National Library of Energy BETA

Sample records for holes time frame

  1. Dragging of inertial frames in the composed black-hole-ring system

    E-Print Network [OSTI]

    Hod, Shahar

    2015-01-01

    A well-established phenomenon in general relativity is the dragging of inertial frames by a spinning object. In particular, due to the dragging of inertial frames by a ring orbiting a central black hole, the angular-velocity of the black-hole horizon in the composed black-hole-ring system is no longer related to the black-hole angular-momentum by the simple Kerr-like (vacuum) relation $\\Omega^{\\text{Kerr}}_{\\text{H}}(J_{\\text{H}})=J_{\\text{H}}/2M^2R_{\\text{H}}$. Will has performed a perturbative treatment of the composed black-hole-ring system in the regime of slowly rotating black holes and found the explicit relation $\\Omega^{\\text{BH-ring}}_{\\text{H}}(J_{\\text{H}}=0,J_{\\text{R}},R)=2J_{\\text{R}}/R^3$ for the angular-velocity of a central black hole with zero angular-momentum. Analyzing a sequence of black-hole-ring configurations with adiabatically varying (decreasing) circumferential radii, we show that the expression found by Will implies a smooth transition of the central black-hole angular-velocity fro...

  2. Dragging of inertial frames in the composed black-hole-ring system

    E-Print Network [OSTI]

    Shahar Hod

    2015-11-10

    A well-established phenomenon in general relativity is the dragging of inertial frames by a spinning object. In particular, due to the dragging of inertial frames by a ring orbiting a central black hole, the angular-velocity of the black-hole horizon in the composed black-hole-ring system is no longer related to the black-hole angular-momentum by the simple Kerr-like (vacuum) relation $\\Omega^{\\text{Kerr}}_{\\text{H}}(J_{\\text{H}})=J_{\\text{H}}/2M^2R_{\\text{H}}$. Will has performed a perturbative treatment of the composed black-hole-ring system in the regime of slowly rotating black holes and found the explicit relation $\\Omega^{\\text{BH-ring}}_{\\text{H}}(J_{\\text{H}}=0,J_{\\text{R}},R)=2J_{\\text{R}}/R^3$ for the angular-velocity of a central black hole with zero angular-momentum. Analyzing a sequence of black-hole-ring configurations with adiabatically varying (decreasing) circumferential radii, we show that the expression found by Will implies a smooth transition of the central black-hole angular-velocity from its asymptotic near-horizon value $\\Omega^{\\text{BH-ring}}_{\\text{H}}(J_{\\text{H}}=0,J_{\\text{R}},R\\to R^{+}_{\\text{H}})$ to its final Kerr (vacuum) value $\\Omega^{\\text{Kerr}}_{\\text{H}}(J^{\\text{new}}_{\\text{H}})$. We use this important observation in order to generalize the result of Will to the regime of black-hole-ring configurations in which the central black holes possess non-zero angular momenta. Remarkably, we find the simple universal relation $\\Delta\\Omega_{\\text{H}}\\equiv\\Omega^{\\text{BH-ring}}_{\\text{H}}(J_{\\text{H}},J_{\\text{R}},R\\to R^{+}_{\\text{H}})-\\Omega^{\\text{Kerr}}_{\\text{H}}(J_{\\text{H}})={{J_{\\text{R}}}/{4M^3}}$ for the asymptotic deviation of the black-hole angular-velocity in the composed black-hole-ring system from the corresponding angular-velocity of the unperturbed (vacuum) Kerr black hole with the same angular-momentum.

  3. Black Hole Radiation with Modified Dispersion Relation in Tunneling Paradigm: Free-fall Frame

    E-Print Network [OSTI]

    Peng Wang; Haitang Yang; Shuxuan Ying

    2015-05-18

    Due to the exponential high gravitational red shift near the event horizon of a black hole, it might appear that the Hawking radiation would be highly sensitive to some unknown high energy physics. To study effects of any unknown physics at the Planck scale on the Hawking radiation, the dispersive field theory models have been proposed, which are variations of Unruh's sonic black hole analogy. In this paper, we use the Hamilton-Jacobi method to investigate the dispersive field theory models. The preferred frame is the free-fall frame of the black hole. The dispersion relation adopted agrees with the relativistic one at low energy but is modified near the Planck mass $m_{p}$. The corrections to the Hawking temperature are calculated for massive and charged particles to $\\mathcal{O}\\left( m_{p}^{-2}\\right) $ and neutral and massless particles with $\\lambda=0$ to all orders. The Hawking temperature of radiation agrees with the standard one at the leading order. After the spectrum of radiation near the horizon is obtained, we use the brick wall model to compute the thermal entropy of a massless scalar field near the horizon of a 4D spherically symmetric black hole and a 2D one. Finally, the luminosity of a Schwarzschild black hole is calculated by using the geometric optics approximation.

  4. Time-bin entangled photon holes

    E-Print Network [OSTI]

    J. Liang; J. D. Franson; T. B. Pittman

    2012-08-23

    The general concept of entangled photon holes is based on a correlated absence of photon pairs in an otherwise constant optical background. Here we consider the specialized case when this background is confined to two well-defined time bins, which allows the formation of time-bin entangled photon holes. We show that when the typical coherent state background is replaced by a true single-photon (Fock state) background, the basic time-bin entangled photon-hole state becomes equivalent to one of the time-bin entangled photon-pair states. We experimentally demonstrate these ideas using a parametric down-conversion photon-pair source, linear optics, and post-selection to violate a Bell inequality with time-bin entangled photon holes.

  5. Black Hole Radiation with Modified Dispersion Relation in Tunneling Paradigm: Static Frame

    E-Print Network [OSTI]

    Peng Wang; Haitang Yang

    2015-05-12

    Due to the exponential high gravitational red shift near the event horizon of a black hole, it might appears that the Hawking radiation would be highly sensitive to some unknown high energy physics. To study possible deviations from the Hawking's prediction, the dispersive field theory models have been proposed, following the Unruh's hydrodynamic analogue of a black hole radiation. In the dispersive field theory models, the dispersion relations of matter fields are modified at high energies, which leads to modifications of equations of motion. In this paper, we use the Hamilton-Jacobi method to investigate the dispersive field theory models. The preferred frame is the static frame of the black hole. The dispersion relation adopted agrees with the relativistic one at low energies but is modified near the Planck mass $m_{p}$. We calculate the corrections to the Hawking temperature for massive and charged particles to $\\mathcal{O}\\left(m_{p}^{-2}\\right) $ and massless and neutral particles to all orders. Our results suggest that the thermal spectrum of radiations near horizon is robust, e.g. corrections to the Hawking temperature are suppressed by $m_{p}$. After the spectrum of radiations near the horizon is obtained, we use the brick wall model to compute the thermal entropy of a massless scalar field near the horizon of a 4D spherically symmetric black hole. We find that the leading term of the entropy depends on how the dispersion relations of matter fields are modified, while the subleading logarithmic term does not. Finally, the luminosities of black holes are computed by using the geometric optics approximation.

  6. Black Hole Radiation with Modified Dispersion Relation in Tunneling Paradigm: Static Frame

    E-Print Network [OSTI]

    Wang, Peng

    2015-01-01

    Due to the exponential high gravitational red shift near the event horizon of a black hole, it might appears that the Hawking radiation would be highly sensitive to some unknown high energy physics. To study possible deviations from the Hawking's prediction, the dispersive field theory models have been proposed, following the Unruh's hydrodynamic analogue of a black hole radiation. In the dispersive field theory models, the dispersion relations of matter fields are modified at high energies, which leads to modifications of equations of motion. In this paper, we use the Hamilton-Jacobi method to investigate the dispersive field theory models. The preferred frame is the static frame of the black hole. The dispersion relation adopted agrees with the relativistic one at low energies but is modified near the Planck mass $m_{p}$. We calculate the corrections to the Hawking temperature for massive and charged particles to $\\mathcal{O}\\left(m_{p}^{-2}\\right) $ and massless and neutral particles to all orders. Our res...

  7. Black Hole Radiation with Modified Dispersion Relation in Tunneling Paradigm: Free-fall Frame

    E-Print Network [OSTI]

    Wang, Peng; Ying, Shuxuan

    2015-01-01

    Due to the exponential high gravitational red shift near the event horizon of a black hole, it might appear that the Hawking radiation would be highly sensitive to some unknown high energy physics. To study effects of any unknown physics at the Planck scale on the Hawking radiation, the dispersive field theory models have been proposed, which are variations of Unruh's sonic black hole analogy. In this paper, we use the Hamilton-Jacobi method to investigate the dispersive field theory models. The preferred frame is the free-fall frame of the black hole. The dispersion relation adopted agrees with the relativistic one at low energy but is modified near the Planck mass $m_{p}$. The corrections to the Hawking temperature are calculated for massive and charged particles to $\\mathcal{O}\\left( m_{p}^{-2}\\right) $ and neutral and massless particles with $\\lambda=0$ to all orders. The Hawking temperature of radiation agrees with the standard one at the leading order. After the spectrum of radiation near the horizon is...

  8. Black hole thermodynamics in finite time

    E-Print Network [OSTI]

    Gruber, Christine

    2016-01-01

    Finite-time thermodynamics provides the means to revisit ideal thermodynamic equilibrium processes in the light of reality and investigate the energetic "price of haste", i.e. the consequences of carrying out a process in finite time, when perfect equilibrium cannot be awaited due to economic reasons or the nature of the process. Employing the formalism of geometric thermodynamics, a lower bound on the energy dissipated during a process is derived from the thermodynamic length of that process. The notion of length is hereby defined via a metric structure on the space of equilibrium thermodynamics, spanned by a set of thermodynamic variables describing the system. Since the aim of finite-time thermodynamics is to obtain realistic limitations on idealized scenarios, it is a useful tool to reassess the efficiency of thermodynamic processes. We examine its implications for black hole thermodynamics, in particular scenarios inspired by the Penrose process, a thought experiment by which work can be extracted from a...

  9. Examining the Variability of Wind Power Output in the Regulation Time Frame: Preprint

    SciTech Connect (OSTI)

    Hodge, B. M.; Shedd, S.; Florita, A.

    2012-08-01

    This work examines the distribution of changes in wind power for different time scales in the regulation time frame as well as the correlation of changes in power output for individual wind turbines in a wind plant.

  10. A Possible Approach to Inclusion of Space and Time in Frame Fields of Quantum Representations of Real and Complex Numbers

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

    Benioff, Paul

    2009-01-01

    This work is based on the field of reference frames based on quantum representations of real and complex numbers described in other work. Here frame domains are expanded to include space and time lattices. Strings of qukits are described as hybrid systems as they are both mathematical and physical systems. As mathematical systems they represent numbers. As physical systems in each frame the strings have a discrete Schrodinger dynamics on the lattices. The frame field has an iterative structure such that the contents of a stagejframe have images in a stagej-1(parent) frame. A discussion of parent frame images includes themore »proposal that points of stagejframe lattices have images as hybrid systems in parent frames. The resulting association of energy with images of lattice point locations, as hybrid systems states, is discussed. Representations and images of other physical systems in the different frames are also described.« less

  11. Distinguishing causal time from Minkowski time and a model for the black hole quantum eigenstates

    E-Print Network [OSTI]

    G. 't Hooft

    1997-11-18

    A discussion is presented of the principle of black hole com- plementarity. It is argued that this principle could be viewed as a breakdown of general relativity, or alternatively, as the introduction of a time variable with multiple `sheets' or `branches' A consequence of the theory is that the stress-energy tensor as viewed by an outside observer is not simply the Lorentz-transform of the tensor viewed by an ingoing observer. This can serve as a justification of a new model for the black hole atmosphere, recently re-introduced. It is discussed how such a model may lead to a dynamical description of the black hole quantum states.

  12. Time history analysis of axial forces (Pass Through Forces) at joints in a braced frame

    E-Print Network [OSTI]

    Paschini, Vincent

    2012-01-01

    As buildings keep getting taller, traditional braced lateral systems take more loads. This generates a phenomenon at every joint of a frame called "Pass Through Force". Pass through forces come from the transfer of axial ...

  13. Legal Framing

    E-Print Network [OSTI]

    Leachman, Gwendolyn

    2013-01-01

    three ideal types of legal framing emerge from the research:body of this research. The ideal types discussed here arelegal framing research. The ideal types of legal framing

  14. The New York Times' Framing of Involvement of the Russian Federation in Arms and Nuclear Trade with the Islamic Republic of Iran in 2009-2011

    E-Print Network [OSTI]

    Bagiev, Artem

    2012-05-31

    This study examines the mediated portrait of nuclear and arms trade between Russia and Iran in The New York Times in 2009-2011, applying framing theory as a tool. I used three frames, pre-defined in earlier studies: attribution of responsibility...

  15. Lumpy AdS$\\bf{_5\\times}$ S$\\bf{^5}$ Black Holes and Black Belts

    E-Print Network [OSTI]

    Oscar J. C. Dias; Jorge E. Santos; Benson Way

    2015-01-26

    Sufficiently small Schwarzschild black holes in global AdS$_5\\times$S$^5$ are Gregory-Laflamme unstable. We construct new families of black hole solutions that bifurcate from the onset of this instability and break the full SO$(6)$ symmetry group of the S$^5$ down to SO$(5)$. These new "lumpy" solutions are labelled by the harmonics $\\ell$. We find evidence that the $\\ell = 1$ branch never dominates the microcanonical/canonical ensembles and connects through a topology-changing merger to a localised black hole solution with S$^8$ topology. We argue that these S$^8$ black holes should become the dominant phase in the microcanonical ensemble for small enough energies, and that the transition to Schwarzschild black holes is first order. Furthermore, we find two branches of solutions with $\\ell = 2$. We expect one of these branches to connect to a solution containing two localised black holes, while the other branch connects to a black hole solution with horizon topology $\\mathrm S^4\\times\\mathrm S^4$ which we call a "black belt".

  16. Holographic Space-time and Black Holes: Mirages As Alternate Reality

    E-Print Network [OSTI]

    Tom Banks; Willy Fischler; Sandipan Kundu; Juan F. Pedraza

    2014-01-30

    We revisit our investigation of the claim of [1] that old black holes contain a firewall, i.e. an in-falling observer encounters highly excited states at a time much shorter than the light crossing time of the Schwarzschild radius. We used the formalism of Holographic Space-time (HST) where there is no dramatic change in particle physics inside the horizon until a time of order the Schwarzschild radius. We correct our description of the interior of the black hole . HST provides a complete description of the quantum mechanics along any time-like trajectory, even those which fall through the black hole horizon. The latter are described as alternative factorizations of the description of an external observer, turning the mirage of the interior provided by that observer's membrane paradigm on the stretched horizon, into reality.

  17. Symmetry and the arrow of time in theoretical black hole astrophysics

    E-Print Network [OSTI]

    David Garofalo

    2015-07-27

    While the basic laws of physics seem time-reversal invariant, our understanding of the apparent irreversibility of the macroscopic world is well grounded in the notion of entropy. Because astrophysics deals with the largest structures in the Universe, one expects evidence there for the most pronounced entropic arrow of time. However, in recent theoretical astrophysics work it appears possible to identify constructs with time-reversal symmetry, which is puzzling in the large-scale realm especially because it involves the engines of powerful outflows in active galactic nuclei which deal with macroscopic constituents such as accretion disks, magnetic fields, and black holes. Nonetheless, the underlying theoretical structure from which this accreting black hole framework emerges displays a time-symmetric harmonic behavior, a feature reminiscent of basic and simple laws of physics. While we may expect such behavior for classical black holes due to their simplicity, manifestations of such symmetry on the scale of galaxies, instead, surprise. In fact, we identify a parallel between the astrophysical tug-of-war between accretion disks and jets in this model and the time symmetry-breaking of a simple overdamped harmonic oscillator. The validity of these theoretical ideas in combination with this unexpected parallel suggests that black holes are more influential in astrophysics than currently recognized and that black hole astrophysics is a more fundamental discipline.

  18. Parallel and real-time implementation of an acoustic echo canceller using oversampled wavelet frame algorithms 

    E-Print Network [OSTI]

    Tam, Pak-Yin

    1995-01-01

    This thesis describes a novel echo cancellation system that eliminates nonstationary echoes with long acoustic delays in real-time. By combining subband adaptive filtering and active system identification based on fast wavelet transform...

  19. Fermion Fields in BTZ Black Hole Space-Time and Entanglement Entropy

    E-Print Network [OSTI]

    Dharm Veer Singh; Sanjay Siwach

    2015-08-07

    We study the entanglement entropy of fermion fields in BTZ black hole space-time and calculate pre- factor of the leading and sub-leading terms and logarithmic divergence term of the entropy using the discretized model. The leading term is the standard Bekenstein-Hawking area law and sub-leading term corresponds to first quantum corrections in black hole entropy. We also investigate the corrections to entanglement entropy for massive fermion fields in BTZ space-time. The mass term does not affect the area law.

  20. Kerr black holes and time profiles of gamma-ray bursts

    E-Print Network [OSTI]

    S. McBreen; B. McBreen; L. Hanlon; F. Quilligan

    2002-08-19

    The cumulative light curves of gamma-ray bursts (GRBs) smooth the spiky nature of the running light curve. The cumulative count increases in an approximately linear way with time t for most bursts. In 19 out of 398 GRBs with T90 > 2s, the cumulative light curve was found to increase with time as \\~t^2 implying a linear increase in the running light curve. The non-linear sections last for a substantial fraction of the GRB duration, have a large proportion of the cumulative count and many resolved pulses that usually end with the highest pulse in the burst. The reverse behaviour was found in 11 GRBs where the running light curve decreased with time and some bursts are good mirror images of the increases. These GRBs are among the spectrally hardest bursts observed by BATSE. The most likely interpretation is that these effects are signatures of black holes that are either being spun up or down in the accretion process. In the spin up case, the increasing Kerr parameter of the black hole allows additional rotational and accretion energy to become available for extraction. The process is reversed if the black hole is spun down by magnetic field torques. The luminosity changes in GRBs are consistent with the predictions of the BZ process and neutrino annihilation and thus provide the link to spinning black holes. GRBs provide a new window for studying the general relativistic effects of Kerr black holes.

  1. Hadamard Renormalization of the Stress Energy Tensor in a Spherically Symmetric Black Hole Space-Time with an Application to Lukewarm Black Holes

    E-Print Network [OSTI]

    Cormac Breen; Adrian C. Ottewill

    2011-12-13

    We consider a quantum field which is in a Hartle-Hawking state propagating in a spherically symmetric black hole space-time. We calculate the components of the stress tensor, renormalized using the Hadamard form of the Green's function, in the exterior region of this space-time. We then specialize these results to the case of the `lukewarm' Riessner-Nordstrom-de Sitter black hole.

  2. Time delay and magnification centroid due to gravitational lensing by black holes and naked singularities

    E-Print Network [OSTI]

    K. S. Virbhadra; C. R. Keeton

    2007-10-11

    We model the massive dark object at the center of the Galaxy as a Schwarzschild black hole as well as Janis-Newman-Winicour naked singularities, characterized by the mass and scalar charge parameters, and study gravitational lensing (particularly time delay, magnification centroid, and total magnification) by them. We find that the lensing features are qualitatively similar (though quantitatively different) for the Schwarzschild black holes, weakly naked, and marginally strongly naked singularities. However, the lensing characteristics of strongly naked singularities are qualitatively very different from those due the Schwarzschild black holes. The images produced by Schwarzschild black hole lenses and weakly naked and marginally strongly naked singularity lenses always have positive time delays. On the other hand, the strongly naked singularity lenses can give rise to images with positive, zero, or negative time delays. In particular, for a large angular source position the direct image (the outermost image on the same side as the source) due to strongly naked singularity lensing always has negative time delay. We also found that the scalar field decreases the time delay and increases the magnitude of magnifications of images; this result could have important implications for cosmology. As the Janis-Newman-Winicour metric also describes the exterior gravitational field of a scalar star, naked singularities as well as scalar star lenses, if these exist in nature, will serve as more efficient cosmic telescopes than regular gravitational lenses.

  3. Time delay and magnification centroid due to gravitational lensing by black holes and naked singularities

    SciTech Connect (OSTI)

    Virbhadra, K. S.; Keeton, C. R.

    2008-06-15

    We model the massive dark object at the center of the Galaxy as a Schwarzschild black hole as well as Janis-Newman-Winicour naked singularities, characterized by the mass and scalar charge parameters, and study gravitational lensing (particularly time delay, magnification centroid, and total magnification) by them. We find that the lensing features are qualitatively similar (though quantitatively different) for Schwarzschild black holes, weakly naked, and marginally strongly naked singularities. However, the lensing characteristics of strongly naked singularities are qualitatively very different from those due to Schwarzschild black holes. The images produced by Schwarzschild black hole lenses and weakly naked and marginally strongly naked singularity lenses always have positive time delays. On the other hand, strongly naked singularity lenses can give rise to images with positive, zero, or negative time delays. In particular, for a large angular source position the direct image (the outermost image on the same side as the source) due to strongly naked singularity lensing always has a negative time delay. We also found that the scalar field decreases the time delay and increases the total magnification of images; this result could have important implications for cosmology. As the Janis-Newman-Winicour metric also describes the exterior gravitational field of a scalar star, naked singularities as well as scalar star lenses, if these exist in nature, will serve as more efficient cosmic telescopes than regular gravitational lenses.

  4. Non-singular rotating black hole with a time delay in the center

    E-Print Network [OSTI]

    De Lorenzo, Tommaso; Speziale, Simone

    2015-01-01

    As proposed by Bambi and Modesto, rotating non-singular black holes can be constructed via the Newman-Janis algorithm. Here we show that if one starts with a modified Hayward black hole with a time delay in the centre, the algorithm succeeds in producing a rotating metric, but curvature divergences reappear. To preserve finiteness, the time delay must be introduced directly at the level of the non-singular rotating metric. This is possible thanks to the deformation of the inner stationarity limit surface caused by the regularisation, and in more than one way. We outline three different possibilities, distinguished by the angular velocity of the event horizon. Along the way, we provide additional results on the Bambi-Modesto rotating Hayward metric, such as the structure of the regularisation occurring at the centre, the behaviour of the quantum gravity scale alike an electric charge in decreasing the angular momentum of the extremal black hole configuration, or details on the deformation of the ergosphere.

  5. Hadamard Renormalisation of the Stress Energy Tensor on the Horizons of a Spherically Symmetric Black Hole Space-Time

    E-Print Network [OSTI]

    Cormac Breen; Adrian C. Ottewill

    2012-01-11

    We consider a quantum field which is in a Hartle-Hawking state propagating in a general spherically symmetric black hole space-time. We make use of uniform approximations to the radial equation to calculate the components of the stress tensor, renormalized using the Hadamard form of the Green's function, on the horizons of this space-time. We then specialize these results to the case of the `lukewarm' Reissner-Nordstrom-de Sitter black hole and derive some conditions on the stress tensor for the regularity of the Hartle-Hawking state.

