cross sections below the neutrino floor the DM signal is observable through a phase shift and a smaller amplitude for the time-dependent event rate. This allows the exclusion power to be improved by up to an order of magnitude for large exposures. In addition we demonstrate that the neutrino floor exists over a wider mass range than has been previously shown, since the large uncertainties in the Dark Matter velocity distribution make the signal spectrum harder to distinguish from the neutrino background. However for most velocity distributions the neutrino floor can still be surpassed using timing information, though certain velocity streams may prove problematic.

  10. Dark Matter vs. Neutrinos: The effect of astrophysical uncertainties and timing information on the neutrino floor

    E-Print Network [OSTI]

    Davis, Jonathan H

    2014-01-01T23:59:59.000Z

    Future multi-tonne Direct Detection experiments will be sensitive to solar neutrino induced nuclear recoils which form an irreducible background to light Dark Matter searches. Indeed for masses around 6 GeV the spectra of neutrinos and Dark Matter are so similar that experiments will run into a neutrino floor, for which sensitivity increases only marginally with exposure past a certain cross section. In this work we show that this floor can be overcome using the different annual modulation expected from solar neutrinos and Dark Matter. Specifically for cross sections below the neutrino floor the DM signal is observable through a phase shift and a smaller amplitude for the time-dependent event rate. This allows the exclusion power to be improved by up to an order of magnitude for large exposures. In addition we demonstrate that the neutrino floor exists over a wider mass range than has been previously shown, since the large uncertainties in the Dark Matter velocity distribution make the signal spectrum harder ...

  11. Dark Matter vs. Neutrinos: The effect of astrophysical uncertainties and timing information on the neutrino floor

    E-Print Network [OSTI]

    Jonathan H. Davis

    2014-12-03T23:59:59.000Z

    Future multi-tonne Direct Detection experiments will be sensitive to solar neutrino induced nuclear recoils which form an irreducible background to light Dark Matter searches. Indeed for masses around 6 GeV the spectra of neutrinos and Dark Matter are so similar that experiments will run into a neutrino floor, for which sensitivity increases only marginally with exposure past a certain cross section. In this work we show that this floor can be overcome using the different annual modulation expected from solar neutrinos and Dark Matter. Specifically for cross sections below the neutrino floor the DM signal is observable through a phase shift and a smaller amplitude for the time-dependent event rate. This allows the exclusion power to be improved by up to an order of magnitude for large exposures. In addition we demonstrate that the neutrino floor exists over a wider mass range than has been previously shown, since the large uncertainties in the Dark Matter velocity distribution make the signal spectrum harder to distinguish from the neutrino background. However for most velocity distributions the neutrino floor can still be surpassed using timing information, though certain velocity streams may prove problematic.

  12. Dark Matter vs. Neutrinos: The effect of astrophysical uncertainties and timing information on the neutrino floor

    E-Print Network [OSTI]

    Davis, Jonathan H

    2015-01-01T23:59:59.000Z

    Future multi-tonne Direct Detection experiments will be sensitive to solar neutrino induced nuclear recoils which form an irreducible background to light Dark Matter searches. Indeed for masses around 6 GeV the spectra of neutrinos and Dark Matter are so similar that experiments will run into a neutrino floor, for which sensitivity increases only marginally with exposure past a certain cross section. In this work we show that this floor can be overcome using the different annual modulation expected from solar neutrinos and Dark Matter. Specifically for cross sections below the neutrino floor the DM signal is observable through a phase shift and a smaller amplitude for the time-dependent event rate. This allows the exclusion power to be improved by up to an order of magnitude for large exposures. In addition we demonstrate that the neutrino floor exists over a wider mass range than has been previously shown, since the large uncertainties in the Dark Matter velocity distribution make the signal spectrum harder ...

  13. NuSTAR observations of the powerful radio-galaxy Cygnus A

    E-Print Network [OSTI]

    Reynolds, Christopher S; Ogle, Patrick M; Harrison, Fiona A; Madsen, Kristin K; Fabian, Andrew C; Wik, Daniel R; Madejski, Grzegorz; Ballantyne, David R; Boggs, Steven E; Christensen, Finn E; Craig, William W; Fuerst, Felix; Hailey, Charles J; Lanz, Lauranne; Miller, Jon M; Saez, Cristian; Stern, Daniel; Walton, Dominic J; Zhang, William

    2015-01-01T23:59:59.000Z

    We present NuSTAR observations of the powerful radio galaxy Cygnus A, focusing on the central absorbed active galactic nucleus (AGN). Cygnus A is embedded in a cool-core galaxy cluster, and hence we also examine archival XMM-Newton data to facilitate the decomposition of the spectrum into the AGN and intracluster medium (ICM) components. NuSTAR gives a source-dominated spectrum of the AGN out to >70keV. In gross terms, the NuSTAR spectrum of the AGN has the form of a power law (Gamma~1.6-1.7) absorbed by a neutral column density of N_H~1.6x10^23 cm^-2. However, we also detect curvature in the hard (>10keV) spectrum resulting from reflection by Compton-thick matter out of our line-of-sight to the X-ray source. Compton reflection, possibly from the outer accretion disk or obscuring torus, is required even permitting a high-energy cutoff in the continuum source; the limit on the cutoff energy is E_cut>111keV (90% confidence). Interestingly, the absorbed power-law plus reflection model leaves residuals suggesting...

  14. Cosmology in One Dimension: Fractal Geometry, Power Spectra and Correlation

    E-Print Network [OSTI]

    Bruce N. Miller; Jean-Louis Rouet

    2010-12-08T23:59:59.000Z

    Concentrations of matter, such as galaxies and galactic clusters, originated as very small density fluctuations in the early universe. The existence of galaxy clusters and super-clusters suggests that a natural scale for the matter distribution may not exist. A point of controversy is whether the distribution is fractal and, if so, over what range of scales. One-dimensional models demonstrate that the important dynamics for cluster formation occur in the position-velocity plane. Here the development of scaling behavior and multifractal geometry is investigated for a family of one-dimensional models for three different, scale-free, initial conditions. The methodology employed includes: 1) The derivation of explicit solutions for the gravitational potential and field for a one-dimensional system with periodic boundary conditions (Ewald sums for one dimension); 2) The development of a procedure for obtaining scale-free initial conditions for the growing mode in phase space for an arbitrary power-law index; 3) The evaluation of power spectra, correlation functions, and generalized fractal dimensions at different stages of the system evolution. It is shown that a simple analytic representation of the power spectra captures the main features of the evolution, including the correct time dependence of the crossover from the linear to nonlinear regime and the transition from regular to fractal geometry. A possible physical mechanism for understanding the self-similar evolution is introduced. It is shown that hierarchical cluster formation depends both on the model and the initial power spectrum. Under special circumstances a simple relation between the power spectrum, correlation function, and correlation dimension in the highly nonlinear regime is confirmed.

  15. Matter Wave Radiation Leading to Matter Teleportation

    E-Print Network [OSTI]

    Yong-Yi Huang

    2015-02-12T23:59:59.000Z

    The concept of matter wave radiation is put forward, and its equation is established for the first time. The formalism solution shows that the probability density is a function of displacement and time. A free particle and a two-level system are reinvestigated considering the effect of matter wave radiation. Three feasible experimental designs, especially a modified Stern-Gerlach setup, are proposed to verify the existence of matter wave radiation. Matter wave radiation effect in relativity has been formulated in only a raw formulae, which offers another explanation of Lamb shift. A possible mechanics of matter teleportation is predicted due to the effect of matter wave radiation.

  16. Hybrid spread spectrum radio system

    DOE Patents [OSTI]

    Smith, Stephen F. (London, TN) [London, TN; Dress, William B. (Camas, WA) [Camas, WA

    2010-02-09T23:59:59.000Z

    Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

  17. Shocking Signals of Dark Matter Annihilation

    E-Print Network [OSTI]

    Davis, Jonathan H; Boehm, Celine; Kotera, Kumiko; Norman, Colin

    2015-01-01T23:59:59.000Z

    We examine whether charged particles injected by self-annihilating Dark Matter into regions undergoing Diffuse Shock Acceleration (DSA) can be accelerated to high energies. We consider three astrophysical sites where shock acceleration is supposed to occur, namely the Galactic Centre, galaxy clusters and Active Galactic Nuclei (AGN). For the Milky Way, we find that the acceleration of cosmic rays injected by dark matter could lead to a bump in the cosmic ray spectrum provided that the product of the efficiency of the acceleration mechanism and the concentration of DM particles is high enough. Among the various acceleration sources that we consider (namely supernova remnants (SNRs), Fermi bubbles and AGN jets), we find that the Fermi bubbles are a potentially more efficient accelerator than SNRs. However both could in principle accelerate electrons and protons injected by dark matter to very high energies. At the extragalactic level, the acceleration of dark matter annihilation products could be responsible fo...

  18. Baryonic matter and beyond

    E-Print Network [OSTI]

    Kenji Fukushima

    2014-10-01T23:59:59.000Z

    We summarize recent developments in identifying the ground state of dense baryonic matter and beyond. The topics include deconfinement from baryonic matter to quark matter, a diquark mixture, topological effect coupled with chirality and density, and inhomogeneous chiral condensates.

  19. Spectrum of Cosmic Microwave Fluctuations and the Formation of Galaxies in a Modified Gravity Theory

    E-Print Network [OSTI]

    J. W. Moffat

    2006-02-27T23:59:59.000Z

    A modified gravity (MOG) possesses a light, neutral vector particle called a ``phion'' associated with a vector field $\\phi^\\mu$, which forms a cold fluid of Bose-Einstein condensates before recombination with zero pressure and zero shear viscosity. The energy density associated with this Bose-Einstein condensate fluid dominates the energy density before recombination and produces a density parameter, $\\Omega_\\phi\\sim 0.3$, that together with the fractional baryon density $\\Omega_b\\sim 0.04$, and a cosmological constant parameter $\\Omega_\\Lambda\\sim 0.7$ yields an approximate fit to the data for the acoustical oscillations in the CMB power spectrum. The quantum phion condensate fluid is abundant well before recombination and can clump and form the primordial structure for galaxies. At late times in the expanding universe, in local bound systems such as galaxies ordinary baryonic matter dominates the matter density. For galactic systems in the present epoch, the modified Newtonian acceleration law determined by MOG describes well galaxy rotation curve data and X-ray cluster mass profile data.

  20. Dark Matter Theory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dark Matter Theory Dark Matter Theory Understanding discoveries at the Energy, Intensity, and Cosmic Frontiers Get Expertise Rajan Gupta (505) 667-7664 Email Bruce Carlsten (505)...

  1. Power Factor Reactive Power

    E-Print Network [OSTI]

    motor power: 117.7 V x 5.1 A = 600 W? = 0.6 kW? NOT the power measured by meter #12;Page 9 PSERC: displacement power factor: angle between voltage and current = 0 degrees pf = cos(0 degrees) = 1.0 true powerPage 1 PSERC Power Factor and Reactive Power Ward Jewell Wichita State University Power Systems

  2. Curvature perturbation spectrum from false vacuum inflation

    SciTech Connect (OSTI)

    Gong, Jinn-Ouk [Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706-1390 (United States)] [Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706-1390 (United States); Sasaki, Misao [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)] [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)

    2009-01-15T23:59:59.000Z

    In the inflationary cosmology it occurs frequently that the inflaton field is trapped in a local, transient minimum with non-zero vacuum energy. The difficulty regarding the curvature perturbation produced during such a stage is that classically the inflaton does not move so that the comoving hypersurfaces are not well defined at linear order in the scalar field perturbation. In this paper, assuming a mechanism of trapping which resembles a high temperature correction to the potential, we explicitly calculate for the first time the resulting power spectrum of the curvature perturbation by evaluating the quantum two-point correlation function directly. The spectrum is steeply blue with the spectral index n{sub R} = 4.

  3. Curvature perturbation spectrum from false vacuum inflation

    E-Print Network [OSTI]

    Jinn-Ouk Gong; Misao Sasaki

    2008-11-17T23:59:59.000Z

    In the inflationary cosmology it occurs frequently that the inflaton field is trapped in a local, transient minimum with non-zero vacuum energy. The difficulty regarding the curvature perturbation produced during such a stage is that classically the inflaton does not move so that the comoving hypersurfaces are not well defined at linear order in the scalar field perturbation. In this paper, assuming a mechanism of trapping which resembles a high temperature correction to the potential, we explicitly calculate for the first time the resulting power spectrum of the curvature perturbation by evaluating the quantum two-point correlation function directly. The spectrum is steeply blue with the spectral index n_R = 4.

  4. Curvature perturbation spectrum from false vacuum inflation

    SciTech Connect (OSTI)

    Gong, Jinn-Ouk [Department of Physics, University of Wisconsin-Madison 1150 University Avenue, Madison, WI 53706-1390 (United States)

    2008-11-23T23:59:59.000Z

    In the inflationary cosmology it occurs frequently that the inflaton field is trapped in a local, transient minimum with non-zero vacuum energy. The difficulty regarding the curvature perturbation produced during such a stage is that classically the inflaton does not move so that the comoving hypersurfaces are not well defined at linear order in the scalar field perturbation. In this paper, assuming a mechanism of trapping which resembles a high temperature correction to the potential, we explicitly calculate for the first time the resulting power spectrum of the curvature perturbation by evaluating the quantum two-point correlation function directly. The spectrum is steeply blue with the spectral index n{sub R} = 4.

  5. Spectrum Sensing and Reconstruction for Cognitive Radio

    E-Print Network [OSTI]

    Qiu, Robert Caiming

    Spectrum Sensing and Reconstruction for Cognitive Radio Amanpreet S Saini, Zhen Hu, Robert Qiu with spectrum sensing and spectrum reconstruction under the umbrella of cognitive radio which is the smart radio to explore and exploit the free spectrum. Spectrum analyzer is used to emulate cognitive radio to do spectrum

  6. Computing High Accuracy Power Spectra with Pico

    E-Print Network [OSTI]

    William A. Fendt; Benjamin D. Wandelt

    2007-12-02T23:59:59.000Z

    This paper presents the second release of Pico (Parameters for the Impatient COsmologist). Pico is a general purpose machine learning code which we have applied to computing the CMB power spectra and the WMAP likelihood. For this release, we have made improvements to the algorithm as well as the data sets used to train Pico, leading to a significant improvement in accuracy. For the 9 parameter nonflat case presented here Pico can on average compute the TT, TE and EE spectra to better than 1% of cosmic standard deviation for nearly all $\\ell$ values over a large region of parameter space. Performing a cosmological parameter analysis of current CMB and large scale structure data, we show that these power spectra give very accurate 1 and 2 dimensional parameter posteriors. We have extended Pico to allow computation of the tensor power spectrum and the matter transfer function. Pico runs about 1500 times faster than CAMB at the default accuracy and about 250,000 times faster at high accuracy. Training Pico can be done using massively parallel computing resources, including distributed computing projects such as Cosmology@Home. On the homepage for Pico, located at http://cosmos.astro.uiuc.edu/pico, we provide new sets of regression coefficients and make the training code available for public use.

  7. PINS Spectrum Identification Guide

    SciTech Connect (OSTI)

    A.J. Caffrey

    2012-03-01T23:59:59.000Z

    The Portable Isotopic Neutron Spectroscopy—PINS, for short—system identifies the chemicals inside munitions and containers without opening them, a decided safety advantage if the fill chemical is a hazardous substance like a chemical warfare agent or an explosive. The PINS Spectrum Identification Guide is intended as a reference for technical professionals responsible for the interpretation of PINS gamma-ray spectra. The guide is divided into two parts. The three chapters that constitute Part I cover the science and technology of PINS. Neutron activation analysis is the focus of Chapter 1. Chapter 2 explores PINS hardware, software, and related operational issues. Gamma-ray spectral analysis basics are introduced in Chapter 3. The six chapters of Part II cover the identification of PINS spectra in detail. Like the PINS decision tree logic, these chapters are organized by chemical element: phosphorus-based chemicals, chlorine-based chemicals, etc. These descriptions of hazardous, toxic, and/or explosive chemicals conclude with a chapter on the identification of the inert chemicals, e.g. sand, used to fill practice munitions.

  8. Structure formation in Multiple Dark Matter cosmologies with long-range scalar interactions

    E-Print Network [OSTI]

    Marco Baldi

    2012-06-11T23:59:59.000Z

    (Abridged) An interaction between Cold Dark Matter (CDM) and a classical scalar field playing the role of the cosmic dark energy (DE) might provide long-range dark interactions without conflicting with solar system bounds. Although presently available observations allow to constrain such interactions to a few percent of the gravitational strength, some recent studies have shown that if CDM is composed by two different particle species having opposite couplings to the DE field, such tight constraints can be considerably relaxed, allowing for long-range scalar forces of order gravity without significantly affecting observations both at the background and at the linear perturbations level. In the present work, we extend the investigation of such Multiple Dark Matter scenarios to the nonlinear regime of structure formation, by presenting the first N-body simulations ever performed for these cosmologies. Our results highlight some characteristic footprints of long-range scalar forces that arise only in the nonlinear regime for specific models that would be otherwise practically indistinguishable from the standard LCDM scenario both in the background and in the growth of linear density perturbations. Among these effects, the formation of "mirror" cosmic structures in the two CDM species, the suppression of the nonlinear matter power spectrum at k > 1 h/Mpc, and the fragmentation of collapsed halos, represent peculiar features that might provide a direct way to constrain this class of cosmological models.

  9. Analysis of Wind Power and Load Data at Multiple Time Scales

    E-Print Network [OSTI]

    Coughlin, Katie

    2011-01-01T23:59:59.000Z

    The spectrum of power from wind turbines. Journal of PowerAWEA 2010. American Wind Energy Association ProjectsErik and Jason Kemper. 2009. Wind Plant Ramping Behavior.

  10. Interference Characterization and Spectrum Sharing in Large Wireless Networks

    E-Print Network [OSTI]

    Yanikomeroglu, Halim

    SUs willing to utilize the spectrum band of the PU. The aggregate inter- ference power received fulfillment of the requirements for the degree of Doctor of Philosophy in Electrical and Computer Engineering Ottawa-Carleton Institute for Electrical and Computer Engineering (OCIECE) Department of Systems

  11. The UV spectrum of nebulae

    E-Print Network [OSTI]

    F. Zagury

    2001-06-18T23:59:59.000Z

    This paper presents an analysis of the UV spectrum of some nebulae with clearly identified illuminating stars, all observed by the IUE satellite. The data show remarkable properties of the UV spectrum of the nebulae. Each spectrum is the product of the star spectrum and a linear function of 1/lambda. There is no peculiar behaviour in the spectrums at 2200A: no bump created in the spectrum of a nebula and no excess of scattering. When moving away from the star, the surface brightness of a nebula decreases as the inverse of the square of the angular distance to the star. These results can logically be interpreted in terms of scattering of starlight. They imply constant properties of the interstellar grains in the UV and in the directions of space sampled by the nebulae, and probably a strong forward scattering phase function. There is no evidence for any particular type of grain which would specifically extinguish starlight at 2200A. Concerning the UV spectrum of a star, this may imply a revisal of the traditional interpretation of the 2200A bump.

  12. Utilization and fairness in spectrum assignment for opportunistic spectrum access

    E-Print Network [OSTI]

    Peng, ChunYi; Zheng, Haitao; Zhao, Ben Y

    2006-01-01T23:59:59.000Z

    985. [4] C AO , L. , AND Z HENG , H. Spectrum allocation in+ [26] Z HAO , J. , Z HENG , H. , AND Y ANG , G. Distributed2005, to appear). [27] Z HENG , H. , AND C AO , L. Device-

  13. Design of programmable matter

    E-Print Network [OSTI]

    Knaian, Ara N. (Ara Nerses), 1977-

    2008-01-01T23:59:59.000Z

    Programmable matter is a proposed digital material having computation, sensing, actuation, and display as continuous properties active over its whole extent. Programmable matter would have many exciting applications, like ...

  14. Asymmetric dark matter

    SciTech Connect (OSTI)

    Kumar, Jason [Department of Physics and Astronomy, University of Hawaii, Honolulu, HI 96822 (United States)

    2014-06-24T23:59:59.000Z

    We review the theoretical framework underlying models of asymmetric dark matter, describe astrophysical constraints which arise from observations of neutron stars, and discuss the prospects for detecting asymmetric dark matter.

  15. Exothermic dark matter

    E-Print Network [OSTI]

    Graham, Peter W.

    We propose a novel mechanism for dark matter to explain the observed annual modulation signal at DAMA/LIBRA which avoids existing constraints from every other dark matter direct detection experiment including CRESST, CDMS, ...

  16. Hot-dark matter, cold dark matter and accelerating universe

    E-Print Network [OSTI]

    Abbas Farmany; Amin Farmany; Mohammad Mahmoodi

    2006-07-07T23:59:59.000Z

    The Friedman equation is solved for a universe contains hotdark matter and cold dark matter. In this scenario, hot-dark matter drives an accelerating universe no cold dark matter.

  17. Visible Spectrum Incandescent Selective Emitter

    SciTech Connect (OSTI)

    Sonsight Inc.

    2004-04-30T23:59:59.000Z

    The purpose of the work performed was to demonstrate the feasibility of a novel bi-layer selective emitter. Selective emitters are incandescent radiant bodies with emissivities that are substantially larger in a selected part of the radiation spectrum, thereby significantly shifting their radiated spectral distribution from that of a blackbody radiating at the same temperature. The major research objectives involved answering the following questions: (1) What maximum VIS/NIR radiant power and emissivity ratios can be attained at 2650 K? (2) What is the observed emitter body life and how does its performance vary with time? (3) What are the design tradeoffs for a dual heating approach in which both an internally mounted heating coil and electrical resistance self-heating are used? (4) What are the quantitative improvements to be had from utilizing a bi-layer emitter body with a low emissivity inner layer and a partially transmissive outer layer? Two approaches to obtaining selective emissivity were investigated. The first was to utilize large optical scattering within an emitter material with a spectral optical absorption that is much greater within the visible spectrum than that within the NIR. With this approach, an optically thick emitter can radiate almost as if optically thin because essentially, scattering limits the distance below the surface from which significant amounts of internally generated radiation can emerge. The performance of thin emitters was also investigated (for optically thin emitters, spectral emissivity is proportional to spectral absorptivity). These emitters were fabricated from thin mono-layer emitter rods as well as from bi-layer rods with a thin emitter layer mounted on a substrate core. With an initially estimated energy efficiency of almost three times that of standard incandescent bulbs, a number of energy, economic and environmental benefits such as less energy use and cost, reduced CO{sub 2} emissions, and no mercury contamination was initially projected. The work performed provided answers to a number of important questions. The first is that, with the investigated approaches, the maximum sustained emitter efficiencies are about 1.5 times that of a standard incandescent bulb. This was seen to be the case for both thick and thin emitters, and for both mono-layer and bi-layer designs. While observed VIS/NIR ratios represent improvements over standard incandescent bulbs, it does not appear sufficient to overcome higher cost (i.e. up to five times that of the standard bulb) and ensure commercial success. Another result is that high temperatures (i.e. 2650 K) are routinely attainable without platinum electrodes. This is significant for reducing material costs. A novel dual heating arrangement and insulated electrodes were used to attain these temperatures. Another observed characteristic of the emitter was significant grain growth soon after attaining operating temperatures. This is an undesirable characteristic that results in substantially less optical scattering and spectral selectivity, and which significantly limits emitter efficiencies to the values reported. Further work is required to address this problem.

  18. in Condensed Matter Physics

    E-Print Network [OSTI]

    van der Torre, Leon

    Master in Condensed Matter Physics ­ Master académique #12;2 #12;3 Students at the University. Condensed matter physics is about explaining and predicting the relationship between the atomic, and broad education in the field of condensed matter physics · introduce you to current research topics

  19. Energy Spectrum of Vortex Tangle

    E-Print Network [OSTI]

    Tsunehiko Araki; Makoto Tsubota; Sergey K. Nemirovskii

    2001-06-29T23:59:59.000Z

    The energy spectrum of superfluid turbulence in the absence of the normal fluid is studied numerically. In order to discuss the statistical properties, we calculated the energy spectra of the 3D velocity field induced by dilute and dense vortex tangles respectively, whose dynamics is calculated by the Biot-Savart law. In the case of a dense tangle, the slope of the energy spectrum is changed at $k=2\\pi/l$, where $l$ is the intervortex spacing. For $k>2\\pi/l$, the energy spectrum has $k^{-1}$ behavior in the same manner as the dilute vortex tangle, while otherwise the slope of the energy spectrum deviates from $k^{-1}$ behavior. We compare the behavior for $k<2\\pi/l$ with the Kolmogorov law.

  20. Spectrum of C_heart

    E-Print Network [OSTI]

    Spectrum of C_heart where 1 + z + 2\\sqrt{1 - z^2} heart(z)= ------------------------- 3 - z + 2\\sqrt{1 - z^2}. Figure 7.1, page 303, of "Composition Operators on Spaces ...

  1. Lyapunov spectrum of granular gases

    SciTech Connect (OSTI)

    McNamara, Sean; Mareschal, Michel

    2001-06-01T23:59:59.000Z

    We calculate and study the Lyapunov spectrum of a granular gas maintained in a steady state by an isokinetic thermostat. Considering restitution coefficients greater than unity allows us to show that the spectra change smoothly and continuously at equilibrium. The shearing instability of the granular gas, however, provokes an abrupt change in the structure of the spectrum. The relationship between various physically relevant quantities and the energy dissipation rate differs from previously studied nonequilibrium steady states.

  2. Power Plant Power Plant

    E-Print Network [OSTI]

    Tingley, Joseph V.

    Basin Center for Geothermal Energy at University of Nevada, Reno (UNR) 2 Nevada Geodetic LaboratoryStillwater Power Plant Wabuska Power Plant Casa Diablo Power Plant Glass Mountain Geothermal Area Lassen Geothermal Area Coso Hot Springs Power Plants Lake City Geothermal Area Thermo Geothermal Area

  3. Stealth Dark Matter: Dark scalar baryons through the Higgs portal

    E-Print Network [OSTI]

    Appelquist, Thomas; Buchoff, Michael I; Fleming, George T; Jin, Xiao-Yong; Kiskis, Joe; Kribs, Graham D; Neil, Ethan T; Osborn, James C; Rebbi, Claudio; Rinaldi, Enrico; Schaich, David; Schroeder, Chris; Syritsyn, Sergey; Vranas, Pavlos; Weinberg, Evan; Witzel, Oliver

    2015-01-01T23:59:59.000Z

    We present a new model of "Stealth Dark Matter": a composite baryonic scalar of an $SU(N_D)$ strongly-coupled theory with even $N_D \\geq 4$. All mass scales are technically natural, and dark matter stability is automatic without imposing an additional discrete or global symmetry. Constituent fermions transform in vector-like representations of the electroweak group that permit both electroweak-breaking and electroweak-preserving mass terms. This gives a tunable coupling of stealth dark matter to the Higgs boson independent of the dark matter mass itself. We specialize to $SU(4)$, and investigate the constraints on the model from dark meson decay, electroweak precision measurements, basic collider limits, and spin-independent direct detection scattering through Higgs exchange. We exploit our earlier lattice simulations that determined the composite spectrum as well as the effective Higgs coupling of stealth dark matter in order to place bounds from direct detection, excluding constituent fermions with dominant...