  6. A Black Hole Mass-Variability Time Scale Correlation at Submillimeter Wavelengths

    E-Print Network [OSTI]

    Bower, Geoffrey C; Markoff, Sera; Gurwell, Mark A; Rao, Ramprasad; McHardy, Ian

    2015-01-01

    We analyze the light curves of 413 radio sources at submillimeter wavelengths using data from the Submillimeter Array calibrator database. The database includes more than 20,000 observations at 1.3 and 0.8 mm that span 13 years. We model the light curves as a damped random walk and determine a characteristic time scale $\\tau$ at which the variability amplitude saturates. For the vast majority of sources, primarily blazars and BL Lac objects, we find only lower limits on $\\tau$. For two nearby low luminosity active galactic nuclei, M81 and M87, however, we measure $\\tau=1.6^{+3.0}_{-0.9}$ days and $\\tau=45^{+61}_{-24}$ days, respectively ($2\\sigma$ errors). Including the previously measured $\\tau=0.33\\pm 0.16$ days for Sgr A*, we show an approximately linear correlation between $\\tau$ and black hole mass for these nearby LLAGN. Other LLAGN with spectra that peak in the submm are expected to follow this correlation. These characteristic time scales are comparable to the minimum time scale for emission processes...

  7. TIME EVOLUTION OF FLARES IN GRB 130925A: JET PRECESSION IN A BLACK HOLE ACCRETION SYSTEM

    SciTech Connect (OSTI)

    Hou, Shu-Jin; Liu, Tong; Gu, Wei-Min; Sun, Mou-Yuan; Lu, Ju-Fu [Department of Astronomy and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China); Lin, Da-Bin [Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University, Nanning, Guangxi 530004 (China); Wu, Xue-Feng, E-mail: tongliu@xmu.edu.cn [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2014-01-20

    GRB 130925A, composed of three gamma-ray emission episodes and a series of orderly flares, has been detected by Swift, Fermi, Konus-Wind, and INTEGRAL. If the third weakest gamma-ray episode can be considered a giant flare, we find that after the second gamma-ray episode observed by INTEGRAL located at about 2000 s, a positive relation exists between the time intervals of the adjacent flares and the time since the episode. We suggest that the second gamma-ray episode and its flares originate from the resumption of the accretion process due to the fragments from the collapsar falling back; such a relation may be related to a hyperaccretion disk around a precessed black hole (BH). We propose that the origin and time evolution of the flares, and the approximately symmetrical temporal structure and spectral evolution of the single flare can be explained well by a jet precession model. In addition, the mass and spin of the BH can be constrained, which indicates a stellar-mass, fast-rotating BH located in the center of GRB 130925A.

  8. Modeling of time dependence of hole current and prediction of QBD and tBD for thin gate MOS devices based upon

    E-Print Network [OSTI]

    Schroder, Dieter K.

    near the hole charge trapped interface during F±N tunneling of electrons. The ®eld at the localized yield, ®rst order trapping kinetics and dierent tunneling conditions for determining the time variation for evaluating the time dependence of injected electron and generated substrate hole current under constant

  9. Object picture, quasinormal modes and late time tails of fermion perturbations in stringy black hole with U(1) charges

    E-Print Network [OSTI]

    Owen Pavel Fernández Piedra; Fidel Sosa; José L. Bernal-Castillo; Yulier Jimenez

    2012-06-09

    The aim of the present report is to study massless fermion perturbations outside five-dimensional stringy black holes with U(1) charges. The Dirac equation was numerically solved to obtain the time profiles for the evolving fermion fields, and the quasinormal frequencies at intermediate times are computed by numerical Prony fitting and semianalytical WKB expansion at sixth order. We also computed numerically the late-time power law decay factors, showing that there are in correspondence with previously reported results for the case of boson fields in higher dimensional odd space-times. The dependence of quasinormal frequencies with U(1) compactification charges are studied, and the stability of this class of higher dimensional black holes under fermion perturbations is established.

  10. Solar/hydrogen systems for the 1985 to 2000 time frame. Volume I. Solar/hydrogen systems assessment. Final report

    SciTech Connect (OSTI)

    Foster, R. W.; Tison, R. R.; Escher, W. J.D.; Hanson, J. A.

    1980-06-01

    The findings of a study of opportunities for commercialization of systems capable of producing hydrogen from solar energy are presented in two volumes. A compendium of monographs by specialists in the fields of solar energy conversion technologies, hydrogen production technologies and related technology descriptions from the general literature comprise Volume II. This data base was used to support an evaluation and selection process that identified four candidate solar/hydrogen systems best suited to commercialization within the next two decades. Volume I first reviews the background of the work and the methods used. Then an evaluation of the hydrogen product costs that might be achieved by the four selected candidate systems (photovoltaic/water electrolysis, thermal-heat engine/water electrolysis, wind energy/water electrolysis, small hydrogen/water electrolysis) is compared with the pricing structure and practices of the commodity gas market. Subsequently, product cost and market price match is noted to exist in the small user sector of the hydrogen marketplace. Barriers to and historical time lags in, commercialization of new technologies are then reviewed. Finally, recommendations for development and demonstration programs designed to accelerate the commercialization of the candidate systems are presented.

  11. Numerical Simulation of Spectral and Timing Properties of a Two Component Advective Flow around a Black Hole

    E-Print Network [OSTI]

    Garain, Sudip K; Chakrabarti, Sandip K

    2013-01-01

    We study the spectral and timing properties of a two component advective flow (TCAF) around a black hole by numerical simulation. Several cases have been simulated by varying the Keplerian disk rate and the resulting spectra and lightcurves have been produced for all the cases. The dependence of the spectral states and quasi-periodic oscillation (QPO) frequencies on the flow parameters is discussed. We also find the earlier explanation of arising of QPOs as the resonance between infall time scale and cooling time scale remain valid even for Compton cooling.

  12. Solution for "geodesic" motion of a Schwarzschild black hole along a magnetic field in AdS2 x S2 space-time

    E-Print Network [OSTI]

    Alekseev, George A

    2015-01-01

    The exact solution of Einstein - Maxwell equations for a Schwarzschild black hole immersed in the static spatially homogeneous AdS${}^2\\times\\mathbb{S}^2$ space-time of Bertotti-Robinson magnetic universe is presented. In this solution, the black hole possesses a finite initial boost in the direction of the magnetic field and performs a "geodesic" oscillating motion interacting with the background gravitational and electromagnetic fields.

  13. Frame-Semantic Parsing

    E-Print Network [OSTI]

    Das, Dipanjan

    Frame semantics is a linguistic theory that has been instantiated for English in the FrameNet lexicon. We solve the problem of frame-semantic parsing using a two-stage statistical model that takes lexical targets (i.e., ...

  14. 7. Flows in a rotating reference frame 7.1. Rotating reference frames

    E-Print Network [OSTI]

    Read, Peter L.

    in a rotating reference frame. We use rotating axes, fixed w.r.t. the rotating system but note that time-derivatives of vectors must be modified: 1 #12;Suppose frame R rotates at constant angular velocity = (0, 0, ) w.r.t. an inertial frame I. Consider vector A(t) ­ suppose for simplicity that it lies in the xy-plane of R and I

  15. Developing stress-monitoring sites using cross-hole seismology to stress-forecast the times and magnitudes of future earthquakes

    E-Print Network [OSTI]

    Developing stress-monitoring sites using cross-hole seismology to stress-forecast the times 2000 Abstract A new understanding of rockmass deformation suggests that changing stress in the crust almost all rocks in the crust. These stress-aligned micro cracks cause the widely observed splitting

  16. Timing and Spectral Properties of X-ray Emission from the Converging Flows onto Black hole: Monte-Carlo Simulations

    E-Print Network [OSTI]

    Philippe Laurent; Lev Titarchuk

    2001-10-11

    We demonstrate that a X-ray spectrum of a converging inflow (CI) onto a black hole is the sum of a thermal (disk) component and the convolution of some fraction of this component with the Comptonization spread (Green's) function. The latter component is seen as an extended power law at energies much higher than the characteristic energy of the soft photons. We show that the high energy photon production (source function) in the CI atmosphere is distributed with the characteristic maximum at about the photon bending radius, 1.5r_S, independently of the seed (soft) photon distribution. We show that high frequency oscillations of the soft photon source in this region lead to the oscillations of the high energy part of the spectrum but not of the thermal component. The high frequency oscillations of the inner region are not significant in the thermal component of the spectrum. We further demonstrate that Doppler and recoil effects (which are responsible for the formation of the CI spectrum) are related to the hard (positive) and soft (negative) time lags between the soft and hard photon energy channels respectively.

  17. Surgery on frames 

    E-Print Network [OSTI]

    Nguyen, Nga Quynh

    2009-05-15

    >q) . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2. The tight unit norm expansion problem (The case pFrames...

  18. Frame for a firearm

    DOE Patents [OSTI]

    Crandall, David L. (Idaho Falls, ID); Watson, Richard W. (Blackfoot, ID)

    2008-03-04

    A firearm frame which is adapted to be disposed in operative relationship as a component part of a firearm, the firearm having disposed in operative relationships each with one or more of the others, a barrel, a receiver, and at least one firing mechanism; wherein the barrel and receiver form operative parts of a movable assembly and the at least one firing mechanism is disposed in a substantially stationary operative relationship therewith; the firearm frame including at least one elongated support structure discrete from the barrel and receiver, the elongated support structure being adapted to directly support the movable assembly in an operative movable relationship therewith; whereby at least one of the barrel and receiver is in direct contact with and movable on the elongated support structure; and, a firing mechanism support structure connected to the at least one elongated support structure, the firing mechanism support structure being adapted to have the firing mechanism connected thereto; the firearm frame also directly supporting the movable assembly and the firing mechanism in corresponding movable and stationary operative relationships each with the other.

  19. Linear and nonlinear time series analysis of the black hole candidate Cygnus X-1 Jens Timmer,1

    E-Print Network [OSTI]

    Timmer, Jens

    Schwarz,2 Henning U. Voss,2 Ingo Wardinski,2 Tomaso Belloni,3 Gu¨nther Hasinger,4 Michael van der Klis,3, Germany Received 16 July 1999 We analyze the variability in the x-ray lightcurves of the black hole

  20. Phase transition and thermodynamical geometry for Schwarzschild AdS black hole in $AdS_5\\times{S^5}$ spacetime

    E-Print Network [OSTI]

    Jia-Lin Zhang; Rong-Gen Cai; Hongwei Yu

    2015-03-03

    We study thermodynamics and thermodynamic geometry of a five-dimensional Schwarzschild AdS black hole in $AdS_5\\times{S^5}$ spacetime by treating the cosmological constant as the number of colors in the boundary gauge theory and its conjugate quantity as the associated chemical potential. It is found that the chemical potential is always negative in the stable branch of black hole thermodynamics and it has a chance to be positive, but appears in the unstable branch. We calculate scalar curvatures of the thermodynamical Weinhold metric, Ruppeiner metric and Quevedo metric, respectively and we find that the divergence of scalar curvature is related to the divergence of specific heat with fixed chemical potential in the Weinhold metric and Ruppeiner metric, while in the Quevedo metric the divergence of scalar curvature is related to the divergence of specific heat with fixed number of colors and the vanishing of the specific heat with fixed chemical potential.

  1. Conformal Frame Dependence of Inflation

    E-Print Network [OSTI]

    Guillem Domènech; Misao Sasaki

    2015-10-15

    Physical equivalence between different conformal frames in scalar-tensor theory of gravity is a known fact. However, assuming that matter minimally couples to the metric of a particular frame, which we call the matter Jordan frame, the matter point of view of the universe may vary from frame to frame. Thus, there is a clear distinction between gravitational sector (curvature and scalar field) and matter sector. In this paper, focusing on a simple power-law inflation model in the Einstein frame, two examples are considered; a super-inflationary and a bouncing universe Jordan frames. Then we consider a spectator curvaton minimally coupled to a Jordan frame, and compute its contribution to the curvature perturbation power spectrum. In these specific examples, we find a blue tilt at short scales for the super-inflationary case, and a blue tilt at large scales for the bouncing case.

  2. Rest frame of bubble nucleation

    SciTech Connect (OSTI)

    Garriga, Jaume; Kanno, Sugumi; Tanaka, Takahiro E-mail: sugumi@cosmos.phy.tufts.edu

    2013-06-01

    Vacuum bubbles nucleate at rest with a certain critical size and subsequently expand. But what selects the rest frame of nucleation? This question has been recently addressed in [1] in the context of Schwinger pair production in 1+1 dimensions, by using a model detector in order to probe the nucleated pairs. The analysis in [1] showed that, for a constant external electric field, the adiabatic ''in'' vacuum of charged particles is Lorentz invariant, (and in this) case pairs tend to nucleate preferentially at rest with respect to the detector. Here, we sharpen this picture by showing that the typical relative velocity between the frame of nucleation and that of the detector is at most of order ?v ? S{sub E}{sup ?1/3} << 1. Here, S{sub E} >> 1 is the action of the instanton describing pair creation. The bound ?v coincides with the minimum uncertainty in the velocity of a non-relativistic charged particle embedded in a constant electric field. A velocity of order ?v is reached after a time interval of order ?t ? S{sub E}{sup ?1/3}r{sub 0} << r{sub 0} past the turning point in the semiclassical trajectory, where r{sub 0} is the size of the instanton. If the interaction takes place in the vicinity of the turning point, the semiclassical description of collision does not apply. Nonetheless, we find that even in this case there is still a strong asymmetry in the momentum transferred from the nucleated particles to the detector, in the direction of expansion after the turning point. We conclude that the correlation between the rest frame of nucleation and that of the detector is exceedingly sharp.

  3. High Performance Commercial Fenestration Framing Systems

    SciTech Connect (OSTI)

    Mike Manteghi; Sneh Kumar; Joshua Early; Bhaskar Adusumalli

    2010-01-31

    A major objective of the U.S. Department of Energy is to have a zero energy commercial building by the year 2025. Windows have a major influence on the energy performance of the building envelope as they control over 55% of building energy load, and represent one important area where technologies can be developed to save energy. Aluminum framing systems are used in over 80% of commercial fenestration products (i.e. windows, curtain walls, store fronts, etc.). Aluminum framing systems are often required in commercial buildings because of their inherent good structural properties and long service life, which is required from commercial and architectural frames. At the same time, they are lightweight and durable, requiring very little maintenance, and offer design flexibility. An additional benefit of aluminum framing systems is their relatively low cost and easy manufacturability. Aluminum, being an easily recyclable material, also offers sustainable features. However, from energy efficiency point of view, aluminum frames have lower thermal performance due to the very high thermal conductivity of aluminum. Fenestration systems constructed of aluminum alloys therefore have lower performance in terms of being effective barrier to energy transfer (heat loss or gain). Despite the lower energy performance, aluminum is the choice material for commercial framing systems and dominates the commercial/architectural fenestration market because of the reasons mentioned above. In addition, there is no other cost effective and energy efficient replacement material available to take place of aluminum in the commercial/architectural market. Hence it is imperative to improve the performance of aluminum framing system to improve the energy performance of commercial fenestration system and in turn reduce the energy consumption of commercial building and achieve zero energy building by 2025. The objective of this project was to develop high performance, energy efficient commercial fenestration framing systems, by investigating new technologies that would improve the thermal performance of aluminum frames, while maintaining their structural and life-cycle performance. The project targeted an improvement of over 30% (whole window performance) over conventional commercial framing technology by improving the performance of commercial framing systems.

  4. Rotating Black Holes and Coriolis Effect

    E-Print Network [OSTI]

    Wu, Xiaoning; Yuan, Pei-Hung; Cho, Chia-Jui

    2015-01-01

    In this work, we consider the fluid/gravity correspondence for general rotating black holes. By using the Petrov-like boundary condition in near horizon limit, we study the correspondence between gravitational perturbation and fluid equation. We find that the dual fluid equation for rotating black holes contains a Coriolis force term, which is closely related to the angular velocity of the black hole horizon. This can be seen as a dual effect for the frame-dragging effect of rotating black hole under the holographic picture.

  5. Rotating Black Holes and Coriolis Effect

    E-Print Network [OSTI]

    Xiaoning Wu; Yi Yang; Pei-Hung Yuan; Chia-Jui Cho

    2015-11-27

    In this work, we consider the fluid/gravity correspondence for general rotating black holes. By using the Petrov-like boundary condition in near horizon limit, we study the correspondence between gravitational perturbation and fluid equation. We find that the dual fluid equation for rotating black holes contains a Coriolis force term, which is closely related to the angular velocity of the black hole horizon. This can be seen as a dual effect for the frame-dragging effect of rotating black hole under the holographic picture.

  6. "Hybrid" Black Holes

    E-Print Network [OSTI]

    Valeri P. Frolov; Andrei V. Frolov

    2014-12-30

    We discuss a solution of the Einstein equations, obtained by gluing the external Kerr metric and the internal Weyl metric, describing an axisymmetric static vacuum distorted black hole. These metrics are glued at the null surfaces representing their horizons. For this purpose we use the formalism of massive thin null shells. The corresponding solution is called a "hybrid" black hole. The massive null shell has an angular momentum which is the origin of the rotation of the external Kerr spacetime. At the same time, the shell distorts the geometry inside the horizon. The inner geometry of the "hybrid" black hole coincides with the geometry of the interior of a non-rotating Weyl-distorted black hole. Properties of the "hybrid" black holes are briefly discussed.

  7. Handbook of normal frames and coordinates

    E-Print Network [OSTI]

    Bozhidar Z. Iliev

    2006-10-01

    The main subject of the book is an up-to-date and in-depth survey of the theory of normal frames and coordinates in differential geometry. The book can be used as a reference manual, review of the existing results and introduction to some new ideas and developments. In the book can be found practically all existing essential results and methods concerning normal frames and coordinates. Most of the results are represented in full detail with full, in some cases new, proofs. All classical results are expanded and generalized in various directions. Theorems of existence, uniqueness and, possibly, holonomicity of the normal frames and coordinates are proved; mostly, the proofs are constructive and some their parts can be used independently for other tasks. Besides published results, their extensions and generalizations, the book contains completely new results which appear for the first time.

  8. Racial Framing and the Multiracial Movement 

    E-Print Network [OSTI]

    Couch, Todd Christopher

    2012-07-16

    of Multiracialism ............................................................ 5 Systemic Analysis of Racism ......................................................... 7 The White Racial Frame... ................................................................................ 37 Individualistic Framing of Racism ................................................. 42 Summary ........................................................................................ 45...

  9. Disformal Gravity Theories: A Jordan Frame Analysis

    E-Print Network [OSTI]

    Sakstein, Jeremy

    2015-01-01

    The late-time cosmology of disformal gravity theories is studied in the Jordan frame using both dynamical systems methods, and by finding approximate solutions. We find that, either the disformal effects are irrelevant, or the universe evolves towards a phantom phase where the equation of state of dark energy is $-3$, in strong tension with observations. There is a marginal case where the asymptotic state of the universe depends on the model parameters and de-Sitter solutions can be obtained.

  10. Contrast from rotating frame relaxation by adiabatic pulses

    DOE Patents [OSTI]

    Michaeli, Shalom (St. Paul, MN); Garwood, Michael G. (Medina, MN); Ugurbil, Kamil (Minneapolis, MN); Sorce, Dennis J. (Cockeysville, MD)

    2007-10-09

    This document discusses, among other things, a system and method for modulating transverse and longitudinal relaxation time contrast in a rotating frame based on a train of radio frequency pulses.

  11. Black holes and gravitational waves in three-dimensional f(R) gravity

    E-Print Network [OSTI]

    Hongsheng Zhang; Dao-Jun Liu; Xin-Zhou Li

    2014-12-19

    In the three-dimensional pure Einstein gravity, the geometries of the vacuum space-times are always trivial, and gravitational waves (gravitons) are strictly forbidden. For the first time, we find a vacuum circularly symmetric black hole with nontrivial geometries in $f(R)$ gravity theory, in which a true singularity appears. In this frame with nontrivial geometry, a perturbative gravitational wave does exist. Beyond the perturbative level, we make a constructive proof of the existence of a gravitational wave in $f(R)$ gravity, where the Birkhoff-like theorem becomes invalid. We find two classes of exact solutions of circularly symmetric pure gravitational wave radiation and absorption.

  12. Framing Change: Social Movement Framing in University Living Wage Movements 

    E-Print Network [OSTI]

    Metcalf, Laurie D.

    2010-01-14

    of these living wage movements, two cases, Texas A&M University and Georgetown University, were selected for this study to examine through the lens of the social movement framing perspective. Data for the cases included interviews with activists and administrators...

  13. Will black holes eventually engulf the universe?

    E-Print Network [OSTI]

    Prado Martin-Moruno; Jose A. Jimenez Madrid; Pedro F. Gonzalez-Diaz

    2006-03-28

    The Babichev-Dokuchaev-Eroshenko model for the accretion of dark energy onto black holes has been extended to deal with black holes with non-static metrics. The possibility that for an asymptotic observer a black hole with large mass will rapidly increase and eventually engulf the Universe at a finite time in the future has been studied by using reasonable values for astronomical parameters. It is concluded that such a phenomenon is forbidden for all black holes in quintessential cosmological models.

  14. Holes in Spectral Lines

    E-Print Network [OSTI]

    Fontana, Peter R.; Srivastava, Rajendra P.

    1973-06-01

    at E = 0 is 2le I' Ib/(t)I = @~ R~R~~»nh'(IRlyt)e"'" (13)a ylal 0 5 '7 FIG. 3. Probabilities of photon emission as a function of time. The frequency corresponds to the energy differ- ence between the unperturbed degenerate excited states and the ground... states 6 is 0. 5 ey. For V= 0 the emission line is Lorentzian, but for V0 a "hole" appears at the frequency equal to the frequency difference between the excited nondecay- ing state and the ground state. The position of the "hole" is independent...

  15. Newton-Cartan Gravity in Noninertial Reference Frames

    E-Print Network [OSTI]

    Leo Rodriguez; James St. Germaine-Fuller; Sujeev Wickramasekara

    2014-12-26

    We study properties of Newton-Cartan gravity under transformations into all noninertial, nonrelativistic reference frames. The set of these transformations has the structure of an infinite dimensional Lie group, called the Galilean line group, which contains as a subgroup the Galilei group. We show that the fictitious forces of noninertial reference frames are naturally encoded in the Cartan connection transformed under the Galilean line group. These noninertial forces, which are coordinate effects, do not contribute to the Ricci tensor which describes the curvature of Newtonian spacetime. We show that only the $00$-component of the Ricci tensor is non-zero and equal to ($4\\pi$ times) the matter density in any inertial or noninetial reference frame and that it leads to what may be called Newtonian ADM mass. While the Ricci field equation and Gauss law are both fulfilled by the same physical matter density in inertial and linearly accelerating reference frames, there appears a discrepancy between the two in rotating reference frames in that Gauss law holds for an effective mass density that differs from the physical matter density. This effective density has its origin in the simulated magnetic field that appears in rotating frames, highlighting a rather striking difference between linearly and rotationally accelerating reference frames. We further show that the dynamical equations that govern the simulated gravitational and magnetic fields have the same form as Maxwell's equations, a surprising conclusion given that these equations are well-known to obey special relativity (and $U(1)$-gauge symmetry), rather than Galilean symmetry.