  4. Effect of resonance broadening on the evolution of the edge of a turbulent spectrum

    E-Print Network [OSTI]

    Karney, Charles

    -hybridwave spectrum is investigated. This narrowing is of concern because it could make control of lower-hybrid heating difficult. It is shown numerically, however, that relatively uniform spatial power deposition

  5. Of Matters Condensed

    E-Print Network [OSTI]

    Shulman, Michael

    2015-01-01T23:59:59.000Z

    The American Physical Society (APS) March Meeting of condensed matter physics has grown to nearly 10,000 participants, comprises 23 individual APS groups, and even warrants its own hashtag (#apsmarch). Here we analyze the text and data from March Meeting abstracts of the past nine years and discuss trends in condensed matter physics over this time period. We find that in comparison to atomic, molecular, and optical physics, condensed matter changes rapidly, and that condensed matter appears to be moving increasingly toward subject matter that is traditionally in materials science and engineering.

  6. Incompressibility of strange matter

    E-Print Network [OSTI]

    Monika Sinha; Manjari Bagchi; Jishnu Dey; Mira Dey; Subharthi Ray; Siddhartha Bhowmick

    2004-04-01T23:59:59.000Z

    Strange stars calculated from a realistic equation of state (EOS), that incorporate chiral symmetry restoration as well as deconfinement at high density show compact objects in the mass radius curve. We compare our calculations of incompressibility for this EOS with that of nuclear matter. One of the nuclear matter EOS has a continuous transition to ud-matter at about five times normal density. Another nuclear matter EOS incorporates density dependent coupling constants. From a look at the consequent velocity of sound, it is found that the transition to ud-matter seems necessary.

  7. Big Questions: Dark Matter

    ScienceCinema (OSTI)

    Lincoln, Don

    2014-08-07T23:59:59.000Z

    Carl Sagan's oft-quoted statement that there are "billions and billions" of stars in the cosmos gives an idea of just how much "stuff" is in the universe. However scientists now think that in addition to the type of matter with which we are familiar, there is another kind of matter out there. This new kind of matter is called "dark matter" and there seems to be five times as much as ordinary matter. Dark matter interacts only with gravity, thus light simply zips right by it. Scientists are searching through their data, trying to prove that the dark matter idea is real. Fermilab's Dr. Don Lincoln tells us why we think this seemingly-crazy idea might not be so crazy after all.

  8. Distance Spectrum Analysis of Third Generation Turbo Codes

    E-Print Network [OSTI]

    unknown authors

    Abstract: Turbo Codes are a class of powerful error correction codes that were introduced in 1993 by a group of researchers from France, which has the performance near the limit of Claude Shannon. After the introduction of turbo codes it has given raise a tremendous research work related to the new coding theory. This paper addresses the performance of Turbo codes by examining the codes ’ distance spectrum. It is well known that error floor occurs in the performance curve of turbo codes at moderate to high signal-to-noise ratio. The cause of error floor is due to the relatively low free distance of the codewords. Several techniques were proposed by researchers to lower the error floor. These techniques are assessed in this paper. To determine the free distance several algorithms were developed by different researchers. In this paper we used one of the recent algorithm to evaluate the distance spectrum of Turbo codes. We concentrate our analysis to measure and explain the distance spectrum of UMTS (Universal Mobile Telecommunication System), cdma2000 and CCSDS (Consultative Committee for Space Data Systems) standards Turbo Codes. It is shown that the distance spectrum depends on the code rate, interleaver size and the interleaver type.This distance spectrum of turbo codes can be used to estimate its performance at medium to higher SNR (signal to noise ratio). From our analysis we find out that the distance spectrum is one of the elementary issues using which one can find the optimum architecture of Turbo codes for specific application.

  9. Flavor evolution of supernova neutrinos in turbulent matter

    SciTech Connect (OSTI)

    Lund, Tina; Kneller, James P. [Department of Physics, North Carolina State University, 2401 Stinson Drive, Raleigh, NC 27695 (United States)

    2014-01-01T23:59:59.000Z

    The neutrino signal from the next galactic supernova carries with it an enormous amount of information on the explosion mechanism of a core-collapse supernova, as well as on the stellar progenitor and on the neutrinos themselves. In order to extract this information we need to know how the neutrino flavor evolves over time due to the interplay of neutrino self-interactions and matter effects. Additional turbulence in the supernova matter may impart its own signatures on the neutrino spectrum, and could partly obscure the imprints of collective and matter effects. We investigate the neutrino flavor evolution due to neutrino self-interactions, matter effects due to the shock wave propagation, and turbulence in three progenitors with masses of 8.8 M?, 10.8 M? and 18.0 M?. In the lightest progenitor we find that the impact of moderate turbulence of the order 10% is limited and occurs only briefly early on. This makes the signatures of collective and matter interactions relatively straightforward to interpret. Similarly, with moderate turbulence the two heavier progenitors exhibit only minor changes in the neutrino spectrum, and collective and matter signatures persists. However, when the turbulence is increased to 30% and 50% the high density matter resonance features in the neutrino spectrum get obscured, while new features arise in the low density resonance channel and in the non-resonant channels. We conclude that with moderate amounts of turbulence spectral features of collective and matter interactions survive in all three progenitors. For the larger amounts of turbulence in the 10.8 M? and 18.0 M? progenitor new features arise, as others disappear.

  10. Longitudinal mode spectrum of GaAs injection lasers under high-frequency microwave modulation

    SciTech Connect (OSTI)

    Lau, K.Y.; Harder, C.; Yariv, A.

    1983-10-01T23:59:59.000Z

    Experimental observations of the lasing spectrum of a single mode semiconductor laser under continuous microwave modulation reveal that the lasing spectrum is apparently locked to a single longitudinal mode for optical modulation depths up to approx.80%, beyond which the lasing spectrum becomes multimoded, whose envelope width increases very rapidly with further increase in modulation depth. These results are satisfactorily explained by a theoretical treatment which enables one to predict the dynamic lasing spectrum of a laser from its cw lasing spectra at various output powers.

  11. Variable enstrophy flux and energy spectrum in two-dimensional turbulence with Ekman friction

    E-Print Network [OSTI]

    Mahendra K. Verma

    2012-03-23T23:59:59.000Z

    Experiments and numerical simulations reveal that in the forward cascade regime, the energy spectrum of two-dimensional turbulence with Ekman friction deviates from Kraichnan's prediction of $k^{-3}$ power spectrum. In this letter we explain this observation using an analytic model based on variable enstrophy flux arising due to Ekman friction. We derive an expression for the enstrophy flux which exhibits a logarithmic dependence in the inertial range for the Ekman-friction dominated flows. The energy spectrum obtained using this enstrophy flux shows a power law scaling for large Reynolds number and small Ekman friction, but has an exponential behaviour for large Ekman friction and relatively small Reynolds number.

  12. The acoustic spectrum of alpha Cen A

    E-Print Network [OSTI]

    F. Bouchy; F. Carrier

    2002-06-04T23:59:59.000Z

    This paper presents the analysis of Doppler p-mode observations of the G2V star $\\alpha$ Cen A obtained with the spectrograph CORALIE in May 2001. Thirteen nights of observations have made it possible to collect 1850 radial velocity measurements with a standard deviation of about 1.5 m s$^{-1}$. Twenty-eight oscillation modes have been identified in the power spectrum between 1.8 and 2.9 mHz with amplitudes in the range 12 to 44 cm s$^{-1}$. The average large and small spacing are respectively equal to 105.5 and 5.6 $\\mu$Hz. A comparison with stellar models of $\\alpha$ Cen A is presented.

  13. Matter: Space without Time

    E-Print Network [OSTI]

    Yousef Ghazi-Tabatabai

    2012-11-19T23:59:59.000Z

    While Quantum Gravity remains elusive and Quantum Field Theory retains the interpretational difficulties of Quantum Mechanics, we have introduced an alternate approach to the unification of particles, fields, space and time, suggesting that the concept of matter as space without time provides a framework which unifies matter with spacetime and in which we anticipate the development of complete theories (ideally a single unified theory) describing observed 'particles, charges, fields and forces' solely with the geometry of our matter-space-time universe.

  14. Energy Matters Mailbag

    Broader source: Energy.gov [DOE]

    This edition of the mailbag tackles follow-up questions from our Energy Matters discussion on breaking our reliance on foreign oil.

  15. A DISTRIBUTED POWER CONTROL ALGORITHM FOR

    E-Print Network [OSTI]

    Mitra, Debasis

    A DISTRIBUTED POWER CONTROL ALGORITHM FOR BURSTY TRANSMISSIONS ON CELLULAR, SPREAD SPECTRUM, USA ABSTRACT We propose a distributed algorithm for power control in cellular, wideband networks, although its parameters are different from data. We propose a distributed algorithm for power control

  16. LyMAS: Predicting Large-Scale Lyman-alpha Forest Statistics from the Dark Matter Density Field

    E-Print Network [OSTI]

    Peirani, Sébastien; Colombi, Stéphane; Blaizot, Jérémy; Dubois, Yohan; Pichon, Christophe

    2013-01-01T23:59:59.000Z

    [abridged] We describe LyMAS (Ly-alpha Mass Association Scheme), a method of predicting clustering statistics in the Ly-alpha forest on large scales from moderate resolution simulations of the dark matter distribution, with calibration from high-resolution hydrodynamic simulations of smaller volumes. We use the "Horizon MareNostrum" simulation, a 50 Mpc/h comoving volume evolved with the adaptive mesh hydrodynamic code RAMSES, to compute the conditional probability distribution P(F_s|delta_s) of the transmitted flux F_s, smoothed (1-dimensionally) over the spectral resolution scale, on the dark matter density contrast delta_s, smoothed (3-dimensionally) over a similar scale. In this study we adopt the spectral resolution of the SDSS-III BOSS at z=2.5, and we find optimal results for a dark matter smoothing length sigma=0.3 Mpc/h (comoving). In extended form, LyMAS exactly reproduces both the 1-dimensional power spectrum and 1-point flux distribution of the hydro simulation spectra. Applied to the MareNostrum ...

  17. Features and nongaussianity in the inflationary power spectrum

    E-Print Network [OSTI]

    James M. Cline

    2008-05-14T23:59:59.000Z

    I summarize recent work on (1) constraining spike-like features in the cosmic microwave background and large scale structure; (2) nonstandard Friedmann equation in stabilized warped 6D brane cosmology, with applications to inflation; and (3) nonlocal inflation models, motivated by string theory, which can yield large nongaussian CMB fluctuations. Work in collaboration with N. Barnaby, T. Biswas, F. Chen, L. Hoi, G. Holder and S. Kanno.

  18. Load Management and Houston Lighting and Power Co.

    E-Print Network [OSTI]

    Drawe, R. G.; Ramsay, I. M.

    1984-01-01T23:59:59.000Z

    Defining Load Management as influencing of customer loads in order to shift the time use of electric power and energy, encompasses a broad spectrum of activities at Houston Lighting & Power Company. This paper describes those activities by directing...

  19. Gravitational waves from a curvaton model with blue spectrum

    SciTech Connect (OSTI)

    Kawasaki, Masahiro; Kitajima, Naoya; Yokoyama, Shuichiro, E-mail: kawasaki@icrr.u-tokyo.ac.jp, E-mail: nk610@icrr.u-tokyo.ac.jp, E-mail: shu@icrr.u-tokyo.ac.jp [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan)

    2013-08-01T23:59:59.000Z

    We investigate the gravitational wave background induced by the first order scalar perturbations in the curvaton models. We consider the quadratic and axion-like curvaton potential which can generate the blue-tilted power spectrum of curvature perturbations on small scales and derive the maximal amount of gravitational wave background today. We find the power spectrum of the induced gravitational wave background has a characteristic peak at the frequency corresponding to the scale reentering the horizon at the curvaton decay, in the case where the curvaton does not dominate the energy density of the Universe. We also find the enhancement of the amount of the gravitational waves in the case where the curvaton dominates the energy density of the Universe. Such induced gravitational waves would be detectable by the future space-based gravitational wave detectors or pulsar timing observations.

  20. On the Oscillation of Neutrinos Produced by the Annihilation of Dark Matter inside the Sun

    E-Print Network [OSTI]

    Arman Esmaili; Yasaman Farzan

    2010-06-14T23:59:59.000Z

    The annihilation of dark matter particles captured by the Sun can lead to a neutrino flux observable in neutrino detectors. Considering the fact that these dark matter particles are non-relativistic, if a pair of dark matter annihilates to a neutrino pair, the spectrum of neutrinos will be monochromatic. We show that in this case, even after averaging over production point inside the Sun, the oscillatory terms of the oscillation probability do not average to zero. This leads to interesting observable features in the annual variation of the number of muon track events. We show that smearing of the spectrum due to thermal distribution of dark matter inside the Sun is too small to wash out this variation. We point out the possibility of studying the initial flavor composition of neutrinos produced by the annihilation of dark matter particles via measuring the annual variation of the number of muon-track events in neutrino telescopes.

  1. Dipolar Dark Matter

    E-Print Network [OSTI]

    Blanchet, Luc

    2015-01-01T23:59:59.000Z

    Massive gravity theories have been developed as viable IR modifications of gravity motivated by dark energy and the problem of the cosmological constant. On the other hand, modified gravity and modified dark matter theories were developed with the aim of solving the problems of standard cold dark matter at galactic scales. Here we propose to adapt the framework of ghost-free massive bigravity theories to reformulate the problem of dark matter at galactic scales. We investigate a promising alternative to dark matter called dipolar dark matter (DDM) in which two different species of dark matter are separately coupled to the two metrics of bigravity and are linked together by an internal vector field. We show that this model successfully reproduces the phenomenology of dark matter at galactic scales (i.e. MOND) as a result of a mechanism of gravitational polarisation. The model is safe in the gravitational sector, but because the two types of dark matter interact through the vector field, a ghostly degree of fre...

  2. Dark matter and cosmology

    SciTech Connect (OSTI)

    Schramm, D.N.

    1992-03-01T23:59:59.000Z

    The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the {Omega} = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between ``cold`` and ``hot`` non-baryonic candidates is shown to depend on the assumed ``seeds`` that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.

  3. Dark matter and cosmology

    SciTech Connect (OSTI)

    Schramm, D.N.

    1992-03-01T23:59:59.000Z

    The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the {Omega} = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between cold'' and hot'' non-baryonic candidates is shown to depend on the assumed seeds'' that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.

  4. The DOE Program in High Energy Density New Initiatives in Matter in Extreme Conditions

    E-Print Network [OSTI]

    The DOE Program in High Energy Density Physics: New Initiatives in Matter in Extreme Conditions Siegfried H. Glenzer (SLAC) December 11, 2013 Presentation to: 2013 FUSION POWER ASSOCIATES 34th Annual to determine pressures of dense matter · Summary · High power laser workshop and outlook towards a bright

  5. Statistical Tools for Analyzing the Cosmic Ray Energy Spectrum

    E-Print Network [OSTI]

    J. D. Hague; B. R. Becker; M. S. Gold; J. A. J. Matthews

    2008-08-20T23:59:59.000Z

    In this paper un-binned statistical tools for analyzing the cosmic ray energy spectrum are developed and illustrated with a simulated data set. The methods are designed to extract accurate and precise model parameter estimators in the presence of statistical and systematic energy errors. Two robust methods are used to test for the presence of flux suppression at the highest energies: the Tail-Power statistic and a likelihood ratio test. Both tests give evidence of flux suppression in the simulated data. The tools presented can be generalized for use on any astrophysical data set where the power-law assumption is relevant and can be used to aid observational design.

  6. Post-WMAP Assessment of Infrared Cutoff in the Primordial Spectrum from Inflation

    E-Print Network [OSTI]

    Rita Sinha; Tarun Souradeep

    2006-08-11T23:59:59.000Z

    The recent Cosmic Microwave Background (CMB) measurements indicate that there is power deficiency of the CMB anisotropies at large scales compared with the $\\Lambda$CDM model. We have investigated the possibility of explaining such effects by a class of primordial power spectra which have infrared cutoffs close to the horizon scale. The primordial power spectrum recovered by direct deconvolution of the observed CMB angular spectrum indicates that the data prefers a sharp infrared cutoff with a localized excess (bump) just above the cutoff. We have been motivated to assess plausible extensions of simplest inflationary scenarios which readily accommodate similar form of infrared cutoff. We carry out a complete Bayesian analysis of the parameter space using {\\it Markov Chain Monte Carlo} technique with such a class of primordial power spectra. We show that primordial power spectrum that have features such as an infrared cutoff followed by a subsequent excess in power give better fit to the observed data compared to a nearly scale-invariant power law or power spectrum with just a monotonic infrared cutoff. However, there is substantial room for improvement in the match to data and calls for exploration of other mechanisms that may lead to infrared cutoff even closer to that recovered by direct deconvolution approach.

  7. DOE/EA-1247; Environmental Assessment for Electrical Power System...

    Broader source: Energy.gov (indexed) [DOE]

    Transmission Cooperative, Inc. PM particulate matter PNM Public Service Company of New Mexico Power Pool Los Alamos Power Pool PRS potential release site ROW right-of-way SDP...

  8. Fourier Analysis of the Parametric Resonance of the Neutrino Oscillation in the Presence of Inhomogeneous Matter

    E-Print Network [OSTI]

    Joe Sato; Masafumi Koike; Toshihiko Ota; Masako Saito

    2008-10-17T23:59:59.000Z

    We study the parametric resonance of the neutrino oscillation through the matter whose density varies spatially. The Fourier analysis of the matter effect enables us to clarify the parametric resonance condition, which is summarized in a frequency matching between the neutrino oscillation and the spatial variation of the matter density. As a result, the n-th Fourier mode of a matter density profile modifies the energy spectrum of the nu_mu -> nu_e appearance probability at around the n-th dip.

  9. Statistical Physics of Dark and Normal Matter Distribution in Galaxy Formation : Dark Matter Lumps and Black Holes in Core and Halo of Galaxy

    E-Print Network [OSTI]

    Ajay Patwardhan

    2008-05-15T23:59:59.000Z

    In unified field theory the cosmological model of the universe has supersymmetric fields. Supersymmetric particles as dark and normal matter in galaxy clusters have a phase separation. Dark matter in halos have a statistical physics equation of state. Neutralino particle gas with gravitation can have a collapse of dark matter lumps. A condensate phase due to boson creation by annhillation and exchange can occur at high densities. The collapse of the boson condensate, including neutralinos, into the Schwarzschild radius creates dark matter black holes. Microscopic dark matter black holes can evaporate with Hawking effect giving gamma ray bursts and create a spectrum of normal particles. The phase separation of normal and dark matter in galaxy clusters and inside galaxies is given by statistical physics.

  10. ON THE ORIGIN OF THE 1/f SPECTRUM IN THE SOLAR WIND MAGNETIC FIELD

    SciTech Connect (OSTI)

    Verdini, Andrea [Solar-Terrestrial Center of Excellence-SIDC, Royal Observatory of Belgium, Bruxelles (Belgium); Grappin, Roland [LUTH, Observatoire de Paris, CNRS, Universite Paris-Diderot, 92190 Meudon (France); Pinto, Rui [Laboratoire AIM Paris-Saclay, CEA/Irfu, and Universite Paris-Diderot CNRS/INSU, Gis-sur-Yvette (France); Velli, Marco, E-mail: verdini@oma.be, E-mail: Roland.Grappin@obspm.fr, E-mail: rui.pinto@cea.fr, E-mail: mvelli@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA (United States)

    2012-05-10T23:59:59.000Z

    We present a mechanism for the formation of the low-frequency 1/f magnetic spectrum based on numerical solutions of a shell-reduced MHD model of the turbulent dynamics inside the sub-Alfvenic solar wind. We assign reasonably realistic profiles to the wind speed and the density along the radial direction, and a radial magnetic field. Alfven waves of short periodicity (600 s) are injected at the base of the chromosphere, penetrate into the corona, and are partially reflected, thus triggering a turbulent cascade. The cascade is strong for the reflected wave while it is weak for the outward propagating waves. Reflection at the transition region recycles the strong turbulent spectrum into the outward weak spectrum, which is advected beyond the Alfvenic critical point without substantial evolution. There, the magnetic field has a perpendicular power-law spectrum with slope close to the Kolmogorov -5/3. The parallel spectrum is inherited from the frequency spectrum of large (perpendicular) eddies. The shape is a double power law with slopes of {approx_equal} - 1 and -2 at low and high frequencies, respectively, with the position of the break depending on the injected spectrum. We suggest that the double power-law spectrum measured by Helios at 0.3 AU, where the average magnetic field is not aligned with the radial (contrary to our assumptions), results from the combination of such different spectral slopes. At low frequency the parallel spectrum dominates with its characteristic 1/f shape, while at higher frequencies its steep spectral slope (-2) is masked by the more energetic perpendicular spectrum (slope -5/3).

  11. Ice particle size matters | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ice particle size matters Ice particle size matters Released: May 04, 2014 Fine-tuning cloud models for improved climate predictions The Science Arctic clouds are widespread and...

  12. Beurling spectrum of functions in Banach space

    E-Print Network [OSTI]

    Dang Vu Giang

    2013-04-02T23:59:59.000Z

    We are interested in Beurling spectrum of $\\mathbb X-$valued functions with application in functional delay differential equations.

  13. Hot and dark matter

    E-Print Network [OSTI]

    D'Eramo, Francesco

    2012-01-01T23:59:59.000Z

    In this thesis, we build new Effective Field Theory tools to describe the propagation of energetic partons in hot and dense media, and we propose two new reactions for dark matter in the early universe. In the first part, ...

  14. Programmable matter by folding

    E-Print Network [OSTI]

    Wood, R. J.

    Programmable matter is a material whose properties can be programmed to achieve specific shapes or stiffnesses upon command. This concept requires constituent elements to interact and rearrange intelligently in order to ...

  15. The Heart of Matter

    E-Print Network [OSTI]

    Rohini M. Godbole

    2010-06-30T23:59:59.000Z

    In this article I trace the development of the human understanding of the "Heart of Matter" from early concepts of "elements" (or alternatively "Panchmahabhootas") to the current status of "quarks" and "leptons" as the fundamental constituents of matter, interacting together via exchange of the various force carrier particles called "gauge bosons" such as the photon, W/Z-boson etc. I would like to show how our understanding of the fundamental constituents of matter has gone hand in hand with our understanding of the fundamental forces in nature. I will also outline how the knowledge of particle physics at the "micro" scale of less than a Fermi(one millionth of a nanometer), enables us to offer explanations of Cosmological observations at the "macro" scale. Consequently these observations, may in turn, help us address some very fundamental questions of the Physics at the "Heart of the Matter".

  16. Matter & Energy Electronics

    E-Print Network [OSTI]

    Suslick, Kenneth S.

    See also: Matter & Energy Electronics· Detectors· Technology· Construction· Sports Science Electronic Tongue Tastes Wine Variety, Vintage (Aug. 12, 2008) -- You don't need a wine expert to Advance

  17. Gaseous dark matter detectors

    E-Print Network [OSTI]

    Martoff, C. J.

    Dark matter (DM) detectors with directional sensitivity have the potential of yielding an unambiguous positive observation of WIMPs as well as discriminating between galactic DM halo models. In this paper, we introduce the ...

  18. Energy Spectrum of Quasi-Geostrophic Turbulence

    E-Print Network [OSTI]

    Peter Constantin

    2002-07-24T23:59:59.000Z

    We consider the energy spectrum of a quasi-geostrophic model of forced, rotating turbulent flow. We provide a rigorous a priori bound E(k) energy spectrum that is expected in a two-dimensional Navier-Stokes inverse cascade. Our bound provides theoretical support for the k^{-2} spectrum observed in recent experiments.

  19. The end of the Galactic spectrum

    E-Print Network [OSTI]

    C. De Donato; G. A. Medina-Tanco

    2007-10-18T23:59:59.000Z

    We use a diffusion galactic model to analyze the end of the Galactic cosmic ray spectrum and its mixing with the extragalactic cosmic ray flux. We analyze the transition between Galactic and extragalactic components using two different extragalactic models. We compare the sum of the diffusive galactic spectrum and extragalactic spectrum with the available experimental data.

  20. The end of the Galactic spectrum

    E-Print Network [OSTI]

    De Donato, C

    2007-01-01T23:59:59.000Z

    We use a diffusion galactic model to analyze the end of the Galactic cosmic ray spectrum and its mixing with the extragalactic cosmic ray flux. We analyze the transition between Galactic and extragalactic components using two different extragalactic models. We compare the sum of the diffusive galactic spectrum and extragalactic spectrum with the available experimental data.

  1. High density matter

    E-Print Network [OSTI]

    J. R. Stone

    2013-02-11T23:59:59.000Z

    The microscopic composition and properties of matter at super-saturation densities have been the subject of intense investigation for decades. The scarcity of experimental and observational data has lead to the necessary reliance on theoretical models. However, there remains great uncertainty in these models, which, of necessity, have to go beyond the over-simple assumption that high density matter consists only of nucleons and leptons. Heavy strange baryons, mesons and quark matter in different forms and phases have to be included to fulfil basic requirements of fundamental laws of physics. In this review the latest developments in construction of the Equation of State (EoS) of high-density matter at zero and finite temperature assuming different composition of the matter are surveyed. Critical comparison of model EoS with available observational data on neutron stars, including gravitational masses, radii and cooling patterns is presented. The effect of changing rotational frequency on the composition of neutron stars during their lifetime is demonstrated. Compatibility of EoS of high-density, low temperature compact objects and low density, high temperature matter created in heavy-ion collisions is discussed.

  2. Adiabatic regularisation of power spectra in $k$-inflation

    E-Print Network [OSTI]

    Alinea, Allan L; Nakanishi, Yukari; Naylor, Wade

    2015-01-01T23:59:59.000Z

    We look at the question posed by Parker {\\it et al.} about the effect of UV regularisation on the power spectrum for inflation. Focusing on the slow-roll $k$-inflation, we show that up to second order in the Hubble and sound flow parameters, the adiabatic regularisation of such model leads to no difference in the power spectrum apart from certain cases that violate near scale invariant power spectra. Furthermore, extending to non-minimal $k$-inflation, we establish the equivalence of the subtraction terms in the adiabatic regularisation of the power spectrum in Jordan and Einstein frames.

  3. Adiabatic regularisation of power spectra in $k$-inflation

    E-Print Network [OSTI]

    Allan L. Alinea; Takahiro Kubota; Yukari Nakanishi; Wade Naylor

    2015-03-26T23:59:59.000Z

    We look at the question posed by Parker {\\it et al.} about the effect of UV regularisation on the power spectrum for inflation. Focusing on the slow-roll $k$-inflation, we show that up to second order in the Hubble and sound flow parameters, the adiabatic regularisation of such model leads to no difference in the power spectrum apart from certain cases that violate near scale invariant power spectra. Furthermore, extending to non-minimal $k$-inflation, we establish the equivalence of the subtraction terms in the adiabatic regularisation of the power spectrum in Jordan and Einstein frames.

  4. 466 IEEE TRANSACTIONS ON SPEECH AND AUDIO PROCESSING, VOL. 11, NO. 5, SEPTEMBER 2003 Noise Spectrum Estimation in Adverse Environments

    E-Print Network [OSTI]

    Cohen, Israel

    --Noise spectrum estimation is a fundamental compo- nent of speech enhancement and speech recognition systems into a speech enhancement system achieves improved speech quality and lower residual noise. I. INTRODUCTION NOISE POWER spectrum estimation is a fundamental component of speech enhancement and speech recog

  5. Hybrid spread spectrum radio system

    DOE Patents [OSTI]

    Smith, Stephen F. (London, TN); Dress, William B. (Camas, WA)

    2010-02-02T23:59:59.000Z

    Systems and methods are described for hybrid spread spectrum radio systems. A method includes modulating a signal by utilizing a subset of bits from a pseudo-random code generator to control an amplification circuit that provides a gain to the signal. Another method includes: modulating a signal by utilizing a subset of bits from a pseudo-random code generator to control a fast hopping frequency synthesizer; and fast frequency hopping the signal with the fast hopping frequency synthesizer, wherein multiple frequency hops occur within a single data-bit time.