  16. Bimetric Gravity From Adjoint Frame Field In Four Dimensions

    E-Print Network [OSTI]

    Guo, Zhi-Qiang

    2015-01-01

    We provide a novel model of gravity by using adjoint frame fields in four dimensions. It has a natural interpretation as a gravitational theory of a complex metric field, which describes interactions between two real metrics. The classical solutions establish three appealing features. The spherical symmetric black hole solution has an additional hair, which includes the Schwarzschild solution as a special case. The de Sitter solution is realized without introducing a cosmological constant. The constant flat background breaks the Lorentz invariance spontaneously, although the Lorentz breaking effect can be localized to the second metric while the first metric still respects the Lorentz invariance.

  17. Natural Cutoffs effect on Charged Rotating TeV-Scale Black Hole Thermodynamics

    E-Print Network [OSTI]

    M. J. Soleimani; N. Abbasvandi; G. Gopir; Zainol Abidin Ibrahim; Shahidan Radiman; W. A. T Wan Abdullah

    2015-10-15

    We study the thermodynamics of charged rotating black hole in large extra dimensions scenario where quantum gravity effects are taken into account. We consider the effects of minimal length, minimal momentum, and maximal momentum as natural cutoffs on the thermodynamics of charged rotating TeV-scale black holes. In this framework the effect of the angular momentum and charge on the thermodynamics of the black hole are discussed. We focus also on frame dragging and Sagnac effect of the micro black holes.

  18. FUSION FRAMES AND THEORETICAL APPLICATIONS: FOR THE FUSION FRAME WEB PAGE

    E-Print Network [OSTI]

    Casazza, Pete

    FUSION FRAMES AND THEORETICAL APPLICATIONS: FOR THE FUSION FRAME WEB PAGE PETER G. CASAZZA The deepest and most difficult question in Fusion Frame Theory is the construction of fusion frames with added that they do not show how to construct the frames. Recently, Casazza and Fickus [4] have developed a Fusion

  19. Graphene and the Zermelo Optical Metric of the BTZ Black Hole

    E-Print Network [OSTI]

    M. Cvetic; G. W. Gibbons

    2012-05-23

    It is well known that the low energy electron excitations of the curved graphene sheet $\\Sigma$ are solutions of the massless Dirac equation on a 2+1 dimensional ultra-static metric on ${\\Bbb R} \\times \\Sigma$. An externally applied electric field on the graphene sheet induces a gauge potential which could be mimicked by considering a stationary optical metric of the Zermelo form, which is conformal to the BTZ black hole when the sheet has a constant negative curvature. The Randers form of the metric can model a magnetic field, which is related by a boost to an electric one in the Zermelo frame. We also show that there is fundamental geometric obstacle to obtaining a model that extends all the way to the black hole horizon.

  20. Do It Yourself Framing and Matting. 

    E-Print Network [OSTI]

    Strassburg, Kay

    1981-01-01

    ? ? ? ? ? ? ? Putting the Frame Together ? ? ? ? ? Cutting the Glass ? ? ???????? Contemporary Framing REFINISHING FRAMES ??? Supplies. ? ? ? ? ? ? ? . ?? Preparing the Raw Wood ?? Refinishing Old Frames Antiquing ????????? Refinishing Techniques... between artwork and glass to protect against mildew and wa terspotting. TYPE Mat board Rag board or museum board COMPOSITION wood pulp cloth fibers THICKNESS 2-ply 1/32" 2-ply *4-ply 1/16" 4-ply 8-ply 1/8" (also called double- weig;ht) COLORS...

  1. What happens to Petrov classification, on horizons of axisymmetric dirty black holes

    SciTech Connect (OSTI)

    Tanatarov, I. V.; Zaslavskii, O. B.

    2014-02-15

    We consider axisymmetric stationary dirty black holes with regular non-extremal or extremal horizons, and compute their on-horizon Petrov types. The Petrov type (PT) in the frame of the observer crossing the horizon can be different from that formally obtained in the usual (but singular in the horizon limit) frame of an observer on a circular orbit. We call this entity the boosted Petrov type (BPT), as the corresponding frame is obtained by a singular boost from the regular one. The PT off-horizon can be more general than PT on-horizon and that can be more general than the BPT on horizon. This is valid for all regular metrics, irrespective of the extremality of the horizon. We analyze and classify the possible relations between the three characteristics and discuss the nature and features of the underlying singular boost. The three Petrov types can be the same only for space-times of PT D and O off-horizon. The mutual alignment of principal null directions and the generator in the vicinity of the horizon is studied in detail. As an example, we also analyze a special class of metrics with utra-extremal horizons (for which the regularity conditions look different from the general case) and compare their off-horizon and on-horizon algebraic structure in both frames.

  2. Holographic Space-time and Newton's Law

    E-Print Network [OSTI]

    Tom Banks; Willy Fischler

    2013-10-25

    We derive Newton's Law from the formalism of Holographic Space-Time (HST). More precisely, we show that for a large class of Hamiltonians of the type proposed previously for the HST description of a geodesic in Minkowski space, the eikonal for scattering of two massless particles at large impact parameter scales as expected with the impact parameter and the energies of the particles in the center of mass (CM) frame. We also discuss the criteria for black hole production in this collision, and find an estimate, purely within the HST framework, for the impact parameter at which it sets in, which coincides with the estimate based on general relativity.

  3. Coronal Holes

    E-Print Network [OSTI]

    Cranmer, Steven R

    2009-01-01

    Coronal holes are the darkest and least active regions of the Sun, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the high-speed solar wind. This paper reviews measurements of the plasma properties in coronal holes and how these measurements are used to reveal details about the physical processes that heat the solar corona and accelerate the solar wind. It is still unknown to what extent the solar wind is fed by flux tubes that remain open (and are energized by footpoint-driven wave-like fluctuations), and to what extent much of the mass and energy is input intermittently from closed loops into the open-field regions. Evidence for both paradigms is summarized in this paper. Special emphasis is also given to spectroscopic and coronagraphic measurements that allow the highly dynamic non-equilibrium evolution of the plasma to be followed as the asymptotic conditions in interplanetary space are establish...

  4. Can Superconducting Cosmic Strings Piercing Seed Black Holes Generate Supermassive Black Holes in the Early Universe?

    E-Print Network [OSTI]

    Lake, Matthew J

    2015-01-01

    The discovery of a large number of supermassive black holes at redshifts $z> 6$, when the Universe was only nine hundred million years old, has raised the fundamental question of how such massive compact objects could form in a (cosmologically) short time interval. Each of the proposed standard scenarios for black hole formation, involving rapid accretion of seed black holes, or black hole mergers, faces severe theoretical difficulties in explaining the short time formation of supermassive objects. In the present Letter, we propose an alternative scenario for the formation of supermassive black holes in the early Universe in which energy transfer from superconducting cosmic strings, piercing small seed black holes, is the main physical process leading to rapid mass increase. The increase in mass of a primordial seed black hole pierced by two antipodal strings is estimated and it is shown that this increases linearly in time. Due to the high energy transfer rate from the cosmic strings, we find that supermassi...

  5. Spin Transport in non-inertial frame

    E-Print Network [OSTI]

    Chowdhury, Debashree

    2014-01-01

    The influence of acceleration and rotation on spintronic applications is theoretically investigated. In our formulation, considering a Dirac particle in a non-inertial frame, different spin related aspects are studied. The spin current appearing due to the inertial spin-orbit coupling (SOC) is enhanced by the interband mixing of the conduction and valence band states. Importantly, one can achieve a large spin current through the $\\vec{k}. \\vec{p}$ method in this non-inertial frame. Furthermore, apart from the inertial SOC term due to acceleration, for a particular choice of the rotation frequency, a new kind of SOC term can be obtained from the spin rotation coupling (SRC). This new kind of SOC is of Dresselhaus type and controllable through the rotation frequency. In the field of spintronic applications, utilizing the inertial SOC and SRC induced SOC term, theoretical proposals for the inertial spin filter, inertial spin galvanic effect are demonstrated. Finally, one can tune the spin relaxation time in semi...

  6. Low energy 2+1 string gravity; black hole solutions

    E-Print Network [OSTI]

    A. A. Garcia Diaz; G. Gutierrez Cano

    2014-12-17

    In this report a detailed derivation of the dynamical equations for an n dimensional heterotic string theory of the Horowitz type is carried out in the string frame and in the Einstein frame too. In particular, the dynamical equations of the three dimensional string theory are explicitly given. The relation of the Horowitz Welch and Horne Horowitz string black hole solution is exhibited. The Chan Mann charged dilaton solution is derived and the subclass of string solutions field is explicitly identified. The stationary generalization, via SL(2;R) transformations, of the static (2+1) Horne Horowitz string black hole solution is given.

  7. Modeling Laser Wakefield Accelerators in a Lorentz Boosted Frame

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

    Modeling Laser Wakefield Accelerators in a Lorentz Boosted Frame Modeling Laser Wakefield Accelerators in a Lorentz Boosted Frame VayBoost.gif An image showing the "boosted frame,"...

  8. Advanced Framing Systems and Packages - Building America Top...

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

    Advanced Framing Systems and Packages - Building America Top Innovation Advanced Framing Systems and Packages - Building America Top Innovation This photo shows advanced framing...

  9. Next Generation Advanced Framing - Building America Top Innovation...

    Energy Savers [EERE]

    Next Generation Advanced Framing - Building America Top Innovation Next Generation Advanced Framing - Building America Top Innovation This photo shows advanced framing on a rim...

  10. A time-domain fourth-order-convergent numerical algorithm to integrate black hole perturbations in the extreme-mass-ratio limit

    E-Print Network [OSTI]

    Carlos O. Lousto

    2006-05-26

    We obtain a fourth order accurate numerical algorithm to integrate the Zerilli and Regge-Wheeler wave equations, describing perturbations of nonrotating black holes, with source terms due to an orbiting particle. Those source terms contain the Dirac's delta and its first derivative. We also re-derive the source of the Zerilli and Regge-Wheeler equations for more convenient definitions of the waveforms, that allow direct metric reconstruction (in the Regge-Wheeler gauge).

  11. Geometry and constructions of finite frames 

    E-Print Network [OSTI]

    Strawn, Nathaniel Kirk

    2009-05-15

    AND CONSTRUCTIONS OF FINITE FRAMES A Thesis by NATHANIEL KIRK STRAWN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved by: Chair of Committee, Kenneth Dykema... of Advisory Committee: Kenneth Dykema Finite frames are special collections of vectors utilized in Harmonic Analysis and Dig- ital Signal Processing. In this thesis, geometric aspects and construction techniques are considered for the family of k-vector frames...

  12. Jets, frames, and their Cartan geometry

    E-Print Network [OSTI]

    Michael Grasseau

    2006-03-24

    Jets frames, that is a generalisation of ordinary frames on a manifold, are described in a language similar to that of gauge theory. This is achieved by constructing the Cartan geometry of a manifold with respect to the diffeomorphism symmetry. This point of vue allows to give new insights and interpretations in the theory of jet frames, in particular by making an interpolation between ordinary gauge theory concepts and pure jet ones.

  13. A Nonsingular Brans Wormhole: An Analogue to Naked Black Holes

    E-Print Network [OSTI]

    Amrita Bhattacharya; Ramil Izmailov; Ettore Laserra; Kamal K. Nandi

    2011-07-28

    In a recent paper, we showed the Jordan frame vacuum Brans Class I solution provided a wormhole analogue to Horowitz-Ross naked black hole in the wormhole range -3/2naked black holes, as described by Horowitz and Ross, are spacetimes where the tidal forces attain their maxima above the black hole horizon. We show that in the non-singular Class II spacetime this maxima is attained above the throat and thus can be treated as a wormhole analogue. Some related issues are also addressed.

  14. Topological Black Holes in Quantum Gravity

    E-Print Network [OSTI]

    J. Kowalski-Glikman; D. Nowak-Szczepaniak

    2000-07-31

    We derive the black hole solutions with horizons of non-trivial topology and investigate their properties in the framework of an approach to quantum gravity being an extension of Bohm's formulation of quantum mechanics. The solutions we found tend asymptotically (for large $r$) to topological black holes. We also analyze the thermodynamics of these space-times.

  15. Canonical structure of 2D black holes

    E-Print Network [OSTI]

    Navarro-Salas, J; Talavera, C F

    1994-01-01

    We determine the canonical structure of two-dimensional black-hole solutions arising in $2D$ dilaton gravity. By choosing the Cauchy surface appropriately we find that the canonically conjugate variable to the black hole mass is given by the difference of local (Schwarzschild) time translations at right and left spatial infinities. This can be regarded as a generalization of Birkhoff's theorem.

  16. The Curvelet Frame Applications of Curvelets

    E-Print Network [OSTI]

    Smith, Hart F.

    The Curvelet Frame Applications of Curvelets An Introduction to Curvelets Hart F. Smith Department Hart F. Smith An Introduction to Curvelets #12;The Curvelet Frame Applications of Curvelets Curvelets on second dyadic decomposition. f(x) = c (x) c = f(x) (x) dx Hart F. Smith An Introduction to Curvelets #12

  17. Integrated seat frame and back support

    SciTech Connect (OSTI)

    Martin, Leo (Coconut Grove, FL)

    1999-01-01

    An integrated seating device comprises a seat frame having a front end and a rear end. The seat frame has a double wall defining an exterior wall and an interior wall. The rear end of the seat frame has a slot cut therethrough both the exterior wall and the interior wall. The front end of the seat frame has a slot cut through just the interior wall thereof. A back support comprising a generally L shape has a horizontal member, and a generally vertical member which is substantially perpendicular to the horizontal member. The horizontal member is sized to be threaded through the rear slot and is fitted into the front slot. Welded slat means secures the back support to the seat frame to result in an integrated seating device.

  18. State-of-the-Art Highly Insulating Window Frames - Research and Market Review

    SciTech Connect (OSTI)

    Gustavsen, Arild; Jelle, Bjorn Petter; Arasteh, Dariush; Kohler, Christian

    2007-01-01

    This document reports the findings of a market and research review related to state-of-the-art highly insulating window frames. The market review focuses on window frames that satisfy the Passivhaus requirements (window U-value less or equal to 0.8 W/m{sup 2}K ), while other examples are also given in order to show the variety of materials and solutions that may be used for constructing window frames with a low thermal transmittance (U-value). The market search shows that several combinations of materials are used in order to obtain window frames with a low U-value. The most common insulating material seems to be Polyurethane (PUR), which is used together with most of the common structural materials such as wood, aluminum, and PVC. The frame research review also shows examples of window frames developed in order to increase the energy efficiency of the frames and the glazings which the frames are to be used together with. The authors find that two main tracks are used in searching for better solutions. The first one is to minimize the heat losses through the frame itself. The result is that conductive materials are replaced by highly thermal insulating materials and air cavities. The other option is to reduce the window frame area to a minimum, which is done by focusing on the net energy gain by the entire window (frame, spacer and glazing). Literature shows that a window with a higher U-value may give a net energy gain to a building that is higher than a window with a smaller U-value. The net energy gain is calculated by subtracting the transmission losses through the window from the solar energy passing through the windows. The net energy gain depends on frame versus glazing area, solar factor, solar irradiance, calculation period and U-value. The frame research review also discusses heat transfer modeling issues related to window frames. Thermal performance increasing measures, surface modeling, and frame cavity modeling are among the topics discussed. The review shows that the current knowledge gives the basis for improving the calculation procedures in the calculation standards. At the same time it is room for improvement within some areas, e.g. to fully understand the natural convection effects inside irregular vertical frame cavities (jambs) and ventilated frame cavities.

  19. The Revival of White Holes as Small Bangs

    E-Print Network [OSTI]

    Alon Retter; Shlomo Heller

    2011-07-17

    Black holes are extremely dense and compact objects from which light cannot escape. There is an overall consensus that black holes exist and many astronomical objects are identified with black holes. White holes were understood as the exact time reversal of black holes, therefore they should continuously throw away material. It is accepted, however, that a persistent ejection of mass leads to gravitational pressure, the formation of a black hole and thus to the "death of while holes". So far, no astronomical source has been successfully tagged a white hole. The only known white hole is the Big Bang which was instantaneous rather than continuous or long-lasting. We thus suggest that the emergence of a white hole, which we name a 'Small Bang', is spontaneous - all the matter is ejected at a single pulse. Unlike black holes, white holes cannot be continuously observed rather their effect can only be detected around the event itself. Gamma ray bursts are the most energetic explosions in the universe. Long gamma-ray bursts were connected with supernova eruptions. There is a new group of gamma-ray bursts, which are relatively close to Earth, but surprisingly lack any supernova emission. We propose identifying these bursts with white holes. White holes seem like the best explanation of gamma-ray bursts that appear in voids. We also predict the detection of rare gigantic gamma-ray bursts with energies much higher than typically observed.

  20. Modeling laser wakefield accelerators in a Lorentz boosted frame

    SciTech Connect (OSTI)

    Vay, J.-L.; Geddes, C.G.R.; Cormier-Michel, E.; Grote, D.P.

    2010-09-15

    Modeling of laser-plasma wakefield accelerators in an optimal frame of reference [1] is shown to produce orders of magnitude speed-up of calculations from first principles. Obtaining these speedups requires mitigation of a high frequency instability that otherwise limits effectiveness in addition to solutions for handling data input and output in a relativistically boosted frame of reference. The observed high-frequency instability is mitigated using methods including an electromagnetic solver with tunable coefficients, its extension to accomodate Perfectly Matched Layers and Friedman's damping algorithms, as well as an efficient large bandwidth digital filter. It is shown that choosing theframe of the wake as the frame of reference allows for higher levels of filtering and damping than is possible in other frames for the same accuracy. Detailed testing also revealed serendipitously the existence of a singular time step at which the instability level is minimized, independently of numerical dispersion, thus indicating that the observed instability may not be due primarily to Numerical Cerenkov as has been conjectured. The techniques developed for Cerenkov mitigation prove nonetheless to be very efficient at controlling the instability. Using these techniques, agreement at the percentage level is demonstrated between simulations using different frames of reference, with speedups reaching two orders of magnitude for a 0.1 GeV class stages. The method then allows direct and efficient full-scale modeling of deeply depleted laser-plasma stages of 10 GeV-1 TeV for the first time, verifying the scaling of plasma accelerators to very high energies. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively.

  1. Self-aligning biaxial load frame

    DOE Patents [OSTI]

    Ward, M.B.; Epstein, J.S.; Lloyd, W.R.

    1994-01-18

    An self-aligning biaxial loading apparatus for use in testing the strength of specimens while maintaining a constant specimen centroid during the loading operation. The self-aligning biaxial loading apparatus consists of a load frame and two load assemblies for imparting two independent perpendicular forces upon a test specimen. The constant test specimen centroid is maintained by providing elements for linear motion of the load frame relative to a fixed cross head, and by alignment and linear motion elements of one load assembly relative to the load frame. 3 figures.

  2. Energy on black hole spacetimes

    E-Print Network [OSTI]

    Alejandro Corichi

    2012-07-18

    We consider the issue of defining energy for test particles on a background black hole spacetime. We revisit the different notions of energy as defined by different observers. The existence of a time-like isometry allows for the notion of a total conserved energy to be well defined, and subsequently the notion of a gravitational potential energy is also meaningful. We then consider the situation in which the test particle is adsorbed by the black hole, and analyze the energetics in detail. In particular, we show that the notion of horizon energy es defined by the isolated horizons formalism provides a satisfactory notion of energy compatible with the particle's conserved energy. As another example, we comment a recent proposal to define energy of the black hole as seen by an observer at rest. This account is intended to be pedagogical and is aimed at the level of and as a complement to the standard textbooks on the subject.

  3. Fusion Frames Peter G. Casazza and Gitta Kutyniok

    E-Print Network [OSTI]

    Kutyniok, Gitta

    Chapter 1 Fusion Frames Peter G. Casazza and Gitta Kutyniok Abstract Novel technological advances. Fusion frames, which can be regarded as frames of subspaces, do satisfy exactly those needs. They analyze, distributed processing, fusion coherence, fusion frame, fusion frame potential, isoclinic subspaces, mutually

  4. Light Steel Framing: Improving the Integral Design 

    E-Print Network [OSTI]

    Amundarain, Aitor; Torero, Jose L; Usmani, Asif; Al-Remal, Ahmad M

    2006-09-11

    Light Steel Framing has been extensively used in cold climate countries due to its good thermal and structural behaviour. Improved thermal behaviour results in positive environmental impact essential for sustainable ...

  5. The Framing and Evaluation of Multiple Hypotheses

    E-Print Network [OSTI]

    Mock, Theodore J.; Wright, Arnold; Srivastava, Rajendra P.; Lu, Hai

    2008-01-01

    This study provides exploratory evidence on auditors’ framing and evaluation of hypotheses, identifies implications for improving audit decision-making and facilitates the interpretation of prior research. Prior studies ...

  6. Quantum communication, reference frames and gauge theory

    E-Print Network [OSTI]

    S. J. van Enk

    2006-04-26

    We consider quantum communication in the case that the communicating parties not only do not share a reference frame but use imperfect quantum communication channels, in that each channel applies some fixed but unknown unitary rotation to each qubit. We discuss similarities and differences between reference frames within that quantum communication model and gauge fields in gauge theory. We generalize the concept of refbits and analyze various quantum communication protocols within the communication model.

  7. Black Hole Thermodynamics and Electromagnetism

    E-Print Network [OSTI]

    Burra G. Sidharth

    2005-07-15

    We show a strong parallel between the Hawking, Beckenstein black hole Thermodynamics and electromagnetism: When the gravitational coupling constant transform into the electromagnetic coupling constant, the Schwarzchild radius, the Beckenstein temperature, the Beckenstein decay time and the Planck mass transform to respectively the Compton wavelength, the Hagedorn temperature, the Compton time and a typical elementary particle mass. The reasons underlying this parallalism are then discussed in detail.

  8. Extracting Energy from Black Hole through Transition Region

    E-Print Network [OSTI]

    Li-Xin Li

    2000-07-24

    A new scenario for extracting energy from a Kerr black hole is proposed. With magnetic field lines connecting plasma particles inside the ergosphere with remote loads, the frame dragging twists the field lines so that energy and angular momentum are extracted from the plasma particles. If the magnetic field is strong enough, the energy extracted from the particles can be so large that the particles have negative energy as they fall into the black hole. So effectively the energy is extracted from the black hole. The particles inside the ergosphere can be continuously replenished with accretion from a disk surrounding the black hole, so a transition region with sufficient amount of plasma is formed between the black hole's horizon and the inner edge of the disk. Thus the energy can be continuously extracted from the black hole through the transition region. This may be the most efficient way for extracting energy from a Kerr black hole: in principle almost all of the rotational energy (up to $\\approx 29%$ of the total energy of the black hole) can be extracted.

  9. Supermassive Black Holes

    E-Print Network [OSTI]

    Laura Ferrarese; David Merritt

    2002-06-13

    After a brief historical introduction, we summarize current efforts and accomplishments in the study of supermassive black holes.