  6. Longitudinal mode spectrum of semiconductor lasers under high-speed modulation

    SciTech Connect (OSTI)

    Lau, K.Y.; Harder, C.; Yariv, A.

    1984-01-01T23:59:59.000Z

    Experimental observations of the lasing spectrum of a single-mode semiconductor laser under continuous microwave modulation reveal that the lasing spectrum is apparently locked to a single-longitudinal mode for optical modulation depths up to about 80 percent, beyond which the lasing spectrum breaks into multimode oscillation. The width of the envelope of the multimode spectrum increases very rapidly with further increase in modulation depth. These results are satisfactorily explained by a theoretical treatment which gives simple analytic results for the time evolution of the individual longitudinal modes. It also yields considerable insight into spectral dynamics, and enables one to predict the dynamic lasing spectrum of a laser from its CW lasing spectra at various output powers. The results can also be used to predict the amount of spectral envelope broadening under single or pseudorandom pulse modulation.

  7. On the Extensive Air Shower density spectrum

    E-Print Network [OSTI]

    Aleksander Zawadzki; Tadeusz Wibig; Jerzy Gawin

    1998-07-29T23:59:59.000Z

    In search for new methods of determining the primary energy spectrum of Cosmic Rays, the attention was paid to the density spectrum measurement. New methods available at present warrant an accurateness of conclusions derived from the density spectrum measurements. The general statement about the change of the spectral index of the charged particle density spectrum is confirmed very clearly. Results concerning the shower size and primary energy spectra are also presented and discussed. Interesting future prospects for applications of the density spectrum method are proposed.

  8. Short range spread-spectrum radiolocation system and method

    DOE Patents [OSTI]

    Smith, Stephen F. (Loudon, TN)

    2003-04-29T23:59:59.000Z

    A short range radiolocation system and associated methods that allow the location of an item, such as equipment, containers, pallets, vehicles, or personnel, within a defined area. A small, battery powered, self-contained tag is provided to an item to be located. The tag includes a spread-spectrum transmitter that transmits a spread-spectrum code and identification information. A plurality of receivers positioned about the area receive signals from a transmitting tag. The position of the tag, and hence the item, is located by triangulation. The system employs three different ranging techniques for providing coarse, intermediate, and fine spatial position resolution. Coarse positioning information is provided by use of direct-sequence code phase transmitted as a spread-spectrum signal. Intermediate positioning information is provided by the use of a difference signal transmitted with the direct-sequence spread-spectrum code. Fine positioning information is provided by use of carrier phase measurements. An algorithm is employed to combine the three data sets to provide accurate location measurements.

  9. Analysis of the High-Resolution Infrared Spectrum of Cyclopropane...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the High-Resolution Infrared Spectrum of Cyclopropane. Analysis of the High-Resolution Infrared Spectrum of Cyclopropane. Abstract: The high resolution infrared spectrum of...

  10. Determination of a mutational spectrum

    DOE Patents [OSTI]

    Thilly, William G. (Winchester, MA); Keohavong, Phouthone (Cambridge, MA)

    1991-01-01T23:59:59.000Z

    A method of resolving (physically separating) mutant DNA from nonmutant DNA and a method of defining or establishing a mutational spectrum or profile of alterations present in nucleic acid sequences from a sample to be analyzed, such as a tissue or body fluid. The present method is based on the fact that it is possible, through the use of DGGE, to separate nucleic acid sequences which differ by only a single base change and on the ability to detect the separate mutant molecules. The present invention, in another aspect, relates to a method for determining a mutational spectrum in a DNA sequence of interest present in a population of cells. The method of the present invention is useful as a diagnostic or analytical tool in forensic science in assessing environmental and/or occupational exposures to potentially genetically toxic materials (also referred to as potential mutagens); in biotechnology, particularly in the study of the relationship between the amino acid sequence of enzymes and other biologically-active proteins or protein-containing substances and their respective functions; and in determining the effects of drugs, cosmetics and other chemicals for which toxicity data must be obtained.

  11. How Small Can Fast-Spectrum Space Reactors Get?

    SciTech Connect (OSTI)

    Hatton, Steven A.; El-Genk, Mohamed S. [Institute for Space and Nuclear Power Studies, University of New Mexico, Albuquerque, NM 87131 (United States); Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, NM 87131 (United States)

    2006-01-20T23:59:59.000Z

    Fast neutron spectrum space reactors are an appropriate choice for high thermal powers, but for low powers, they may not satisfy the excess reactivity requirement while remaining sub-critical when immersed in wet sand and flooded with seawater following a launch abort accident. This paper identifies the smallest size fast spectrum, Sectored, Compact Reactor loaded with Single UN fuel pins (SCoRe-S7), which satisfy the requirements of cold clean excess reactivity > $4.00 and remains at least $1.00 subcritical at shutdown and in submersion conditions. Results indicate that increasing the diameter of the SCoRe-S core reduces its active height and the UN fuel enrichment, but increases the Spectrum-Shift Absorber (SSA) of 157GdN additive to the fuel. All SCoRe-S cores also have a 0.1 mm thick 157Gd2O3 SSA coating on the outer surface of the reactor vessel to reduce the effect of the wet sand reflector, while the SSA fuel additive reduces the effect on the criticality of the flooded reactor caused by thermal neutron fission. The active core height decreases from 42.4 cm for the smallest SCoRe-S7 to as much as to 37.4 cm for the largest core of SCoRe-S11. For a 1.8 MWth reactor thermal power the UN fuel specific power decreases from 17.0 in the SCoRe-S7 to 11.5 Wth/kg in the -S11. The corresponding reactor total mass, including the BeO reflector, increases from 440 kg to 512 kg.

  12. Phase transition from hadronic matter to quark matter

    E-Print Network [OSTI]

    P. Wang; A. W. Thomas; A. G. Williams

    2007-04-03T23:59:59.000Z

    We study the phase transition from nuclear matter to quark matter within the SU(3) quark mean field model and NJL model. The SU(3) quark mean field model is used to give the equation of state for nuclear matter, while the equation of state for color superconducting quark matter is calculated within the NJL model. It is found that at low temperature, the phase transition from nuclear to color superconducting quark matter will take place when the density is of order 2.5$\\rho_0$ - 5$\\rho_0$. At zero density, the quark phase will appear when the temperature is larger than about 148 MeV. The phase transition from nuclear matter to quark matter is always first order, whereas the transition between color superconducting quark matter and normal quark matter is second order.

  13. Electric power annual 1992

    SciTech Connect (OSTI)

    Not Available

    1994-01-06T23:59:59.000Z

    The Electric Power Annual presents a summary of electric utility statistics at national, regional and State levels. The objective of the publication is to provide industry decisionmakers, government policymakers, analysts and the general public with historical data that may be used in understanding US electricity markets. The Electric Power Annual is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); US Department of Energy. ``The US Electric Power Industry at a Glance`` section presents a profile of the electric power industry ownership and performance, and a review of key statistics for the year. Subsequent sections present data on generating capability, including proposed capability additions; net generation; fossil-fuel statistics; retail sales; revenue; financial statistics; environmental statistics; electric power transactions; demand-side management; and nonutility power producers. In addition, the appendices provide supplemental data on major disturbances and unusual occurrences in US electricity power systems. Each section contains related text and tables and refers the reader to the appropriate publication that contains more detailed data on the subject matter. Monetary values in this publication are expressed in nominal terms.

  14. Closed String Thermodynamics and a Blue Tensor Spectrum

    E-Print Network [OSTI]

    Robert H. Brandenberger; Ali Nayeri; Subodh P. Patil

    2014-03-26T23:59:59.000Z

    The BICEP-2 team has reported the detection of primordial cosmic microwave background B-mode polarization, with hints of a suppression of power at large angular scales relative to smaller scales. Provided that the B-mode polarization is due to primordial gravitational waves, this might imply a blue tilt of the primordial gravitational wave spectrum. Such a tilt would be incompatible with standard inflationary models, although it was predicted some years ago in the context of a mechanism that thermally generates the primordial perturbations through a Hagedorn phase of string cosmology. The purpose of this note is to encourage greater scrutiny of the data with priors informed by a model that is immediately falsifiable, but which \\textit{predicts} features that might be favoured by the data-- namely a blue tensor tilt with an induced and complimentary red tilt to the scalar spectrum, with a naturally large tensor to scalar ratio that relates to both.

  15. The X-ray Spectrum of SAX J1808.4-3658

    E-Print Network [OSTI]

    W. A. Heindl; D. M. Smith

    1998-08-07T23:59:59.000Z

    We report on the X-ray spectrum of the 401 Hz X-ray pulsar and type I burst source SAX J1808.4-3658, during its 1998 April/May hard outburst. The observations were made with RXTE over a period of three weeks. The spectrum is well-described by a power law with photon index 1.86+/-0.01 that is exponentially cut off at high energies. Excess soft emission above the power law is present as well as a weak Fe-K line. This is the first truly simultaneous broad-band (2.5-250 keV) spectrum of a type I burst source in the hard state. The spectrum is consistent with other hard state burster spectra which cover either only the soft (1-20 keV) or hard (>20 keV) bands, or cover both, but not simultaneously. The cut-off power law resembles black hole candidates (BHCs) in their low states, observed with RXTE. We compare the SAX J1808.4-3658 spectrum to three BHCs and find that the power law is somewhat softer. This suggests that the photon index may provide a way to distinguish between low state emission from Galactic black holes and type I bursters.

  16. Thermodynamics of clusterized matter

    E-Print Network [OSTI]

    Ad. R. Raduta; F. Gulminelli

    2009-08-26T23:59:59.000Z

    Thermodynamics of clusterized matter is studied in the framework of statistical models with non-interacting cluster degrees of freedom. At variance with the analytical Fisher model, exact Metropolis simulation results indicate that the transition from homogeneous to clusterized matter lies along the $\\rho=\\rho_0$ axis at all temperatures and the limiting point of the phase diagram is not a critical point even if the surface energy vanishes at this point. Sensitivity of the inferred phase diagram to the employed statistical framework in the case of finite systems is discussed by considering the grand-canonical and constant-pressure canonical ensembles. A Wigner-Seitz formalism in which the fragment charge is neutralized by an uniform electron distribution allows to build the phase diagram of neutron star matter.

  17. Axion Dark Matter Searches

    E-Print Network [OSTI]

    I. Stern

    2014-03-21T23:59:59.000Z

    Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a $\\mu$eV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 $\\mu$eV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  18. Axion dark matter searches

    SciTech Connect (OSTI)

    Stern, Ian P. [Department of Physics, Univerisity of Florida, Gainesville, FL 32611-8440 (United States); Collaboration: ADMX Collaboration; ADMX-HF Collaboration

    2014-06-24T23:59:59.000Z

    Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a ?eV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 ?eV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  19. Stealth Dark Matter: Dark scalar baryons through the Higgs portal

    E-Print Network [OSTI]

    Thomas Appelquist; Richard C. Brower; Michael I. Buchoff; George T. Fleming; Xiao-Yong Jin; Joe Kiskis; Graham D. Kribs; Ethan T. Neil; James C. Osborn; Claudio Rebbi; Enrico Rinaldi; David Schaich; Chris Schroeder; Sergey Syritsyn; Pavlos Vranas; Evan Weinberg; Oliver Witzel

    2015-03-13T23:59:59.000Z

    We present a new model of "Stealth Dark Matter": a composite baryonic scalar of an $SU(N_D)$ strongly-coupled theory with even $N_D \\geq 4$. All mass scales are technically natural, and dark matter stability is automatic without imposing an additional discrete or global symmetry. Constituent fermions transform in vector-like representations of the electroweak group that permit both electroweak-breaking and electroweak-preserving mass terms. This gives a tunable coupling of stealth dark matter to the Higgs boson independent of the dark matter mass itself. We specialize to $SU(4)$, and investigate the constraints on the model from dark meson decay, electroweak precision measurements, basic collider limits, and spin-independent direct detection scattering through Higgs exchange. We exploit our earlier lattice simulations that determined the composite spectrum as well as the effective Higgs coupling of stealth dark matter in order to place bounds from direct detection, excluding constituent fermions with dominantly electroweak-breaking masses. A lower bound on the dark baryon mass $m_B \\gtrsim 300$ GeV is obtained from the indirect requirement that the lightest dark meson not be observable at LEP II. We briefly survey some intriguing properties of stealth dark matter that are worthy of future study, including: collider studies of dark meson production and decay; indirect detection signals from annihilation; relic abundance estimates for both symmetric and asymmetric mechanisms; and direct detection through electromagnetic polarizability, a detailed study of which will appear in a companion paper.

  20. SAW correlator spread spectrum receiver

    DOE Patents [OSTI]

    Brocato, Robert W

    2014-04-01T23:59:59.000Z

    A surface acoustic wave (SAW) correlator spread-spectrum (SS) receiver is disclosed which utilizes a first demodulation stage with a chip length n and a second demodulation stage with a chip length m to decode a transmitted SS signal having a code length l=n.times.m which can be very long (e.g. up to 2000 chips or more). The first demodulation stage utilizes a pair of SAW correlators which demodulate the SS signal to generate an appropriate code sequence at an intermediate frequency which can then be fed into the second demodulation stage which can be formed from another SAW correlator, or by a digital correlator. A compound SAW correlator comprising two input transducers and a single output transducer is also disclosed which can be used to form the SAW correlator SS receiver, or for use in processing long code length signals.

  1. Shear and magnification angular power spectra and higher-order moments from weak gravitational lensing

    E-Print Network [OSTI]

    Andrew J. Barber; A. N. Taylor

    2003-06-06T23:59:59.000Z

    We present new results on the gravitational lensing shear and magnification power spectra obtained from numerical simulations of a flat cosmology with a cosmological constant. These results are of considerable interest since both the shear and the magnification are observables. We find that the power spectrum in the convergence behaves as expected, but the magnification develops a shot-noise spectrum due to the effects of discrete, massive clusters and symptomatic of moderate lensing beyond the weak-lensing regime. We find that this behaviour can be suppressed by "clipping" of the largest projected clusters. Our results are compared with predictions from a Halo Model-inspired functional fit for the non-linear evolution of the matter field and show excellent agreement. We also study the higher-order moments of the convergence field and find a new scaling relationship with redshift. In particular, the statistic $S_3$ is found to vary as $z_s^{-2.00\\pm 0.08}$ (where $z_s$ is the source redshift) for the cosmology studied, which makes corrections for different median redshifts in different observational surveys particularly simple to apply.

  2. Dark matter axions `96

    SciTech Connect (OSTI)

    Sikivie, P.

    1996-12-31T23:59:59.000Z

    This report discusses why axions have been postulated to exist, what cosmology implies about their presence as cold dark matter in the galactic halo, how axions might be detected in cavities wherein strong magnetic fields stimulate their conversion into photons, and relations between axions` energy spectra and galactic halos` properties.

  3. Matter & Energy Solar Energy

    E-Print Network [OSTI]

    Rogers, John A.

    See Also: Matter & Energy Solar Energy· Electronics· Materials Science· Earth & Climate Energy at the University of Illinois, the future of solar energy just got brighter. Although silicon is the industry Electronics Over 1.2 Million Electronics Parts, Components and Equipment. www.AlliedElec.com solar energy

  4. Matter & Energy Engineering

    E-Print Network [OSTI]

    Sóbester, András

    .com/products/seahawk/ Maryland Solar Panels-- Solar Installations from BGE HOME $0 Down For Big Energy Savings! www.bgehome.com/SolarLike 6 0 | More APA MLA See Also: Matter & Energy Petroleum Engineering Fossil Fuels Earth believe may be contributing to global warming. The UK government has just announced it is investing £1

  5. Asymmetric condensed dark matter

    E-Print Network [OSTI]

    Aguirre, Anthony

    2015-01-01T23:59:59.000Z

    We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate can be very light, $10^{-22}\\,{\\rm eV} \\lesssim m \\lesssim 10^2\\,{\\rm eV}$; the lower limit arises from constraints on small-scale structure formation, while the upper bound ensures that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of deco...

  6. Energy Matters in Washington State Page 1 Energy Matters

    E-Print Network [OSTI]

    Collins, Gary S.

    Energy Matters in Washington State ­ Page 1 Energy Matters in Washington State June 2008 Updated November 2009 Updated and Revised October 2013 Grand Coulee Dam #12;Energy Matters in Washington State ­ Page 2 Copyright © 2013 Washington State University Energy Program. 905 Plum Street SE, P.O. Box 43169

  7. Self assembly in soft matter 

    E-Print Network [OSTI]

    Chremos, Alexandros

    2009-01-01T23:59:59.000Z

    The term “soft matter” applies to a variety of physical systems, such as liquids, colloids, polymers, foams, gels, and granular materials. The most fascinating aspect of soft matter lies in the fact that they are not ...

  8. Self Assembly in Soft Matter 

    E-Print Network [OSTI]

    Chremos, Alexandros

    2009-01-01T23:59:59.000Z

    The term “soft matter” applies to a variety of physical systems, such as liquids, colloids, polymers, foams, gels, and granular materials. The most fascinating aspect of soft matter lies in the fact that they are not ...

  9. The Search for Dark Matter

    ScienceCinema (OSTI)

    Orrell, John

    2014-07-24T23:59:59.000Z

    More than 25 years ago, PNNL scientists began the first underground measurements searching for dark matter using specialized radiation detector technology. Dark matter is yet to be discovered says Physicist John L. Orrell.

  10. The Search for Dark Matter

    SciTech Connect (OSTI)

    Orrell, John

    2013-11-20T23:59:59.000Z

    More than 25 years ago, PNNL scientists began the first underground measurements searching for dark matter using specialized radiation detector technology. Dark matter is yet to be discovered says Physicist John L. Orrell.

  11. Particulate Matter Standards (Ohio)

    Broader source: Energy.gov [DOE]

    This chapter of the law establishes that the Ohio Environmental Protection Agency sets the standards for particulate emissions from a variety of sources, including facilities that generate power. ...

  12. Mixed axion-wino dark matter

    E-Print Network [OSTI]

    Bae, Kyu Jung; Lessa, Andre; Serce, Hasan

    2015-01-01T23:59:59.000Z

    A variety of supersymmetric models give rise to a split mass spectrum characterized by very heavy scalars but sub-TeV gauginos, usually with a wino-like LSP. Such models predict a thermally-produced underabundance of wino-like WIMP dark matter so that non-thermal DM production mechanisms are necessary. We examine the case where theories with a wino-like LSP are augmented by a Peccei-Quinn sector including an axion-axino-saxion supermultiplet in either the SUSY KSVZ or SUSY DFSZ models and with/without saxion decays to axions/axinos. We show allowed ranges of PQ breaking scale f_a for various cases which are generated by solving the necessary coupled Boltzmann equations. We also present results for a model with radiatively-driven naturalness but with a wino-like LSP.

  13. Searching for dark matter with helium atom

    E-Print Network [OSTI]

    Imre Ferenc Barna

    2006-08-10T23:59:59.000Z

    With the help of the boost operator we can model the interaction between a weakly interacting particle(WIMP) of dark matter(DAMA) and an atomic nuclei. Via this "kick" we calculate the total electronic excitation cross section of the helium atom. The bound spectrum of He is calculated through a diagonalization process with a configuration interaction (CI) wavefunction built up from Slater orbitals. All together 19 singly- and doubly-excited atomic sates were taken with total angular momenta of L=0,1 and 2. Our calculation may give a rude estimation about the magnitude of the total excitation cross section which could be measured in later scintillator experiments. The upper limit of the excitation cross section is $9.7\\cdot 10^{-8}$ barn.

  14. Structure formation and CMBR anisotropy spectrum in the inflessence model

    E-Print Network [OSTI]

    A. A. Sen; V. F. Cardone; S. Capozziello; A. Troisi

    2006-07-25T23:59:59.000Z

    The inflessence model has recently been proposed in an attempt to explain both early inflation and present day accelerated expansion within a single mechanism. The model has been successfully tested against the Hubble diagram of Type Ia Supernovae, the shift parameter, and the acoustic peak parameter. As a further mandatory test, we investigate here structure formation in the inflessence model determining the evolution of matter density contrast $\\delta \\equiv \\delta \\rho_M/\\rho_M$ in the linear regime. We compare the growth factor $D(a) \\equiv \\delta/a$ and the growth index $f(z) \\equiv d\\ln{\\delta}/d\\ln{a}$ to these same quantities for the successful concordance $\\Lambda$CDM model with a particular emphasis on the role of the inflessence parameters $(\\gamma, z_Q)$. We also evaluate the anisotropy spectrum of the cosmic microwave background radiation (CMBR) to check whether the inflessence model may be in agreement with the observations. We find that, for large values of $(\\gamma, z_Q)$, structure formation proceeds in a similar way to that in the $\\Lambda$CDM scenario, and it is also possible to nicely fit the CMBR spectrum.

  15. The gravitational wave spectrum from cosmological B-L breaking

    SciTech Connect (OSTI)

    Buchmüller, W.; Domcke, V.; Kamada, K. [Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg (Germany); Schmitz, K., E-mail: buchmuwi@mail.desy.de, E-mail: valerie.domcke@desy.de, E-mail: kohei.kamada@desy.de, E-mail: kai.schmitz@ipmu.jp [Kavli IPMU (WPI), University of Tokyo, Kashiwa 277-8583 (Japan)

    2013-10-01T23:59:59.000Z

    Cosmological B-L breaking is a natural and testable mechanism to generate the initial conditions of the hot early universe. If B-L is broken at the grand unification scale, the false vacuum phase drives hybrid inflation, ending in tachyonic preheating. The decays of heavy B-L Higgs bosons and heavy neutrinos generate entropy, baryon asymmetry and dark matter and also control the reheating temperature. The different phases in the transition from inflation to the radiation dominated phase produce a characteristic spectrum of gravitational waves. We calculate the complete gravitational wave spectrum due to inflation, preheating and cosmic strings, which turns out to have several features. The production of gravitational waves from cosmic strings has large uncertainties, with lower and upper bounds provided by Abelian Higgs strings and Nambu-Goto strings, implying ?{sub GW}h{sup 2} ? 10{sup ?13}–10{sup ?8}, much larger than the spectral amplitude predicted by inflation. Forthcoming gravitational wave detectors such as eLISA, advanced LIGO, ET, BBO and DECIGO will reach the sensitivity needed to test the predictions from cosmological B-L breaking.

  16. Normal matter storage of antiprotons

    SciTech Connect (OSTI)

    Campbell, L.J.

    1987-01-01T23:59:59.000Z

    Various simple issues connected with the possible storage of anti p in relative proximity to normal matter are discussed. Although equilibrium storage looks to be impossible, condensed matter systems are sufficiently rich and controllable that nonequilibrium storage is well worth pursuing. Experiments to elucidate the anti p interactions with normal matter are suggested. 32 refs.

  17. dark matter dark energy inflation

    E-Print Network [OSTI]

    Hu, Wayne

    theory dark matter dark energy inflation The National Science Foundation The Kavli Foundation NSF Site Review November 28-29, 2005 #12;dark matter dark energy inflation NSF Site Visit ­ November 28 Gravitation initial conditions beyond single-field slow roll #12;dark matter dark energy inflation NSF Site

  18. Dark Energy and Dark Matter

    E-Print Network [OSTI]

    Keith A. Olive

    2010-01-27T23:59:59.000Z

    A brief overview of our current understanding of abundance and properties of dark energy and dark matter is presented. A more focused discussion of supersymmetric dark matter follows. Included is a frequentist approach to the supersymmetric parameter space and consequences for the direct detection of dark matter.

  19. Mechanisms of Fetal Alcohol Spectrum Disorders

    E-Print Network [OSTI]

    Wilson, Shannon Elizabeth

    2011-10-21T23:59:59.000Z

    MECHANISMS OF FETAL ALCOHOL SPECTRUM DISORDERS A Dissertation by SHANNON ELIZABETH WILSON Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of DOCTOR OF PHILOSOPHY August 2010 Major Subject: Biomedical Sciences Mechanisms of Fetal Alcohol Spectrum Disorders Copyright 2010 Shannon Elizabeth Wilson MECHANISMS OF FETAL ALCOHOL...

  20. Wavelet Spectrum Analysis and Ocean Wind Waves

    E-Print Network [OSTI]

    Wavelet Spectrum Analysis and Ocean Wind Waves Paul C. Liu Abstract. Wavelet spectrum analysis characteristics. These insights are due to the nature of the wavelet transform that would not be immediately or decay, is Wavelets in Geophysics 151 Efi Foufoula-Georgiou and Praveen Kumar (eds.), pp. 151-166. ISBN 0

  1. Particulate matter dynamics

    E-Print Network [OSTI]

    Cionco, Rodolfo G; Caligaris, Marta G

    2012-01-01T23:59:59.000Z

    A substantial fraction of the particulate matter released into the atmosphere by industrial or natural processes corresponds to particles whose aerodynamic diameters are greater than 50 mm. It has been shown that, for these particles, the classical description of Gaussian plume diffusion processes, is inadequate to describe the transport and deposition. In this paper we present new results concerning the dispersion of coarse particulate matter. The simulations are done with our own code that uses the Bulirsch Stoer numerical integrator to calculate threedimensional trajectories of particles released into the environment under very general conditions. Turbulent processes are simulated by the Langevin equation and weather conditions are modeled after stable (Monin-Obukhov length L> 0) and unstable conditions (L <0). We present several case studies based on Monte Carlo simulations and discusses the effect of weather on the final deposition of these particles.

  2. Constraining Decaying Dark Matter

    E-Print Network [OSTI]

    Ran Huo

    2011-07-13T23:59:59.000Z

    We revisited the decaying dark matter (DDM) model, in which one collisionless particle decays early into two collisionless particles, that are potentially dark matter particles today. The effect of DDM will be manifested in the cosmic microwave background (CMB) and structure formation. With a systematic modification of CMB calculation tool \\texttt{camb}, we can numerically calculated this effect, and compare it to observations. Further Markov Chain Monte Carlo \\texttt{cosmomc} runnings update the constraints in that model: the free streaming length $\\lambda_{FS}\\lesssim0.5$Mpc for nonrelativistic decay, and $((M_{DDM}/keV) Y)^2 (T_d/yr)\\lesssim5\\times10^{-5}$ for relativistic decay.

  3. Closed loop adaptive control of spectrum-producing step using neural networks

    DOE Patents [OSTI]

    Fu, C.Y.

    1998-11-24T23:59:59.000Z

    Characteristics of the plasma in a plasma-based manufacturing process step are monitored directly and in real time by observing the spectrum which it produces. An artificial neural network analyzes the plasma spectrum and generates control signals to control one or more of the process input parameters in response to any deviation of the spectrum beyond a narrow range. In an embodiment, a plasma reaction chamber forms a plasma in response to input parameters such as gas flow, pressure and power. The chamber includes a window through which the electromagnetic spectrum produced by a plasma in the chamber, just above the subject surface, may be viewed. The spectrum is conducted to an optical spectrometer which measures the intensity of the incoming optical spectrum at different wavelengths. The output of optical spectrometer is provided to an analyzer which produces a plurality of error signals, each indicating whether a respective one of the input parameters to the chamber is to be increased or decreased. The microcontroller provides signals to control respective controls, but these lines are intercepted and first added to the error signals, before being provided to the controls for the chamber. The analyzer can include a neural network and an optional spectrum preprocessor to reduce background noise, as well as a comparator which compares the parameter values predicted by the neural network with a set of desired values provided by the microcontroller. 7 figs.