  10. Effects of Framing on the Thermal Performance of Wood and Steel-Framed Walls 

    E-Print Network [OSTI]

    Kosny, J.; Yarbrough, D. W.; Childs, P.; Mohiuddin, S. A.

    2006-01-01

    ON THE THERMAL PERFORMANCE OF WOOD AND STEEL-FRAMED WALLS JAN KOSNY, PhD DAVID W. YARBROUGH PhD, PE PHILLIP CHILDS Senior research engineer Senior research engineer Research engineer Oak Ridge National Laboratory, Oak Ridge, TN SYED AZAM MOHIUDDIN...% framing factor for US homes. This paper reports, experimental work and numerical analysis of the thermal performance of various configurations of structural components in wood and steel-framed walls. In addition, the consequences of installation...

  11. Black Holes and Galaxy Dynamics

    E-Print Network [OSTI]

    David Merritt

    1999-06-02

    The consequences of nuclear black holes for the structure and dynamics of stellar spheroids are reviewed. Slow growth of a black hole in a pre-existing core produces a steep power-law density profile similar to the cusps seen in faint elliptical galaxies. The weaker cusps in bright ellipticals may result from ejection of stars by a coalescing black-hole binary; there is marginal kinematical evidence for such a process having occurred in M87. Stellar orbits in a triaxial nucleus are mostly regular at radii where the gravitational force is dominated by the black hole; however the orbital shapes are not conducive to reinforcing the triaxial figure, hence nuclei are likely to be approximately axisymmetric. In triaxial potentials, a ``zone of chaos'' extends outward to a radius where the enclosed stellar mass is roughly 100 times the mass of the black hole; in this chaotic zone, no regular, box-like orbits exist. At larger radii, the phase space in triaxial potentials is complex, consisting of stochastic orbits as well as regular orbits associated with stable resonances. Figure rotation tends to increase the degree of stochasticity. Both test-particle integrations and N-body simulations suggest that a triaxial galaxy responds globally to the presence of a central mass concentration by evolving toward more axisymmetric shapes; the evolution occurs rapidly when the mass of the central object exceeds roughly 2% of the mass in stars. The lack of significant triaxiality in most early-type galaxies may be a consequence of orbital evolution induced by nuclear black holes.

  12. The effects of fastener hole defects 

    E-Print Network [OSTI]

    Andrews, Scot D.

    1991-01-01

    ) August 1991 ABSTRACT The Effects of Fastener Hole Defects. (August 1991) Scot D. Andrews, B. S. , Texas A8rM University Chair of Advisory Committee: Dr. Orden O. Ochoa The influence of drilling-induced defects, such as delamination, on the fatigue... ambient and elevated temperature wet conditions. Specimens were tested in a bearing tension frame to static failure in order to measure the failure load and to calculate pin bearing stress. From static test results, a fatigue load was selected as 66...

  13. Design and Development of Novel Electroplating Spring Frame Mems Structure Specimens for the Microtensile Testing of Thin Film Materials

    E-Print Network [OSTI]

    Lin, Ming-Tzer; Chiang, Chung-Hsun

    2007-01-01

    Microelectromechanical systems (MEMS) technologies are developing rapidly with increasing study of the design, fabrication and commercialization of microscale systems and devices. Accurate mechanical properties are important for successful design and development of MEMS. We have demonstrated here a novel electroplating spring frame MEMS Structure Specimen integrates pin-pin align holes, misalignment compensate spring structure frame, load sensor beam and freestanding thin film. The specimen can be fit into a specially designed microtensile apparatus which is capable of carrying out a series of tests on sub-micro scale freestanding thin films.

  14. Rethinking Sustainability on Planet Earth: A Time for New Framings

    E-Print Network [OSTI]

    Dylan, Arielle

    2012-01-01

    Dawkins, R. (2001). Sustainability does not come naturally–AFoley, J. (Ed. ). (2004). Sustainability and social justice.commerce: A declaration of sustainability. New York: Harper.

  15. Rethinking Sustainability on Planet Earth: A Time for New Framings

    E-Print Network [OSTI]

    Dylan, Arielle

    2012-01-01

    2009). Carbon shift: How peak oil and the climate crisisEds. ), Carbon shift: How peak oil and the climate crisisof climate change, peak oil, and environmental degradation

  16. ARS 41-1072 Licensing Time Frames | Open Energy Information

    Open Energy Info (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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EAand Dalton JumpProgramInformation ALLETE,ARCHDecisions |30-101ARS

  17. Free fall onto evaporating black holes at the quantum limit

    E-Print Network [OSTI]

    Maurice H. P. M. van Putten

    2015-11-11

    Black hole space times evaporate in discrete steps due to remarkably slow Hawking radiation. We here identify evaporation with essentially extremal states at the limit of quantum computation, performing $2.7\\times 10^{79}$ bit calculations per photon emission in a one solar mass black hole. During evaporation, particles in free fall co-evolve satisfying $EM=$constant, where $E$ and $M$ denote the total mass energy-at-infinity of the particle and, respectively, black hole. Particles are hereby increasingly entangled with the black hole space-time over the course of its evaporation.

  18. Absence of a local rest frame in far from equilibrium quantum matter

    E-Print Network [OSTI]

    Peter Arnold; Paul Romatschke; Wilke van der Schee

    2014-10-21

    In a collision of strongly coupled quantum matter we find that the dynamics of the collision produces regions where a local rest frame cannot be defined because the energy-momentum tensor does not have a real time-like eigenvector. This effect is purely quantum mechanical, since for classical systems, a local rest frame can always be defined. We study the relation with the null and weak energy condition, which are violated in even larger regions, and compare with previously known examples. While no pathologies or instabilities arise, it is interesting that regions without a rest frame are possibly present in heavy ion collisions.

  19. Some remarks on black hole thermodynamics

    E-Print Network [OSTI]

    R. Y. Chiao

    2011-02-04

    Two thermodynamic "paradoxes" of black hole physics are re-examined. The first is that there is a thermal instability involving two coupled blackbody cavities containing two black holes, and second is that a classical black hole can swallow up entropy in the form of ambient blackbody photons without increasing its mass. The resolution of the second paradox by Bekenstein and by Hawking is re-visited. The link between Hawking radiation and Wigner's superluminal tunneling time is discussed using two equivalent Feynman diagrams, and Feynman's re-interpretation principle.

  20. Testing the Kerr black hole hypothesis

    E-Print Network [OSTI]

    Cosimo Bambi

    2011-10-13

    It is thought that the final product of the gravitational collapse is a Kerr black hole and astronomers have discovered several good astrophysical candidates. While there is some indirect evidence suggesting that the latter have an event horizon, and therefore that they are black holes, a proof that the space-time around these objects is described by the Kerr geometry is still lacking. Recently, there has been an increasing interest in the possibility of testing the Kerr black hole hypothesis with present and future experiments. In this paper, I briefly review the state of the art of the field, focussing on some recent results and work in progress.

  1. Is the Universe a White-Hole?

    E-Print Network [OSTI]

    Marcelo Samuel Berman

    2008-08-06

    Pathria(1972) has shown, for a pressureless closed Universe, that it is inside a black (or white) hole. We show now, that the Universe with a cosmic pressure obeying Einstein's field equations, can be inside a white-hole. In the closed case, a positive cosmological constant does the job; for the flat and open cases, the condition we find is not verified for the very early Universe, but with the growth of the scale-factor, the condition will be certainly fulfilled for a positive cosmological constant, after some time. We associate the absolute temperature of the Universe, with the temperature of the corresponding white-hole.

  2. Microlens frames for laser diode arrays

    DOE Patents [OSTI]

    Skidmore, J.A.; Freitas, B.L.

    1999-07-13

    Monolithic microlens frames enable the fabrication of monolithic laser diode arrays and are manufactured inexpensively with high registration, and with inherent focal length compensation for any lens diameter variation. A monolithic substrate is used to fabricate a low-cost microlens array. The substrate is wet-etched or sawed with a series of v-grooves. The v-grooves can be created by wet-etching, by exploiting the large etch-rate selectivity of different crystal planes. The v-grooves provide a support frame for either cylindrical or custom-shaped microlenses. Because the microlens frames are formed by photolithographic semiconductor batch-processing techniques, they can be formed inexpensively over large areas with precise lateral and vertical registration. The v-groove has an important advantage for preserving the correct focus for lenses of varying diameter. 12 figs.

  3. Thermodynamics of Schrödinger black holes with hyperscaling violation

    E-Print Network [OSTI]

    J. Sadeghi; B. Pourhassan; F. Pourasadollah

    2012-11-06

    In this work, we follow Kim and Yamada (JHEP1107 (2011) 120) and utilize AdS in light-cone frame to derive thermodynamic and transport properties of two kinds of Schr\\"{o}dinger black holes with hyperscaling violation. In that case, we show entropy and temperature are depend on $\\theta$. In $\\theta=0$ we see our results are agree with the work of Kim and Yamada. We also construct R-charged black hole with hyperscaling violation and obtain thermodynamics and transport properties.

  4. Constructing Fusion Frames with Desired Parameters Robert Calderbank,1

    E-Print Network [OSTI]

    Kutyniok, Gitta

    Constructing Fusion Frames with Desired Parameters Robert Calderbank,1 Peter G. Casazza,2 Andreas Colorado State University, Fort Collins, CO 80523-1373, USA ABSTRACT A fusion frame is a frame representation. In this paper, we study the existence and construction of fusion frames. We first introduce two

  5. Fusion Frames and Robust Dimension Reduction Ali Pezeshki

    E-Print Network [OSTI]

    Kutyniok, Gitta

    Fusion Frames and Robust Dimension Reduction Ali Pezeshki Princeton University Princeton, NJ 08544 fusion frame measurements in presence noise and subspace erasures. Each fusion frame mea- surement is a low-dimensional vector whose elements are inner products of an orthogonal basis for a fusion frame

  6. High frame-rate, large field wavefront sensor

    SciTech Connect (OSTI)

    Avicola, K.; Salmon, J.T.; Brase, J.; Waltjen, K.; Presta, R.; Balch, K.S.

    1992-03-01

    A two-stage intensified 192 {times} 239 pixel imager developed by Eastman Kodak for motion analysis was used to construct a 1 kHz frame-rate Hartmann wavefront sensor. The sensor uses a monolithic array of lenslets with a focal length that is adjusted by an index fluid between the convex surface and an optical flat. The accuracy of the calculated centroid position, which is related to wavefront measurement accuracy, was obtained as a function of spot power and spot size. The sensor was then dynamically tested at a 1 kHz frame-rate with a 9 {times} 9 lenslet array and a fast steering mirror, which swept a plane wavefront across the wavefront sensor. An 8 cm diameter subaperture will provide a return signal (589 nm) level of about 1000 photons/ms using the AVLIS 1 kW laser (stretched pulse) as guide star source, which is sufficient to yield a wavefront measurement of better than {gamma}/10 rms. If an area of 6 {times} 6 pixels per Hartmann spot were allocated, this wavefront sensor could support a 32 {times} 32, or 1024, element deformable mirror.

  7. Composite RCS frame systems: construction and peformance 

    E-Print Network [OSTI]

    Steele, John Phillip

    2004-09-30

    The objective of this research program is to further evaluate the performance and constructability of reinforced concrete (RC) column-steel beam-slab systems (RCS) for use in low- to mid-rise space frame buildings located in regions of high wind...

  8. Accreting Black Holes

    E-Print Network [OSTI]

    Begelman, Mitchell C

    2014-01-01

    I outline the theory of accretion onto black holes, and its application to observed phenomena such as X-ray binaries, active galactic nuclei, tidal disruption events, and gamma-ray bursts. The dynamics as well as radiative signatures of black hole accretion depend on interactions between the relatively simple black-hole spacetime and complex radiation, plasma and magnetohydrodynamical processes in the surrounding gas. I will show how transient accretion processes could provide clues to these interactions. Larger global magnetohydrodynamic simulations as well as simulations incorporating plasma microphysics and full radiation hydrodynamics will be needed to unravel some of the current mysteries of black hole accretion.

  9. Topological Black Holes -- Outside Looking In

    E-Print Network [OSTI]

    R. B. Mann

    1997-09-15

    I describe the general mathematical construction and physical picture of topological black holes, which are black holes whose event horizons are surfaces of non-trivial topology. The construction is carried out in an arbitrary number of dimensions, and includes all known special cases which have appeared before in the literature. I describe the basic features of massive charged topological black holes in $(3+1)$ dimensions, from both an exterior and interior point of view. To investigate their interiors, it is necessary to understand the radiative falloff behaviour of a given massless field at late times in the background of a topological black hole. I describe the results of a numerical investigation of such behaviour for a conformally coupled scalar field. Significant differences emerge between spherical and higher genus topologies.

  10. A Quantum Material Model of Static Schwarzschild Black Holes

    E-Print Network [OSTI]

    S. -T. Sung

    1997-03-16

    A quantum-mechanical prescription of static Einstein field equation is proposed in order to construct the matter-metric eigen-states in the interior of a static Schwarzschild black hole where the signature of space-time is chosen as (--++). The spectrum of the quantum states is identified to be the integral multiples of the surface gravity. A statistical explanation of black hole entropy is given and a quantisation rule for the masses of Schwarzschild black holes is proposed.

  11. Rotating Hairy Black Holes

    E-Print Network [OSTI]

    B. Kleihaus; J. Kunz

    2000-12-20

    We construct stationary black holes in SU(2) Einstein-Yang-Mills theory, which carry angular momentum and electric charge. Possessing non-trivial non-abelian magnetic fields outside their regular event horizon, they represent non-perturbative rotating hairy black holes.

  12. Virtual Black Holes in Hyperbolic Metamaterials

    E-Print Network [OSTI]

    Igor I. Smolyaninov

    2011-01-24

    Optical space in electromagnetic metamaterials may be engineered to emulate various exotic space-time geometries. However, these metamaterial models are limited in many respects. It is believed that real physical space-time strongly fluctuates on the Planck scale. These fluctuations are usually described as virtual black holes. Static metamaterial models introduced so far do not exhibit similar behavior. Here we demonstrate that thermal fluctuations of optical space in hyperbolic metamaterials lead to creation of virtual electromagnetic black holes. This effect is very large if the dielectric component of the metamaterial exhibits critical opalescence.

  13. Magnetized black hole as a gravitational lens

    E-Print Network [OSTI]

    R. A. Konoplya

    2006-11-19

    We use the Ernst-Schwarzschild solution for a black hole immersed in a uniform magnetic field to estimate corrections to the bending angle and time delay due-to presence of weak magnetic fields in galaxies and between galaxies, and also due-to influence of strong magnetic field near supermassive black holes. The magnetic field creates a kind of confinement in space, that leads to increasing of the bending angle and time delay for a ray of light propagating in the equatorial plane.

  14. Optimal Panel Zone Participation in Steel Moment Frames 

    E-Print Network [OSTI]

    Ngo, Thanh Tat

    2014-01-03

    the overall seismic performance of that frame. As a result, the safety or reliability of a steel moment frame under earthquakes can be improved while maintaining the fabrication of the structure at an effective cost....

  15. Making Steel Framing as Thermally Efficient as Wood 

    E-Print Network [OSTI]

    Kosny, J.; Childs, P.

    2002-01-01

    In many world regions like North America and Scandinavia wood framing is dominant technology for residential buildings. During last two decades several companies around the world started to promote a low-gage steel framing for residential...

  16. Nonlinear seismic response analysis of steel-concrete composite frames

    E-Print Network [OSTI]

    Barbato, Michele

    2008-01-01

    frame model 10TN (Northridge seismic input) floor 1 floor 2frame model 10TC (Northridge seismic input) Slip (mm) floorframe models 06TC, 10TC and 14TC (Northridge seismic input)

  17. Thermodynamics of rotating black holes in conformal gravity

    E-Print Network [OSTI]

    Kamvar, Negin; Soroushfar, Saheb

    2015-01-01

    In this paper we consider a metric of a rotating black hole in conformal gravity. We calculate the thermodynamical quantities for this rotating black hole including Hawking temperature and entropy in four dimensional space-time, as we obtain the effective value of Komar angular momentum. The result is valid on the event horizon of the black hole, and at any radial distance out of it. Also we verify that the first law of thermodynamics will be held for this type of black hole.

  18. Minimal Length Effects on Tunnelling from Spherically Symmetric Black Holes

    E-Print Network [OSTI]

    Benrong Mu; Peng Wang; Haitang Yang

    2015-01-24

    In this paper, we investigate effects of the minimal length on quantum tunnelling from spherically symmetric black holes using the Hamilton-Jacobi method incorporating the minimal length. We first derive the deformed Hamilton-Jacobi equations for scalars and fermions, both of which have the same expressions. The minimal length correction to the Hawking temperature is found to depend on the black hole's mass and the mass and angular momentum of emitted particles. Finally, we calculate a Schwarzschild black hole's luminosity and find the black hole evaporates to zero mass in infinite time.

  19. Minimal Length Effects on Tunnelling from Spherically Symmetric Black Holes

    E-Print Network [OSTI]

    Mu, Benrong; Yang, Haitang

    2015-01-01

    In this paper, we investigate effects of the minimal length on quantum tunnelling from spherically symmetric black holes using the Hamilton-Jacobi method incorporating the minimal length. We first derive the deformed Hamilton-Jacobi equations for scalars and fermions, both of which have the same expressions. The minimal length correction to the Hawking temperature is found to depend on the black hole's mass and the mass and angular momentum of emitted particles. Finally, we calculate a Schwarzschild black hole's luminosity and find the black hole evaporates to zero mass in infinite time.

  20. Black Holes and Galaxy Evolution

    E-Print Network [OSTI]

    David Merritt

    1999-10-29

    Supermassive binary black holes and their influence on the structure and evolution of galaxies is reviewed.

  1. The generalized Fr enet's frame and its relation with

    E-Print Network [OSTI]

    Henri Poincaré -Nancy-Université, Université

    The generalized Fr#19;enet's frame and its relation with ag manifolds. Xavier CHARUEL Abstract#12;nitions and notations 3 2.3. The generalized Fr#19;enet's frame 4 3. A preliminary study of kernels 8 4. Orbits on ag manifolds 12 4.1. The diÃ?culty for generalizing the Fr#19;enet's frame 12 4

  2. Media Framing and Public Attitudes Toward Biofuels Ashlie Delshad

    E-Print Network [OSTI]

    Media Framing and Public Attitudes Toward Biofuels Ashlie Delshad Department of Political Science between media framing and public opinion on the issue of biofuels--transportation fuels made from plants, animal products, or organic waste. First, the paper investigates how media framing of biofuels has

  3. FRAME BASED KERNEL METHODS FOR AUTOMATIC CLASSIFICATION IN HYPERSPECTRAL DATA

    E-Print Network [OSTI]

    Hirn, Matthew

    FRAME BASED KERNEL METHODS FOR AUTOMATIC CLASSIFICATION IN HYPERSPECTRAL DATA John J. Benedetto, instead of (orthonormal) bases. Our frames are data-dependent and are based on endmember demixing schemes propose a new kernel and frame based dimension reduc- ing algorithm by exploiting the synergy between

  4. Fusion Frames and Wireless Sensor Networks Gitta Kutyniok

    E-Print Network [OSTI]

    Kutyniok, Gitta

    Fusion Frames and Wireless Sensor Networks Gitta Kutyniok Institut f¨ur Mathematik Technische Universit¨at Berlin 10623 Berlin Germany Email: kutyniok@math.tu-berlin.de Abstract--Fusion frames provide science, information theory, and signal processing, to name a few. Fusion frames extend this notion

  5. Explanation of the Random Lengths Framing Lumber Composite Price

    E-Print Network [OSTI]

    Explanation of the Random Lengths Framing Lumber Composite Price May 10, 2006 The Random Lengths Framing Lumber Composite is a broad measure of price behavior in the U.S. framing lumber market prices, 33% comes from Western U.S. prices, and 34% comes from Canadian prices. The Composite does

  6. Frame Indifferent Formulation of Maxwell's Elastic Fluid and the Rational Continuum Mechanics of the Electromagnetic Field

    E-Print Network [OSTI]

    Christo I. Christov

    2011-03-06

    We show that the linearized equations of the incompressible elastic medium admit a `Maxwell form' in which the shear component of the stress vector plays the role of the electric field, and the vorticity plays the role of the magnetic field. Conversely, the set of dynamic Maxwell equations are strict mathematical corollaries from the governing equations of the incompressible elastic medium. This suggests that the nature of `electromagnetic field' may actually be related to an elastic continuous medium. The analogy is complete if the medium is assumed to behave as fluid in shear motions, while it may still behave as elastic solid under compressional motions. Then the governing equations of the elastic fluid are re-derived in the Eulerian frame by replacing the partial time derivatives by the properly invariant (frame indifferent) time rates. The `Maxwell from' of the frame indifferent formulation gives the frame indifferent system that is to replace the Maxwell system. This new system comprises terms already present in the classical Maxwell equations, alongside terms that are the progenitors of the Biot--Savart, Oersted--Ampere's, and Lorentz--force laws. Thus a frame indifferent (truly covariant) formulation of electromagnetism is achieved from a single postulate that the electromagnetic field is a kind of elastic (partly liquid partly solid) continuum.

  7. Schwarzschild black hole in dark energy background

    E-Print Network [OSTI]

    Ngangbam Ishwarchandra; Ng. Ibohal; K. Yugindro Singh

    2014-09-27

    In this paper we present an exact solution of Einstein's field equations describing the Schwarzschild black hole in dark energy background. It is also regarded as an embedded solution that the Schwarzschild black hole is embedded into the dark energy space producing Schwarzschild-dark energy black hole. It is found that the space-time geometry of Schwarzschild-dark energy solution is non-vacuum Petrov type $D$ in the classification of space-times. We study the energy conditions (like weak, strong and dominant conditions) for the energy-momentum tensor of the Schwarzschild-dark energy solution. We also find that the energy-momentum tensor of the Schwarzschild-dark energy solution violates the strong energy condition due to the negative pressure leading to a repulsive gravitational force of the matter field in the space-time. It is shown that the time-like vector field for an observer in the Schwarzschild-dark energy space is expanding, accelerating, shearing and non-rotating. We investigate the surface gravity and the area of the horizons for the Schwarzschild-dark energy black hole.

  8. Interior of Black Holes and Information Recovery

    E-Print Network [OSTI]

    Hikaru Kawai; Yuki Yokokura

    2015-09-28

    We analyze time evolution of a collapsing matter from a point of view that black holes evaporate by nature. We first consider a spherical thin shell that falls in the metric of an evaporating Schwarzschild black hole whose radius $a(t)$ decreases as $\\frac{da(t)}{dt}=-\\frac{2\\sigma(a(t))}{a(t)^2}$. The shell can never reach $a(t)$, but it approaches $a(t)+\\frac{2\\sigma(a(t))}{a(t)}$ in the time scale $\\sim a(t)$. Then the radiation from the hole is extremely weakened because of the large redshift caused by the shell. This time, however, the shell itself starts to radiate and exhausts energy. After that, the hole starts to radiate again. We can repeat this argument recursively because the motion of a shell in a spherically symmetric system is independent of the outside. In this way we can analyze a spherically symmetric collapsing matter with a general continuous distribution, and find that it evaporates without forming a trapped region. If the theory has considerably more species of matter fields, the trans-Planckian problems are avoided. There is a clear boundary at $r=a+\\frac{2\\sigma}{a}$ as the surface of the object. Although the matter distribution inside the object depends on the initial data, from the outside it looks almost the same as a conventional black hole. A strong angular pressure is induced by the Hawking radiation, because of which the matter loses energy when it collapses. We then discuss how the information of the matter is recovered in this picture. Next we consider a black hole that is adiabatically grown from a small one in the heat bath, and obtain the interior metric. We show that it is the self-consistent solution of $G_{\\mu\

  9. Thermal Gravitational Waves from Primordial Black Holes

    E-Print Network [OSTI]

    C. Sivaram; Kenath Arun

    2010-05-19

    Thermal gravitational waves can be generated in various sources such as, in the cores of stars, white dwarfs and neutron stars due to the fermion collisions in the dense degenerate Fermi gas. Such high frequency thermal gravitational waves can also be produced during the collisions in a gamma ray burst or during the final stages of the evaporation of primordial black holes. Here we estimate the thermal gravitational waves from primordial black holes and estimate the integrated energy of the gravitational wave emission over the entire volume of the universe and over Hubble time. We also estimate the gravitational wave flux from gamma ray bursts and jets.

  10. Frame-based Matching Algorithms for Optical Switches Yihan Li, Shivendra Panwar and H. Jonathan Chao

    E-Print Network [OSTI]

    Panwar, Shivendra S.

    Frame-based Matching Algorithms for Optical Switches Yihan Li, Shivendra Panwar and H. Jonathan used by fixed- length high-speed electronic switches to overcome head-of-line blocking. This is done, in every time slot, a new matching set is calculated and the switch fabric is updated to connect matched

  11. Saha Equation in an Uniformly Accelerated Reference Frame and Some of Its Physical Implications

    E-Print Network [OSTI]

    Sanchari De; Somenath Chakrabarty

    2014-12-06

    The Saha equations for the photo-ionization of hydrogen atoms and the electron positron pair production at high temperature are obtained in a reference frame undergoing a uniform accelerated motion in an otherwise flat Minkowski space-time geometry. Some of the physical implications of our findings are discussed.

  12. Polymer Quantization predicts radiation in inertial frames

    E-Print Network [OSTI]

    Kajuri, Nirmalya

    2015-01-01

    We investigate the response of an Unruh-DeWitt detector coupled to a polymer quantized massless scalar field in flat spacetime, using the propagator obtained by Hossain, Husain and Seahra. As this propagator violates Lorentz invariance, frames moving at different constant velocities are no longer equivalent. This means that it is possible in principle for even an observer moving at constant velocity to detect radiation. We show that such an observer indeed detects radiation. Remarkably, we show that the rate of this radiation does not decrease with the decrease in the characteristic length scale of polymer quantization. Thus the radiation cannot be suppressed by making the polymer length scale arbitrarily small. Our results should bring this theory within the ambit of low-energy experiments and place a lower limit on the characteristic polymer length scale.

  13. Inertial frames without the relativity principle

    E-Print Network [OSTI]

    Baccetti, Valentina; Visser, Matt

    2011-01-01

    Ever since the work of von Ignatowsky circa 1910 it has been known that the relativity principle, combined with the mild physical assumption of linearity and the less mild assumption of isotropy, leads almost uniquely to either the Lorentz transformations of special relativity or to Galileo's transformations of classical Newtonian mechanics. Consequently, if one wishes to entertain the possibility of Lorentz symmetry breaking, then it seems likely that one will have to abandon or at the very least grossly modify the relativity principle. We reassess the notion of spacetime transformations between inertial frames in the absence of the relativity principle, arguing that significant nontrivial physics can still be extracted as long as the transformations are at least linear. An interesting technical aspect of the analysis is that the transformations now form a groupoid/pseudo-group - it is this technical point that permits one to evade the von Ignatowsky argument. Even in the absence of a relativity principle we...

  14. Polymer Quantization predicts radiation in inertial frames

    E-Print Network [OSTI]

    Nirmalya Kajuri

    2015-08-04

    We investigate the response of an Unruh-DeWitt detector coupled to a polymer quantized massless scalar field in flat spacetime, using the propagator obtained by Hossain, Husain and Seahra. As this propagator violates Lorentz invariance, frames moving at different constant velocities are no longer equivalent. This means that it is possible in principle for even an observer moving at constant velocity to detect radiation. We show that such an observer indeed detects radiation. Remarkably, we show that the rate of this radiation does not decrease with the decrease in the characteristic length scale of polymer quantization. Thus the radiation cannot be suppressed by making the polymer length scale arbitrarily small. Our results should bring this theory within the ambit of low-energy experiments and place a lower limit on the characteristic polymer length scale.

  15. Numerical Analysis of Black Hole Evaporation

    E-Print Network [OSTI]

    Tsvi Piran; Andrew Strominger

    1993-04-28

    Black hole formation/evaporation in two-dimensional dilaton gravity can be described, in the limit where the number $N$ of matter fields becomes large, by a set of second-order partial differential equations. In this paper we solve these equations numerically. It is shown that, contrary to some previous suggestions, black holes evaporate completely a finite time after formation. A boundary condition is required to evolve the system beyond the naked singularity at the evaporation endpoint. It is argued that this may be naturally chosen so as to restore the system to the vacuum. The analysis also applies to the low-energy scattering of $S$-wave fermions by four-dimensional extremal, magnetic, dilatonic black holes.

  16. Investigating Dark Energy with Black Hole Binaries

    E-Print Network [OSTI]

    Laura Mersini-Houghton; Adam Kelleher

    2009-06-08

    The accelerated expansion of the universe is ascribed to the existence of dark energy. Black holes accretion of dark energy induces a mass change proportional to the energy density and pressure of the background dark energy fluid. The time scale during which the mass of black holes changes considerably is too long relative to the age of the universe, thus beyond detection possibilities. We propose to take advantage of the modified black hole masses for exploring the equation of state $w[z]$ of dark energy, by investigating the evolution of supermassive black hole binaries on a dark energy background. Deriving the signatures of dark energy accretion on the evolution of binaries, we find that dark energy imprints on the emitted gravitational radiation and on the changes in the orbital radius of the binary can be within detection limits for certain supermassive black hole binaries. In this talk I describe how binaries can provide a useful tool in obtaining complementary information on the nature of dark energy, based on the work done with A.Kelleher.

  17. Black Holes In Astronomy Black Holes In Astronomy

    E-Print Network [OSTI]

    Wagner, Stephan

    Black Hole horizon static limit ergosphere radiation magnetic fields jet jet #12;Black-hole accretion with a central bulge. #12;Click to edit Master text styles Second level Third level Fourth level Fifth level Jets and lobes of Cygnus A Carilli et al. Supermassive black holes are the most powerful engines in the Universe

  18. Consistency of equations of motion in conformal frames

    E-Print Network [OSTI]

    J. R. Morris

    2014-11-05

    Four dimensional scalar-tensor theory is considered within two conformal frames, the Jordan frame (JF) and the Einstein frame (EF). The actions for the theory are equivalent and equations of motion can be obtained from each action. It is found that the JF equations of motion, expressed in terms of EF variables, translate directly into and agree with the EF equations of motion obtained from the EF action, provided that certain simple consistency conditions are satisfied, which is always the case. The implication is that a solution set obtained in one conformal frame can be reliably translated into a solution set for the other frame, and therefore the two frames are, at least, mathematically equivalent.

  19. Communication between inertial observers with partially correlated reference frames

    E-Print Network [OSTI]

    Mehdi Ahmadi; Alexander R. H. Smith; Andrzej Dragan

    2015-08-13

    In quantum communication protocols the existence of a shared reference frame between two spatially separated parties is normally presumed. However, in many practical situations we are faced with the problem of misaligned reference frames. In this paper, we study communication between two inertial observers who have partial knowledge about the Lorentz transformation that relates their frames of reference. Since every Lorentz transformation can be decomposed into a pure boost followed by a rotation, we begin by analysing the effects on communication when the parties have partial knowledge about the transformation relating their frames, when the transformation is either a rotation or pure boost. This then enables us to investigate how the efficiency of communication is affected due to partially correlated inertial reference frames related by an arbitrary Lorentz transformation. Furthermore, we show how the results of previous studies where reference frames are completely uncorrelated are recovered from our results in appropriate limits.

  20. Black Holes And Their Entropy 

    E-Print Network [OSTI]

    Mei, Jianwei

    2010-10-12

    . . . . . . . . . 21 1. Solutions in Four Dimensions . . . . . . . . . . . . . . 22 2. Solutions in Higher Dimensions . . . . . . . . . . . . . 27 C. Black Hole Solutions in Supergravity Theories . . . . . . . 30 D. Plebanski-Demianski Type Solutions in d = 5... is to discuss the construction of new black hole solutions and the calculation of the black hole entropy. In Chapter II, we shall re- port some new black hole solutions that we have found during the past few years [21, 22, 23] and we will discuss some...

  1. Molecular-Frame Angular Distributions of Resonant Auger Electrons

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

    Wednesday, 27 May 2009 00:00 Molecular-frame electron angular distribution (MFAD) measurements provide access to an unprecedented level of detailed information about phenomena...

  2. A Simple Criterion for Nonrotating Reference Frames Peter Collas1

    E-Print Network [OSTI]

    Klein, David

    WORDS: Nonrotating frames; Fermi-Walker transport. 1Department of Physics and Astronomy, California of Mathematics, California State University, Northridge, Northridge, CA 91330-8313. Email: david

  3. Black Holes at Accelerators

    E-Print Network [OSTI]

    Bryan Webber

    2006-04-06

    In theories with large extra dimensions and TeV-scale gravity, black holes are copiously produced in particle collisions at energies well above the Planck scale. I briefly review some recent work on the phenomenology of this process, with emphasis on theoretical uncertainties and possible strategies for measuring the number of extra dimensions.

  4. Quantum black hole inflation

    E-Print Network [OSTI]

    M. B. Altaie

    2001-05-07

    In this paper we follow a new approach for particle creation by a localized strong gravitational field. The approach is based on a definition of the physical vacuum drawn from Heisenberg uncertainty principle. Using the fact that the gravitational field red-shifts the frequency modes of the vacuum, a condition on the minimum stregth of the gravitational field required to achieve real particle creation is derived. Application of this requirement on a Schwartzchid black hole resulted in deducing an upper limit on the region, outside the event horizon, where real particles can be created. Using this regional upper limit, and considering particle creation by black holes as a consequence of the Casimir effect, with the assumption that the created quanta are to be added to the initial energy, we deduce a natural power law for the development of the event horizon, and consequently a logarithmic law for the area spectrum of an inflating black hole. Application of the results on a cosmological model shows that if we start with a Planck-dimensional black hole, then through the process of particle creation we end up with a universe having the presently estimated critical density. Such a universe will be in a state of eternal inflation.

  5. Laser bottom hole assembly

    DOE Patents [OSTI]

    Underwood, Lance D; Norton, Ryan J; McKay, Ryan P; Mesnard, David R; Fraze, Jason D; Zediker, Mark S; Faircloth, Brian O

    2014-01-14

    There is provided for laser bottom hole assembly for providing a high power laser beam having greater than 5 kW of power for a laser mechanical drilling process to advance a borehole. This assembly utilizes a reverse Moineau motor type power section and provides a self-regulating system that addresses fluid flows relating to motive force, cooling and removal of cuttings.

  6. Stellar Orbits Around the Galactic Center Black Hole

    E-Print Network [OSTI]

    A. M. Ghez; S. Salim; S. D. Hornstein; A. Tanner; J. R. Lu; M. Morris; E. E. Becklin; G. Duchene

    2004-11-02

    We present new proper motion measurements and simultaneous orbital solutions for three newly identified (S0-16, S0-19, and S0-20) and four previously known (S0-1, S0-2, S0-4, and S0-5) stars at the Galactic Center. This analysis pinpoints the Galaxy's central dark mass to within +-1 milli-arcsec and, for the first time from orbital dynamics, limits its proper motion to 1.5+-0.5 mas/y, which is consistent with our derivation of the position of Sgr A* in the infrared reference frame (+-10 mas). The estimated central dark mass from orbital motions is 3.7 (+-0.2) x 10^6 (Ro/8kpc)^3 Mo; this is a more direct measure of mass than those obtained from velocity dispersion measurements, which are as much as a factor of two smaller. The smallest closest approach is achieved by S0-16, which confines the mass to within a radius of a mere 45 AU and increases the inferred dark mass density by four orders of magnitude compared to earlier analyses based on velocity and acceleration vectors, making the Milky Way the strongest existing case by far for a supermassive black hole at the center of any normal type galaxy. The stellar orbital properties suggest that the distributions of eccentricities and angular momentum vector and apoapse directions are consistent with those of an isotropic system. Therefore many of the mechanisms proposed for the formation of young stars in the vicinity of a supermassive black hole, such as formation from a pre-existing disk, are unlikely solutions for the Sgr A* cluster stars. Unfortunately, all existing alternative theories are also somewhat problematic. Understanding the apparent youth of stars in the Sgr A* cluster, as well as the more distant He I emission line stars, has now become one of the major outstanding issues in the study of the Galactic Center.

  7. Accretion onto the First Stellar Mass Black Holes

    E-Print Network [OSTI]

    Marcelo A. Alvarez; John H. Wise; Tom Abel

    2008-11-07

    The first stars in the universe, forming at redshifts z>15 in minihalos with masses of order 10^6 Msun, may leave behind black holes as their remnants. These objects could conceivably serve as "seeds" for much larger black holes observed at redshifts z~6. We study the growth of the remnant black holes through accretion including for the first time the emitted accretion radiation with adaptive mesh refinement cosmological radiation-hydrodynamical simulations. The effects of photo-ionization and heating dramatically affect the accretion flow from large scales, resulting in negligible mass growth of the black hole. We compare cases with the accretion luminosity included and neglected to show that the accretion radiation drastically changes the environment within 100 pc of the black hole, where gas temperatures are increased by an order of magnitude. The gas densities are reduced and further star formation in the same minihalo prevented for the two hundred million years of evolution we followed. These calculations show that even without the radiative feedback included most seed black holes do not gain mass as efficiently as has been hoped for in previous theories, implying that black hole remnants of Pop III stars that formed in minihalos are not likely to be the origin of miniquasars. Most importantly, however, these calculations demonstrate that if early stellar mass black holes are indeed accreting close to the Bondi-Hoyle rate with ten percent efficiency they have a dramatic local effect in regulating star formation in the first galaxies.

  8. Gravitational-wave modes from precessing black-hole binaries

    E-Print Network [OSTI]

    Michael Boyle; Lawrence E. Kidder; Serguei Ossokine; Harald P. Pfeiffer

    2014-09-22

    Gravitational waves from precessing black-hole binaries exhibit features that are absent in nonprecessing systems. The most prominent of these is a parity-violating asymmetry that beams energy and linear momentum preferentially along or opposite to the orbital angular momentum, leading to recoil of the binary. The asymmetry will appear as amplitude and phase modulations at the orbital frequency. For strongly precessing systems, it accounts for at least 3% amplitude modulation for binaries in the sensitivity band of ground-based gravitational-wave detectors, and can exceed 50% for massive systems. Such asymmetric features are also clearly visible when the waves are decomposed into modes of spin-weighted spherical harmonics, and are inherent in the waves themselves---rather than resulting from residual eccentricity in numerical simulations, or from mode-mixing due to precession. In particular, there is generically no instantaneous frame for which the mode decomposition will have any symmetry. We introduce a method to simplify the expressions for waveforms given in analytical relativity, which can be used to combine existing high-order waveforms for nonprecessing systems with expressions for the precessing contributions, leading to improved accuracy and a unified treatment of precessing and nonprecessing binaries. Using this method, it is possible to clarify the nature and the origins of the asymmetries and show the effects of asymmetry on recoils more clearly. We present post-Newtonian (PN) expressions for the waveform modes that include these terms, complete to the relative 2PN level in spin (proportional to $v^4/c^4$ times a certain combination of the spins). Comparing the results of those expressions to numerical results, we find good qualitative agreement. We also demonstrate how these expressions can be used to efficiently calculate waveforms for gravitational-wave astronomy.

  9. Statistical Mechanics of Black Holes

    E-Print Network [OSTI]

    B. Harms; Y. Leblanc

    1992-05-11

    We analyze the statistical mechanics of a gas of neutral and charged black holes. The microcanonical ensemble is the only possible approach to this system, and the equilibrium configuration is the one for which most of the energy is carried by a single black hole. Schwarzschild black holes are found to obey the statistical bootstrap condition. In all cases, the microcanonical temperature is identical to the Hawking temperature of the most massive black hole in the gas. U(1) charges in general break the bootstrap property. The problems of black hole decay and of quantum coherence are also addressed.

  10. UGA DESIGN & CONSTRUCTION SUPPLEMENTAL GENERAL REQUIREMENTS & STANDARDS DOOR AND FRAMES

    E-Print Network [OSTI]

    Arnold, Jonathan

    have welded joints. B. Knock down door frames (factory pre-finished steel door frames which exception below for UGA Housing). F. For UGA Housing Only (New Construction) i. Design Professional for tested, labeled door construction for Project. 6) Lite/lock conflicts: follow door manufacturer

  11. DESIGN OF PARTIALLY RESTRAINED STEEL FRAMES USING ADVANCED ANALYSIS AND

    E-Print Network [OSTI]

    Foley, Christopher M.

    DESIGN OF PARTIALLY RESTRAINED STEEL FRAMES USING ADVANCED ANALYSIS AND AN OBJECT by the experience and intuition of the designer. However, researchers are continually developing analysis of the steel frames in lieu of design specification and code requirements. The advanced analysis based design

  12. Frame expansions for Gabor multipliers John J. Benedetto 1

    E-Print Network [OSTI]

    Benedetto, John J.

    design, where redundant frame decompositions are increasingly applicable. Key words: Gabor multipliers, Gabor frames 1 Introduction Inspired and initiated by von Neumann in quantum mechanics [1], pp.405 ff of the unitary operator U. The equivalence of (1) and (2) follows from the elementary calculation () Pg,h () f

  13. The Evolution of Accreting Black Holes in Outburst

    E-Print Network [OSTI]

    John A. Tomsick

    2004-01-12

    Black hole binaries exhibit dramatic changes in their X-ray spectral and timing properties over time, providing important clues about the physical processes that occur in these systems. Black holes and black hole candidates are prime targets for RXTE with observational goals including the study of extreme gravitational fields and jet formation mechanisms. The great wealth of data from RXTE has helped us to learn about these systems as well as raising new questions about accreting black holes. RXTE observations have allowed us to study a wide range of black hole science topics including the connection between the accretion disk and jets, the geometry of the inner accretion flow, and the physical changes that occur between spectral states. In this presentation, I discuss significant results on these topics that have been obtained for persistent and transient black holes over the past several years, and I present results from our program of X-ray and radio observations during the decays of black hole transient outbursts.

  14. Static Charged Black Hole Solutions in Horava-Lifshitz Gravity

    E-Print Network [OSTI]

    Jin-Zhang Tang

    2010-01-12

    In the present work, we search static charged black hole solutions to Ho\\v{r}ava-Lifshitz gravity with or without projectability condition. We consider the most general form of action which electromagnetic field couples with Ho\\v{r}ava-Lifshitz gravity. With the projectability condition, we find dS-Reissner-Nordstrom black hole solution in Painlev\\'e-Gullstrand type coordinates in the IR region and a de-Sitter space-time solution in the UV region. Without the projectability condition, in the IR region, we find an especial static charged black hole solution.

  15. Time-periodic universes

    E-Print Network [OSTI]

    De-Xing Kong; Kefeng Liu; Ming Shen

    2008-08-30

    In this letter we construct a new time-periodic solution of the vacuum Einstein's field equations whose Riemann curvature norm takes the infinity at some points. We show that this solution is intrinsically time-periodic and describes a time-periodic universe with the "black hole". New physical phenomena are investigated and new singularities are analyzed for this universal model.

  16. Black Hole Scan

    E-Print Network [OSTI]

    Juan Crisostomo; Ricardo Troncoso; Jorge Zanelli

    2000-09-22

    Gravitation theories selected by requiring that they have a unique anti-de Sitter vacuum with a fixed cosmological constant are studied. For a given dimension d, the Lagrangians under consideration are labeled by an integer k=1,2,...,[(d-1)/2]. Black holes for each d and k are found and are used to rank these theories. A minimum possible size for a localized electrically charged source is predicted in the whole set of theories, except General Relativity. It is found that the thermodynamic behavior falls into two classes: If d-2k=1, these solutions resemble the three dimensional black hole, otherwise, their behavior is similar to the Schwarzschild-AdS_4 geometry.

  17. Black holes at accelerators.

    E-Print Network [OSTI]

    Webber, Bryan R

    be presented and the effects of some of the uncertainties can be investigated. 3.1. Hawking Spectrum With the above assumptions, the spectrum of particles emitted during black hole decay takes the form dN dE ? ?E2 (eE/TH ? 1) T n+6H (8) where as usual... the trapped surface area [6, 7]. T030 02 4 6 8 10 0 0.2 0.4 0.6 0.8 1 1.2 n=0 n=1 n=2 n=6 E rS ?ˆ (0 ) ab s/ pi r2 S Figure 4: Grey-body factors for scalar emission on the brane from a (4 + n)D black hole. 0 2 4 6 8 10 0 0.2 0.4 0.6 0.8 1 1.2 n=0 n=1 n=2 n=6 E...

  18. Black Hole Demographics

    E-Print Network [OSTI]

    Laura Ferrarese

    2002-03-04

    The purpose of this contribution is to review the current status of black hole demographics in light of recent advances in the study of high redshift QSOs (section 2), local AGNs (section 3) and local quiescent galaxies (section 4). I will then outline the prospects for future progress (section 5), and discuss what I believe will be the challenges for the years to come [ABRIDGED].

  19. Electromagnetic wave scattering by Schwarzschild black holes

    E-Print Network [OSTI]

    Luís C. B. Crispino; Sam R. Dolan; Ednilton S. Oliveira

    2009-05-20

    We analyze the scattering of a planar monochromatic electromagnetic wave incident upon a Schwarzschild black hole. We obtain accurate numerical results from the partial wave method for the electromagnetic scattering cross section, and show that they are in excellent agreement with analytical approximations. The scattering of electromagnetic waves is compared with the scattering of scalar, spinor and gravitational waves. We present a unified picture of the scattering of all massless fields for the first time.

  20. Ultrafast gated intensifier design for laser fusion x-ray framing applications

    SciTech Connect (OSTI)

    Price, R.H.; Wiedwald, J.D.; Kalibjian, R.; Thomas, S.W.; Cook, W.M.