  4. Closed loop adaptive control of spectrum-producing step using neural networks

    DOE Patents [OSTI]

    Fu, Chi Yung (San Francisco, CA)

    1998-01-01T23:59:59.000Z

    Characteristics of the plasma in a plasma-based manufacturing process step are monitored directly and in real time by observing the spectrum which it produces. An artificial neural network analyzes the plasma spectrum and generates control signals to control one or more of the process input parameters in response to any deviation of the spectrum beyond a narrow range. In an embodiment, a plasma reaction chamber forms a plasma in response to input parameters such as gas flow, pressure and power. The chamber includes a window through which the electromagnetic spectrum produced by a plasma in the chamber, just above the subject surface, may be viewed. The spectrum is conducted to an optical spectrometer which measures the intensity of the incoming optical spectrum at different wavelengths. The output of optical spectrometer is provided to an analyzer which produces a plurality of error signals, each indicating whether a respective one of the input parameters to the chamber is to be increased or decreased. The microcontroller provides signals to control respective controls, but these lines are intercepted and first added to the error signals, before being provided to the controls for the chamber. The analyzer can include a neural network and an optional spectrum preprocessor to reduce background noise, as well as a comparator which compares the parameter values predicted by the neural network with a set of desired values provided by the microcontroller.

  5. Developments in Chiral effective Field Theory for Nuclear Matter

    E-Print Network [OSTI]

    J. A. Oller

    2012-06-12T23:59:59.000Z

    We review on a chiral power counting scheme for in-medium chiral perturbation theory with nucleons and pions as degrees of freedom \\cite{ref}. It allows for a systematic expansion taking into account local as well as pion-mediated inter-nucleon interactions. Based on this power counting, one can identify classes of non-perturbative diagrams that require a resummation. We then calculate the nuclear matter energy density for the symmetric and purely neutron matter cases up-to-and-including next-to-leading order (NLO), in good agreement with sophisticated many-body calculations. Next, the neutron matter equation of state is applied to calculate the upper limit for neutron stars, with an upper bound around 2.3 solar masses, large enough to accommodate the most massive neutron star observed until now. We also apply our equation state to constraint $G_N$ in exceptionally large gravitational fields.

  6. Dark matter particles

    E-Print Network [OSTI]

    V. Berezinsky

    1996-10-31T23:59:59.000Z

    The baryonic and cold dark matter are reviewed in the context of cosmological models. The theoretical search for the particle candidates is limited by supersymmetric extension of the Standard Model. Generically in such models there are just two candidates associated with each other: generalized neutralino, which components are usual neutralino and axino, and axion which is a partner of axino in supermultiplet. The status of these particles as DM candidates is described.

  7. Dark matter axions revisited

    SciTech Connect (OSTI)

    Visinelli, Luca; Gondolo, Paolo [Department of Physics, University of Utah, 115 S 1400 E 201, Salt Lake City, Utah 84102 (United States)

    2009-08-01T23:59:59.000Z

    We study for what specific values of the theoretical parameters the axion can form the totality of cold dark matter. We examine the allowed axion parameter region in the light of recent data collected by the WMAP5 mission plus baryon acoustic oscillations and supernovae, and assume an inflationary scenario and standard cosmology. We also upgrade the treatment of anharmonicities in the axion potential, which we find important in certain cases. If the Peccei-Quinn symmetry is restored after inflation, we recover the usual relation between axion mass and density, so that an axion mass m{sub a}=(85{+-}3) {mu}eV makes the axion 100% of the cold dark matter. If the Peccei-Quinn symmetry is broken during inflation, the axion can instead be 100% of the cold dark matter for m{sub a}<15 meV provided a specific value of the initial misalignment angle {theta}{sub i} is chosen in correspondence to a given value of its mass m{sub a}. Large values of the Peccei-Quinn symmetry breaking scale correspond to small, perhaps uncomfortably small, values of the initial misalignment angle {theta}{sub i}.

  8. Hidden vector dark matter

    E-Print Network [OSTI]

    Thomas Hambye

    2010-03-16T23:59:59.000Z

    We show that dark matter could be made of massive gauge bosons whose stability doesn't require to impose by hand any discrete or global symmetry. Stability of gauge bosons can be guaranteed by the custodial symmetry associated to the gauge symmetry and particle content of the model. The particle content we consider to this end is based on a hidden sector made of a vector multiplet associated to a non-abelian gauge group and of a scalar multiplet charged under this gauge group. The hidden sector interacts with the Standard Model particles through the Higgs portal quartic scalar interaction in such a way that the gauge bosons behave as thermal WIMPS. This can lead easily to the observed dark matter relic density in agreement with the other various constraints, and can be tested experimentally in a large fraction of the parameter space. In this model the dark matter direct detection rate and the annihilation cross section can decouple if the Higgs portal interaction is weak.

  9. RIKEN Center for Emergent Matter Sciencewww.cems.riken.jp

    E-Print Network [OSTI]

    Kazama, Hokto

    ;Director, Yoshinori Tokura Computers using injection- locking lasers can solve a 3D Ising model of an NP. Printed in Japan. RIKEN 2013-036 May 2013 RIKEN Center for Emergent Matter Science 2-1 Hirosawa, Wako materials that have powerful energy properties, such as very low consumption, minimal electricity loss

  10. Weak Lensing: Dark Matter, Dark Energy

    SciTech Connect (OSTI)

    Jain, Bhuvnesh (University of Pennsylvania) [University of Pennsylvania

    2006-02-27T23:59:59.000Z

    The light rays from distant galaxies are deflected by massive structures along the line of sight, causing the galaxy images to be distorted. Measurements of these distortions, known as weak lensing, provide a way of measuring the distribution of dark matter as well as the spatial geometry of the universe. I will describe the ideas underlying this approach to cosmology. With planned large imaging surveys, weak lensing is a powerful probe of dark energy. I will discuss the observational challenges ahead and recent progress in developing multiple, complementary approaches to lensing measurements.

  11. Exploring the Nature of Matter | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField8,Dist. Category UC-l 1,EnergyExploring the Nature of Matter November 3,

  12. The energy production rate & the generation spectrum of UHECRs

    E-Print Network [OSTI]

    Boaz Katz; Ran Budnik; Eli Waxman

    2009-03-18T23:59:59.000Z

    We derive simple analytic expressions for the flux and spectrum of ultra-high energy cosmic-rays (UHECRs) predicted in models where the CRs are protons produced by extra-Galactic sources. For a power-law scaling of the CR production rate with redshift and energy, d\\dot{n} /dE\\propto E^-\\alpha (1+z)^m, our results are accurate at high energy, E>10^18.7 eV, to better than 15%, providing a simple and straightforward method for inferring d\\dot{n}/dE from the observed flux at E. We show that current measurements of the UHECR spectrum, including the latest Auger data, imply E^2d\\dot{n}/dE(z=0)=(0.45\\pm0.15)(\\alpha-1) 10^44 erg Mpc^-3 yr^-1 at E<10^19.5 eV with \\alpha roughly confined to 2\\lesseq\\alpha<2.7. The uncertainty is dominated by the systematic and statistic errors in the experimental determination of individual CR event energy, (\\Delta E/E)_{sys} (\\Delta E/E)_{stat} ~20%. At lower energy, d\\dot{n}/dE is uncertain due to the unknown Galactic contribution. Simple models in which \\alpha\\simeq 2 and the transition from Galactic to extra-Galactic sources takes place at the "ankle", E ~10^19 eV, are consistent with the data. Models in which the transition occurs at lower energies require a high degree of fine tuning and a steep spectrum, \\alpha\\simeq 2.7, which is disfavored by the data. We point out that in the absence of accurate composition measurements, the (all particle) energy spectrum alone cannot be used to infer the detailed spectral shapes of the Galactic and extra-Galactic contributions.

  13. The Role of Subsurface Flows in Solar Surface Convection: Modeling the Spectrum of Supergranular and Larger Scale Flows

    E-Print Network [OSTI]

    Lord, J W; Rast, M P; Rempel, M; Roudier, T

    2014-01-01T23:59:59.000Z

    We model the solar horizontal velocity power spectrum at scales larger than granulation using a two-component approximation to the mass continuity equation. The model takes four times the density scale height as the integral (driving) scale of the vertical motions at each depth. Scales larger than this decay with height from the deeper layers. Those smaller are assumed to follow a Kolomogorov turbulent cascade, with the total power in the vertical convective motions matching that required to transport the solar luminosity in a mixing length formulation. These model components are validated using large scale radiative hydrodynamic simulations. We reach two primary conclusions: 1. The model predicts significantly more power at low wavenumbers than is observed in the solar photospheric horizontal velocity spectrum. 2. Ionization plays a minor role in shaping the observed solar velocity spectrum by reducing convective amplitudes in the regions of partial helium ionization. The excess low wavenumber power is also ...

  14. Observation of relaxation resonance effects in the field spectrum of semiconductor lasers

    SciTech Connect (OSTI)

    Vahala, K.; Harder, C.; Yariv, A.

    1983-02-01T23:59:59.000Z

    Subsidiary maxima are observed in the field spectra of single mode semiconductor lasers. Measurements of their power dependence show they are linked to the relaxation resonance. We attribute these maxima to combined phase and amplitude fluctuations at the relaxation resonance. A theoretical calculation of the field spectrum using the results of a noise analysisincorporating carrier dynamics agrees very well with observations.

  15. Game Theoretic Analysis of Distributed Spectrum Sharing With Database Xu Chen and Jianwei Huang

    E-Print Network [OSTI]

    Huang, Jianwei

    licensed holders of TV spectrum) provide the database with the up-to-date information including TV tower transmission parameters and TV receiver protection requirements. Based on this information, the database location, given the white-space device's transmission parameters such as the transmission power. Although

  16. Non-linear hydrodynamics of axion dark matter: relative velocity effects and "quantum forces"

    E-Print Network [OSTI]

    Marsh, David J E

    2015-01-01T23:59:59.000Z

    The non-linear hydrodynamic equations for axion/scalar field dark matter (DM) in the non-relativistic Madelung-Shcr\\"{o}dinger form are derived in a simple manner, including the effects of universal expansion and Hubble drag. The hydrodynamic equations are used to investigate the relative velocity between axion DM and baryons, and the moving-background perturbation theory (MBPT) derived. Axions massive enough to be all of the DM do not affect the coherence length of the relative velocity, but the MBPT equations are modified by the inclusion of the axion effective sound speed. These MBPT equations are necessary for accurately modelling the effects of axion DM on the formation of the first cosmic structures, and suggest that the 21cm power spectrum could improve constraints on axion mass by up to four orders of magnitude with respect to the current best constraints. A further application of these results uses the "quantum force" analogy to model scalar field gradient energy in a smoothed-particle hydrodynamics ...

  17. The frequency spectrum of the Casimir effect

    SciTech Connect (OSTI)

    Lang, Andrew S.I.D. [Computer Science and Mathematics Department, Oral Roberts University, Tulsa, Oklahoma 74171 (United States)

    2005-10-01T23:59:59.000Z

    The frequency spectrum of the Casimir effect between parallel plates is studied. Calculations are performed for both the massless scalar field and the electromagnetic field cases, first using a spectral weight function, and then via the Fourier transform of the renormalized expectation of the Casimir energy-momentum operator. The Casimir force is calculated using the spectrum for two plates which are perfectly transparent in a frequency band. The result of this calculation suggests a way to detect the frequency spectrum of the Casimir effect.

  18. Power-law tailed spectra from equilibrium

    E-Print Network [OSTI]

    T. S. Biro; G. Purcsel; G. Gyorgyi; A. Jakovac; Zs. Schram

    2005-10-03T23:59:59.000Z

    We propose that power-law tailed hadron spectra may be viewed as stemming from a matter in an unconventional equilibrium state typical for non-extensive thermodynamics. A non-extensive Boltzmann equation, which is able to form such spectra as a stationary solution, is utilized as a rough model of quark matter hadronization. Basic ideas about non-extensive simulation of the QCD equation of state on the lattice are presented.

  19. Wino Dark Matter in the light of AMS-02 2015

    E-Print Network [OSTI]

    Ibe, Masahiro; Shirai, Satoshi; Yanagida, Tsutomu T

    2015-01-01T23:59:59.000Z

    The AMS-02 collaboration has recently reported the antiproton to proton ratio with improved accuracy. In view of uncertainties of the production and the propagation of the cosmic rays, the observed ratio is still consistent with the secondary astrophysical antiproton to proton ratio. However, it is nonetheless enticing to examine whether the observed spectrum can be explained by a strongly motivated dark matter, the wino dark matter. As we will show, we find that the antiproton flux from the wino annihilation can explain the observed spectrum well for its mass range 2.5-3 TeV. The fit to data becomes particularly well compared to the case without the annihilation for the thermal wino dark matter case with a mass about 3 TeV. The ratio is predicted to be quickly decreased at the energy several hundreds of GeV, if this possibility is true, and it will be confirmed or ruled out in near future when the AMS-02 experiment accumulates enough data at this higher energy region.

  20. Initial Blackbeard power survey results

    SciTech Connect (OSTI)

    Murphy, T.; Devenport, J.; Holden, D.

    1996-06-01T23:59:59.000Z

    The Blackbeard broadband VHF radio receiver is in low-earth orbit aboard the ALEXIS satellite. The receiver has been used to measure the transmitted power in four VHF bands (55.2-75.8, 28.0-94.8, 132.3-152.2, and 107.7-166.0 MHz) over quiet and noisy parts of the earth. The authors present the results of the survey and discuss their implications. They find that there are remote ocean areas over which the observed spectrum is largely free of man-made interference, but that the spectrum over most of the earth is dominated by broadcast VHF signals. The signal characteristics observed over a given area are quite constant when observed at different times of day and at intervals of several weeks to months. It appears that in many cases the bulk of the signal power is coming from a small number of sources.

  1. Do high redshift quasars have powerful jets?

    E-Print Network [OSTI]

    Fabian, A. C.; Walker, S. A.; Celotti, A.; Ghisellini, G.; Mocz, P.; Blundell, K. M.; McMahon, R. G.

    2014-06-04T23:59:59.000Z

    for the injection spectrum and surrounding gas profile (set [A] in Mocz et al (2011): the in- jection spectrum is given by a power-law index 2.14 and Lorentz factors ranging between 1 to 106; the surrounding density profile has a powerlaw index of 1.5). We assume... the galaxy hosts of quasars at z > 3 are com- pact (Szomoru et al 2013), and their group and cluster gas have more energy than is explainable by gravitational infall alone (Wu et al 2000; McCarthy et al 2012). Powerful jets are a considerable source of energy...

  2. Superconnections and Matter

    E-Print Network [OSTI]

    Roepstorff, G

    1998-01-01T23:59:59.000Z

    In a previous paper, the superconnection formalism was used to naturally fit the Higgs field into a U(n) gauge theory where we aimed at the reconstruction of the standard model. The approach provides an alternative to non-commutative geometry. This work is now continued by including matter field (leptons). The essentially new ingredient is the right-handed neutrino field and a new kind of interaction that goes with it. All interactions follow from one Dirac operator associated to a superconnection.

  3. Superconnections and Matter

    E-Print Network [OSTI]

    G. Roepstorff

    2000-08-17T23:59:59.000Z

    In a previous paper (hep-th/9801040), the superconnection formalism was used to fit the Higgs field into a U(n) gauge theory with particular emphasis on the n=2 case, aiming at the reconstruction of certain parts of the Standard Model. The approach provides an alternative to the one bases on non-commutative geometry. This work is continued by including matter fields (leptons only). We extend the Standard Model by including the right-handed neutrino field. The possibility of a finite neutrino mass is thus accounted for.

  4. Thermodynamics of electroweak matter

    E-Print Network [OSTI]

    A. Gynther

    2006-09-21T23:59:59.000Z

    This paper is a slightly modified version of the introductory part of a PhD thesis, also containing the articles hep-ph/0303019, hep-ph/0510375 and hep-ph/0512177. We provide a short history of the research of electroweak thermodynamics and a brief introduction to the theory as well as to the necessary theoretical tools needed to work at finite temperatures. We then review computations regarding the pressure of electroweak matter at high temperatures (the full expression of the perturbative expansion of the pressure is given in the appendix) and the electroweak phase diagram at finite chemical potentials. Finally, we compare electroweak and QCD thermodynamics.

  5. Discrete dark matter

    SciTech Connect (OSTI)

    Hirsch, M.; Morisi, S.; Peinado, E.; Valle, J. W. F. [AHEP Group, Institut de Fisica Corpuscular--C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apartado 22085, E-46071 Valencia (Spain)

    2010-12-01T23:59:59.000Z

    We propose a new motivation for the stability of dark matter (DM). We suggest that the same non-Abelian discrete flavor symmetry which accounts for the observed pattern of neutrino oscillations, spontaneously breaks to a Z{sub 2} subgroup which renders DM stable. The simplest scheme leads to a scalar doublet DM potentially detectable in nuclear recoil experiments, inverse neutrino mass hierarchy, hence a neutrinoless double beta decay rate accessible to upcoming searches, while {theta}{sub 13}=0 gives no CP violation in neutrino oscillations.

  6. Particulate Matter Aerosols

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > TheNuclear Astrophysics OneOutreach EffortsSearchParticulate Matter

  7. Economic Viability of Dynamic Spectrum Management

    E-Print Network [OSTI]

    Huang, Jianwei

    providers, and government regulatory bodies. Providing proper economic incentives for everyone involved, proper economic incentives, and timely policy reforms. DSM is a promising solution to this issue. In DSMEconomic Viability of Dynamic Spectrum Management Jianwei Huang Network Communications

  8. Decision Analysis of Dynamic Spectrum Access Rules

    SciTech Connect (OSTI)

    Juan D. Deaton; Luiz A. DaSilva; Christian Wernz

    2011-12-01T23:59:59.000Z

    A current trend in spectrum regulation is to incorporate spectrum sharing through the design of spectrum access rules that support Dynamic Spectrum Access (DSA). This paper develops a decision-theoretic framework for regulators to assess the impacts of different decision rules on both primary and secondary operators. We analyze access rules based on sensing and exclusion areas, which in practice can be enforced through geolocation databases. Our results show that receiver-only sensing provides insufficient protection for primary and co-existing secondary users and overall low social welfare. On the other hand, using sensing information between the transmitter and receiver of a communication link, provides dramatic increases in system performance. The performance of using these link end points is relatively close to that of using many cooperative sensing nodes associated to the same access point and large link exclusion areas. These results are useful to regulators and network developers in understanding in developing rules for future DSA regulation.

  9. The vibrational Raman spectrum of CS?

    E-Print Network [OSTI]

    Ballard, Harold Noble

    1950-01-01T23:59:59.000Z

    THE VIBRATIONAL RAMAN SPECTRUM OF CSp A Thesis By HAROLD NOBLE BALLARD Approved as to style and content by Chairman o| Committee THE VIBRATIONAL RAMAN SPECTRUM OF CS2 HAROLD NOBLE BALLARD A Thesis Suhmitted to the Graduate School... in the procurement of necessary equipment. SECTION I: INTRODUCTION. SECTION II: CLASSICAL THEORY OF RAHAM SCATTERING . SECTION III: THEORY OF NORMAL VIBRATIONS AND VIBRATIONAL WAVE EQUATIONS. A, Morsel Vibrations B. Vibrational Wave Eqnation and lhergy Levels...

  10. Axion isocurvature fluctuations with extremely blue spectrum

    SciTech Connect (OSTI)

    Kasuya, Shinta [Department of Information Science, Kanagawa University, Kanagawa 259-1293 (Japan); Kawasaki, Masahiro [Institute for Cosmic Ray Research, University of Tokyo, Chiba 277-8582 (Japan); Institute for the Physics and Mathematics of the Universe, University of Tokyo, Chiba 277-8582 (Japan)

    2009-07-15T23:59:59.000Z

    We construct an axion model for generating isocurvature fluctuations with blue spectrum, n{sub iso}=2-4, which is suggested by recent analyses of admixture of adiabatic and isocurvature perturbations with independent spectral indices, n{sub ad}{ne}n{sub iso}. The distinctive feature of the model is that the spectrum is blue at large scales while scale invariant at small scales. This is naturally realized by the dynamics of the Peccei-Quinn scalar field.

  11. Annihilation vs. decay: constraining dark matter properties from a gamma-ray detection

    SciTech Connect (OSTI)

    Palomares-Ruiz, Sergio [Centro de Física Teórica de Partículas, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Siegal-Gaskins, Jennifer M., E-mail: sergio.palomares.ruiz@ist.utl.pt, E-mail: jsg@mps.ohio-state.edu [Center for Cosmology and AstroParticle Physics, The Ohio State University, 191 W. Woodruff Ave., Columbus OH 43210 (United States)

    2010-07-01T23:59:59.000Z

    Most proposed dark matter candidates are stable and are produced thermally in the early Universe. However, there is also the possibility of unstable (but long-lived) dark matter, produced thermally or otherwise. We propose a strategy to distinguish between dark matter annihilation and/or decay in the case that a clear signal is detected in gamma-ray observations of Milky Way dwarf spheroidal galaxies with gamma-ray experiments. The sole measurement of the energy spectrum of an indirect signal would render the discrimination between these cases impossible. We show that by examining the dependence of the intensity and energy spectrum on the angular distribution of the emission, the origin could be identified as decay, annihilation, or both. In addition, once the type of signal is established, we show how these measurements could help to extract information about the dark matter properties, including mass, annihilation cross section, lifetime, dominant annihilation and decay channels, and the presence of substructure. Although an application of the approach presented here would likely be feasible with current experiments only for very optimistic dark matter scenarios, the improved sensitivity of upcoming experiments could enable this technique to be used to study a wider range of dark matter models.

  12. Nuclear Matter and Nuclear Dynamics

    E-Print Network [OSTI]

    M Colonna

    2009-02-26T23:59:59.000Z

    Highlights on the recent research activity, carried out by the Italian Community involved in the "Nuclear Matter and Nuclear Dynamics" field, will be presented.

  13. Ion Distribution And Electronic Stopping Power For Au ions In...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    power for heavy ions in light targets is highly desired due to the large errors in prediction by the widely used Stopping and Range of Ions in Matter (SRIM) code. In this study,...

  14. Technique Recovers Atomic Resolution in Spectrum Images | ornl...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in Spectrum Images April 08, 2015 Raw Fe L-shell spectrum image data, which indicate magnetic properties of the material, were acquired using scanning transmission electron...

  15. BINGO: A code for the efficient computation of the scalar bi-spectrum

    E-Print Network [OSTI]

    Dhiraj Kumar Hazra; L. Sriramkumar; Jerome Martin

    2013-05-18T23:59:59.000Z

    We present a new and accurate Fortran code, the BI-spectra and Non-Gaussianity Operator (BINGO), for the efficient numerical computation of the scalar bi-spectrum and the non-Gaussianity parameter f_{NL} in single field inflationary models involving the canonical scalar field. The code can calculate all the different contributions to the bi-spectrum and the parameter f_{NL} for an arbitrary triangular configuration of the wavevectors. Focusing firstly on the equilateral limit, we illustrate the accuracy of BINGO by comparing the results from the code with the spectral dependence of the bi-spectrum expected in power law inflation. Then, considering an arbitrary triangular configuration, we contrast the numerical results with the analytical expression available in the slow roll limit, for, say, the case of the conventional quadratic potential. Considering a non-trivial scenario involving deviations from slow roll, we compare the results from the code with the analytical results that have recently been obtained in the case of the Starobinsky model in the equilateral limit. As an immediate application, we utilize BINGO to examine of the power of the non-Gaussianity parameter f_{NL} to discriminate between various inflationary models that admit departures from slow roll and lead to similar features in the scalar power spectrum. We close with a summary and discussion on the implications of the results we obtain.

  16. Full Spectrum Light Therapy Full spectrum light bulbs are said to not only improve mood, but also

    E-Print Network [OSTI]

    Bates, Rebecca A.

    Full Spectrum Light Therapy Full spectrum light bulbs are said to not only improve mood, but also spectrum light bulbs produce light that is seen by the human eye in a bluish-white tint. Where is full

  17. Effective temperature and glassy dynamics of active matter

    E-Print Network [OSTI]

    Shenshen Wang; Peter G. Wolynes

    2011-06-10T23:59:59.000Z

    A systematic expansion of the many-body master equation for active matter, in which motors power configurational changes as in the cytoskeleton, is shown to yield a description of the steady state and responses in terms of an effective temperature. The effective temperature depends on the susceptibility of the motors and a Peclet number which measures their strength relative to thermal Brownian diffusion. The analytic prediction is shown to agree with previous numerical simulations and experiments. The mapping also establishes a description of aging in active matter that is also kinetically jammed.

  18. Orthogonal Technicolor with Isotriplet Dark Matter on the Lattice

    E-Print Network [OSTI]

    Ari Hietanen; Claudio Pica; Francesco Sannino; Ulrik Ishøj Søndergaard

    2012-11-21T23:59:59.000Z

    We study the gauge dynamics of an SO(4)-gauge theory with two Dirac Wilson fermions transforming according to the vector representation of the gauge group. We determine the lattice phase diagram by locating the strong coupling bulk phase transition line and the zero PCAC mass line. We present results for the spectrum of the theory. In particular we measure the pseudoscalar, vector and axial meson masses. The data are consistent with a chiral symmetry breaking scenario rather than a conformal one. When used to break the electroweak symmetry dynamically the model leads to a natural dark matter candidate.

  19. Gamma-ray boxes from axion-mediated dark matter

    SciTech Connect (OSTI)

    Ibarra, Alejandro; Gehler, Sergio López; Pato, Miguel [Physik-Department T30d, Technische Universität München, James-Franck-Strasse, 85748 Garching (Germany); Lee, Hyun Min; Park, Wan-Il, E-mail: ibarra@tum.de, E-mail: hyun.min.lee@cern.ch, E-mail: sergio.lopez@ph.tum.de, E-mail: wipark@kias.re.kr, E-mail: miguel.pato@tum.de [School of Physics, KIAS, Seoul 130-722 (Korea, Republic of)

    2013-05-01T23:59:59.000Z

    We compute the gamma-ray output of axion-mediated dark matter and derive the corresponding constraints set by recent data. In such scenarios the dark matter candidate is a Dirac fermion that pair-annihilates into axions and/or scalars. Provided that the axion decays (at least partly) into photons, these models naturally give rise to a box-shaped gamma-ray spectrum that may present two distinct phenomenological behaviours: a narrow box, resembling a line at half the dark matter mass, or a wide box, spanning an extensive energy range up to the dark matter mass. Remarkably, we find that in both cases a sizable gamma-ray flux is predicted for a thermal relic without fine-tuning the model parameters nor invoking boost factors. This large output is in line with recent Fermi-LAT observations towards the galactic centre region and is on the verge of being excluded. We then make use of the Fermi-LAT and H.E.S.S. data to derive robust, model-independent upper limits on the dark matter annihilation cross section for the narrow and wide box scenarios. H.E.S.S. constraints, in particular, turn out to match the ones from Fermi-LAT at hundreds of GeV and extend to multi-TeV masses. Future ?erenkov telescopes will likely probe gamma-ray boxes from thermal dark matter relics in the whole multi-TeV range, a region hardly accessible to direct detection, collider searches and other indirect detection strategies.