    1983-11-01

    A major challenge for laser fusion is the study of the symmetry and the hydrodynamic stability of imploding fuel capsules. Streaked x-radiography, in one space and one time dimension, does not provide sufficient information. Two (spatial) dimensional frames of 10 to 100 ps duration are required with good image quality, minimum geometrical distortion (approximately 1%), dynamic range greater than 1000 and greater than 200 x 200 pixels. A gated transmission line imager (TLI) can meet these requirements with frame times between 30 and 100 ps. An instrument of this type is now being developed. Progress on this instrument including theory of operation, ultrafast pulse generation and propagation, component integration, and high resolution phosphor screen development are presented.

  1. Means to flexibly attach lens frames to temple members

    DOE Patents [OSTI]

    Smith, Harry D. (Richland, WA)

    1995-01-01

    The invention is a band hinge for flexibly connecting the temple member to the lens frame thereby preventing damage from inadvertent pressure or cyclic wear. A distinguishing feature of the invention is the use of a band hinge that holds together the temple member and the lens frame without the use of a pin or screw hinging mechanism. The invention allows for a high degree of freedom of movement for the temple member with respect to the lens frame which will prevent most forms of damages to the glasses from these types of events.

  2. The no-drag frame for anomalous chiral fluid

    E-Print Network [OSTI]

    Stephanov, Mikhail A

    2015-01-01

    We show that for an anomalous fluid carrying dissipationless chiral magnetic and/or vortical currents there is a frame in which a stationary obstacle experiences no drag, but energy and charge currents do not vanish, resembling superfluidity. However, unlike ordinary superfluid flow, the anomalous chiral currents do transport entropy in this frame. We show that the second law of thermodynamics completely determines the amounts of these anomalous non-dissipative currents in the "no-drag frame" as polynomials in temperature and chemical potential with known anomaly coefficients. These general results are illustrated and confirmed by a calculation in the chiral kinetic theory and quark-gluon plasma at high temperature.

  3. The proper characteristics of frame reference as a 4-invariants

    E-Print Network [OSTI]

    V. V. Voytik

    2015-06-02

    The paper derived 4-dimensional equation for the proper characteristics of the rigid frame of reference. From these conditions it follows the laws of motion of its proper tetrad and inverse kinematics equation, i. e., differential equations, which solves the problem of recovering the parameters of the motion of rigid frame of reference for their proper acceleration and angular velocity. In particular it is shown that the commission boost the moving frame of reference having Thomas precession for a new laboratory system will have a combination of two rotations: a new self-Thomas precession and rotation Wigner, which combine to give an initial frequency of the Thomas precession.

  4. Identification of Astrophysical Black Holes

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1998-03-19

    Black holes are by definition black, and therefore cannot be directly observed by using electromagnetic radiations. Convincing identification of black holes must necessarily depend on the identification of a very specially behaving matter and radiation which surround them. A major problem in this subject of black hole astrophysics is to quantify the behaviour of matter and radiation close to the horizon. In this review, the subject of black hole accretion and outflow is systematically developed. It is shown that both the stationary as well as the non-stationary properties of the observed spectra could be generally understood by these solutions. It is suggested that the solutions of radiative hydrodynamic equations may produce clear spectral signatures of black holes. Other circumstantial evidences of black holes, both in the galactic centers as well as in binary systems, are also presented.

  5. Gravitational wave production by rotating primordial black holes

    E-Print Network [OSTI]

    Dong, Ruifeng; Stojkovic, Dejan

    2015-01-01

    In this paper we analyze in detail a rarely discussed question of gravity waves production from evaporating black holes. Evaporating black holes emit gravitons which are at classical level registered as gravity waves. We use the latest constraints on the primordial black hole abundance, and calculate the power emitted in gravitons at the time of their evaporation. We then solve the coupled system of equations that gives us the evolution of the frequency and amplitude of gravity waves during the expansion of the universe. The spectrum of gravitational waves that can be detected today depends on multiple factors: fraction of the total energy density which was occupied by black holes, the epoch in which the black holes are formed, and quantities like mass and angular momentum of evaporating black holes. We conclude that very small primordial black holes which evaporate before the nucleosynthesis emit gravitons whose spectral energy fraction today can be as large as $10^{-5}$. On the other hand, primordial black ...

  6. Black holes in general relativity

    E-Print Network [OSTI]

    Visser, Matt

    2009-01-01

    What is going on (as of August 2008) at the interface between theoretical general relativity, string-inspired models, and observational astrophysics? Quite a lot. In this mini-survey I will make a personal choice and focus on four specific questions: Do black holes "exist"? (For selected values of the word "exist".) Is black hole formation and evaporation unitary? Can one mimic a black hole to arbitrary accuracy? Can one detect the presence of a horizon using local physics?

  7. Quantum Mechanics and Black Holes

    E-Print Network [OSTI]

    Jose N. Pecina-Cruz

    2005-11-27

    This paper discusses the existence of black holes from the foundations of quantum mechanics. It is found that quantum mechanics rule out a possible gravitational collapse.

  8. Ultra-high speed burst-mode imager for multi-frame radiography

    SciTech Connect (OSTI)

    Kwiatkowski, Kris; Nedrow, Paul; Mariam, Fesseha; Merrill, Frank E; Morris, Chris L; Saunders, Abdy; Hogan, Gary; Douance, Vincent; Bal, Yibin; Joshi, Atul; Auyeung, John

    2010-01-01

    A 720 x 720 pixel hybrid-CMOS imager was fabricated by Rockwell Scientific (now Teledyne Imaging Sensors). Several cameras have been in operation for 5 years, in a variety of static and dynamic experiments, at the 800MeV proton radiography (pRAD) facility at the LANSCE accelerator. The cameras can operate with a per-pulse adjustable inter-frame time of 250ns to 2s, and with an exposure/integration-time as short as 150 ns. Given the 800 ms total readout time, the imager can be externally synchronized to 0.1-to-5Hz, 50-ns wide proton beam pulses, and record 1000-frame radiographic movies of 5-to-30 minute duration. The effectiveness and dependence of the global electronic shutter on the pixelated Si photo-sensor bias voltage is discussed. The spatial resolution dependence of the full imaging system on various monolithic and structured scintillators is presented. We also present features of a new-generation 10-frame, 1024 x 1024 pixel, 50-ns exposure, 12-bit dynamic range imager, which is now in the design phase.

  9. Deep Frames, White Men's Discourse, and Black Female Bodies 

    E-Print Network [OSTI]

    Slatton, Brittany C.

    2012-02-14

    the bounds of hegemonic femininity, beauty, sexuality, and womanhood. Using the theoretical concept deep frame, which is the "conceptual infrastructure of the mind" (Lakoff 2006a:12) and representative of one's commonsense world view, I argue that the ways...

  10. Quantum geometrodynamical description of the Universe in different reference frames

    E-Print Network [OSTI]

    T. P. Shestakova

    2002-05-16

    Several years ago the so-called quantum geometrodynamics in extended phase space was proposed. The main role in this version of quantum geometrodynamics is given to a wave function that carries information about geometry of the Universe as well as about a reference frame in which this geometry is studied. We consider the evolution of a physical object (the Universe) in ``physical'' subspace of extended configurational space, the latter including gauge and ghost degrees of freedom. A measure of the ``physical'' subspace depends on a chosen reference frame, in particular, a small variation of a gauge-fixing function results in changing the measure. Thus, a transition to another gauge condition (another reference frame) leads to non-unitary transformation of a physical part of the wave function. From the viewpoint of the evolution of the Universe in the ``physical'' subspace a transition to another reference frame is an irreversible process that may be important when spacetime manifold has a nontrivial topology.

  11. Gesturing beyond the Frame: Transnational Trauma and US War Fiction

    E-Print Network [OSTI]

    Lahti, Ruth A. H.

    2012-01-01

    of Civilians in America’s Wars (New York: Oxford UniversityButler, Judith. Frames of War: When Is Life Grievable? NewRacial Melancholy in Vietnam War Representation. ” Arizona

  12. Frame: An Imperative Coordination Language for Parallel Programming 

    E-Print Network [OSTI]

    Cole, Murray

    2000-01-01

    We present Frame, a simple language which facilitates structured expression of imperative parallelism. Programs are described at two levels. The top level captures the main parallel algorithmic structure (which may be nested) and is independent...

  13. Inertial frames without the relativity principle: breaking Lorentz symmetry

    E-Print Network [OSTI]

    Baccetti, Valentina; Visser, Matt

    2013-01-01

    We investigate inertial frames in the absence of Lorentz invariance, reconsidering the usual group structure implied by the relativity principle. We abandon the relativity principle, discarding the group structure for the transformations between inertial frames, while requiring these transformations to be at least linear (to preserve homogeneity). In theories with a preferred frame (aether), the set of transformations between inertial frames forms a groupoid/pseudogroup instead of a group, a characteristic essential to evading the von Ignatowsky theorems. In order to understand the dynamics, we also demonstrate that the transformation rules for energy and momentum are in general affine. We finally focus on one specific and compelling model implementing a minimalist violation of Lorentz invariance.

  14. Thermal BEC black holes

    E-Print Network [OSTI]

    Roberto Casadio; Andrea Giugno; Octavian Micu; Alessio Orlandi

    2015-11-04

    We review some features of BEC models of black holes obtained by means of the HWF formalism. We consider the KG equation for a toy graviton field coupled to a static matter current in spherical symmetry. The classical field reproduces the Newtonian potential generated by the matter source, while the corresponding quantum state is given by a coherent superposition of scalar modes with continuous occupation number. An attractive self-interaction is needed for bound states to form, so that (approximately) one mode is allowed, and the system of N bosons can be self-confined in a volume of the size of the Schwarzschild radius. The HWF is then used to show that the radius of such a system corresponds to a proper horizon. The uncertainty in the size of the horizon is related to the typical energy of Hawking modes: it decreases with the increasing of the black hole mass (larger number of gravitons), in agreement with semiclassical calculations and different from a single very massive particle. The spectrum contains a discrete ground state of energy $m$ (the bosons forming the black hole), and a continuous spectrum with energy $\\omega > m$ (representing the Hawking radiation and modelled with a Planckian distribution at the expected Hawking temperature). The $N$-particle state can be collectively described by a single-particle wave-function given by a superposition of a total ground state with energy $M = N m$ and a Planckian distribution for $E > M$ at the same Hawking temperature. The partition function is then found to yield the usual area law for the entropy, with a logarithmic correction related with the Hawking component. The backreaction of modes with $\\omega > m$ is also shown to reduce the Hawking flux and the evaporation properly stops for vanishing mass.

  15. Artificial ozone holes

    E-Print Network [OSTI]

    S. N. Dolya

    2014-10-18

    This article considers an opportunity of disinfecting a part of the Earth surface, occupying a large area of ten thousand square kilometers. The sunlight will cause dissociation of molecular bromine into atoms; each bromine atom kills thirty thousand molecules of ozone. Each bromine plate has a mass of forty milligrams grams and destroys ozone in the area of hundred square meters. Thus, to form the ozone hole over the area of ten thousand square kilometers, it is required to have the total mass of bromine equal to the following four tons.

  16. Holographic Black Hole Chemistry

    E-Print Network [OSTI]

    Andreas Karch; Brandon Robinson

    2015-11-02

    Thermodynamic quantities associated with black holes in Anti-de Sitter space obey an interesting identity when the cosmological constant is included as one of the dynamical variables, the generalized Smarr relation. We show that this relation can easily be understood from the point of view of the dual holographic field theory. It amounts to the simple statement that the extensive thermodynamic quantities of a large $N$ gauge theory only depend on the number of colors, $N$, via an overall factor of $N^2$.

  17. Black hole evaporation in a noncommutative charged Vaidya model

    SciTech Connect (OSTI)

    Sharif, M. Javed, W.

    2012-06-15

    We study the black hole evaporation and Hawking radiation for a noncommutative charged Vaidya black hole. For this purpose, we determine a spherically symmetric charged Vaidya model and then formulate a noncommutative Reissner-Nordstroem-like solution of this model, which leads to an exact (t - r)-dependent metric. The behavior of the temporal component of this metric and the corresponding Hawking temperature are investigated. The results are shown in the form of graphs. Further, we examine the tunneling process of charged massive particles through the quantum horizon. We find that the tunneling amplitude is modified due to noncommutativity. Also, it turns out that the black hole evaporates completely in the limits of large time and horizon radius. The effect of charge is to reduce the temperature from a maximum value to zero. We note that the final stage of black hole evaporation is a naked singularity.

  18. Probing Dark Energy with Black Hole Binaries

    E-Print Network [OSTI]

    Laura Mersini-Houghton; Adam Kelleher

    2008-08-25

    The equation of state (EoS) of dark energy $w$ remains elusive despite enormous experimental efforts to pin down its value and its time variation. Yet it is the single most important handle we have in our understanding of one of the most mysterious puzzle in nature, dark energy. This letter proposes a new method for measuring the EoS of dark energy by using the gravitational waves (GW) of black hole binaries. The method described here offers an alternative to the standard way of large scale surveys. It is well known that the mass of a black hole changes due to the accretion of dark energy but at an extremely slow rate. However, a binary of supermassive black holes (SBH) radiates gravitational waves with a power proportional to the masses of these accreting stars and thereby carries information on dark energy. These waves can propagate through the vastness of structure in the universe unimpeded. The orbital changes of the binary, induced by the energy loss from gravitational radiation, receive a large contribution from dark energy accretion. This contribution is directly proportional to $(1+w)$ and is dominant for SBH binaries with separation $R \\ge 1000$ parsec, thereby accelerating the merging process for $w > -1$ or ripping the stars apart for phantom dark energy with $w < -1$. Such orbital changes, therefore $w$, can be detected with LIGO and LISA near merging time, or with X-ray and radio measurements of Chandra and VLBA experiments.

  19. Identifying Alternative Frames and Values to Increase Public Support for Health Policies that Target Obesity

    E-Print Network [OSTI]

    Ortiz, Selena E.

    2013-01-01

    51 4.3. Alternative Frame No.2: The Manipulation206 8.2. Alternative Frames and ValuesReframing Obesity through Alternative Frames and Values 4.1.

  20. Frame flow between government and the news media and its effects on the public: Framing of North Korea

    E-Print Network [OSTI]

    Lim, Jeongsub; Seo, Hyunjin

    2009-07-01

    Public opinion is likely to be susceptible to the way a government and the news media frame foreign countries, because unlike domestic issues, foreign news is typically beyond a person's direct experience. How does the ...

  1. Black Holes of Negative Mass

    E-Print Network [OSTI]

    R. B. Mann

    1997-05-06

    I demonstrate that, under certain circumstances, regions of negative energy density can undergo gravitational collapse into a black hole. The resultant exterior black hole spacetimes necessarily have negative mass and non-trivial topology. A full theory of quantum gravity, in which topology-changing processes take place, could give rise to such spacetimes.

  2. The Ozone Hole Some perspective

    E-Print Network [OSTI]

    Toohey, Darin W.

    The Ozone Hole · Some perspective · The British Antarctic Survey · The "Ozone Hole" · International of the predicted ozone losses! This was quite a controversy. Ultimately, ozone losses started appearing in the late 1980s (see Figure below), but by then, there was already a credibility issue for ozone scientists. #12

  3. Making Molecular Movies: 10,000,000,000,000 Frames per Second

    SciTech Connect (OSTI)

    Gaffney, Kelly

    2006-12-12

    Movies have transformed our perception of the world. With slow motion photography, we can see a hummingbird flap its wings, and a bullet pierce an apple. The remarkably small and extremely fast molecular world that determines how your body functions cannot be captured with even the most sophisticated movie camera today. To see chemistry in real time requires a camera capable of seeing molecules that are one ten billionth of a foot with a frame rate of 10 trillion frames per second! SLAC has embarked on the construction of just such a camera. Please join me as I discuss how this molecular movie camera will work and how it will change our perception of the molecular world.

  4. Angular velocity of gravitational radiation from precessing binaries and the corotating frame

    E-Print Network [OSTI]

    Michael Boyle

    2013-04-10

    This paper defines an angular velocity for time-dependent functions on the sphere, and applies it to gravitational waveforms from compact binaries. Because it is geometrically meaningful and has a clear physical motivation, the angular velocity is uniquely useful in helping to solve an important---and largely ignored---problem in models of compact binaries: the inverse problem of deducing the physical parameters of a system from the gravitational waves alone. It is also used to define the corotating frame of the waveform. When decomposed in this frame, the waveform has no rotational dynamics and is therefore as slowly evolving as possible. The resulting simplifications lead to straightforward methods for accurately comparing waveforms and constructing hybrids. As formulated in this paper, the methods can be applied robustly to both precessing and nonprecessing waveforms, providing a clear, comprehensive, and consistent framework for waveform analysis. Explicit implementations of all these methods are provided in accompanying computer code.

  5. New Twists In The Study Of Gravity Wave Emission In Systems With Massive Black Holes

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1996-11-10

    Traditionlly, gravitational wave emission from a coalescing binary system is computed using point mass approximations without considering any accretion disk. However, it is believed that in many of the galactic nuclei, there are supermassive central black holes surrounded by accretion disks. These accretion disks must be necessarily supersonic on and outside the horizon simply because the radial velocity (in the corotating frame) has to be the velocity of light on the horizon while the sound speed must be smaller. However, supersonic flows are typically sub-Keplerian. Thus, smaller black holes and neutron stars (which are on instantaneously Keplerian orbit and lose energy and angular momentum through gravitational radiation) on their way to coalesce with the central black hole must accrete negative angular momentum from the disk. We study here the way these disks affect the gravitational wave emission.

  6. Non-minimal Higgs inflation and frame dependence in cosmology

    SciTech Connect (OSTI)

    Steinwachs, Christian F.; Kamenshchik, Alexander Yu.

    2013-02-21

    We investigate a very general class of cosmological models with scalar fields non-minimally coupled to gravity. A particular representative in this class is given by the non-minimal Higgs inflation model in which the Standard Model Higgs boson and the inflaton are described by one and the same scalar particle. While the predictions of the non-minimal Higgs inflation scenario come numerically remarkably close to the recently discovered mass of the Higgs boson, there remains a conceptual problem in this model that is associated with the choice of the cosmological frame. While the classical theory is independent of this choice, we find by an explicit calculation that already the first quantum corrections induce a frame dependence. We give a geometrical explanation of this frame dependence by embedding it into a more general field theoretical context. From this analysis, some conceptional points in the long lasting cosmological debate: 'Jordan frame vs. Einstein frame' become more transparent and in principle can be resolved in a natural way.

  7. The mass function of high redshift seed black holes

    E-Print Network [OSTI]

    Giuseppe Lodato; Priyamvada Natarajan

    2007-02-13

    In this paper we derive the mass function of seed black holes that result from the central mass concentrated via disc accretion in collapsed haloes at redshift $z\\approx 15$. Using standard arguments including stability, we show that these pre-galactic discs can assemble a significant mass concentration in the inner regions, providing fuel for the formation and initial growth of super-massive black holes. Assuming that these mass concentrations do result in central seed black holes, we determine the mass distribution of these seeds as a function of key halo properties. The seed mass distribution determined here turns out to be asymmetric and skewed to higher masses. Starting with these initial seeds, building up to $10^9$ solar masses by $z = 6$ to power the bright quasars is not a problem in the standard LCDM cosmogony. These seed black holes in gas rich environments are likely to grow into the supermassive black holes at later times via mergers and accretion. Gas accretion onto these seeds at high redshift will produce miniquasars that likely play an important role in the reionization of the Universe. Some of these seed black holes on the other hand could be wandering in galaxy haloes as a consequence of frequent mergers, powering the off-nuclear ultra-luminous X-ray sources detected in nearby galaxies.

  8. A characteristic observable signature of preferred frame effects in relativistic binary pulsars

    E-Print Network [OSTI]

    N. Wex; M. Kramer

    2007-06-15

    In this paper we develop a consistent, phenomenological methodology to measure preferred-frame effects (PFEs) in binary pulsars that exhibit a high rate of periastron advance. We show that in these systems the existence of a preferred frame for gravity leads to an observable characteristic `signature' in the timing data, which uniquely identifies this effect. We expand the standard Damour-Deruelle timing formula to incorporate this `signature' and show how this new PFE timing model can be used to either measure or constrain the parameters related to a violation of the local Lorentz invariance of gravity in the strong internal fields of neutron stars. In particular, we demonstrate that in the presence of PFEs we expect a set of the new timing parameters to have a unique relationship that can be measured and tested incontrovertibly. This new methodology is applied to the Double Pulsar, which turns out to be the ideal test system for this kind of experiments.The currently available dataset allows us only to study the impact of PFEs on the orbital precession rate, d omega/dt, providing limits that are, at the moment, clearly less stringent than existing limits on PFE strong-field parameters. However, simulations show that the constraints improve fast in the coming years, allowing us to study all new PFE timing parameters and to check for the unique relationship between them. Finally, we show how a combination of several suitable systems in a "PFE antenna array", expected to be availabe for instance with the Square-Kilometre-Array (SKA), provides full sensitivity to possible violations of local Lorentz invariance in strong gravitational fields in all directions of the sky. This PFE antenna array may eventually allow us to determine the direction of a preferred frame should it exist.

  9. The Hawking evaporation process of rapidly-rotating black holes: An almost continuous cascade of gravitons

    E-Print Network [OSTI]

    Shahar Hod

    2015-06-17

    It is shown that rapidly-rotating Kerr black holes are characterized by the dimensionless ratio $\\tau_{\\text{gap}}/\\tau_{\\text{emission}}=O(1)$, where $\\tau_{\\text{gap}}$ is the average time gap between the emission of successive Hawking quanta and $\\tau_{\\text{emission}}$ is the characteristic timescale required for an individual Hawking quantum to be emitted from the black hole. This relation implies that the Hawking cascade from rapidly-rotating black holes has an almost continuous character. Our results correct some inaccurate claims that recently appeared in the literature regarding the nature of the Hawking black-hole evaporation process.

  10. The Hawking evaporation process of rapidly-rotating black holes: An almost continuous cascade of gravitons

    E-Print Network [OSTI]

    Hod, Shahar

    2015-01-01

    It is shown that rapidly-rotating Kerr black holes are characterized by the dimensionless ratio $\\tau_{\\text{gap}}/\\tau_{\\text{emission}}=O(1)$, where $\\tau_{\\text{gap}}$ is the average time gap between the emission of successive Hawking quanta and $\\tau_{\\text{emission}}$ is the characteristic timescale required for an individual Hawking quantum to be emitted from the black hole. This relation implies that the Hawking cascade from rapidly-rotating black holes has an almost continuous character. Our results correct some inaccurate claims that recently appeared in the literature regarding the nature of the Hawking black-hole evaporation process.

  11. Fuel cell repeater unit including frame and separator plate

    SciTech Connect (OSTI)

    Yamanis, Jean; Hawkes, Justin R; Chiapetta, Jr., Louis; Bird, Connie E; Sun, Ellen Y; Croteau, Paul F

    2013-11-05

    An example fuel cell repeater includes a separator plate and a frame establishing at least a portion of a flow path that is operative to communicate fuel to or from at least one fuel cell held by the frame relative to the separator plate. The flow path has a perimeter and any fuel within the perimeter flow across the at least one fuel cell in a first direction. The separator plate, the frame, or both establish at least one conduit positioned outside the flow path perimeter. The conduit is outside of the flow path perimeter and is configured to direct flow in a second, different direction. The conduit is fluidly coupled with the flow path.

  12. Mesoscopic Mechanical Resonators as Quantum Non-Inertial Reference Frames

    E-Print Network [OSTI]

    B. N. Katz; M. P. Blencowe; K. C. Schwab

    2015-10-11

    An atom attached to a micrometer-scale wire that is vibrating at a frequency of 100 MHz and with displacement amplitude 1 nm experiences an acceleration magnitude 10^9 ms^-2, approaching the surface gravity of a neutron star. As one application of such extreme non-inertial forces in a mesoscopic setting, we consider a model two-path atom interferometer with one path consisting of the 100 MHz vibrating wire atom guide. The vibrating wire guide serves as a non-inertial reference frame and induces an in principle measurable phase shift in the wave function of an atom traversing the wire frame. We furthermore consider the effect on the two-path atom wave interference when the vibrating wire is modeled as a quantum object, hence functioning as a quantum non-inertial reference frame. We outline a possible realization of the vibrating wire, atom interferometer using a superfluid helium quantum interference setup.

  13. Does the mass of a black hole decrease due to the accretion of phantom energy?

    SciTech Connect (OSTI)

    Gao Changjun; Chen Xuelei; Faraoni, Valerio; Shen Yougen

    2008-07-15

    According to Babichev et al., the accretion of a phantom test fluid onto a Schwarzschild black hole will induce the mass of the black hole to decrease, however the backreaction was ignored in their calculation. Using new exact solutions describing black holes in a background Friedmann-Robertson-Walker universe, we find that the physical black hole mass may instead increase due to the accretion of phantom energy. If this is the case, and the future universe is dominated by phantom dark energy, the black hole apparent horizon and the cosmic apparent horizon will eventually coincide and, after that, the black hole singularity will become naked in finite comoving time before the big rip occurs, violating the cosmic censorship conjecture.

  14. Navier-Stokes on Black Hole Horizons and DC Thermoelectric Conductivity

    E-Print Network [OSTI]

    Donos, Aristomenis

    2015-01-01

    We consider a general class of black hole solutions of Einstein-Maxwell theory which are holographically dual to CFTs with spatially dependent sources. We show that an averaged DC thermoelectric conductivity matrix can be obtained by solving the forced, linearised, time-independent Navier-Stokes equations on the black hole horizon for an incompressible and charged fluid.

  15. The thermal performance of steel-framed walls

    SciTech Connect (OSTI)

    Barbour, C.E. [NAHB Research Center, Upper Marlboro, MD (United States). Building Systems Div.; Goodrow, J. [Holometrix, Bedford, MA (United States)

    1995-12-31

    Thermal bridges are areas in constructions that have highly conductive materials, allowing higher heat transfer through less conductive areas. In a wall, thermal bridges can increase heat loss, cause dust to accumulate on the studs (ghosting) due to temperature distribution, and cause condensation to form in and on the walls. The effects of thermal bridges are often misunderstood by engineers, buildings, and manufacturers of construction products. This study attempts to provide a better understanding of the effects of thermal bridges in steel-framed walls, as well as information leading to improved methods of predicting R-value of walls containing thermal bridges. An improved method for estimating R-value would allow an equitable comparison of thermal performance with other construction types and materials. This would increase the number of alternative materials for walls available to designers, thus allowing them the freedom to correctly choose the optimum choice for construction. In order to arrive at an improved method, experimental data on the heat transfer characteristics of steel-framed walls were collected. Twenty-three wall samples were tested in a calibrated hot box (ASTM C976) to measure the thermal performance of steel-framed wall systems. The tests included an array of stud frame configurations, exterior sheathing, and fiberglass batt insulations. Other studies of thermal bridging in steel-framed walls have not included the use of insulating sheathing, which reduces the extent of the thermal bridges and improves total thermal performance. The purpose of the project was to provide measured R-values for commonly used steel-framed wall configurations and to improve R-value estimating methods. Also, detailed monitoring of temperature gradients in the test walls combined with numerical analysis provided new insights into heat transfer phenomena concerning thermal bridges.

  16. Strings, higher curvature corrections, and black holes

    E-Print Network [OSTI]

    Thomas Mohaupt

    2005-12-05

    We review old and recent results on subleading contributions to black hole entropy in string theory.

  17. The Woods Hole Laboratory, 1885-1985

    E-Print Network [OSTI]

    The Woods Hole Laboratory, 1885-1985: A Century of Service Woods Hole Laboratory Northeast, Lectures, and Rededication of the Woods Hole Laboratory Contents Foreword and Acknowledgments Committees and Contributions of the Woods Hole Fisheries Laboratory Centennial Lecture II: The MBL and the Fisheries-A Century

  18. Electromagnetic pulses which have a zero momentum frame

    E-Print Network [OSTI]

    John Lekner

    2003-04-08

    One set of the Ziolkowski family of exact solutions of the wave equation are shown to represent pulses propagating with momentum smaller than energy/c. This is explicitly demonstrated for special cases by calculating the total electromagnetic momentum and energy. Since the ratio of momentum to energy is a constant smaller than 1/c, there exists a Lorentz transformation to a frame in which the total momentum is zero. In the zero-momentum frame the fields are those of an annular pulse converging onto or diverging from a focal region.

  19. Can accretion disk properties observationally distinguish black holes from naked singularities?

    E-Print Network [OSTI]

    Z. Kovacs; T. Harko

    2010-12-06

    Naked singularities are hypothetical astrophysical objects, characterized by a gravitational singularity without an event horizon. Penrose has proposed a conjecture, according to which there exists a cosmic censor who forbids the occurrence of naked singularities. Distinguishing between astrophysical black holes and naked singularities is a major challenge for present day observational astronomy. A possibility of differentiating naked singularities from black holes is through the comparative study of thin accretion disks properties around rotating naked singularities and Kerr-type black holes, respectively. In the present paper, we consider accretion disks around rotating naked singularities, obtained as solutions of the field equations in the Einstein-massless scalar field theory. A first major difference between rotating naked singularities and Kerr black holes is in the frame dragging effect, the angular velocity of a rotating naked singularity being inversely proportional to its spin parameter. Due to the differences in the exterior geometry, the thermodynamic and electromagnetic properties of the disks are different for these two classes of compact objects, consequently giving clear observational signatures that could discriminate between black holes and naked singularities. For specific values of the spin parameter and of the scalar charge, the energy flux from the disk around a rotating naked singularity can exceed by several orders of magnitude the flux from the disk of a Kerr black hole. The conversion efficiency of the accreting mass into radiation by rotating naked singularities is always higher than the conversion efficiency for black holes. Thus, these observational signatures may provide the necessary tools from clearly distinguishing rotating naked singularities from Kerr-type black holes.

  20. Black hole horizons Eric Gourgoulhon

    E-Print Network [OSTI]

    Gourgoulhon, Eric

    on a black hole: up to 42% of the mass-energy mc2 of accreted matter ! NB: thermonuclear reactions release: a very deep gravitational potential well Release of potential gravitational energy by accretion

  1. Thermodynamics of regular black hole

    E-Print Network [OSTI]

    Yun Soo Myung; Yong-Wan Kim; Young-Jai Park

    2008-09-21

    We investigate thermodynamics for a magnetically charged regular black hole (MCRBH), which comes from the action of general relativity and nonlinear electromagnetics, comparing with the Reissner-Norstr\\"om (RN) black hole in both four and two dimensions after dimensional reduction. We find that there is no thermodynamic difference between the regular and RN black holes for a fixed charge $Q$ in both dimensions. This means that the condition for either singularity or regularity at the origin of coordinate does not affect the thermodynamics of black hole. Furthermore, we describe the near-horizon AdS$_2$ thermodynamics of the MCRBH with the connection of the Jackiw-Teitelboim theory. We also identify the near-horizon entropy as the statistical entropy by using the AdS$_2$/CFT$_1$ correspondence.

  2. Black Holes and Nuclear Dynamics

    E-Print Network [OSTI]

    David Merritt

    2006-02-17

    Supermassive black holes inhabit galactic nuclei, and their presence influences in crucial ways the evolution of the stellar distribution. The low-density cores observed in bright galaxies are probably a result of black hole infall, while steep density cusps like those at the Galactic center are a result of energy exchange between stars moving in the gravitational field of the single black hole. Loss-cone dynamics are substantially more complex in galactic nuclei than in collisionally-relaxed systems like globular clusters due to the wider variety of possible geometries and orbital populations. The rate of star-black hole interactions has begun to be constrained through observations of energetic events associated with stellar tidal disruptions.

  3. You Cannot Press Out the Black Hole

    E-Print Network [OSTI]

    Daisuke Ida; Takahiro Okamoto

    2012-01-03

    It is shown that a ball-shaped black hole region homeomorphic with D**n cannot be pressed out, along whichever axis penetrating the black hole region, into a black ring with a doughnut-shaped black hole region homeomorphic with S**1 x D**(n-1). A more general prohibition law for the change of the topology of black holes, including a version of no-bifurcation theorems for black holes, is given.

  4. On geodesic dynamics in deformed black-hole fields

    E-Print Network [OSTI]

    Old?ich Semerák; Petra Suková

    2015-09-28

    "Almost all" seems to be known about isolated stationary black holes in asymptotically flat space-times and about the behaviour of {\\em test} matter and fields in their backgrounds. The black holes likely present in galactic nuclei and in some X-ray binaries are commonly being represented by the Kerr metric, but actually they are not isolated (they are detected only thanks to a strong interaction with the surroundings), they are not stationary (black-hole sources are rather strongly variable) and they also probably do not live in an asymptotically flat universe. Such "perturbations" may query the classical black-hole theorems (how robust are the latter against them?) and certainly affect particles and fields around, which can have observational consequences. In the present contribution we examine how the geodesic structure of the static and axially symmetric black-hole space-time responds to the presence of an additional matter in the form of a thin disc or ring. We use several different methods to show that geodesic motion may become chaotic, to reveal the strength and type of this irregularity and its dependence on parameters. The relevance of such an analysis for galactic nuclei is briefly commented on.

  5. Image Framing in Climate Change News Stories, p-1 Image Themes and Frames in U.S. Print News Stories about Climate Change

    E-Print Network [OSTI]

    Hespanha, João Pedro

    Image Framing in Climate Change News Stories, p-1 Image Themes and Frames in U.S. Print News Stories about Climate Change Stacy Rebich-Hespanha, Ronald E. Rice, Daniel R. Montello, Sean Retzloff, Sandrine Tien & João P. Hespanha Research on frames in climate change news coverage has advanced

  6. The Effect of Connection Fractures on Steel Moment Resisting Frame

    E-Print Network [OSTI]

    Sweetman, Bert

    The Effect of Connection Fractures on Steel Moment Resisting Frame Seismic Demands and Safety - The Effect of Connection Fractures on SMRF Seismic Demands and Safety 1. Contents, Approach, Models........................................................................................C-1 "Numerical Example of the Proposed SAC Procedure for Assessing the Annual Exceedance Probabilities

  7. Building America Top Innovations 2012: Advanced Framing Systems and Packages

    SciTech Connect (OSTI)

    none,

    2013-01-01

    This Building America Top Innovations profile describes Building America research showing advanced 2x6, 24-inch on-center framing, single top plates, open headers, and 2-stud corners reduced board feet of lumber by more than 1,000 feet, cut energy use by 13%, and cut material and labor costs by more than $1,000 on a typical home.

  8. Frame Theory and Optimal Anchor Geometries in Wireless Localization

    E-Print Network [OSTI]

    Steendam, Heidi

    for an arbitrary number of anchors is governed by the fundamental inequality in frame theory. Furthermore theory is S. Van de Velde and H. Steendam are with the Department of Telecom- munications and Information, they have been successfully applied in fields where redundancy is the key such as coding theory, robust

  9. Ultrathin Single-Walled Carbon Nanotube Network Framed Graphene Hybrids

    E-Print Network [OSTI]

    Wikswo, John

    Ultrathin Single-Walled Carbon Nanotube Network Framed Graphene Hybrids Rui Wang, Tu Hong, and Ya ABSTRACT: Graphene and single-walled carbon nanotubes (SWNTs) have shown superior potential in electronics method is developed to synthesize ultrathin SWNT-graphene films through chemical vapor deposition

  10. Demonstrating genuine multipartite entanglement and nonseparability without shared reference frames

    E-Print Network [OSTI]

    Celal Furkan Senel; Thomas Lawson; Marc Kaplan; Damian Markham; Eleni Diamanti

    2015-04-02

    Multipartite nonlocality is of great fundamental interest and constitutes a useful resource for many quantum information protocols. However, demonstrating it in practice, by violating a Bell inequality, can be difficult. In particular, standard experimental setups require the alignment of distant parties' reference frames, which can be challenging or impossible in practice. In this work we study the violation of certain Bell inequalities, namely the Mermin, Mermin-Klyshko and Svetlichny inequalities, without shared reference frames, when parties share a Greenberger-Horne-Zeilinger (GHZ) state. Furthermore, we analyse how these violations demonstrate genuine multipartite features of entanglement and nonlocality. For 3, 4 and 5 parties, we show that it is possible to violate these inequalities with high probability, when the parties choose their measurements from the three Pauli operators, defined only with respect to their local frames. Moreover, the probability of violation, and the amount of violation, are increased when each party chooses their measurements from the four operators describing the vertices of a tetrahedron. We also consider how many randomly chosen measurement directions are needed to violate the Bell inequalities with high probability. We see that the obtained levels of violation are sufficient to also demonstrate genuine multipartite entanglement and nonseparability. Finally, we show analytically that choosing from two measurement settings per party is sufficient to demonstrate the maximum degree of genuine multipartite entanglement and nonseparability with certainty when the parties' reference frames are aligned in one direction so that they differ only in rotations around one axis.

  11. Generalizing Case Frames Using a Thesaurus and the MDL Principle

    E-Print Network [OSTI]

    Generalizing Case Frames Using a Thesaurus and the MDL Principle Hang Li* NEC Corporation Naoki Abe, the proposed method makes use of an existing thesaurus and restricts its attention to those partitions that are present as "cuts" in the thesaurus tree, thus reducing thegeneralization problem to that ofestimating

  12. Inter-frame Motion Correction for MR Thermometry

    E-Print Network [OSTI]

    van Vliet, Lucas J.

    Inter-frame Motion Correction for MR Thermometry S. Suprijanto1 , M.W. Vogel3 , F.M. Vos1 , H.A. Vrooman2,3 , and A.M. Vossepoel1,2,3 1 Quantitative Imaging, Delft University of Technology, 2628 CJ Delft with MRI to monitor changes in thermal therapy. Phase shift based MR thermome- try gives an estimate

  13. Seismic Retrofitting of RC Frames with RC Infilling

    E-Print Network [OSTI]

    Seismic Retrofitting of RC Frames with RC Infilling SERIES Workshop: "Role of research infrastructures in seismic rehabilitation" 8 - 9 February 2012, Istanbul, Turkey C. Z. Chrysostomou, N. Kyriakides, P. Kotronis, P. Roussis, M. Poljansek, F. Taucer RC Infilling of Existing RC Structures for Seismic

  14. Performance of Wood-Frame Structures during Hurricane Katrina

    E-Print Network [OSTI]

    Gupta, Rakesh

    Performance of Wood-Frame Structures during Hurricane Katrina John W. van de Lindt, M.ASCE1 ; and Kenneth J. Fridley, M.ASCE6 Abstract: The costliest natural disaster in U.S. history was Hurricane Katrina; Hurricanes; Damage; Gulf of Mexico. Introduction The data reconnaissance consisted of 3 days of data

  15. Fishing in Black Holes

    E-Print Network [OSTI]

    A. Brotas

    2006-09-01

    The coordinate system $(\\bar{x},\\bar{t})$ defined by $r = 2m + K\\bar{x}- c K \\bar{t}$ and $t=\\bar{x}/cK - 1 /cK \\int_{r_a}^r (1- 2m/r + K^2)^{1/2} (1 - 2m/r)^{-1}dr$ allow us to write the Schwarzschild metric in the form: \\[ds^2=c^2 d\\bar{t}^2 + (W^2/K^2 - 2W/K) d\\bar{x}^2 + 2c (1 + W/K) d\\bar{x}d\\bar{t} - r^2 (d\\theta^2 + cos^2\\theta d\\phi^2)\\] with $W=(1 - 2m/r + K^2)^{1/2}$, in which the coefficients' pathologies are moved to $r_K = 2m/(1+K^2)$. This new coordinate system is used to study the entrance into a black hole of a rigid line (a line in which the shock waves propagate with velocity c).

  16. Thermal performance of steel-framed walls. Final report

    SciTech Connect (OSTI)

    Barbour, E. [NAHB Research Center, Inc., Upper Marlboro, MD (United States); Goodrow, J. [Holometrix, Inc., Bedford, MA (United States); Kosny, J.; Christian, J.E. [Oak Ridge National Lab., TN (United States)

    1994-11-21

    In wall construction, highly conductive members spaced along the wall, which allow higher heat transfer than that through less conductive areas, are referred to as thermal bridges. Thermal bridges in walls tend to increase heat loss and, under certain adverse conditions, can cause dust streaking (``ghosting``) on interior walls over studs due to temperature differentials, as well as condensation in and on walls. Although such adverse conditions can be easily avoided by proper thermal design of wall systems, these effects have not been well understood and thermal data has been lacking. Therefore, the present study was initiated to provide (1) a better understanding of the thermal behavior of steel-framed walls, (2) a set of R-values for typical wall constructions, and (3) information that could be used to develop improved methods of predicting R-values. An improved method for estimating R-value would allow an equitable comparison of thermal performance with other construction types and materials. This would increase the number of alternative materials for walls available to designers, thus allowing them to choose the optimum choice for construction. Twenty-three wall samples were tested in a calibrated hot box (ASTM C9761) to measure the thermal performance of steel-framed wall systems. The tests included an array of stud frame configurations, exterior sheathing and fiberglass batt insulations. Other studies have not included the use of insulating sheathing, which reduces the extent of the thermal bridges and improves total thermal performance. The purpose of the project was to provide measured R-values for commonly used steel-framed wall configurations and to improve R-value estimating methods. Test results were compared to R-value estimates using the parallel path method, the isothermal planes method and the ASHRAE Zone method. The comparison showed that the known procedures do not fully account for the three-dimensional effects created by steel framing in a wall.

  17. Interface-induced heavy-hole/light-hole splitting of acceptors in silicon

    SciTech Connect (OSTI)

    Mol, J. A.; Salfi, J.; Simmons, M. Y.; Rogge, S.; Rahman, R.; Hsueh, Y.; Klimeck, G.; Miwa, J. A.

    2015-05-18

    The energy spectrum of spin-orbit coupled states of individual sub-surface boron acceptor dopants in silicon have been investigated using scanning tunneling spectroscopy at cryogenic temperatures. The spatially resolved tunnel spectra show two resonances, which we ascribe to the heavy- and light-hole Kramers doublets. This type of broken degeneracy has recently been argued to be advantageous for the lifetime of acceptor-based qubits [R. Ruskov and C. Tahan, Phys. Rev. B 88, 064308 (2013)]. The depth dependent energy splitting between the heavy- and light-hole Kramers doublets is consistent with tight binding calculations, and is in excess of 1?meV for all acceptors within the experimentally accessible depth range (<2?nm from the surface). These results will aid the development of tunable acceptor-based qubits in silicon with long coherence times and the possibility for electrical manipulation.

  18. Reissner-Nordstrom black hole in dark energy background

    E-Print Network [OSTI]

    Ngangbam Ishwarchandra; Ng. Ibohal; K. Yugindro Singh

    2014-11-29

    In this paper we propose a stationary solution of Einstein's field equations describing Reissner-Nordstrom black hole in dark energy background. It is to be regarded as the Reissner-Nordstrom black hole is embedded into the dark energy solution producing Reissner-Nordstrom-dark energy black hole. We find that the space-time geometry of Reissner-Nordstrom-dark energy solution is Petrov type $D$ in the classification of space-times. It is also shown that the embedded space-time possesses an energy-momentum tensor of the electromagnetic field interacting with the dark energy having negative pressure. We find the energy-momentum tensor for dark energy violates the the strong energy condition due to the negative pressure, whereas that of the electromagnetic field obeys the strong energy condition. It is shown that the time-like vector field for an observer in the Reissner-Nordstrom-dark energy space is expanding, accelerating, shearing and non-rotating. We investigate the surface gravity of the horizons for the embedded dark energy black hole. The characteristic properties of relativistic dark energy based on the de Sitter solution is discussed in an appendix.

  19. The Hawking cascade from a black hole is extremely sparse

    E-Print Network [OSTI]

    Finnian Gray; Sebastian Schuster; Alexander Van-Brunt; Matt Visser

    2015-06-12

    The Hawking flux from a black hole, (at least as seen from large distances), is extremely sparse and thin, with the average time between emission of successive Hawking quanta being hundreds of times larger than the natural timescale set by the energies of the emitted quanta. Some aspects of this result have been known for over 30 years, but have been largely forgotten, possibly because authors focussed mainly on the late-time high-temperature regime. We shall instead focus on the early-stage low-temperature regime, and shall both quantify and significantly extend these observations in a number of different ways. First we shall identify several natural dimensionless figures of merit, and thereby compare the mean time between emission of successive Hawking quanta to several quite natural timescales that can be associated with the emitted quanta, demonstrating that ratios of 300 or more are typical for emission of photons or gravitons from a Schwarzschild black hole. Furthermore these ratios are independent of the mass of the black hole as it slowly evolves. The situation for fermion emission (massless neutrinos) is actually worse. Second, we shall then show that the situation for Reissner-Nordstrom, Kerr, Kerr-Newman and "dirty" black holes is even worse. Third, we consider the effects of particle rest mass. Overall, the Hawking quanta are seen to be dribbling out of the black hole one at a time, in an extremely slow cascade of 3-body decays. This implies that the Hawking flux is subject to "shot noise". Observationally, the Planck spectrum of the Hawking flux can only be determined by collecting and integrating data over a very long time. We conclude by connecting these points back to various kinematic aspects of the Hawking evaporation process.

  20. Absolute Time Derivatives

    E-Print Network [OSTI]

    T. Matolcsi; P. Van

    2006-10-23

    A four dimensional treatment of nonrelativistic space-time gives a natural frame to deal with objective time derivatives. In this framework some well known objective time derivatives of continuum mechanics appear as Lie-derivatives. Their coordinatized forms depends on the tensorial properties of the relevant physical quantities. We calculate the particular forms of objective time derivatives for scalars, vectors, covectors and different second order tensors from the point of view of a rotating observer. The relation of substantial, material and objective time derivatives is treated.

  1. Universal cell frame for high-pressure water electrolyzer and electrolyzer including the same

    DOE Patents [OSTI]

    Schmitt, Edwin W.; Norman, Timothy J.