  20. (submitted, August 4, 2009) Network-state modulation of power-law frequency-scaling

    E-Print Network [OSTI]

    Bal, Thierry

    of activity distributed across large assemblies. They share in common a power-law frequency-scaling structure density of Vm activity displays a power-law structure at high frequencies, with a frac- tional scaling of correlation, often man- ifested through power-law scaling behaviour. In such systems, the power spectrum

  1. Power-Law and Long-Memory Characteristics of the Atmospheric General Circulation DMITRY I. VYUSHIN AND PAUL J. KUSHNER

    E-Print Network [OSTI]

    Power-Law and Long-Memory Characteristics of the Atmospheric General Circulation DMITRY I. VYUSHIN memory'' or ``power-law'' model. Such a model fits a temporal spectrum to a single power-law function, which thereby accumulates more power at lower frequencies than an AR1 fit. In this study, several power

  2. Comparing Predictive Power in Climate Data: Clustering Matters

    E-Print Network [OSTI]

    Chawla, Nitesh V.

    . Chawla1 , and Auroop R. Ganguly2 1 Department of Computer Science and Engineering, Interdisciplinary-Mail: {ksteinha,nchawla}@nd.edu 2 Computational Sciences and Engineering Division, Oak Ridge National Laboratory with field data (which can be costly or even impossible to acquire). Here we focus on one particular task

  3. The Power of Efficiency: Why Momentum Savings Really Do Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in the Earth's LowerFacility |The

  4. Charmonium mass in nuclear matter

    E-Print Network [OSTI]

    Lee, S. H.; Ko, Che Ming.

    2003-01-01T23:59:59.000Z

    The mass shift of charmonium states in nuclear matter is studied in the perturbative QCD approach. The leading-order effect due to the change of gluon condensate in nuclear matter is evaluated using the leading-order QCD formula, while the higher...

  5. Astronomical Evidence for Dark Matter

    E-Print Network [OSTI]

    Golwala, Sunil

    weapon in "Quake 4" is the Dark Matter Gun. In Futurama they use dark matter fuel, where "one pound is 10 and neutrons, can compute relative ratio. Using nuclear reaction rates, can compute relative abundances oscillations). Peak is from maximal compression of photon-baryon fluid. Peak sensitive to curvature

  6. Energy Matters in Washington State

    E-Print Network [OSTI]

    Collins, Gary S.

    Energy Matters in Washington State Energy Matters in Washington State www.energy.wsu.edu/library/ November 2009 #12;905 Plum Street SE, Building 3 P.O. Box 43169 Olympia, Washington 98504-3169 Energy University Extension Energy Program. 905 Plum Street SE, Building 3, P.O. Box 43169, Olympia, Washington

  7. Nuclear Power

    E-Print Network [OSTI]

    Vilhena and Bardo E.J. Bodmann Carbon-#1;? in Terrestrial and Aquatic Environment of Ignalina Nuclear Power Plant: Sources of Production, Releases and Dose Estimates #3;?? Jonas Mazeika Impact of radionuclide discharges from Temel?n Nuclear Power... (chapter 5), ? Instrumentation and control (chapter 6), ? Diagnostics (chapter 7), ? Safety evaluation methods (chapters 6, 8, 9 and 10), ? Environment and nuclear power plants (chapters 11 - 15), ? Human factors (chapter 16), ? Software development...

  8. Quantum vacuum and dark matter

    E-Print Network [OSTI]

    Dragan Slavkov Hajdukovic

    2011-11-21T23:59:59.000Z

    Recently, the gravitational polarization of the quantum vacuum was proposed as alternative to the dark matter paradigm. In the present paper we consider four benchmark measurements: the universality of the central surface density of galaxy dark matter haloes, the cored dark matter haloes in dwarf spheroidal galaxies, the non-existence of dark disks in spiral galaxies and distribution of dark matter after collision of clusters of galaxies (the Bullet cluster is a famous example). Only some of these phenomena (but not all of them) can (in principle) be explained by the dark matter and the theories of modified gravity. However, we argue that the framework of the gravitational polarization of the quantum vacuum allows the understanding of the totality of these phenomena.

  9. Power LCAT

    ScienceCinema (OSTI)

    Drennen, Thomas

    2014-06-27T23:59:59.000Z

    POWER LCAT is a software tool used to compare elements of efficiency, cost, and environmental effects between different sources of energy.

  10. Power LCAT

    SciTech Connect (OSTI)

    Drennen, Thomas

    2012-08-15T23:59:59.000Z

    POWER LCAT is a software tool used to compare elements of efficiency, cost, and environmental effects between different sources of energy.

  11. Simplified Dark Matter Models for the Galactic Center Gamma-Ray Excess

    SciTech Connect (OSTI)

    Berlin, Asher; Hooper, Dan; McDermott, Samuel D.

    2014-06-01T23:59:59.000Z

    Motivated by the gamma-ray excess observed from the region surrounding the Galactic Center, we explore particle dark matter models that could potentially account for the spectrum and normalization of this signal. Taking a model-independent approach, we consider an exhaustive list of tree-level diagrams for dark matter annihilation, and determine which could account for the observed gamma-ray emission while simultaneously predicting a thermal relic abundance equal to the measured cosmological dark matter density. We identify a wide variety of models that can meet these criteria without conflicting with existing constraints from direct detection experiments or the Large Hadron Collider (LHC). The prospects for detection in near future dark matter experiments and/or the upcoming 14 TeV LHC appear quite promising.

  12. Educating Michigan's Students with Autism Spectrum Disorder: Educating Michigan's Students with Autism Spectrum Disorder (ASD)

    E-Print Network [OSTI]

    Liu, Taosheng

    1 Educating Michigan's Students with Autism Spectrum Disorder: Educating Michigan's Students with Autism Spectrum Disorder (ASD): An Initial Exploration of Programming "The ASD-Michigan Project" August 3, 2011 Final Report Sara Bolt, Ph.D. and Summer Ferreri, Ph.D. College of Education Michigan State

  13. Emergent irreversibility and entanglement spectrum statistics

    E-Print Network [OSTI]

    Claudio Chamon; Alioscia Hamma; Eduardo R. Mucciolo

    2014-06-24T23:59:59.000Z

    We study the problem of irreversibility when the dynamical evolution of a many-body system is described by a stochastic quantum circuit. Such evolution is more general than a Hamiltonian one, and since energy levels are not well defined, the well-established connection between the statistical fluctuations of the energy spectrum and irreversibility cannot be made. We show that the entanglement spectrum provides a more general connection. Irreversibility is marked by a failure of a disentangling algorithm and is preceded by the appearance of Wigner-Dyson statistical fluctuations in the entanglement spectrum. This analysis can be done at the wave-function level and offers an alternative route to study quantum chaos and quantum integrability.

  14. Analytical energy spectrum for hybrid mechanical systems

    E-Print Network [OSTI]

    Honghua Zhong; Qiongtao Xie; Xiwen Guan; Murray T. Batchelor; Kelin Gao; Chaohong Lee

    2013-11-07T23:59:59.000Z

    We investigate the energy spectrum for hybrid mechanical systems described by non-parity-symmetric quantum Rabi models. A set of analytical solutions in terms of the confluent Heun functions and their analytical energy spectrum are obtained. The analytical energy spectrum includes regular and exceptional parts, which are both confirmed by direct numerical simulation. The regular part is determined by the zeros of the Wronskian for a pair of analytical solutions. The exceptional part is relevant to the isolated exact solutions and its energy eigenvalues are obtained by analyzing the truncation conditions for the confluent Heun functions. By analyzing the energy eigenvalues for exceptional points, we obtain the analytical conditions for the energy-level-crossings, which correspond to two-fold energy degeneracy.

  15. The QCD spectrum with three quark flavors

    E-Print Network [OSTI]

    Claude Bernard; Tom Burch; Thomas A. DeGrand; Saumen Datta; Carleton DeTar; Steven Gottlieb; Urs M. Heller; Kostas Orginos; Robert Sugar; Doug Toussaint

    2001-05-29T23:59:59.000Z

    We present results from a lattice hadron spectrum calculation using three flavors of dynamical quarks - two light and one strange, and quenched simulations for comparison. These simulations were done using a one-loop Symanzik improved gauge action and an improved Kogut-Susskind quark action. The lattice spacings, and hence also the physical volumes, were tuned to be the same in all the runs to better expose differences due to flavor number. Lattice spacings were tuned using the static quark potential, so as a byproduct we obtain updated results for the effect of sea quarks on the static quark potential. We find indications that the full QCD meson spectrum is in better agreement with experiment than the quenched spectrum. For the 0++ (a0) meson we see a coupling to two pseudoscalar mesons, or a meson decay on the lattice.

  16. Dynamic Spectrum Management for Green DSL

    E-Print Network [OSTI]

    to a power-rate-complexity trade-off. EDICS: SPC-TDLS Telephone networks and digital subscriber loops SPC

  17. Gravitational wave energy spectrum of hyperbolic encounters

    E-Print Network [OSTI]

    Lorenzo De Vittori; Philippe Jetzer; Antoine Klein

    2012-07-23T23:59:59.000Z

    The emission of gravitational waves is studied for a system of massive objects interacting on hyperbolic orbits within the quadrupole approximation following the work of Capozziello et al. Here we focus on the derivation of an analytic formula for the energy spectrum of the emitted waves. We checked numerically that our formula is in agreement with the two limiting cases for which results were already available: for the eccentricity {\\epsilon} = 1, the parabolic case whose spectrum was computed by Berry and Gair, and the large {\\epsilon} limit with the formula given by Turner.

  18. Gravitational wave energy spectrum of hyperbolic encounters

    E-Print Network [OSTI]

    De Vittori, Lorenzo; Klein, Antoine

    2012-01-01T23:59:59.000Z

    The emission of gravitational waves is studied for a system of massive objects interacting on hyperbolic orbits within the quadrupole approximation following the work of Capozziello et al. Here we focus on the derivation of an analytic formula for the energy spectrum of the emitted waves. We checked numerically that our formula is in agreement with the two limiting cases for which results were already available: for the eccentricity {\\epsilon} = 1, the parabolic case whose spectrum was computed by Berry and Gair, and the large {\\epsilon} limit with the formula given by Turner.

  19. Methods and apparatuses using filter banks for multi-carrier spread-spectrum signals

    DOE Patents [OSTI]

    Moradi, Hussein; Farhang, Behrouz; Kutsche, Carl A

    2014-10-14T23:59:59.000Z

    A transmitter includes a synthesis filter bank to spread a data symbol to a plurality of frequencies by encoding the data symbol on each frequency, apply a common pulse-shaping filter, and apply gains to the frequencies such that a power level of each frequency is less than a noise level of other communication signals within the spectrum. Each frequency is modulated onto a different evenly spaced subcarrier. A demodulator in a receiver converts a radio frequency input to a spread-spectrum signal in a baseband. A matched filter filters the spread-spectrum signal with a common filter having characteristics matched to the synthesis filter bank in the transmitter by filtering each frequency to generate a sequence of narrow pulses. A carrier recovery unit generates control signals responsive to the sequence of narrow pulses suitable for generating a phase-locked loop between the demodulator, the matched filter, and the carrier recovery unit.

  20. Methods and apparatuses using filter banks for multi-carrier spread-spectrum signals

    DOE Patents [OSTI]

    Moradi, Hussein; Farhang, Behrouz; Kutsche, Carl A

    2014-05-20T23:59:59.000Z

    A transmitter includes a synthesis filter bank to spread a data symbol to a plurality of frequencies by encoding the data symbol on each frequency, apply a common pulse-shaping filter, and apply gains to the frequencies such that a power level of each frequency is less than a noise level of other communication signals within the spectrum. Each frequency is modulated onto a different evenly spaced subcarrier. A demodulator in a receiver converts a radio frequency input to a spread-spectrum signal in a baseband. A matched filter filters the spread-spectrum signal with a common filter having characteristics matched to the synthesis filter bank in the transmitter by filtering each frequency to generate a sequence of narrow pulses. A carrier recovery unit generates control signals responsive to the sequence of narrow pulses suitable for generating a phase-locked loop between the demodulator, the matched filter, and the carrier recovery unit.

  1. Tailoring the Neutron Spectrum from a 14-MeV Neutron Generator to Approximate a Spontaneous-Fission Spectrum

    SciTech Connect (OSTI)

    James Simpson; David Chichester

    2011-06-01T23:59:59.000Z

    Many applications of neutrons for non-invasive measurements began with isotopic sources such as AmBe or Cf-252. Political factors have rendered AmBe undesirable in the United States and other countries, and the supply of Cf-252 is limited and significantly increasing in price every few years. Compact and low-power deuterium-tritium (DT) electronic neutron generators can often provide sufficient flux, but the 14-MeV neutron spectrum is much more energetic (harder) than an isotopic neutron source. A series of MCNP simulations were run to examine the extent to which the 14-MeV DT neutron spectrum could be softened through the use of high-Z and low-Z materials. Some potential concepts of operation require a portable neutron generator system, so the additional weight of extra materials is also a trade-off parameter. Using a reference distance of 30 cm from the source, the average neutron energy can be lowered to be less than that of either AmBe or Cf-252, while obtaining an increase in flux at the reference distance compared to a bare neutron generator. This paper discusses the types and amounts of materials used, the resulting neutron spectra, neutron flux levels, and associated photon production.

  2. Power system

    DOE Patents [OSTI]

    Hickam, Christopher Dale (Glasford, IL)

    2008-03-18T23:59:59.000Z

    A power system includes a prime mover, a transmission, and a fluid coupler having a selectively engageable lockup clutch. The fluid coupler may be drivingly connected between the prime mover and the transmission. Additionally, the power system may include a motor/generator drivingly connected to at least one of the prime mover and the transmission. The power-system may also include power-system controls configured to execute a control method. The control method may include selecting one of a plurality of modes of operation of the power system. Additionally, the control method may include controlling the operating state of the lockup clutch dependent upon the mode of operation selected. The control method may also include controlling the operating state of the motor/generator dependent upon the mode of operation selected.

  3. Laser Driven Dynamic Loading of Condensed Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Laser Driven Dynamic Loading of Condensed Matter Laser Driven Dynamic Loading of Condensed Matter Advanced diagnostics of experiments covering many orders of magnitude in strain...

  4. Can unstable relics save pure Cold Dark Matter?

    E-Print Network [OSTI]

    A. Masiero; D. Montanino; M. Peloso

    1999-08-02T23:59:59.000Z

    The standard CDM model fails to describe the power spectrum of fluctuations since it gives too much power at small scales. Among other possible improvements, it has been suggested that an agreement with observations can be achieved with the addition of a late decaying particle, through the injection of non-thermal radiation and the consequent increase of the horizon length at the equivalence time. We analyze the possibility of implementing this idea in some extensions of the electroweak standard model, discussing the cosmological and astrophysical bounds to which these schemes are subject.

  5. The Energy of Charged Matter

    E-Print Network [OSTI]

    Jan Philip Solovej

    2004-06-07T23:59:59.000Z

    In this talk I will discuss some of the techniques that have been developed over the past 35 years to estimate the energy of charged matter. These techniques have been used to solve stability of (fermionic) matter in different contexts, and to control the instability of charged bosonic matter. The final goal will be to indicate how these techniques with certain improvements can be used to prove Dyson's 1967 conjecture for the energy of a charged Bose gas--the sharp $N^{7/5}$ law.

  6. The Unification and Cogeneration of Dark Matter and Baryonic Matter

    E-Print Network [OSTI]

    S. M. Barr

    2011-09-18T23:59:59.000Z

    In grand unified theories with gauge groups larger than SU(5), the multiplets that contain the known quarks and leptons also contain fermions that are singlets under the Standard Model gauge group. Some of these could be the dark matter of the universe. Grand unified theories can also have accidental U(1) global symmetries (analogous to B-L in minimal SU(5)) that can stabilize dark matter. These ideas are illustrated in an SU(6) model.

  7. The Unification and Cogeneration of Dark Matter and Baryonic Matter

    E-Print Network [OSTI]

    Barr, S M

    2011-01-01T23:59:59.000Z

    In grand unified theories with gauge groups larger than SU(5), the multiplets that contain the known quarks and leptons also contain fermions that are singlets under the Standard Model gauge group. Some of these could be the dark matter of the universe. Grand unified theories can also have accidental U(1) global symmetries (analogous to B-L in minimal SU(5)) that can stabilize dark matter. These ideas are illustrated in an SU(6) model.

  8. Green Wireless Cognition: Future Efficient Spectrum Sharing

    E-Print Network [OSTI]

    Shihada, Basem

    Underwater Vehicles The project aims to develop an unmanned fully autonomous under water vehicles (UWV Spectrum Wireless Sensor in Underwater Networks * Bell's Law of Computer Classes formulated by Gordon Bell the challenges of underwater communications by an integration of sensor and multihop networks. Human

  9. Adaptive, full-spectrum solar energy system

    DOE Patents [OSTI]

    Muhs, Jeffrey D.; Earl, Dennis D.

    2003-08-05T23:59:59.000Z

    An adaptive full spectrum solar energy system having at least one hybrid solar concentrator, at least one hybrid luminaire, at least one hybrid photobioreactor, and a light distribution system operably connected to each hybrid solar concentrator, each hybrid luminaire, and each hybrid photobioreactor. A lighting control system operates each component.

  10. The hadron spectrum from lattice QCD

    SciTech Connect (OSTI)

    Peardon, Mike [School of Mathematics, Trinity College Dublin (Ireland)

    2010-08-05T23:59:59.000Z

    Lattice spectroscopy is becoming increasingly sophisticated. This review will introduce the methodology and describe progress made recently probing the spectrum of excitations of QCD. The focus will be on describing new developments that enable excited states, exotic quantum numbers and resonances to be explored.

  11. Strathclyde powerS ahead

    E-Print Network [OSTI]

    Mottram, Nigel

    Strathclyde powerS ahead the future of renewable energy SHARING AND ENHANCING RESEARCH Discover the vision of Principal Professor Jim McDonald THE FUTURE OF ENERGY Strathclyde pioneers renewableEdicinE Snapshot the reSearcher Following a decade of environmental research in her native egypt, nabila saleem

  12. Red and blue tilted tensor spectrum from Gibbons-Hawking temperature

    E-Print Network [OSTI]

    Subhendra Mohanty; Akhilesh Nautiyal

    2015-01-09T23:59:59.000Z

    The scale invariant scalar and tensor perturbations, which are predicted from inflation, are eigenmodes in the conformal coordinates. The 'out' observer in the de Sitter space observes a thermal spectrum with a Gibbons-Hawking temperature $H/2\\pi$ of these 'Bunch-Davies' particles. The tensor power spectrum observed in experiments can have an imprint of the Gibbons-Hawking thermal distribution due to the mode mixing between 'in' state conformal coordinates and the coordinate frame of the observer. We find that the the Bunch-Davies modes appear as thermal modes to the asymptotic Minkowski observer in the future and the power spectrum of the gravitational waves is blue-tilted with a spectral index $n_T \\sim 1$ even in the standard slow-roll inflation. On the other hand if the coordinate frame of the observer is taken to be static coordinates, the tensor spectrum is red-tilted with $n_T\\sim -1$. A likelihood analysis shows and find the best fit values of the slow-roll parameters for both cases. We find that the blue-tilted tensor gives a better fit and reconciles the PLANCK upper bound on the tensor-to-scalar ratio, $r <0.11$ with BICEP2 measurement of $r=0.2$. This supports the idea of particle production due to the mode mixing between the initial Bunch-Davies vacuum modes and the asymptotic Minkowski vacuum of the post-inflation universe.

  13. On the Moduli Space of SU(3) Seiberg-Witten Theory with Matter

    E-Print Network [OSTI]

    Brett J. Taylor

    2002-11-20T23:59:59.000Z

    We present a qualitative model of the Coulomb branch of the moduli space of low-energy effective N=2 SQCD with gauge group SU(3) and up to five flavours of massive matter. Overall, away from double cores, we find a situation broadly similar to the case with no matter, but with additional complexity due to the proliferation of extra BPS states. We also include a revised version of the pure SU(3) model which can accommodate just the orthodox weak coupling spectrum.

  14. Reducing cosmological small scale structure via a large dark matter-neutrino interaction: constraints and consequences

    E-Print Network [OSTI]

    Bridget Bertoni; Seyda Ipek; David McKeen; Ann E. Nelson

    2014-12-09T23:59:59.000Z

    Cold dark matter explains a wide range of data on cosmological scales. However, there has been a steady accumulation of evidence for discrepancies between simulations and observations at scales smaller than galaxy clusters. Solutions to these small scale structure problems may indicate that simulations need to improve how they include feedback from baryonic matter, or may imply that dark matter properties differ from the standard cold, noninteracting scenario. One promising way to affect structure formation on small scales is a relatively strong coupling of dark matter to neutrinos. We construct an experimentally viable, simple, renormalizable, model with new interactions between neutrinos and dark matter. We show that addressing the small scale structure problems requires dark matter with a mass that is tens of MeV, and a present-day density determined by an initial particle-antiparticle asymmetry in the dark sector. Generating a sufficiently large dark matter-neutrino coupling requires a new heavy neutrino with a mass around 100 MeV. The heavy neutrino is mostly sterile but has a substantial $\\tau$ neutrino component, while the three nearly massless neutrinos are partly sterile. We provide the first discussion of how such dark matter-neutrino interactions affect neutrino (especially $\\tau$ neutrino) phenomenology. This model can be tested by future astrophysical, particle physics, and neutrino oscillation data. A feature in the neutrino energy spectrum and flavor content from a future nearby supernova would provide strong evidence of neutrino-dark matter interactions. Promising signatures include anomalous matter effects in neutrino oscillations due to nonstandard interactions and a component of the $\\tau$ neutrino with mass around 100 MeV.

  15. Influence of Dark Matter on Light Propagation in Solar System

    E-Print Network [OSTI]

    Hideyoshi Arakida

    2009-11-17T23:59:59.000Z

    We investigated the influence of dark matter on light propagation in the solar system. We assumed the spherical symmetry of spacetime and derived the approximate solution of the Einstein equation, which consists of the gravitational attractions caused by the central celestial body, i.e. the Sun, and the dark matter surrounding it. We expressed the dark matter density in the solar system in the following simple power-law form, $\\varrho(t, r) = \\rho(t)(\\ell/r)^k$, where $t$ is the coordinate time; $r$, the radius from the central body; $\\ell$, the normalizing factor; $k$, the exponent characterizing $r$-dependence of dark matter density; and $\\rho(t)$, the arbitrary function of time $t$. On the basis of the derived approximate solution, we focused on light propagation and obtained the additional corrections of the gravitational time delay and the relative frequency shift caused by the dark matter. As an application of our results, we considered the secular increase in the astronomical unit reported by Krasinsky and Brumberg (2004) and found that it was difficult to provide an explanation for the observed $d{\\rm AU}/dt = 15 \\pm 4 ~[{\\rm m/century}]$.

  16. Distribution and Structure of Matter in and around Galaxies

    E-Print Network [OSTI]

    Schulz, Norbert S; Bautz, Mark W; Canizares, Claude C; Davis, John; Dewey, Dan; Huenemoerder, David P; Heilmann, Ralf; Houck, John; Marshall, Herman L; Nowak, Mike; Schattenburg, Mark; Bregman, Joel; Diaz-Trigo, Maria; Fang, Taotao; Gagne, Marc; Kallman, Tim; Lautenegger, Maurice; Lee, Julia; Miller, Jon; Mukai, Koji; Parerels, Frits; Pollock, Andy; Rasmussen, Andy; Raymond, John; Smith, Randall; Yao, Yangsen

    2009-01-01T23:59:59.000Z

    Understanding the origins and distribution of matter in the Universe is one of the most important quests in physics and astronomy. Themes range from astro-particle physics to chemical evolution in the Galaxy to cosmic nucleosynthesis and chemistry in an anticipation of a full account of matter in the Universe. Studies of chemical evolution in the early Universe will answer questions about when and where the majority of metals were formed, how they spread and why they appar today as they are. The evolution of matter in our Universe cannot be characterized as a simple path of development. In fact the state of matter today tells us that mass and matter is under constant reformation through on-going star formation, nucleosynthesis and mass loss on stellar and galactic scales. X-ray absorption studies have evolved in recent years into powerful means to probe the various phases of interstellar and intergalactic media. Future observatories such as IXO and Gen-X will provide vast new opportunities to study structure ...

  17. Physical Protection of Classified Matter

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1988-02-03T23:59:59.000Z

    The order establishes policy and objectives for physical protection of classified matter. This directive does not cancel another directive. Chg 1, 7-30-93. Canceled by 5632.1C.

  18. The Cold Dark Matter Search test stand warm electronics card

    SciTech Connect (OSTI)

    Hines, Bruce; /Colorado U., Denver; Hansen, Sten; /Fermilab; Huber, Martin; /Colorado U., Denver; Kiper, Terry; /Fermilab; Rau, Wolfgang; /Queen's U., Kingston; Saab, Tarek; /Florida U.; Seitz, Dennis; Sundqvist, Kyle; /UC, Berkeley; Mandic, Vuk; /Minnesota U.

    2010-11-01T23:59:59.000Z

    A card which does the signal processing for four SQUID amplifiers and two charge sensitive channels is described. The card performs the same functions as is presently done with two custom 9U x 280mm Eurocard modules, a commercial multi-channel VME digitizer, a PCI to GPIB interface, a PCI to VME interface and a custom built linear power supply. By integrating these functions onto a single card and using the power over Ethernet standard, the infrastructure requirements for instrumenting a Cold Dark Matter Search (CDMS) detector test stand are significantly reduced.

  19. Power spectra of outflow-driven turbulence

    E-Print Network [OSTI]

    Moraghan, Anthony; Yoon, Suk-Jin

    2015-01-01T23:59:59.000Z

    We investigate the power spectra of outflow-driven turbulence through high-resolution three-dimensional isothermal numerical simulations where the turbulence is driven locally in real-space by a simple spherical outflow model. The resulting turbulent flow saturates at an average Mach number of ~2.5 and is analysed through density and velocity power spectra, including an investigation of the evolution of the solenoidal and compressional components. We obtain a shallow density power spectrum with a slope of ~-1.2 attributed to the presence of a network of localised dense filamentary structures formed by strong shock interactions. The total velocity power spectrum slope is found to be ~-2.0, representative of Burgers shock dominated turbulence model. The density weighted velocity power spectrum slope is measured as ~-1.6, slightly less than the expected Kolmogorov scaling value (slope of -5/3) found in previous works. The discrepancy may be caused by the nature of our real space driving model and we suggest ther...

  20. Cosmology, Thermodynamics and Matter Creation

    E-Print Network [OSTI]

    J. A. S. Lima; M. O. Calvao; I. Waga

    2007-08-24T23:59:59.000Z

    Several approaches to the matter creation problem in the context of cosmological models are summarily reviewed. A covariant formulation of the general relativistic imperfect simple fluid endowed with a process of matter creation is presented. By considering the standard big bang model, it is shown how the recent results of Prigogine et alii \\cite{1} can be recovered and, at the same time their limits of validity are explicited.

  1. ?CDM cosmology from matter only

    E-Print Network [OSTI]

    Herman Telkamp

    2015-04-08T23:59:59.000Z

    I discuss a matter-only interpretation of {\\Lambda}CDM cosmology, based on conservation of energy and assuming a Machian definition of inertia. {\\Lambda}CDM cosmology can be linked to a Newtonian cosmic potential, subject to a propagating gravitational horizon. In a matter-only universe where total energy is conserved, Machian inertia related to the evolving potential may cause both deceleration and acceleration of recession.

  2. Shear viscosity of nuclear matter

    E-Print Network [OSTI]

    Jun Xu

    2013-02-01T23:59:59.000Z

    In this talk I report my recent study on the shear viscosity of neutron-rich nuclear matter from a relaxation time approach. An isospin- and momentum-dependent interaction is used in the study. Effects of density, temperature, and isospin asymmetry of nuclear matter on its shear viscosity have been discussed. Similar to the symmetry energy, the symmetry shear viscosity is defined and its density and temperature dependence are studied.

  3. Dark Matter Triggers of Supernovae

    E-Print Network [OSTI]

    Peter W. Graham; Surjeet Rajendran; Jaime Varela

    2015-05-17T23:59:59.000Z

    The transit of primordial black holes through a white dwarf causes localized heating around the trajectory of the black hole through dynamical friction. For sufficiently massive black holes, this heat can initiate runaway thermonuclear fusion causing the white dwarf to explode as a supernova. The shape of the observed distribution of white dwarfs with masses up to $1.25 M_{\\odot}$ rules out primordial black holes with masses $\\sim 10^{19}$ gm - $10^{20}$ gm as a dominant constituent of the local dark matter density. Black holes with masses as large as $10^{24}$ gm will be excluded if recent observations by the NuStar collaboration of a population of white dwarfs near the galactic center are confirmed. Black holes in the mass range $10^{20}$ gm - $10^{22}$ gm are also constrained by the observed supernova rate, though these bounds are subject to astrophysical uncertainties. These bounds can be further strengthened through measurements of white dwarf binaries in gravitational wave observatories. The mechanism proposed in this paper can constrain a variety of other dark matter scenarios such as Q balls, annihilation/collision of large composite states of dark matter and models of dark matter where the accretion of dark matter leads to the formation of compact cores within the star. White dwarfs, with their astronomical lifetimes and sizes, can thus act as large space-time volume detectors enabling a unique probe of the properties of dark matter, especially of dark matter candidates that have low number density. This mechanism also raises the intriguing possibility that a class of supernova may be triggered through rare events induced by dark matter rather than the conventional mechanism of accreting white dwarfs that explode upon reaching the Chandrasekhar mass.

  4. Power combiner

    DOE Patents [OSTI]

    Arnold, Mobius; Ives, Robert Lawrence

    2006-09-05T23:59:59.000Z

    A power combiner for the combining of symmetric and asymmetric traveling wave energy comprises a feed waveguide having an input port and a launching port, a reflector for reflecting launched wave energy, and a final waveguide for the collection and transport of launched wave energy. The power combiner has a launching port for symmetrical waves which comprises a cylindrical section coaxial to the feed waveguide, and a launching port for asymmetric waves which comprises a sawtooth rotated about a central axis.

  5. Matter-antimatter asymmetry and dark matter from torsion

    SciTech Connect (OSTI)

    Poplawski, Nikodem J. [Department of Physics, Indiana University, Swain Hall West, 727 East Third Street, Bloomington, Indiana 47405 (United States)

    2011-04-15T23:59:59.000Z

    We propose a simple scenario which explains the observed matter-antimatter imbalance and the origin of dark matter in the Universe. We use the Einstein-Cartan-Sciama-Kibble theory of gravity which naturally extends general relativity to include the intrinsic spin of matter. Spacetime torsion produced by spin generates, in the classical Dirac equation, the Hehl-Datta term which is cubic in spinor fields. We show that under a charge-conjugation transformation this term changes sign relative to the mass term. A classical Dirac spinor and its charge conjugate therefore satisfy different field equations. Fermions in the presence of torsion have higher energy levels than antifermions, which leads to their decay asymmetry. Such a difference is significant only at extremely high densities that existed in the very early Universe. We propose that this difference caused a mechanism, according to which heavy fermions existing in such a Universe and carrying the baryon number decayed mostly to normal matter, whereas their antiparticles decayed mostly to hidden antimatter which forms dark matter. The conserved total baryon number of the Universe remained zero.

  6. The matter in extreme conditions instrument at the Linac Coherent Light Source

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nagler, Bob; Arnold, Brice; Bouchard, Gary; Boyce, Richard F.; Boyce, Richard M.; Callen, Alice; Campell, Marc; Curiel, Ruben; Galtier, Eric; Garofoli, Justin; et al

    2015-05-01T23:59:59.000Z

    The LCLS beam provides revolutionary capabilities for studying the transient behavior of matter in extreme conditions. The particular strength of the Matter in Extreme Conditions instrument is that it combines the unique LCLS beam with high-power optical laser beams, and a suite of dedicated diagnostics tailored for this field of science. In this paper an overview of the beamline, the capabilities of the instrumentation, and selected highlights of experiments and commissioning results are presented.

  7. Cleco Power- Power Miser New Home Program

    Broader source: Energy.gov [DOE]

    Louisiana's Cleco Power offers energy efficiency incentives to eligible customers. Cleco Power offers a rate discount for residential customers building homes that meet the Power Miser Program...

  8. Perturbation spectrum in inflation with cutoff

    E-Print Network [OSTI]

    A. Kempf; J. C. Niemeyer

    2001-09-20T23:59:59.000Z

    It has been pointed out that the perturbation spectrum predicted by inflation may be sensitive to a natural ultraviolet cutoff, thus potentially providing an experimentally accessible window to aspects of Planck scale physics. A priori, a natural ultraviolet cutoff could take any form, but a fairly general classification of possible Planck scale cutoffs has been given. One of those categorized cutoffs, also appearing in various studies of quantum gravity and string theory, has recently been implemented into the standard inflationary scenario. Here, we continue this approach by investigating its effects on the predicted perturbation spectrum. We find that the size of the effect depends sensitively on the scale separation between cutoff and horizon during inflation.

  9. PROSPECT - A precision oscillation and spectrum experiment

    E-Print Network [OSTI]

    ,

    2015-01-01T23:59:59.000Z

    Segmented antineutrino detectors placed near a compact research reactor provide an excellent opportunity to probe short-baseline neutrino oscillations and precisely measure the reactor antineutrino spectrum. Close proximity to a reactor combined with minimal overburden yield a high background environment that must be managed through shielding and detector technology. PROSPECT is a new experimental effort to detect reactor antineutrinos from the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, managed by UT Battelle for the U.S. Department of Energy. The detector will use novel lithium-loaded liquid scintillator capable of neutron/gamma pulse shape discrimination and neutron capture tagging. These enhancements improve the ability to identify neutrino inverse-beta decays and reject background events in analysis. Results from these efforts will be covered along with their implications for an oscillation search and a precision spectrum measurement.

  10. PROSPECT - A precision oscillation and spectrum experiment

    E-Print Network [OSTI]

    T. J. Langford

    2014-12-22T23:59:59.000Z

    Segmented antineutrino detectors placed near a compact research reactor provide an excellent opportunity to probe short-baseline neutrino oscillations and precisely measure the reactor antineutrino spectrum. Close proximity to a reactor combined with minimal overburden yield a high background environment that must be managed through shielding and detector technology. PROSPECT is a new experimental effort to detect reactor antineutrinos from the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, managed by UT Battelle for the U.S. Department of Energy. The detector will use novel lithium-loaded liquid scintillator capable of neutron/gamma pulse shape discrimination and neutron capture tagging. These enhancements improve the ability to identify neutrino inverse-beta decays and reject background events in analysis. Results from these efforts will be covered along with their implications for an oscillation search and a precision spectrum measurement.

  11. Power Spectra to 1% Accuracy between Dynamical Dark Energy Cosmologies

    E-Print Network [OSTI]

    Matthew J. Francis; Geraint F. Lewis; Eric V. Linder

    2007-04-03T23:59:59.000Z

    For dynamical dark energy cosmologies we carry out a series of N-body gravitational simulations, achieving percent level accuracy in the relative mass power spectra at any redshift. Such accuracy in the power spectrum is necessary for next generation cosmological mass probes. Our matching procedure reproduces the CMB distance to last scattering and delivers subpercent level power spectra at z=0 and z~3. We discuss the physical implications for probing dark energy with surveys of large scale structure.

  12. Perturbed Power-law parameters from WMAP7

    E-Print Network [OSTI]

    Minu Joy; Tarun Souradeep

    2010-11-19T23:59:59.000Z

    We present a perturbative approach for studying inflation models with soft departures from scale free spectra of the power law model. In the perturbed power law (PPL) approach one obtains at the leading order both the scalar and tensor power spectra with the running of their spectral indices, in contrast to the widely used slow roll expansion. The PPL spectrum is confronted data and we show that the PPL parameters are well estimated from WMAP-7 data.

  13. Perturbed Power-law parameters from WMAP7

    E-Print Network [OSTI]

    Joy, Minu

    2010-01-01T23:59:59.000Z

    We present a perturbative approach for studying inflation models with soft departures from scale free spectra of the power law model. In the perturbed power law (PPL) approach one obtains at the leading order both the scalar and tensor power spectra with the running of their spectral indices, in contrast to the widely used slow roll expansion. The PPL spectrum is confronted data and we show that the PPL parameters are well estimated from WMAP-7 data.

  14. Reconnection of vortex filaments and Kolmogorov spectrum

    E-Print Network [OSTI]

    Sergey K. Nemirovskii

    2014-04-19T23:59:59.000Z

    The energy spectrum of the 3D velocity field, induced by collapsing vortex filaments is studied. One of the aims of this work is to clarify the appearance of the Kolmogorov type energy spectrum $E(k)\\varpropto k^{-5/3}$, observed in many numerical works on discrete vortex tubes (quantized vortex filaments in quantum fluids). Usually, explaining classical turbulent properties of quantum turbulence, the model of vortex bundles, is used. This model is necessary to mimic the vortex stretching, which is responsible for the energy transfer in classical turbulence. In our consideration we do not appeal to the possible "bundle arrangement" but explore alternative idea that the turbulent spectra appear from singular solution, which describe the collapsing line at moments of reconnection. One more aim is related to an important and intensively discussed topic - a role of hydrodynamic collapse in the formation of turbulent spectra. We demonstrated that the specific vortex filament configuration generated the spectrum $E(k)$ close to the Kolmogorov dependence and discussed the reason for this as well as the reason for deviation. We also discuss the obtained results from point of view of the both classical and quantum turbulence.

  15. Enhancing spectrum utilization through cooperation and cognition in wireless systems

    E-Print Network [OSTI]

    Rahul, Hariharan Shankar, 1975-

    2013-01-01T23:59:59.000Z

    We have seen a proliferation of wireless technologies and devices in recent years. The resulting explosion of wireless demand has put immense pressure on available spectrum. Improving spectrum utilization is therefore ...

  16. On the Characteristics of Spectrum-Agile Communication Networks

    E-Print Network [OSTI]

    Liu, Xin

    , both the Federal Communications Commission (FCC) and the federal government have made important1 On the Characteristics of Spectrum-Agile Communication Networks Xin Liu Wei Wang Department almost all spectrum suitable for wireless communications have been allocated, preliminary studies

  17. A Comprehensive Search for Dark Matter Annihilation in Dwarf Galaxies

    E-Print Network [OSTI]

    Alex Geringer-Sameth; Savvas M. Koushiappas; Matthew G. Walker

    2015-03-11T23:59:59.000Z

    We present a new formalism designed to discover dark matter annihilation occurring in the Milky Way's dwarf galaxies. The statistical framework extracts all available information in the data by simultaneously combining observations of all the dwarf galaxies and incorporating the impact of particle physics properties, the distribution of dark matter in the dwarfs, and the detector response. The method performs maximally powerful frequentist searches and produces confidence limits on particle physics parameters. Probability distributions of test statistics under various hypotheses are constructed exactly, without relying on large sample approximations. The derived limits have proper coverage by construction and claims of detection are not biased by imperfect background modeling. We implement this formalism using data from the Fermi Gamma-ray Space Telescope to search for an annihilation signal in the complete sample of Milky Way dwarfs whose dark matter distributions can be reliably determined. We find that the observed data is consistent with background for each of the dwarf galaxies individually as well as in a joint analysis. The strongest constraints are at small dark matter particle masses. Taking the median of the systematic uncertainty in dwarf density profiles, the cross section upper limits are below the pure s-wave weak scale relic abundance value (2.2 x 10^-26 cm^3/s) for dark matter masses below 26 GeV (for annihilation into b quarks), 29 GeV (tau leptons), 35 GeV (up, down, strange, and charm quarks and gluons), 6 GeV (electrons/positrons), and 114 GeV (two-photon final state). For dark matter particle masses less than 1 TeV, these represent the strongest limits obtained to date using dwarf galaxies.

  18. Multicarrier orthogonal spread-spectrum (MOSS) data communications

    DOE Patents [OSTI]

    Smith, Stephen F. (London, TN); Dress, William B. (Camas, WA)

    2008-01-01T23:59:59.000Z

    Systems and methods are described for multicarrier orthogonal spread-spectrum (MOSS) data communication. A method includes individually spread-spectrum modulating at least two of a set of orthogonal frequency division multiplexed carriers, wherein the resulting individually spread-spectrum modulated at least two of a set of orthogonal frequency division multiplexed carriers are substantially mutually orthogonal with respect to both frequency division multiplexing and spread-spectrum modulation.

  19. Relating spontaneous BOLD oscillatory power scale to whole-brain functional and structural organization

    E-Print Network [OSTI]

    Apkarian, A. Vania

    at every voxel. The series were transformed to frequency domain and power spectrum plotted on a log of each voxel (Panel 1a). Large a = more power in low frequency BOLD. · Functional linRelating spontaneous BOLD oscillatory power scale to whole-brain functional and structural

  20. Power Factor Compensation (PFC) Power Factor Compensation

    E-Print Network [OSTI]

    Knobloch,Jürgen

    Power Factor Compensation (PFC) Power Factor Compensation The power factor (PF) is defined as the ratio between the active power and the apparent power of a system. If the current and voltage are periodic with period , and [ ), then the active power is defined by ( ) ( ) (their inner product

  1. Star Power

    ScienceCinema (OSTI)

    None

    2014-11-18T23:59:59.000Z

    The U.S. Department of Energy's Princeton Plasma Physics Laboratory has released ''Star Power,'' a new informational video that uses dramatic and beautiful images and thought-provoking interviews to highlight the importance of the Laboratory's research into magnetic fusion.

  2. Star Power

    SciTech Connect (OSTI)

    None

    2014-10-17T23:59:59.000Z

    The U.S. Department of Energy's Princeton Plasma Physics Laboratory has released ''Star Power,'' a new informational video that uses dramatic and beautiful images and thought-provoking interviews to highlight the importance of the Laboratory's research into magnetic fusion.

  3. Precision Reactor e Spectrum Measurements: Recent Results and PROSPECTs

    E-Print Network [OSTI]

    Precision Reactor e Spectrum Measurements: Recent Results and PROSPECTs Bryce Littlejohn Illinois;Outline · Intro: Reactor e Flux and Spectrum Predictions · Reactor Anomaly and recent flux for PROSPECT 2 #12;Outline · Intro: Reactor e Flux and Spectrum Predictions · Reactor Anomaly and recent flux

  4. Dynamical dark matter. II. An explicit model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dienes, Keith R.; Thomas, Brooks

    2012-04-01T23:59:59.000Z

    In a recent paper [K. R. Dienes and B. Thomas, Phys. Rev. D 85, 083523 (2012).], we introduced “dynamical dark matter,” a new framework for dark-matter physics, and outlined its underlying theoretical principles and phenomenological possibilities. Unlike most traditional approaches to the dark-matter problem which hypothesize the existence of one or more stable dark-matter particles, our dynamical dark-matter framework is characterized by the fact that the requirement of stability is replaced by a delicate balancing between cosmological abundances and lifetimes across a vast ensemble of individual dark-matter components. This setup therefore collectively produces a time-varying cosmological dark-matter abundance, and the different dark-matter components can interact and decay throughout the current epoch. While the goal of our previous paper was to introduce the broad theoretical aspects of this framework, the purpose of the current paper is to provide an explicit model of dynamical dark matter and demonstrate that this model satisfies all collider, astrophysical, and cosmological constraints. The results of this paper therefore constitute an “existence proof” of the phenomenological viability of our overall dynamical dark-matter framework, and demonstrate that dynamical dark matter is indeed a viable alternative to the traditional paradigm of dark-matter physics. Dynamical dark matter must therefore be considered alongside other approaches to the dark-matter problem, particularly in scenarios involving large extra dimensions or string theory in which there exist large numbers of particles which are neutral under standard-model symmetries.

  5. Phi Meson in Dense Matter

    E-Print Network [OSTI]

    Ko, Che Ming; Levai, P.; Qiu, X. J.; Li, C. T.

    1992-01-01T23:59:59.000Z

    PHYSICAL REVIEW C VOLUME 45, NUMBER 3 MARCH 1992 Phi meson in dense matter C. M. Ko, P. Levai, * and X. J. Qiu Cyclotron Institute and Physics Department, Texas A &M University, College Station, Texas 77843 C. T. Li Physics Department, National... Taiwan University, Taipei, Taiwan 10764, China {Received 3 September 1991) The effect of the kaon loop correction to the property of a phi meson in dense matter is studied in the vector dominance model. Using the density-dependent kaon effective mass...

  6. Explaining Low Energy ?-ray Excess from the Galactic Centre using a Two Component Dark Matter Model

    E-Print Network [OSTI]

    Anirban Biswas

    2014-12-04T23:59:59.000Z

    Over the past few years, there has been a hint of the $\\gamma$-ray excess observed by the Fermi-LAT satellite borne telescope from the region surrounding the Galactic Centre at an energy range $\\sim 1$-$3$ GeV. The nature of this excess $\\gamma$-ray spectrum is found to be consistent with the $\\gamma$-ray emission expected from dark matter annihilation at the Galactic Centre while disfavouring other known astrophysical sources as the possible origin of this phenomena. It is also reported that the spectrum and morphology of this excess $\\gamma$-rays can well be explained by the dark matter particles having mass in the range $30\\sim 40$ GeV annihilating into ${\\rm b}$ $\\bar{\\rm b}$ final state with an annihilation cross section ${\\sigma {\\rm v}} \\sim 1.4 - 2.0\\times10^{-26}$ cm$^3/$s at the Galactic centre. In this work, we propose a two component dark matter model where two different types of dark matter particles namely a complex scalar and a Dirac fermion are considered. The stability of both the dark sector particles are maintained by virtue of an additional local U$(1)_{\\rm X}$ gauge symmetry. We find that our proposed scenario can provide a viable explanation besides satisfying all the existing relevant theoretical, experimental and observational bounds.

  7. Constraints on decaying dark matter from Fermi observations of nearby galaxies and clusters

    SciTech Connect (OSTI)

    Dugger, Leanna; Profumo, Stefano [Department of Astronomy and Department of Physics, University of California Berkeley, 601 Campbell Hall, Berkeley, CA (United States); Jeltema, Tesla E., E-mail: greentee01@gmail.com, E-mail: tesla@ucolick.org, E-mail: profumo@scipp.ucsc.edu [UCO/Lick Observatories, 1156 High St., Santa Cruz, CA 95064 (United States)

    2010-12-01T23:59:59.000Z

    We analyze the impact of Fermi gamma-ray observations (primarily non-detections) of selected nearby galaxies, including dwarf spheroidals, and of clusters of galaxies on decaying dark matter models. We show that the fact that galaxy clusters do not shine in gamma rays puts the most stringent limits available to-date on the lifetime of dark matter particles for a wide range of particle masses and decay final states. In particular, our results put strong constraints on the possibility of ascribing to decaying dark matter both the increasing positron fraction reported by PAMELA and the high-energy feature in the electron-positron spectrum measured by Fermi. Observations of nearby dwarf galaxies and of the Andromeda Galaxy (M31) do not provide as strong limits as those from galaxy clusters, while still improving on previous constraints in some cases.

  8. Dark matter from the scalar sector of 3-3-1 models without exotic electric charges

    E-Print Network [OSTI]

    Simonetta Filippi; William A. Ponce; Luis A. Sanchez

    2005-10-27T23:59:59.000Z

    We show that three SU(2) singlet neutral scalars (two CP-even and one CP-odd) in the spectrum of models based on the gauge symmetry SU(3)_c X SU(3)_L X U(1)_X, which do not contain exotic electric charges, are realistic candidates for thermally generated self-interacting dark matter in the Universe, a type of dark matter that has been recently proposed in order to overcome some difficulties of collisionless cold dark matter models at the galactic scale. These candidates arise without introducing a new mass scale in the model and/or without the need for a discrete symmetry to stabilize them, but at the expense of tuning several combinations of parameters of the scalar potential.

  9. Moments of $\\phi$ meson spectral functions in vacuum and nuclear matter

    E-Print Network [OSTI]

    Gubler, Philipp

    2015-01-01T23:59:59.000Z

    Moments of the $\\phi$ meson spectral function in vacuum and in nuclear matter are analyzed, combining a model based on chiral SU(3) effective field theory (with kaonic degrees of freedom) and finite-energy QCD sum rules. For the vacuum we show that the spectral density is strongly constrained by a recent accurate measurement of the $e^+ e^- \\to K^+ K^-$ cross section. In nuclear matter the $\\phi$ spectrum is modified by interactions of the decay kaons with the surrounding nuclear medium, leading to a significant broadening and an asymmetric deformation of the $\\phi$ meson peak. We demonstrate that both in vacuum and nuclear matter, the first two moments of the spectral function are compatible with finite-energy QCD sum rules. A brief discussion of the next-higher spectral moment involving strange four-quark condensates is also presented.

  10. Dynamic Spectrum Management for Green DSL

    E-Print Network [OSTI]

    Chiang, Mung

    identified as a significant contributor to global warming. In this paper we extend traditional DSM design be balanced carefully, as increasing one user's transmit power increases its data rate but also causes

  11. Spectrum tailoring of the neutron energy spectrum in the context of delayed neutron detection

    SciTech Connect (OSTI)

    Koehler, William E [Los Alamos National Laboratory; Tobin, Steve J [Los Alamos National Laboratory; Sandoval, Nathan P [Los Alamos National Laboratory; Fensin, Mike L [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    For the purpose of measuring plutonium mass in spent fuel, a delayed neutron instrument is of particular interest since, if properly designed, the delayed neutron signal from {sup 235}U is significantly stronger than the signature from {sup 239}Pu or {sup 241}Pu. A key factor in properly designing a delayed neutron instrument is to minimize the fission of {sup 238}U. This minimization is achieved by keeping the interrogating neutron spectrum below {approx} 1 MeV. In the context of spent fuel measurements it is desirable to use a 14 MeV (deuterium and tritium) neutron generator for economic reasons. Spectrum tailoring is the term used to describe the inclusion of material between the 14 MeV neutrons and the interrogated object that lower the neutron energy through nuclear reactions and moderation. This report quantifies the utility of different material combination for spectrum tailoring.

  12. Energy spectrum control for modulated proton beams

    SciTech Connect (OSTI)

    Hsi, Wen C.; Moyers, Michael F.; Nichiporov, Dmitri; Anferov, Vladimir; Wolanski, Mark; Allgower, Chris E.; Farr, Jonathan B.; Mascia, Anthony E.; Schreuder, Andries N. [Midwest Proton Radiotherapy Institute, Bloomington, Indiana 47408 and University Florida Proton Therapy Institute, Jacksonville, Florida 32206 (United States); Proton Therapy, Inc., Colton, California 92324 (United States); Indiana University Cyclotron Facility, Bloomington, Indiana 47408 (United States); Midwest Proton Radiotherapy Institute, Bloomington, Indiana 47408 and University Florida Proton Therapy Institute, Jacksonville, Florida 32206 (United States); Midwest Proton Radiotherapy Institute, Bloomington, Indiana 47408 (United States); University Florida Proton Therapy Institute, Jacksonville, Florida 32206 (United States) and Westdeutsches Protonentherapiezentrum, Universitaetsklinikum, Hufelandstrasse 55, 45147 Essen (Germany); Midwest Proton Radiotherapy Institute, Bloomington, Indiana 47408 (United States); University Florida Proton Therapy Institute, Jacksonville, Florida 32206 (United States) and ProCure Treatment Centers, Inc., Bloomington, Indiana 47404 (United States)

    2009-06-15T23:59:59.000Z

    In proton therapy delivered with range modulated beams, the energy spectrum of protons entering the delivery nozzle can affect the dose uniformity within the target region and the dose gradient around its periphery. For a cyclotron with a fixed extraction energy, a rangeshifter is used to change the energy but this produces increasing energy spreads for decreasing energies. This study investigated the magnitude of the effects of different energy spreads on dose uniformity and distal edge dose gradient and determined the limits for controlling the incident spectrum. A multilayer Faraday cup (MLFC) was calibrated against depth dose curves measured in water for nonmodulated beams with various incident spectra. Depth dose curves were measured in a water phantom and in a multilayer ionization chamber detector for modulated beams using different incident energy spreads. Some nozzle entrance energy spectra can produce unacceptable dose nonuniformities of up to {+-}21% over the modulated region. For modulated beams and small beam ranges, the width of the distal penumbra can vary by a factor of 2.5. When the energy spread was controlled within the defined limits, the dose nonuniformity was less than {+-}3%. To facilitate understanding of the results, the data were compared to the measured and Monte Carlo calculated data from a variable extraction energy synchrotron which has a narrow spectrum for all energies. Dose uniformity is only maintained within prescription limits when the energy spread is controlled. At low energies, a large spread can be beneficial for extending the energy range at which a single range modulator device can be used. An MLFC can be used as part of a feedback to provide specified energy spreads for different energies.

  13. ADAPTIVE FULL-SPECTRUM SOLOR ENERGY SYSTEMS

    SciTech Connect (OSTI)

    Byard D. Wood

    2004-04-01T23:59:59.000Z

    This RD&D project is a three year team effort to develop a hybrid solar lighting (HSL) system that transports solar light from a paraboloidal dish concentrator to a luminaire via a large core polymer fiber optic. The luminaire can be a device to distribute sunlight into a space for the production of algae or it can be a device that is a combination of solar lighting and electric lighting. A benchmark prototype system has been developed to evaluate the HSL system. Sunlight is collected using a one-meter paraboloidal concentrator dish with two-axis tracking. A secondary mirror consisting of eight planar-segmented mirrors directs the visible part of the spectrum to eight fibers (receiver) and subsequently to eight luminaires. This results in about 8,200 lumens incident at each fiber tip. Each fiber can illuminate about 16.7 m{sup 2} (180 ft{sup 2}) of office space. The IR spectrum is directed to a thermophotovoltaic (TPV) array to produce electricity. During this reporting period, the project team made advancements in the design of the second generation (Alpha) system. For the Alpha system, the eight individual 12 mm fibers have been replaced with a centralized bundle of 3 mm fibers. The TRNSYS Full-Spectrum Solar Energy System model has been updated and new components have been added. The TPV array and nonimaging device have been tested and progress has been made in the fiber transmission models. A test plan was developed for both the high-lumen tests and the study to determine the non-energy benefits of daylighting. The photobioreactor team also made major advancements in the testing of model scale and bench top lab-scale systems.

  14. Matter Bounce Loop Quantum Cosmology from $F(R)$ Gravity

    E-Print Network [OSTI]

    S. D. Odintsov; V. K. Oikonomou

    2014-12-04T23:59:59.000Z

    Using the reconstruction method, we investigate which $F(R)$ theories, with or without the presence of matter fluids, can produce the matter bounce scenario of holonomy corrected Loop Quantum Cosmology. We focus our study in two limits of the cosmic time, the large cosmic time limit and the small cosmic time limit. For the former, we found that, in the presence of non-interacting and non-relativistic matter, the $F(R)$ gravity that reproduces the late time limit of the matter bounce solution is actually the Einstein-Hilbert gravity plus a power law term. In the early time limit, since it corresponds to large spacetime curvatures, assuming that the Jordan frame is described by a general metric that when it is conformally transformed to the Einstein frame, produces an accelerating Friedmann-Robertson-Walker metric, we found explicitly the scalar field dependence on time. After demonstrating that the solution in the Einstein frame is indeed accelerating, we calculate the spectral index derived from the Einstein frame scalar-tensor counterpart theory of the $F(R)$ theory and compare it with the Planck experiment data. In order to implement the resulting picture, we embed the $F(R)$ gravity explicitly in a Loop Quantum Cosmology framework by introducing holonomy corrections to the $F(R)$ gravity. In this way, the resulting inflation picture corresponding to the $F(R)$ gravity can be corrected in order it coincides to some extent with the current experimental data.

  15. Bilinear control of discrete spectrum Schrödinger operators

    E-Print Network [OSTI]

    Kais Ammari; Zied Ammari

    2010-05-17T23:59:59.000Z

    The bilinear control problem of the Schr\\"odinger equation $i\\frac{\\partial}{\\partial t}\\psi(t)$ $=(A+u(t) B)\\psi(t)$, where $u(t)$ is the control function, is investigated through topological irreducibility of the set $\\mathfrak{M}=\\{e^{-it (A+u B)}, u\\in \\mathbb{R}, t>0\\}$ of bounded operators. This allows to prove the approximate controllability of such systems when the uncontrolled Hamiltonian $A$ has a simple discrete spectrum and under an appropriate assumption on $B$.

  16. Spectrum Policy Seminar | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directed offOCHCO Overview OCHCO OverviewRepositoryManagement |SolarSpecial Report:Spectrum Policy Seminar

  17. Spectrum Policy Seminar | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOriginEducationVideo »UsageSecretaryVideos Solid-State|Special3020-2015 June 2015Spectrum Policy

  18. Transmission Matters Now: How Will Power Market Regulations Impact the Industrial's Power Supply Costs and Reliability?

    E-Print Network [OSTI]

    James, F.; Beidas, H.; Fox, R.

    and reliability. The paper also identifies what specifically may be involved, from a technical and regulatory standpoint, in the following three areas: 1) Transmission Risks -SMD and RTO/ISO, 2) Alternative Retail Supply, and 3) Self-Generation....

  19. Power superconducting power transmission cable

    DOE Patents [OSTI]

    Ashworth, Stephen P. (Cambridge, GB)

    2003-01-01T23:59:59.000Z

    The present invention is for a compact superconducting power transmission cable operating at distribution level voltages. The superconducting cable is a conductor with a number of tapes assembled into a subconductor. These conductors are then mounted co-planarly in an elongated dielectric to produce a 3-phase cable. The arrangement increases the magnetic field parallel to the tapes thereby reducing ac losses.

  20. Power Right. Power Smart. Efficient Computer Power Supplies and...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AC power that you get from your electric company into the DC power consumed by most electronics, including your computer. We expect our power supplies to be safe, reliable, and...

  1. Solar Power To Help Convert Carbon Dioxide Into Fuel : Renewable Energy News

    E-Print Network [OSTI]

    Lovley, Derek

    Solar Power To Help Convert Carbon Dioxide Into Fuel : Renewable Energy News TUESDAY 25 MAY, 2010 | | Solar Power To Help Convert Carbon Dioxide Into Fuel by Energy Matters Microbiologist Derek Lovley dioxide into transportation fuels, with the help of special micro-organisms and solar power. The team

  2. Silicon Valley Power and Oklahoma Municipal Power Authority Win...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Silicon Valley Power and Oklahoma Municipal Power Authority Win 2014 Public Power Wind Awards Silicon Valley Power and Oklahoma Municipal Power Authority Win 2014 Public Power Wind...

  3. Laser Cooling of Matter INTRODUCTION

    E-Print Network [OSTI]

    Kaiser, Robin

    - velopment of techniques that have allowed the ion motion to be cooled into the ground state of the confiningLaser Cooling of Matter INTRODUCTION Laser cooling of neutral atoms in the past decades has been a breakthrough in the understanding of their dy- namics and led to the seminal proposals of laser cooling

  4. Magnets & Magnet Condensed Matter Science

    E-Print Network [OSTI]

    McQuade, D. Tyler

    18 No. 1 CONDENSED MATTER SCIENCE Technique development, graphene, magnetism & magnetic materials Pressure 9 Metal to Insulator Transition on the N=0 Landau Level in Graphene 10 Evidence for Fractional Quantum Hall States in Suspended Bilayer and Trilayer Graphene 11 Fractional Quantum Hall Effect

  5. Solar Neutrino Matter Effects Redux

    E-Print Network [OSTI]

    A. B. Balantekin; A. Malkus

    2011-12-19T23:59:59.000Z

    Following recent low-threshold analysis of the Sudbury Neutrino Observatory and asymmetry measurements of the BOREXINO Collaboration of the solar neutrino flux, we revisit the analysis of the matter effects in the Sun. We show that solar neutrino data constrains the mixing angle $\\theta_{13}$ poorly and that subdominant Standard Model effects can mimic the effects of the physics beyond the Standard Model.

  6. States of Matter Deepak Dhar

    E-Print Network [OSTI]

    Udgaonkar, Jayant B.

    - logical classification of different animal species) or some mixture of these (e.g. books in a library answer in this case is that states of matter is a classification scheme, like filing cabinets classification schemes could be alphabetical (e.g. in a dictionary), or based on some common properties ( zoo

  7. Apparatus for particulate matter analysis

    DOE Patents [OSTI]

    Gundel, Lara A.; Apte, Michael G.; Hansen, Anthony D.; Black, Douglas R.

    2007-01-30T23:59:59.000Z

    The apparatus described herein is a miniaturized system for particle exposure assessment (MSPEA) for the quantitative measurement and qualitative identification of particulate content in gases. The present invention utilizes a quartz crystal microbalance (QCM) or other mass-sensitive temperature compensated acoustic wave resonator for mass measurement. Detectors and probes and light sources are used in combination for the qualitative determination of particulate matter.

  8. Initial exploration of 21-cm cosmology with imaging and power spectra from the Murchison Widefield Array

    E-Print Network [OSTI]

    Williams, Christopher Leigh

    2012-01-01T23:59:59.000Z

    The Murchison Widefield Array (MWA) is a new low-frequency radio array under construction in Western Australia with a primary goal of measuring the power spectrum of the 21-cm signal from neutral hydrogen during the Epoch ...

  9. Dynamical insight into dark-matter haloes

    E-Print Network [OSTI]

    Walter Dehnen; Dean McLaughlin

    2005-06-22T23:59:59.000Z

    We investigate, using the spherical Jeans equation, self-gravitating dynamical equilibria satisfying a relation rho/sigma_r^3 propto r^-alpha, which holds for simulated dark-matter haloes over their whole resolved radial range. Considering first the case of velocity isotropy, we find that this problem has only one solution with realistic density profile, which occurs only for a critical value of alpha_crit = 35/18 ~= 1.94, which is consistent with the empirical value of 1.9+/-0.05. We extend our analysis in two ways: first we introduce a parameter epsilon to allow for a more general relation rho/\\sigma_r^epsilon propto r^-alpha; second we consider velocity anisotropy. If we assume beta(r) := 1- sigma_theta^2 / sigma_r^2 to be linearly related to the logarithmic density slope gamma(r) := -dln(rho)/dln(r), which is in agreement with simulations, the problem remains analytically tractable and is equivalent to the simpler isotropic case: there exists only one physical solution, which occurs at a critical alpha value. Remarkably, this value of alpha and the density and velocity-dispersion profiles depend only on epsilon and the value beta_0 := beta(r=0), but not on the slope of the linear beta-gamma relation. For epsilon=3, alpha_crit = 35/18 - 2beta_0/9 and the resulting density profile is fully analytic (as are the velocity dispersion and circular speed) with an inner cusp rho propto r^{-(7+10beta_0)/9} and a very smooth transition to a steeper outer power-law asymptote. These models are in excellent agreement with the density, velocity-dispersion and anisotropy profiles of simulated dark-matter haloes over their full resolved radial range. If epsilon=3 is a universal constant, some scatter in beta_0 ~= 0 may account for some diversity in the density profiles. (ABRIDGED)

  10. Tidal power

    SciTech Connect (OSTI)

    Hammons, T.J. (Glasgow Univ., Scotland (United Kingdom))

    1993-03-01T23:59:59.000Z

    The paper reviews the physics of tidal power considering gravitational effects of moon and sun; semidiurnal, diurnal, and mixed tides; and major periodic components that affect the tidal range. Shelving, funneling, reflection, and resonance phenomena that have a significant effect on tidal range are also discussed. The paper then examines tidal energy resource for principal developments estimated from parametric modeling in Europe and worldwide. Basic parameters that govern the design of tidal power schemes in terms of mean tidal range and surface area of the enclosed basin are identified. While energy extracted is proportional to the tidal amplitude squared, requisite sluicing are is proportional to the square root of the tidal amplitude. Sites with large tidal amplitudes are therefore best suited for tidal power developments, whereas sites with low tidal amplitudes have sluicing that may be prohibitive. It is shown that 48% of the European tidal resource is in the United Kingdom, 42% in France and 8% in Ireland, other countries having negligible potential. Worldwide tidal resource is identified. Tidal barrage design and construction using caissons is examined, as are alternative operating modes (single-action generation, outflow generation, flood generation, two-way generation, twin basin generation, pumping, etc), development trends and possibilities, generation cost at the barrage boundary, sensitivity to discount rates, general economics, and markets. Environmental effects, and institutional constraints to the development of tidal barrage schemes are also discussed.

  11. Energy Matters: Our Energy Independence | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Matters: Our Energy Independence Energy Matters: Our Energy Independence Addthis Description In this installment of the livechat series "Energy Matters," Dr. Arun Majumdar takes...

  12. Why Geology Matters: Decoding the Past, Anticipating the Future

    E-Print Network [OSTI]

    Anderson, Byron P.

    2011-01-01T23:59:59.000Z

    Review: Why Geology Matters: Decoding the Past, AnticipatingUSA Macdougall, Doug. Why Geology Matters: Decoding theE-book available. Why Geology Matters pursues two goals: to

  13. Exotic Matter and Space-Time

    E-Print Network [OSTI]

    Terazawa, Hidezumi

    2013-01-01T23:59:59.000Z

    Exotic forms of matter such as carbon nanofoams, hexalambdas and strange stars, pentaquarks, color-balls, etc. and their relations to current problems in cosmo-particle physics such as dark matter and energy are discussed in some details.

  14. Dark matter axions and caustic rings

    SciTech Connect (OSTI)

    Sikivie, P.

    1997-11-01T23:59:59.000Z

    This report contains discussions on the following topics: the strong CP problem; dark matter axions; the cavity detector of galactic halo axions; and caustic rings in the density distribution of cold dark matter halos.

  15. Distribution Function in Center of Dark Matter Halo

    E-Print Network [OSTI]

    Ding Ma; Ping He

    2008-08-01T23:59:59.000Z

    N-body simulations of dark matter halos show that the density profiles of halos behave as $\\rho(r)\\propto r^{-\\alpha(r)}$, where the density logarithmic slope $\\alpha \\simeq 1\\sim1.5$ in the center and $\\alpha \\simeq 3\\sim 4$ in the outer parts of halos. However, some observations are not in agreement with simulations in the very central region of halos. The simulations also show that velocity dispersion anisotropy parameter $\\beta\\approx 0$ in the inner part of the halo and the so called "pseudo phase-space density" $\\rho/\\sigma^3$ behaves as a power-law in radius $r$. With these results in mind, we study the distribution function and the pseudo phase-space density $\\rho/\\sigma^3$ of the center of dark matter halos and find that they are closely-related.

  16. Statistical mechanics of hot dense matter

    SciTech Connect (OSTI)

    More, R.

    1986-10-01T23:59:59.000Z

    Research on properties of hot dense matter produced with high intensity laser radiation is described in a brief informal review.

  17. Operations & Maintenance Best Practices Guide: Front Matter

    Broader source: Energy.gov [DOE]

    Guide describes the front matter of the Operations and Maintenance Best Practices: a Guide to Achieving Operational Efficiency.

  18. Wind power and Wind power and

    E-Print Network [OSTI]

    Wind power and the CDM #12; Wind power and the CDM Emerging practices in developing wind power 2005 Jyoti P. Painuly, Niels-Erik Clausen, Jørgen Fenhann, Sami Kamel and Romeo Pacudan #12; WIND POWER AND THE CDM Emerging practices in developing wind power projects for the Clean Development Mechanism Energy

  19. Nuclear matter to strange matter transition in holographic QCD

    E-Print Network [OSTI]

    Youngman Kim; Yunseok Seo; Sang-Jin Sin

    2009-11-19T23:59:59.000Z

    We construct a simple holographic QCD model to study nuclear matter to strange matter transition. The interaction of dense medium and hadrons is taken care of by imposing the force balancing condition for stable D4/D6/D6 configuration. By considering the intermediate and light flavor branes interacting with baryon vertex homogeneously distributed along R^3 space and requesting the energy minimization, we find that there is a well defined transition density as a function of current quark mass. We also find that as density goes up very high, intermediate (or heavy) and light quarks populate equally as expected from the Pauli principle. In this sense, the effect of the Pauli principle is realized as dynamics of D-branes.

  20. Personal Finance Make Your Money Matter

    E-Print Network [OSTI]

    Stevenson, Mark

    Personal Finance Make Your Money Matter Name: Registration number: Department: Year of study of your portfolio. #12;Personal Finance Make Your Money Matter2 Contents Timetable Page 3 Introduction 16 #12;Personal Finance Make Your Money Matter3 Timetable Friday 6.00 pm Introduction

  1. Power Recovery

    E-Print Network [OSTI]

    Murray, F.

    , will be the use of the ASTM Theoretical Steam Rate Tables. In addition, the author's experience regarding the minimum size for power recovery units that are economic in a Culf Coast plant will be presented. INTROD\\Jr.'rION When surveying an operation... will be discussed in detail. Each term in the equation will be considered in English units. Secondly, the use of Mollier diagrams to estimate the enthalphy change between the initial and final conditions will be considered. The last method, specific to steam...

  2. Yakama Power

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsingWhatY-12 recognized for ...BER/NERSCYakama Power May

  3. Fusion Power

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField8,Dist.Newof EnergyFunding Opportunity fromFusion Links Fusion

  4. The School of Physics and Astronomy has a world-leading research profile that covers a broad spectrum from fundamental to applied physics. The research is grouped into the three areas of photonics,

    E-Print Network [OSTI]

    Greenaway, Alan

    The School of Physics and Astronomy has a world-leading research profile that covers a broad spectrum from fundamental to applied physics. The research is grouped into the three areas of photonics, condensed matter physics, and astronomy. In the 2008 Research Assessment Exercise, the School was rated

  5. Symmetry and Dirac points in graphene spectrum

    E-Print Network [OSTI]

    Gregory Berkolaiko; Andrew Comech

    2014-12-28T23:59:59.000Z

    Existence and stability of Dirac points in the dispersion relation of operators periodic with respect to the hexagonal lattice is investigated for different sets of additional symmetries. The following symmetries are considered: rotation by $2\\pi/3$ and inversion, rotation by $2\\pi/3$ and horizontal reflection, inversion or reflection with weakly broken rotation symmetry, and the case where no Dirac points arise: rotation by $2\\pi/3$ and vertical reflection. All proofs are based on symmetry considerations and are elementary in nature. In particular, existence of degeneracies in the spectrum is proved by a transplantation argument (which is deduced from the (co)representation of the relevant symmetry group). The conical shape of the dispersion relation is obtained from its invariance under rotation by $2\\pi/3$. Persistence of conical points when the rotation symmetry is weakly broken is proved using a geometric phase in one case and parity of the eigenfunctions in the other.

  6. Symmetry and Dirac points in graphene spectrum

    E-Print Network [OSTI]

    Gregory Berkolaiko; Andrew Comech

    2015-04-23T23:59:59.000Z

    Existence and stability of Dirac points in the dispersion relation of operators periodic with respect to the hexagonal lattice is investigated for different sets of additional symmetries. The following symmetries are considered: rotation by $2\\pi/3$ and inversion, rotation by $2\\pi/3$ and horizontal reflection, inversion or reflection with weakly broken rotation symmetry, and the case where no Dirac points arise: rotation by $2\\pi/3$ and vertical reflection. All proofs are based on symmetry considerations and are elementary in nature. In particular, existence of degeneracies in the spectrum is proved by a transplantation argument (which is deduced from the (co)representation of the relevant symmetry group). The conical shape of the dispersion relation is obtained from its invariance under rotation by $2\\pi/3$. Persistence of conical points when the rotation symmetry is weakly broken is proved using a geometric phase in one case and parity of the eigenfunctions in the other.

  7. Expanding the solar spectrum used by photosynthesis

    SciTech Connect (OSTI)

    Chen, Min; Blankenship, R. E.

    2011-01-01T23:59:59.000Z

    A limiting factor for photosynthetic organisms is their light-harvesting efficiency, that is the efficiency of their conversion of light energy to chemical energy. Small modifications or variations of chlorophylls allow photosynthetic organisms to harvest sunlight at different wavelengths. Oxygenic photosynthetic organisms usually utilize only the visible portion of the solar spectrum. The cyanobacterium Acaryochloris marina carries out oxygenic photosynthesis but contains mostly chlorophyll d and only traces of chlorophyll a. Chlorophyll d provides a potential selective advantage because it enables Acaryochloris to use infrared light (700–750 nm) that is not absorbed by chlorophyll a. Recently, an even more red-shifted chlorophyll termed chlorophyll f has been reported. Here, we discuss using modified chlorophylls to extend the spectral region of light that drives photosynthetic organisms.

  8. Phase transition towards strange matter

    E-Print Network [OSTI]

    F. Gulminelli; Ad. R. Raduta; M. Oertel

    2012-08-31T23:59:59.000Z

    The phase diagram of a system constituted of neutrons and $\\Lambda$-hyperons in thermal equilibrium is evaluated in the mean-field approximation. It is shown that this simple system exhibits a complex phase diagram with first and second order phase transitions. Due to the generic presence of attractive and repulsive couplings, the existence of phase transitions involving strangeness appears independent of the specific interaction model. In addition we will show under which conditions a phase transition towards strange matter at high density exists, which is expected to persist even within a complete treatment including all the different strange and non- strange baryon states. The impact of this transition on the composition of matter in the inner core of neutron stars is discussed.

  9. Power management system

    DOE Patents [OSTI]

    Algrain, Marcelo C. (Peoria, IL); Johnson, Kris W. (Washington, IL); Akasam, Sivaprasad (Peoria, IL); Hoff, Brian D. (East Peoria, IL)

    2007-10-02T23:59:59.000Z

    A method of managing power resources for an electrical system of a vehicle may include identifying enabled power sources from among a plurality of power sources in electrical communication with the electrical system and calculating a threshold power value for the enabled power sources. A total power load placed on the electrical system by one or more power consumers may be measured. If the total power load exceeds the threshold power value, then a determination may be made as to whether one or more additional power sources is available from among the plurality of power sources. At least one of the one or more additional power sources may be enabled, if available.

  10. Solar powered desalination system

    E-Print Network [OSTI]

    Mateo, Tiffany Alisa

    2011-01-01T23:59:59.000Z

    2008, uses concentrated solar power to split water. Figurethe main reason the potential for solar power is boundless.a clean energy source, solar power is inexhaustible, fairly

  11. ELECTROCHEMICAL POWER FOR TRANSPORTATION

    E-Print Network [OSTI]

    Cairns, Elton J.

    2012-01-01T23:59:59.000Z

    electric power generating plant, and the distributionrequired on the power-generating plant and not on the vehi-in either power-generating plants or combustion engines,

  12. Southwestern Power Administration

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Courses Instructors NERC Continuing Education Power Operations Training Center You'll find the "Power" of learning at Southwestern's Power Operations Training Center (POTC). POTC's...

  13. A new high power, fast charge, sealed lead acid battery

    SciTech Connect (OSTI)

    Juergens, T.; Nelson, R.F.; Ruderman, M.A. [Bolder Technology Corp., Wheat Ridge, CO (United States)

    1994-12-31T23:59:59.000Z

    A new approach to the design of lead acid batteries has been developed based on the use of very thin lead foil current collectors and very high current carrying capacity. The basic cell construction and the performance characteristics for the new cell are described. Spiral wrap cells based on this electrode concept exhibit extremely high power output with excellent capacity maintenance. Additionally, these cells exhibit flat voltage at all currents, and are capable of very rapid recharge. Applications for this high power technology cover a broad spectrum such as portable power tools, UPS systems, electrically heated catalytic converters, pulse power applications and electric and hybrid vehicles. 9 refs.

  14. Radio observations of the Galactic Centre and the Coma cluster as a probe of light dark matter self-annihilations and decay

    E-Print Network [OSTI]

    Celine Boehm; Joseph Silk; Torsten Ensslin

    2010-09-30T23:59:59.000Z

    We update our earlier calculations of gamma ray and radio observational constraints on annihilations of dark matter particles lighter than 10 GeV. We predict the synchrotron spectrum as well as the morphology of the radio emission associated with light decaying and annihilating dark matter candidates in both the Coma cluster and the Galactic Centre. Our new results basically confirm our previous findings: synchrotron emission in the very inner part of the Milky Way constrains or even excludes dark matter candidates if the magnetic field is larger than 50 micro Gauss. In fact, our results suggest that light annihilating candidates must have a S-wave suppressed pair annihilation cross section into electrons (or the branching ratio into electron positron must be small). If dark matter is decaying, it must have a life time that is larger than t = 3. 10^{25} s. Therefore, radio emission should always be considered when one proposes a "light" dark matter candidate.

  15. Section on prospects for dark matter detection of the white paper on the status and future of ground-based TeV gamma-ray astronomy.

    SciTech Connect (OSTI)

    Byrum, K.; Horan, D.; Tait, T.; Wanger, R.; Zaharijas, G.; Buckley , J.; Baltz, E. A.; Bertone, G.; Dingus, B.; Fegan, S.; Ferrer, F.; Gondolo, P.; Hall, J.; Hooper, D.; Horan, D.; Koushiappas, S.; Krawczynksi, H.; LeBohec, S.; Pohl, M.; Profumo, S.; Silk , J; Vassilev, V.; Wood , M.; Wakely, S.; High Energy Physics; FNAL; Univ. of St. Louis; Stanford Univ.; Insti. d' Astrophysique; LANL; Univ. of California; Washington Univ.; Univ. of Utah; Brown Univ.; Oxford Univ.; Iowa State Univ.; Univ. of Chicago

    2009-05-13T23:59:59.000Z

    This is a report on the findings of the dark matter science working group for the white paper on the status and future of TeV gamma-ray astronomy. The white paper was commissioned by the American Physical Society, and the full white paper can be found on astro-ph (arXiv:0810.0444). This detailed section discusses the prospects for dark matter detection with future gamma-ray experiments, and the complementarity of gamma-ray measurements with other indirect, direct or accelerator-based searches. We conclude that any comprehensive search for dark matter should include gamma-ray observations, both to identify the dark matter particle (through the characteristics of the gamma-ray spectrum) and to measure the distribution of dark matter in galactic halos.

  16. Superconducting Detectors for Super Light Dark Matter

    E-Print Network [OSTI]

    Yonit Hochberg; Yue Zhao; Kathryn M. Zurek

    2015-04-27T23:59:59.000Z

    We propose and study a new class of of superconducting detectors which are sensitive to O(meV) electron recoils from dark matter-electron scattering. Such devices could detect dark matter as light as the warm dark matter limit, mX > keV. We compute the rate of dark matter scattering off free electrons in a (superconducting) metal, including the relevant Pauli blocking factors. We demonstrate that classes of dark matter consistent with all astrophysical and terrestrial constraints could be detected by such detectors with a moderate size exposure.

  17. Superconducting Detectors for Super Light Dark Matter

    E-Print Network [OSTI]

    Hochberg, Yonit; Zurek, Kathryn M

    2015-01-01T23:59:59.000Z

    We propose and study a new class of of superconducting detectors which are sensitive to O(meV) electron recoils from dark matter-electron scattering. Such devices could detect dark matter as light as the warm dark matter limit, mX > keV. We compute the rate of dark matter scattering off free electrons in a (superconducting) metal, including the relevant Pauli blocking factors. We demonstrate that classes of dark matter consistent with all astrophysical and terrestrial constraints could be detected by such detectors with a moderate size exposure.

  18. POWER PURCHASE AGREEMENT DELMARVA POWER & LIGHT COMPANY

    E-Print Network [OSTI]

    Firestone, Jeremy

    POWER PURCHASE AGREEMENT between DELMARVA POWER & LIGHT COMPANY ("Buyer") and BLUEWATER WIND 3.5 Energy Forecasts, Scheduling and Balancing.......................................... 39 3

  19. On Math, Matter and Mind

    E-Print Network [OSTI]

    Piet Hut; Mark Alford; Max Tegmark

    2006-01-15T23:59:59.000Z

    We discuss the nature of reality in the ontological context of Penrose's math-matter-mind triangle. The triangle suggests the circularity of the widespread view that math arises from the mind, the mind arises out of matter, and that matter can be explained in terms of math. Non-physicists should be wary of any claim that modern physics leads us to any particular resolution of this circularity, since even the sample of three theoretical physicists writing this paper hold three divergent views. Some physicists believe that current physics has already found the basic framework for a complete description of reality, and only has to fill in the details. Others suspect that no single framework, from physics or other sources, will ever capture reality. Yet others guess that reality might be approached arbitrarily closely by some form of future physics, but probably based on completely different frameworks. We will designate these three approaches as the fundamentalist, secular and mystic views of the world, as seen by practicing physicists. We present and contrast each of these views, which arguably form broad categories capturing most if not all interpretations of physics. We argue that this diversity in the physics community is more useful than an ontological monoculture, since it motivates physicists to tackle unsolved problems with a wide variety of approaches.

  20. The Eighth Liquid Matter Conference This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Dellago, Christoph

    interdisciplinary topics, ranging from simple liquids to soft matter and biophysical systems. The vast spectrum · Confined fluids, interfacial phenomena · Supercooled liquids, glasses, gels · Non-equilibrium systems science, as discussed at the conference, and demonstrate the scientific as well as methodological progress

  1. Effects of Advanced Combustion Technologies on Particulate Matter...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Advanced Combustion Technologies on Particulate Matter Emissions Characteristics Effects of Advanced Combustion Technologies on Particulate Matter Emissions Characteristics...

  2. OPTI-583: Computational Optics I: Ultrafast pulses and strong-field light-matter interactions.

    E-Print Network [OSTI]

    Arizona, University of

    OPTI-583: Computational Optics I: Ultrafast pulses and strong-field light-matter interactions. Time-power femtosecond pulses. Prerequisites: Knowledge of basic electromagnetic theory (e.g. Phys-241). While previous that govern the interaction of ultrashort pulses with var- ious media, and the Numerical methods track

  3. DENSE MATTER IN LASER DRIVEN FUSION ! LABORATORY EXPERIMENTS R.L. Mc Crory and J. Wilson

    E-Print Network [OSTI]

    Boyer, Edmond

    irradiation to heat and compress a target containing thermonuclear fuel to fusion conditions. This is stillDENSE MATTER IN LASER DRIVEN FUSION ! LABORATORY EXPERIMENTS R.L. Mc Crory and J. Wilson Laboratory. The high power lasers in quaestion were constructed with laser fusion studies as the goal, i

  4. Dark energy and dust matter phases from an exact $f(R)$-cosmology model

    E-Print Network [OSTI]

    S. Capozziello; P. Martin-Moruno; C. Rubano

    2008-04-28T23:59:59.000Z

    We show that dust matter-dark energy combined phases can be achieved by the exact solution derived from a power law $f(R)$ cosmological model. This example answers the query by which a dust-dominated decelerated phase, before dark-energy accelerated phase, is needed in order to form large scale structures.

  5. Strange Quark Matter and Compact Stars

    E-Print Network [OSTI]

    Fridolin Weber

    2004-09-27T23:59:59.000Z

    Astrophysicists distinguish between three different types of compact stars. These are white dwarfs, neutron stars, and black holes. The former contain matter in one of the densest forms found in the Universe which, together with the unprecedented progress in observational astronomy, make such stars superb astrophysical laboratories for a broad range of most striking physical phenomena. These range from nuclear processes on the stellar surface to processes in electron degenerate matter at subnuclear densities to boson condensates and the existence of new states of baryonic matter--like color superconducting quark matter--at supernuclear densities. More than that, according to the strange matter hypothesis strange quark matter could be more stable than nuclear matter, in which case neutron stars should be largely composed of pure quark matter possibly enveloped in thin nuclear crusts. Another remarkable implication of the hypothesis is the possible existence of a new class of white dwarfs. This article aims at giving an overview of all these striking physical possibilities, with an emphasis on the astrophysical phenomenology of strange quark matter. Possible observational signatures associated with the theoretically proposed states of matter inside compact stars are discussed as well. They will provide most valuable information about the phase diagram of superdense nuclear matter at high baryon number density but low temperature, which is not accessible to relativistic heavy ion collision experiments.

  6. Ship response using a compact wave spectrum model

    E-Print Network [OSTI]

    Linn, Larry Donald

    1985-01-01T23:59:59.000Z

    statistical technique, known as principal component analysis, is used to compact large data bases of theoretical and real spectral information. Statistical properties of the various data bases are examined in their original and compacted forms. Sensitivity.... The available spectrum models fall into two basic categories. Formulas which use the first, or "classic, " approach use wind speed as the independent variable to define the spectrum. The Pierson-Noskowitz Spectrum is an example of this type...

  7. On the essential spectrum of certain non-commutative oscillators

    SciTech Connect (OSTI)

    Parmeggiani, Alberto, E-mail: alberto.parmeggiani@unibo.it; Venni, Alberto, E-mail: alberto.venni@unibo.it [Department of Mathematics, University of Bologna, Piazza di Porta S.Donato 5, 40126 Bologna (Italy)] [Department of Mathematics, University of Bologna, Piazza di Porta S.Donato 5, 40126 Bologna (Italy)

    2013-12-15T23:59:59.000Z

    We show here that the spectrum of the family of non-commutative harmonic oscillators Q{sub (?,?)}{sup w}(x,D) for ?,??R{sub +} in the range ?? = 1 is [0, +?) and is entirely essential spectrum. The previous existing results concern the case ?? > 1 (case in which Q{sub (?,?)}{sup w}(x,D) is globally elliptic with a discrete spectrum whose qualitative properties are being extensively studied), and ours therefore extend the picture to the range of parameters ?? ? 1.

  8. Possible dark energy imprints in gravitational wave spectrum of mixed neutron-dark-energy stars

    E-Print Network [OSTI]

    Stoytcho S. Yazadjiev; Daniela D. Doneva

    2011-12-19T23:59:59.000Z

    In the present paper we study the oscillation spectrum of neutron stars containing both ordinary matter and dark energy in different proportions. Within the model we consider, the equilibrium configurations are numerically constructed and the results show that the properties of the mixed neuron-dark-energy star can differ significantly when the amount of dark energy in the stars is varied. The oscillations of the mixed neuron-dark-energy stars are studied in the Cowling approximation. As a result we find that the frequencies of the fundamental mode and the higher overtones are strongly affected by the dark energy content. This can be used in the future to detect the presence of dark energy in the neutron stars and to constrain the dark-energy models.

  9. Power oscillator

    DOE Patents [OSTI]

    Gitsevich, Aleksandr (Montgomery Village, MD)

    2001-01-01T23:59:59.000Z

    An oscillator includes an amplifier having an input and an output, and an impedance transformation network connected between the input of the amplifier and the output of the amplifier, wherein the impedance transformation network is configured to provide suitable positive feedback from the output of the amplifier to the input of the amplifier to initiate and sustain an oscillating condition, and wherein the impedance transformation network is configured to protect the input of the amplifier from a destructive feedback signal. One example of the oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to match the driving frequency of the oscillator to a plurality of tuning states of the lamp.

  10. Matter-radiation interactions in extremes

    SciTech Connect (OSTI)

    Garnett, Robert W [Los Alamos National Laboratory; Gulley, Mark S [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    LANSCE has been the centerpiece of large-scale science at Los Alamos National Laboratory for many decades. Recently, funding has been obtained to ensure continued reliable operation of the LANSCE linac and to allow planning to enable the first in a new generation of scientific facilities for the materials community. The emphasis of this new facility is 'Matter-Radiation Interactions in Extremes' (MaRIE) which will be used to discover and design the advanced materials needed to meet 21st century national security and energy security challenges. MaRIE will provide the tools scientists need to develop next-generation materials that will perform predictably and on-demand for currently unattainable lifetimes in extreme environments. The MaRIE facility is based on a high-power upgrade to the existing LANSCE proton linac, a new electron linac and associated X-ray FEL to provide additional probe beams, and new experimental areas. A conceptual description of this new facility and its requirements will be presented.

  11. Use Remote Sensing Data (selected visible and infrared spectrums...

    Broader source: Energy.gov (indexed) [DOE]

    Use Remote Sensing Data (selected visible and infrared spectrums) to locate high temperature ground anomalies in Colorado. Confirm heat flow potential with on-site surveys to drill...

  12. Use Remote Sensing Data (selected visible and infrared spectrums...

    Broader source: Energy.gov (indexed) [DOE]

    City - May 19, 2010 * Project Title - "Use Remote Sensing Data (selected visible and infrared spectrums) to locate high temperature ground anomalies in Colorado. Confirm heat flow...

  13. advanced spectrum management: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    communicate efficiently avoiding interference with licensed or unlicensed users. In this work, a fuzzy logic based system for spectrum management is proposed where the radio can...

  14. age spectrum epidemiology: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of a young supernova. We associate this break with the phenomenon of synchrotron aging of radiating electrons. From the break in the spectrum we calculate the magnetic field...

  15. adult schizophrenia spectrum: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (ASD): Scores on the Autism Spectrum Quotient (AQ) and CiteSeer Summary: Abstract While knowledge about symptom presentation of adults with mild ASD, including comorbid...

  16. auditory neuropathy spectrum: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of symptoms concentrate on speech and language development, especially ... Bullock, Bennett (Bennett Charles) 2010-01-01 3 Multisensory integration in autism spectrum disorders:...

  17. Department of Energy to Host Spectrum Policy Seminar for the...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    technologies. At this spectrum policy seminar, senior officials from the Federal Communications Commission (FCC) and the Commerce Department's National Telecommunications and...

  18. The Evolution of Galaxies by the Incompatibility between Dark Matter and Baryonic Matter

    E-Print Network [OSTI]

    Ding-Yu Chung

    2011-02-10T23:59:59.000Z

    In this paper, the evolution of galaxies is by the incompatibility between dark matter and baryonic matter. Due to the structural difference, baryonic matter and dark matter are incompatible to each other as oil droplet and water in emulsion. In the interfacial zone between dark matter and baryonic matter, this incompatibility generates the modification of Newtonian dynamics to keep dark matter and baryonic matter apart. The five periods of baryonic structure development in the order of increasing incompatibility are the free baryonic matter, the baryonic droplet, the galaxy, the cluster, and the supercluster periods. The transition to the baryonic droplet generates density perturbation in the CMB. In the galaxy period, the first-generation galaxies include elliptical, normal spiral, barred spiral, irregular, and dwarf spheroidal galaxies. In the cluster period, the second-generation galaxies include modified giant ellipticals, cD, evolved S0, dwarf elliptical, BCD, and tidal dwarf galaxies. The whole observable expanding universe behaves as one unit of emulsion with increasing incompatibility between dark matter and baryonic matter. The properties of dark matter and baryonic matter are based on cosmology derived from the two physical structures: the space structure and the object structure. Baryonic matter can be described by the periodic table of elementary particles.

  19. Mass spectrum of primordial black holes from inflationary perturbation in the Randall-Sundrum braneworld: a limit on blue spectra

    E-Print Network [OSTI]

    Yuuiti Sendouda; Shigehiro Nagataki; Katsuhiko Sato

    2006-06-07T23:59:59.000Z

    The mass spectrum of the primordial black holes formed by density perturbation in the radiation-dominated era of the Randall-Sundrum type-2 cosmology is given. The spectrum coincides with standard four-dimensional one on large scales but the deviation is apparent on smaller scales. The mass spectrum is initially softer than standard four-dimensional one, while after accretion during the earliest era it becomes harder than that. We also show expected extragalactic diffuse photon background spectra varying the initial perturbation power-law power spectrum and give constraints on the blue spectra and/or the reheating temperature. The most recent observations on the small scale density perturbation from WMAP, SDSS and Lyman-\\alpha Forest are used. What we get are interpreted as constraints on the smaller scale inflation on the brane connected to the larger one at the scale of Lyman-\\alpha Forest. If we set the bulk curvature radius to be 0.1 mm and assume the reheating temperature is higher than 10^6 GeV, the scalar spectral index from the smaller scale inflation is constrained to be n \\lesssim 1.3. Typically, the constraints are tighter than standard four-dimensional one, which is also revised by us using the most recent observations.

  20. EXTRAGALACTIC DARK MATTER AND DIRECT DETECTION EXPERIMENTS

    SciTech Connect (OSTI)

    Baushev, A. N., E-mail: baushev@gmail.com [DESY, D-15738 Zeuthen (Germany); Institut fuer Physik und Astronomie, Universitaet Potsdam, D-14476 Potsdam-Golm (Germany)

    2013-07-10T23:59:59.000Z

    Recent astronomical data strongly suggest that a significant part of the dark matter content of the Local Group and Virgo Supercluster is not incorporated into the galaxy halos and forms diffuse components of these galaxy clusters. A portion of the particles from these components may penetrate the Milky Way and make an extragalactic contribution to the total dark matter containment of our Galaxy. We find that the particles of the diffuse component of the Local Group are apt to contribute {approx}12% to the total dark matter density near Earth. The particles of the extragalactic dark matter stand out because of their high speed ({approx}600 km s{sup -1}), i.e., they are much faster than the galactic dark matter. In addition, their speed distribution is very narrow ({approx}20 km s{sup -1}). The particles have an isotropic velocity distribution (perhaps, in contrast to the galactic dark matter). The extragalactic dark matter should provide a significant contribution to the direct detection signal. If the detector is sensitive only to the fast particles (v > 450 km s{sup -1}), then the signal may even dominate. The density of other possible types of the extragalactic dark matter (for instance, of the diffuse component of the Virgo Supercluster) should be relatively small and comparable with the average dark matter density of the universe. However, these particles can generate anomaly high-energy collisions in direct dark matter detectors.

  1. Superconducting Radio Frequency Cavities as Axion Dark Matter Detectors

    E-Print Network [OSTI]

    P. Sikivie

    2013-01-20T23:59:59.000Z

    A modification of the cavity technique for axion dark matter detection is described in which the cavity is driven with input power instead of being permeated by a static magnetic field. A small fraction of the input power is pumped by the axion field to a receiving mode of frequency $\\omega_1$ when the resonance condition $\\omega_1 = \\omega_0 \\pm m_a$ is satisfied, where $\\omega_0$ is the frequency of the input mode and $m_a$ the axion mass. The relevant form factor is calculated for any pair of input and output modes in a cylindrical cavity. The overall search strategy is discussed and the technical challenges to be overcome by an actual experiment are listed.

  2. Apparatus for synthesis of a solar spectrum

    DOE Patents [OSTI]

    Sopori, Bhushan L. (Denver, CO)

    1993-01-01T23:59:59.000Z

    A xenon arc lamp and a tungsten filament lamp provide light beams that together contain all the wavelengths required to accurately simulate a solar spectrum. Suitable filter apparatus selectively direct visible and ultraviolet light from the xenon arc lamp into two legs of a trifurcated randomized fiber optic cable. Infrared light selectively filtered from the tungsten filament lamp is directed into the third leg of the fiber optic cable. The individual optic fibers from the three legs are brought together in a random fashion into a single output leg. The output beam emanating from the output leg of the trifurcated randomized fiber optic cable is extremely uniform and contains wavelengths from each of the individual filtered light beams. This uniform output beam passes through suitable collimation apparatus before striking the surface of the solar cell being tested. Adjustable aperture apparatus located between the lamps and the input legs of the trifurcated fiber optic cable can be selectively adjusted to limit the amount of light entering each leg, thereby providing a means of "fine tuning" or precisely adjusting the spectral content of the output beam. Finally, an adjustable aperture apparatus may also be placed in the output beam to adjust the intensity of the output beam without changing the spectral content and distribution of the output beam.

  3. THE SUBMILLIMETER POLARIZATION SPECTRUM OF M17

    SciTech Connect (OSTI)

    Zeng Lingzhen; Jimenez-Serra, Izaskun [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bennett, Charles L. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Chapman, Nicholas L.; Novak, Giles [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States); Chuss, David T. [Observational Cosmology Laboratory, NASA Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Vaillancourt, John E., E-mail: lingzhen@cfa.harvard.edu [SOFIA Science Center, Universities Space Research Association, NASA Ames Research Center, MS 232-11, Moffett Field, CA 94035 (United States)

    2013-08-10T23:59:59.000Z

    We present 450 {mu}m polarimetric observations of the M17 molecular cloud obtained with the SHARP polarimeter at the Caltech Submillimeter Observatory. Across the observed region, the magnetic field orientation is consistent with previous submillimeter and far-infrared polarization measurements. Our observations are centered on a region of the molecular cloud that has been compressed by stellar winds from a cluster of OB stars. We have compared these new data with previous 350 {mu}m polarimetry and find an anti-correlation between the 450 and 350 {mu}m polarization magnitude ratio and the ratio of 21 cm to 450 {mu}m intensity. The polarization ratio is lower near the east end of the studied region where the cloud is exposed to stellar winds and radiation. At the west end of the region, the polarization ratio is higher. We interpret the varying polarization spectrum as evidence supporting the radiative alignment torque model for grain alignment, implying higher alignment efficiency in the region that is exposed to a higher anisotropic radiation field.

  4. HIGH AVERAGE POWER UV FREE ELECTRON LASER EXPERIMENTS AT JLAB

    SciTech Connect (OSTI)

    Douglas, David; Evtushenko, Pavel; Gubeli, Joseph; Hernandez-Garcia, Carlos; Legg, Robert; Neil, George; Powers, Thomas; Shinn, Michelle D; Tennant, Christopher

    2012-07-01T23:59:59.000Z

    Having produced 14 kW of average power at {approx}2 microns, JLAB has shifted its focus to the ultraviolet portion of the spectrum. This presentation will describe the JLab UV Demo FEL, present specifics of its driver ERL, and discuss the latest experimental results from FEL experiments and machine operations.

  5. Radiative transitions of high energy neutrino in dense matter

    E-Print Network [OSTI]

    A. E. Lobanov

    2005-06-01T23:59:59.000Z

    The quantum theory of the ``spin light'' (electromagnetic radiation emitted by a massive neutrino propagating in dense matter due to the weak interaction of a neutrino with background fermions) is developed. In contrast to the Cherenkov radiation, this effect does not disappear even if the medium refractive index is assumed to be equal to unity. The formulas for the transition rate and the total radiation power are obtained. It is found out that radiation of photons is possible only when the sign of the particle helicity is opposite to that of the effective potential describing the interaction of a neutrino (antineutrino) with the background medium. Due to the radiative self-polarization the radiating particle can change its helicity. As a result, the active left-handed polarized neutrino (right-handed polarized antineutrino) converting to the state with inverse helicity can become practically ``sterile''. Since the sign of the effective potential depends on the neutrino flavor and the matter structure, the ``spin light'' can change a ratio of active neutrinos of different flavors. In the ultra relativistic approach, the radiated photons averaged energy is equal to one third of the initial neutrino energy, and two thirds of the energy are carried out by the final ``sterile'' neutrinos. This fact can be important for the understanding of the ``dark matter'' formation mechanism on the early stages of evolution of the Universe.

  6. Statistical Issues in Astrophysical Searches for Particle Dark Matter

    E-Print Network [OSTI]

    Jan Conrad

    2014-10-14T23:59:59.000Z

    In this review statistical issues appearing in astrophysical searches for particle dark matter, i.e. indirect detection (dark matter annihilating into standard model particles) or direct detection (dark matter particles scattering in deep underground detectors) are discussed. One particular aspect of these searches is the presence of very large uncertainties in nuisance parameters (astrophysical factors) that are degenerate with parameters of interest (mass and annihilation/decay cross sections for the particles). The likelihood approach has become the most powerful tool, offering at least one well motivated method for incorporation of nuisance parameters and increasing the sensitivity of experiments by allowing a combination of targets superior to the more traditional data stacking. Other statistical challenges appearing in astrophysical searches are to large extent similar to any new physics search, for example at colliders, a prime example being the calculation of trial factors. Frequentist methods prevail for hypothesis testing and interval estimation, Bayesian methods are used for assessment of nuisance parameters and parameter estimation in complex parameter spaces. The basic statistical concepts will be exposed, illustrated with concrete examples from experimental searches and caveats will be pointed out.

  7. The CRESST Dark Matter Search

    E-Print Network [OSTI]

    B. Majorovits; G. Angloher; C. Bucci; P. Christ; C. Cozzini; F. von Feilitzsch; D. Hauff; S. Henry; Th. Jagemann; J. Jochum; H. Kraus; V. Mikhailik; J. Ninkovic; F. Petricca; W. Potzel; F. Proebst; Y. Ramachers; M. Razeti; W. Rau; W. Seidel; M. Stark; L. Stodolsky; A. J. B. Tolhurst; D. Wahl; W. Westphal; H. Wulandari

    2004-11-15T23:59:59.000Z

    We present first competitive results on WIMP dark matter using the phonon-light-detection technique. A particularly strong limit for WIMPs with coherent scattering results from selecting a region of the phonon-light plane corresponding to tungsten recoils. The observed count rate in the neutron band is compatible with the rate expected from neutron background. CRESST is presently being upgraded with a 66 channel SQUID readout system, a neutron shield and a muon veto system. This results in a significant improvement in sensitivity.

  8. Axion hot dark matter bounds

    E-Print Network [OSTI]

    G. Raffelt; S. Hannestad; A. Mirizzi; Y. Y. Y. Wong

    2008-08-06T23:59:59.000Z

    We derive cosmological limits on two-component hot dark matter consisting of neutrinos and axions. We restrict the large-scale structure data to the safely linear regime, excluding the Lyman-alpha forest. We derive Bayesian credible regions in the two-parameter space consisting of m_a and sum(m_nu). Marginalizing over sum(m_nu) provides m_aaxions the same data and methods give sum(m_nu)< 0.63 eV (95% CL).

  9. Holographic Viscosity of Fundamental Matter

    E-Print Network [OSTI]

    David Mateos; Robert C. Myers; Rowan M. Thomson

    2006-10-16T23:59:59.000Z

    A holographic dual of a finite-temperature SU(N_c) gauge theory with a small number of flavours N_f viscosity to entropy ratio in these theories saturates the conjectured universal bound eta/s >= 1/4\\pi. The contribution of the fundamental matter eta_fund is therefore enhanced at strong 't Hooft coupling lambda; for example, eta_fund ~ lambda N_c N_f T^3 in four dimensions. Other transport coefficients are analogously enhanced. These results hold with or without a baryon number chemical potential.

  10. Diffractive Interaction and Scaling Violation in pp->pi^0 Interaction and GeV Excess in Galactic Diffuse Gamma-Ray Spectrum of EGRET

    E-Print Network [OSTI]

    T. Kamae; T. Abe; T. Koi

    2005-01-21T23:59:59.000Z

    We present here a new calculation of the gamma-ray spectrum from pp->pi^0 in the Galactic ridge environment. The calculation includes the diffractive pp interaction and incorporates the Feynman scaling violation for the first time. Galactic diffuse gamma-rays come, predominantly, from pi^0->gamma gamma in the sub-GeV to multi-GeV range. Hunter et al. found, however, an excess in the GeV range ("GeV Excess") in the EGRET Galactic diffuse spectrum above the prediction based on experimental pp->pi^0 cross-sections and the Feynman scaling hypothesis. We show, in this work, that the diffractive process makes the gamma-ray spectrum harder than the incident proton spectrum by ~0.05 in power-law index, and, that the scaling violation produces 30-80% more pi^0 than the scaling model for incident proton energies above 100GeV. Combination of the two can explain about a half of the "GeV Excess" with the local cosmic proton (power-law index ~2.7). The excess can be fully explained if the proton spectral index in the Galactic ridge is a little harder (~0.2 in power-law index) than the local spectrum. Given also in the paper is that the diffractive process enhances e^+ over e^- and the scaling violation gives 50-100% higher p-bar yield than without the violation, both in the multi-GeV range.

  11. Analytic spectrum of relic gravitational waves modified by neutrino free streaming and dark energy

    SciTech Connect (OSTI)

    Miao, H. X.; Zhang, Y. [Astrophysics Center, University of Science and Technology of China, Hefei, Anhui (China)

    2007-05-15T23:59:59.000Z

    We include the effect of neutrino free streaming into the spectrum of relic gravitational waves (RGWs) in the currently accelerating universe. For the realistic case of a varying fractional neutrino energy density and a nonvanishing derivative of the mode function at the neutrino decoupling, the integro-differential equation of RGWs is solved by a perturbation method for the period from the neutrino decoupling to the matter-dominant stage. Incorporating it into the analytic solution of RGWs for the whole history of expansion of the universe, the analytic solution of RGWs is obtained, evolving from inflation up to the current acceleration. The resulting spectrum of RGWs covers the whole range of frequency (10{sup -19}-10{sup 10}) Hz and improves the previous results. It is found that neutrino free streaming causes a reduction of the spectral amplitude by {approx}20% in the range (10{sup -16}-10{sup -10}) Hz, and leaves the other portion of the spectrum almost unchanged. This agrees with the earlier numerical calculations. Examination is made on the difference between the accelerating and nonaccelerating models, and our analysis shows that the ratio of the spectral amplitude in the accelerating {lambda}CDM model over that in the CDM model is {approx}0.7, and within the various accelerating models of {omega}{sub {lambda}}>{omega}{sub m} the spectral amplitude is proportional to {omega}{sub m}/{omega}{sub {lambda}} for the whole range of frequency. Comparison with LIGO S5 run sensitivity shows that RGWs are not yet detectable by the present LIGO, and in the future LISA may be able to detect RGWs in some inflationary models.

  12. Modeling of combustion noise spectrum from turbulent premixed flames

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Modeling of combustion noise spectrum from turbulent premixed flames Y. Liu, A. P. Dowling, T. D, Nantes, France 2321 #12;Turbulent combustion processes generate sound radiation due to temporal changes, this temporal correlation and its role in the modeling of combustion noise spectrum are studied by analyzing

  13. atmospheric energy spectrum: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    atmospheric energy spectrum First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 High-energy spectrum and...

  14. CENSORED TRUNCATED SEQUENTIAL SPECTRUM SENSING FOR COGNITIVE RADIO NETWORKS

    E-Print Network [OSTI]

    Leus, Geert

    interference to the primary user and the false alarm rate controls the loss in spectrum utilization. The ideal Leus Faculty of Electrical Engineering, Delft University of Technology, Delft, The Netherlands E is con- sidered as an energy saving approach for a cooperative spectrum sensing system. In order

  15. Supporting Dynamic Spectrum Access in Heterogeneous LTE+ Networks

    SciTech Connect (OSTI)

    Luiz A. DaSilva; Ryan E. Irwin; Mike Benonis

    2012-08-01T23:59:59.000Z

    As early as 2014, mobile network operators’ spectral capac- ity is expected to be overwhelmed by the demand brought on by new devices and applications. With Long Term Evo- lution Advanced (LTE+) networks likely as the future one world 4G standard, network operators may need to deploy a Dynamic Spectrum Access (DSA) overlay in Heterogeneous Networks (HetNets) to extend coverage, increase spectrum efficiency, and increase the capacity of these networks. In this paper, we propose three new management frameworks for DSA in an LTE+ HetNet: Spectrum Accountability Client, Cell Spectrum Management, and Domain Spectrum Man- agement. For these spectrum management frameworks, we define protocol interfaces and operational signaling scenar- ios to support cooperative sensing, spectrum lease manage- ment, and alarm scenarios for rule adjustment. We also quan- tify, through integer programs, the benefits of using DSA in an LTE+ HetNet, that can opportunistically reuse vacant TV and GSM spectrum. Using integer programs, we consider a topology using Geographic Information System data from the Blacksburg, VA metro area to assess the realistic benefits of DSA in an LTE+ HetNet.

  16. The QCD string spectrum and conformal field theory

    SciTech Connect (OSTI)

    Keisuke Jimmy Juge; Julius Kuti; Colin Morningstar

    2002-12-19T23:59:59.000Z

    The low energy excitation spectrum of the critical Wilson surface is discussed between the roughening transition and the continuum limit of lattice QCD. The fine structure of the spectrum is interpreted within the framework of two-dimensional conformal field theory.

  17. Power spectrum of passive scalars in two dimensional chaotic flows Guo-Cheng Yuan

    E-Print Network [OSTI]

    Rubloff, Gary W.

    for Plasma Research, University of Maryland, College Park, Maryland 20742 Parvez N. Guzdar Institute for Plasma Research, University of Maryland, College Park, Maryland 20742 Received 2 April 1999; accepted

  18. Physics 214 Notes on Cherenkov radiation Winter 2013 The power spectrum of Cherenkov radiation

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    velocity v, with no accel- eration. In this case, the particle trajectory is given by r(t) = vt. Using · v c + O 1 r2 . (8) If ^n · v = c/nr (which is possible if the charged particle is moving faster than

  19. A study of wind variability in the lower troposphere through power spectrum analysis at mesoscale frequencies

    E-Print Network [OSTI]

    Cornett, John Sheldon

    1966-01-01T23:59:59.000Z

    major energy peaks. One major peak occurred at a period of about 4 days and the second peak at a period of about 1 min with a rather broad, flat spectral curve in between these peaks. He attributed the low frequency peak to fluctuations in wind speed... tropospheze, both Mantis (1963) and Chiu (1960) found a high energy peak in the spectra of the horizontal wind components corresponding to synoptic-scale periods of 4 to 6 days. However, they were limited to considering periods of 2 days or more because...

  20. Axion Dark Matter Detection using Atomic Transitions

    E-Print Network [OSTI]

    P. Sikivie

    2014-09-09T23:59:59.000Z

    Dark matter axions may cause transitions between atomic states that differ in energy by an amount equal to the axion mass. Such energy differences are conveniently tuned using the Zeeman effect. It is proposed to search for dark matter axions by cooling a kilogram-sized sample to milliKelvin temperatures and count axion induced transitions using laser techniques. This appears an appropriate approach to axion dark matter detection in the $10^{-4}$ eV mass range.