    2013-01-08

    Universal cell frame generic for use as an anode frame and as a cathode frame in a water electrolyzer. According to one embodiment, the universal cell frame includes a unitary annular member having a central opening. Four trios of transverse openings are provided in the annular member, each trio being spaced apart by about 90 degrees. A plurality of internal radial passageways fluidly interconnect the central opening and each of the transverse openings of two diametrically-opposed trios of openings, the other two trios of openings lacking corresponding radial passageways. Sealing ribs are provided on the top and bottom surfaces of the annular member. The present invention is also directed at a water electrolyzer that includes two such cell frames, one being used as the anode frame and the other being used as the cathode frame, the cathode frame being rotated 90 degrees relative to the anode frame.

  2. The Synchronic Frame of Photospheric Magnetic Flux: The Improved Synoptic Frame

    E-Print Network [OSTI]

    Zhao, Xuepu

    of the middle panel). Because of the differential rotation of magnetic elements, the solar surface distribution from a synoptic chart do not cover the whole solar surface at any time within the period of one solar transpot models to predict better instantaneous photospheric field distribution on the portions of solar

  3. Black hole energy extraction via stationary scalar clouds

    E-Print Network [OSTI]

    Wilson-Gerow, Jordan

    2015-01-01

    We study scalar field configurations around Kerr black holes with a time-independent energy-momentum tensor. These stationary `scalar clouds', confined near the black hole (BH) by their own mass or a mirror at fixed radius, exist at the threshold for energy extraction via superradiance. Motivated by the electromagnetic Blandford-Znajek (BZ) mechanism, we explore whether scalar clouds could serve as a proxy for the force-free magnetosphere in the BZ process. We find that a stationary energy-extracting scalar cloud solution exists when the reflecting mirror is replaced by a semi-permeable surface which allows the cloud to radiate some energy to infinity while maintaining self-sustained superradiance. The radial energy flux displays the same behaviour for rapidly rotating holes as magnetohydrodynamic simulations predict for the BZ mechanism.

  4. Black hole energy extraction via stationary scalar clouds

    E-Print Network [OSTI]

    Jordan Wilson-Gerow; Adam Ritz

    2015-09-22

    We study scalar field configurations around Kerr black holes with a time-independent energy-momentum tensor. These stationary `scalar clouds', confined near the black hole (BH) by their own mass or a mirror at fixed radius, exist at the threshold for energy extraction via superradiance. Motivated by the electromagnetic Blandford-Znajek (BZ) mechanism, we explore whether scalar clouds could serve as a proxy for the force-free magnetosphere in the BZ process. We find that a stationary energy-extracting scalar cloud solution exists when the reflecting mirror is replaced by a semi-permeable surface which allows the cloud to radiate some energy to infinity while maintaining self-sustained superradiance. The radial energy flux displays the same behaviour for rapidly rotating holes as magnetohydrodynamic simulations predict for the BZ mechanism.

  5. Aspects of Accretion Processes On a Rotating Black Hole

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1996-11-10

    We describe the most general nature of accretion and wind flows around a compact object and emphasize on the properties which are special to black hole accretion. The angular momentum distribution in the most general solution is far from Keplerian, and the non-Keplerian disks can include standing shock waves. We also present fully time dependent numerical simulation results to show that they agree with these analytical solutions. We describe the spectral properties of these accretion disks and show that the soft and hard states of the black hole candidates could be explained by the change of the accretion rate of the disk. We present fits of the observational data to demonstrate the presence of sub-Keplerian flows around black holes.

  6. Semi-classical approach to quantum black holes

    E-Print Network [OSTI]

    Euro Spallucci; Anais Smailagic

    2014-10-07

    In this Chapter we would like to review a "~phenomenological~" approach taking into account the most fundamental feature of string theory or, more in general, of quantum gravity, whatever its origin, which is the existence of a minimal length in the space-time fabric. This length is generally identified with the Planck length, or the string length, but it could be also much longer down to the TeV region. A simple and effective way to keep track of the effects the minimal length in black hole geometries is to solve the Einstein equations with an energy momentum tensor describing non point-like matter. The immediate consequence is the absence of any curvature singularity. Where textbook solutions of the Einstein equations loose any physical meaning because of infinite tidal forces, we find a de Sitter vacuum core of high, but finite, energy density and pressure. An additional improvement regards the final stage of the black hole evaporation leading to a vanishing Hawking temperature even in the neutral, non-rotating, case. In spite of th simplicity of this model we are able to describe the final stage of the black hole evaporation, resulting in a cold remnant with a degenerate, extremal, horizon of radius of the order of the minimal length. In this chapter we shall describe only neutral, spherically symmetric, regular black holes although charged, rotating and higher dimensional black holes can be found in the literature.

  7. Slant hole completion test (1991) sidetrack ``as built`` report

    SciTech Connect (OSTI)

    Myal, F.R.

    1992-05-01

    During the summer of 1990, a slant hole test well, funded by the US Department of Energy, was drilled to 9,466 ft to evaluate the effectiveness of directional drilling in the tight, naturally fractured gas sands and coals of the Mesaverde Group. The surface location of the SHCT No. 1 is 700 ft south of the DOE Multiwell Experiment (MWX) site in Section 34, T6S, R94W, Garfield County, Colorado, approximately 7.5 miles west of Rifle. Mechanical problems following cementing of a production liner resulted in loss of the completion interval, and operations were suspended. In early 1991, DOE decided to sidetrack the hole to permit production testing of the lost interval. The sidetrack was designed to parallel the original wellbore, but to be drilled 1,000 ft to the east to minimize the chances of encountering formation damage from the original hole. The sidetrack, like the original hole, was to intersect the paludal lenticular sands and coals at 60{degrees} and to penetrate the underlying Cozzette sand horizonally. The sidetrack was spudded May 12, 1991. After re-entering the well in late 1991, early production testing of the Cozzette showed that the 300 ft of in-pay horizontal hole can produce at rate 5 to 10 times higher than vertical wells in the same area. This report contains the geological summary and sidetrack drilling operations summary.

  8. Slant hole completion test (1991) sidetrack as built'' report

    SciTech Connect (OSTI)

    Myal, F.R.

    1992-05-01

    During the summer of 1990, a slant hole test well, funded by the US Department of Energy, was drilled to 9,466 ft to evaluate the effectiveness of directional drilling in the tight, naturally fractured gas sands and coals of the Mesaverde Group. The surface location of the SHCT No. 1 is 700 ft south of the DOE Multiwell Experiment (MWX) site in Section 34, T6S, R94W, Garfield County, Colorado, approximately 7.5 miles west of Rifle. Mechanical problems following cementing of a production liner resulted in loss of the completion interval, and operations were suspended. In early 1991, DOE decided to sidetrack the hole to permit production testing of the lost interval. The sidetrack was designed to parallel the original wellbore, but to be drilled 1,000 ft to the east to minimize the chances of encountering formation damage from the original hole. The sidetrack, like the original hole, was to intersect the paludal lenticular sands and coals at 60{degrees} and to penetrate the underlying Cozzette sand horizonally. The sidetrack was spudded May 12, 1991. After re-entering the well in late 1991, early production testing of the Cozzette showed that the 300 ft of in-pay horizontal hole can produce at rate 5 to 10 times higher than vertical wells in the same area. This report contains the geological summary and sidetrack drilling operations summary.

  9. The mass function of high redshift seed black holes

    E-Print Network [OSTI]

    Lodato, G; Lodato, Giuseppe; Natarajan, Priyamvada

    2007-01-01

    In this paper we derive the mass function of seed black holes that result from the central mass concentrated via disc accretion in collapsed haloes at redshift $z\\approx 15$. Using standard arguments including stability, we show that these pre-galactic discs can assemble a significant mass concentration in the inner regions, providing fuel for the formation and initial growth of super-massive black holes. Assuming that these mass concentrations do result in central seed black holes, we determine the mass distribution of these seeds as a function of key halo properties. The seed mass distribution determined here turns out to be asymmetric and skewed to higher masses. Starting with these initial seeds, building up to $10^9$ solar masses by $z = 6$ to power the bright quasars is not a problem in the standard LCDM cosmogony. These seed black holes in gas rich environments are likely to grow into the supermassive black holes at later times via mergers and accretion. Gas accretion onto these seeds at high redshift ...

  10. A scale-free analysis of magnetic holes in the solar wind

    E-Print Network [OSTI]

    Stevens, M. L. (Michael Louis)

    2006-01-01

    Magnetic holes are isolated intervals of depleted interplanetary magnetic field (IMF) strength on timescales of several seconds to several hours. These intervals have been seen as often as several times per day in the ...

  11. Photoionization microscopy in terms of local frame transformation theory

    E-Print Network [OSTI]

    P. Giannakeas; F. Robicheaux; Chris H. Greene

    2014-10-27

    Two-photon ionization of an alkali-metal atom in the presence of a uniform electric field is investigated using a standardized form of local frame transformation and generalized quantum defect theory. The relevant long-range quantum defect parameters in the combined Coulombic plus Stark potential is calculated with eigenchannel R-matrix theory applied in the downstream parabolic coordinate $\\eta$. The present formulation permits us to express the corresponding microscopy observables in terms of the local frame transformation, and it gives a critical test of the accuracy of the Harmin-Fano theory permitting a scholastic investigation of the claims presented in Zhao {\\it et al.} [Phys. Rev. A 86, 053413 (2012)].

  12. Communication channel of fermionic system in accelerated frame

    E-Print Network [OSTI]

    Jinho Chang; Younghun Kwon

    2012-08-23

    In this article, we investigate the communication channel of fermionic system in an accelerated frame. We observe that at the infinite acceleration, the mutual information of single rail quantum channel coincides with that of double rail quantum channel, but those of classical ones reach different values. Furthermore, we find that at the infinite acceleration, the conditional entropy of single(or double) rail quantum channel vanishes, but those of classical ones may have finite values. In addition, we see that even when considering a method beyond the single mode approximation, the dual rail entangled state seems to provide better channel capacity than the single rail entangled state, unlike the bosonic case. Moreover, we find that the single-mode approximation is not sufficient to analyze the communication channel of fermionic system in an accelerated frame.

  13. On the dark energy rest frame and the CMB

    E-Print Network [OSTI]

    Jose Beltran Jimenez; Antonio L. Maroto

    2008-12-11

    Dark energy is usually parametrized as a perfect fluid with negative pressure and a certain equation of state. Besides, it is supposed to interact very weakly with the rest of the components of the universe and, as a consequence, there is no reason to expect it to have the same large-scale rest frame as matter and radiation. Thus, apart from its equation of state $w$ and its energy density $\\Omega_{DE}$ one should also consider its velocity as a free parameter to be determined by observations. This velocity defines a cosmological preferred frame, so the universe becomes anisotropic and, therefore, the CMB temperature fluctuations will be affected, modifying mainly the dipole and the quadrupole.

  14. Heat Engine of black holes

    E-Print Network [OSTI]

    J. Sadeghi; Kh. Jafarzade

    2015-06-23

    As we know, the cosmological constant in different theories of gravity acts as a thermodynamics variable. The cosmological constant exists in different actions of gravity and also appears in the solution of such theories. These lead to use the black hole as a heat engines. Also, there are two values for the cosmological constant as positive and negative values. The case of negative cosmological constant supplies a natural realization of these engines in terms of the field theory description of the fluids to which they are holographically dual. In this paper, we are going to define heat engines for two different black holes as Dyonic BH and Kerr BH. And also, we calculate maximum efficiency for two black holes.

  15. Quantum Criticality and Black Holes

    ScienceCinema (OSTI)

    Sachdev, Subir [Harvard University, Cambridge, Massachusetts, United States

    2009-09-01

    I will describe the behavior of a variety of condensed matter systems in the vicinity of zero temperature quantum phase transitions. There is a remarkable analogy between the hydrodynamics of such systems and the quantum theory of black holes. I will show how insights from this analogy have shed light on recent experiments on the cuprate high temperature superconductors. Studies of new materials and trapped ultracold atoms are yielding new quantum phases, with novel forms of quantum entanglement. Some materials are of technological importance: e.g. high temperature superconductors. Exact solutions via black hole mapping have yielded first exact results for transport coefficients in interacting many-body systems, and were valuable in determining general structure of hydrodynamics. Theory of VBS order and Nernst effect in cuprates. Tabletop 'laboratories for the entire universe': quantum mechanics of black holes, quark-gluon plasma, neutrons stars, and big-bang physics.

  16. Use of explosives to demolish multistory steel frame buildings 

    E-Print Network [OSTI]

    Landry, Charles Vernon

    1988-01-01

    OF CONTENTS LIST OF FIGURES . 1. INTRODUCTION. vi 1. 1 Problem Definition . 1. 2 Work Done to Date. 1. 3 Purpose of the Study . 1. 4 Approach. 2. GENERAL PLANNING FOR STEEL FRAME MULTISTORY DEMOLITION. 2. 1 Introduction. 2. 2 General Mechanics... of the other companies who use these techniques, have, in the past, worked for Controiled Demolition Inc. Due in part to these connections, many of these companies consider all of the information on their controlled demolition techniques as proprietary...

  17. High image quality sub 100 picosecond gated framing camera development

    SciTech Connect (OSTI)

    Price, R.H.; Wiedwald, J.D.

    1983-11-17

    A major challenge for laser fusion is the study of the symmetry and hydrodynamic stability of imploding fuel capsules. Framed x-radiographs of 10-100 ps duration, excellent image quality, minimum geometrical distortion (< 1%), dynamic range greater than 1000, and more than 200 x 200 pixels are required for this application. Recent progress on a gated proximity focused intensifier which meets these requirements is presented.

  18. Framing Cinematic Indians within the Social Construction of Place

    E-Print Network [OSTI]

    Coleman, Cynthia-Lou

    2006-03-01

    Framing Cinematic Indians within the Social Construction of Place Cynthia-Lou Coleman Native American images have become ubiquitous in the marketplace of goods, with raven-haired maidens adorning grapefruit boxes and aftershave bottles shaped...-American values that emerge from distinct conceptualizations of "place." By examining the role of place in cinematic Westerns, we begin to understand deeply held beliefs that not only permeate cinema, but continue to unfold in modern-day controversies involving...

  19. Flavor twisted boundary conditions in the Breit frame

    SciTech Connect (OSTI)

    Jiang, F.-J.; Tiburzi, B. C.

    2008-08-01

    We use a generalization of chiral perturbation theory to account for the effects of flavor twisted boundary conditions in the Breit frame. The relevant framework for two light flavors is an SU(6|4) partially quenched theory, where the extra valence quarks differ only by their boundary conditions. Focusing on the pion electromagnetic form factor, finite volume corrections are calculated at next-to-leading order in the chiral expansion and are estimated to be small on current lattices.

  20. A Large Area Detector proposed for the Large Observatory for X-ray Timing (LOFT)

    E-Print Network [OSTI]

    Zane, S; Kennedy, T; Feroci, M; Herder, J -W Den; Ahangarianabhari, M; Argan, A; Azzarello, P; Baldazzi, G; Barret, D; Bertuccio, G; Bodini, P; Bozzo, E; Cadoux, F; Cais, P; Campana, R; Coker, J; Cros, A; Del Monte, E; De Rosa, A; Di Cosimo, S; Donnarumma, I; Evangelista, Y; Favre, Y; Feldman, C; Fraser, G; Fuschino, F; Grassi, M; Hailey, M R; Hudec, R; Labanti, C; Macera, D; Malcovati, P; Marisaldi, M; Martindale, A; Mineo, T; Muleri, F; Nowak, M; Orlandini, M; Pacciani, L; Perinati, E; Petracek, V; Pohl, M; Rachevski, A; Smith, P; Santangelo, A; Seyler, J -Y; Schmid, C; Soffitta, P; Suchy, S; Tenzer, C; Uttley, P; Vacchi, A; Zampa, G; Zampa, N; Wilms, J; Winter, B

    2012-01-01

    The Large Observatory for X-ray Timing (LOFT) is one of the four candidate ESA M3 missions considered for launch in the 2022 time-frame. It is specifically designed to perform fast X-ray timing and probe the status of the matter near black holes and neutron stars. The LOFT scientific payload is composed of a Large Area Detector (LAD) and a Wide Field Monitor (WFM). The LAD is a 10 m2-class pointed instrument with 20 times the collecting area of the best past timing missions (such as RXTE) over the 2-30 keV range, which holds the capability to revolutionize studies of X-ray variability down to the millisecond time scales. Its ground-breaking characteristic is a low mass per unit surface, enabling an effective area of ~10 m^2 (@10 keV) at a reasonable weight. The development of such large but light experiment, with low mass and power per unit area, is now made possible by the recent advancements in the field of large-area silicon detectors - able to time tag an X-ray photon with an accuracy <10 {\\mu}s and an...

  1. Seismic Rehabilitation of RC Frames by Using Steel Panels

    SciTech Connect (OSTI)

    Mowrtage, Waiel [Kandilli Observatory and Earthquake Research Institute of Bogazici University, Earthquake Engineering Department, Istanbul (Turkey)

    2008-07-08

    Every major earthquake in Turkey causes a large number of building suffer moderate damage due to poor construction. If a proper and fast retrofit is not applied, the aftershocks, which may sometimes come days or weeks after the main shock, can push a moderately damaged building into a major damage or even total collapse. This paper presents a practical retrofit method for moderately damaged buildings, which increases the seismic performance of the structural system by reducing the displacement demand. Fabricated steel panels are used for the retrofit. They are light-weight, easy to handle, and can be constructed very quickly. Moreover, they are cheap, and do not need formwork or skilled workers. They can be designed to compensate for the stiffness and strength degradation, and to fit easily inside a moderately damaged reinforced concrete frame.To test the concept, a half-scale, single-story 3D reinforced concrete frame specimen was constructed at the shake-table laboratories of the Kandilli Observatory and Earthquake Research Institute of Bogazici University, and subjected to recorded real earthquake base accelerations. The amplitudes of base accelerations were increased until a moderate damage level is reached. Then, the damaged RC frames was retrofitted by means of steel panels and tested under the same earthquake. The seismic performance of the specimen before and after the retrofit was evaluated using FEMA356 standards, and the results were compared in terms of stiffness, strength, and deformability. The results have confirmed effectiveness of the proposed retrofit scheme.

  2. Using FRAMES to Manage Environmental and Water Resources

    SciTech Connect (OSTI)

    Whelan, Gene; Millard, W. David; Gelston, Gariann M.; Khangaonkar, Tarang P.; Pelton, Mitch A.; Strenge, Dennis L.; Yang, Zhaoqing; Lee, Cheegwan; Sivaraman, Chitra; Stephan, Alex J.; Hoopes, Bonnie L.; Castleton, Karl J.

    2007-05-16

    The Framework for Risk Analysis in Multimedia Environmental Systems FRAMES) is decision-support middleware that provides users the ability to design software solutions for complex problems. It is a software platform that provides seamless and transparent communication between modeling components by using a multi-thematic approach to provide a flexible and holistic understanding of how environmental factors potentially affect humans and the environment. It incorporates disparate components (e.g., models, databases, and other frameworks) that integrate across scientific disciplines, allowing for tailored solutions to specific activities. This paper discusses one example application of FRAMES, where several commercialoff-the-shelf (COTS) software products are seamlessly linked into a planning and decision-support tool that helps manage water-based emergency situations and sustainable response. Multiple COTS models, including three surface water models, and a number of databases are linked through FRAMES to assess the impact of three asymmetric and simultaneous events, two of which impact water resources. The asymmetric events include 1) an unconventional radioactive release into a large potable water body, 2) a conventional contaminant (oil) release into navigable waters, and 3) an instantaneous atmospheric radioactive release.

  3. Introduction to Black Hole Evaporation

    E-Print Network [OSTI]

    Pierre-Henry Lambert

    2014-01-16

    These lecture notes are an elementary and pedagogical introduction to the black hole evaporation, based on a lecture given by the author at the Ninth Modave Summer School in Mathematical Physics and are intended for PhD students. First, quantum field theory in curved spacetime is studied and tools needed for the remaining of the course are introduced. Then, quantum field theory in Rindler spacetime in 1+1 dimensions and in the spacetime of a spherically collapsing star are considered, leading to Unruh and Hawking effects, respectively. Finally, some consequences such as thermodynamics of black holes and information loss paradox are discussed.

  4. Does phantom energy produce black hole?

    E-Print Network [OSTI]

    F. Rahaman; A. Ghosh; M. Kalam

    2006-12-23

    We have found an exact solution of spherically symmetrical Einstein equations describing a black hole with a special type phantom energy source. It is surprising to note that our solution is analogous to Reissner-Nordstr\\"{o}m black hole.

  5. Classical and thermodynamic stability of black holes

    E-Print Network [OSTI]

    Ricardo Monteiro

    2010-06-28

    We consider the stability of black holes within both classical general relativity and the semiclassical thermodynamic description. In particular, we study linearised perturbations and their contribution to the gravitational partition function, addressing technical issues for charged (Reissner-Nordstrom) and rotating (Kerr-AdS) black holes. Exploring the connection between classical and thermodynamic stability, we find classical instabilities of Myers-Perry black holes and bifurcations to new black hole families.

  6. Hawking Emission and Black Hole Thermodynamics

    E-Print Network [OSTI]

    Don N. Page

    2006-12-18

    A brief review of Hawking radiation and black hole thermodynamics is given, based largely upon hep-th/0409024.

  7. A connection between plasma conditions near black hole event horizons and outflow properties

    E-Print Network [OSTI]

    Koljonen, K I I; Ontiveros, J A Fernández; Markoff, S; Russell, T D; Miller-Jones, J C A; van der Horst, A J; Bernardini, F; Casella, P; Curran, P A; Gandhi, P; Soria, R

    2015-01-01

    Accreting black holes are responsible for producing the fastest, most powerful outflows of matter in the Universe. The formation process of powerful jets close to black holes is poorly understood, and the conditions leading to jet formation are currently hotly debated. In this paper, we report an unambiguous empirical correlation between the properties of the plasma close to the black hole and the particle acceleration properties within jets launched from the central regions of accreting stellar-mass and supermassive black holes. In these sources the emission of the plasma near the black hole is characterized by a power law at X-ray energies during times when the jets are produced. We find that the photon index of this power law, which gives information on the underlying particle distribution, correlates with the characteristic break frequency in the jet spectrum, which is dependent on magnetohydrodynamical processes in the outflow. The observed range in break frequencies varies by five orders of magnitude, i...

  8. Time parallel gravitational collapse simulation

    E-Print Network [OSTI]

    Kreienbuehl, Andreas; Ruprecht, Daniel; Krause, Rolf

    2015-01-01

    This article demonstrates the applicability of the parallel-in-time method Parareal to the numerical solution of the Einstein gravity equations for the spherical collapse of a massless scalar field. To account for the shrinking of the spatial domain in time, a tailored load balancing scheme is proposed and compared to load balancing based on number of time steps alone. The performance of Parareal is studied for both the sub-critical and black hole case; our experiments show that Parareal generates substantial speedup and, in the super-critical regime, can also reproduce the black hole mass scaling law.

  9. Scattering by regular black holes: Planar massless scalar waves impinging upon a Bardeen black hole

    E-Print Network [OSTI]

    Macedo, Caio F B; Crispino, Luís C B

    2015-01-01

    Singularities are common features of general relativity black holes. However, within general relativity, one can construct black holes that present no singularities. These regular black hole solutions can be achieved by, for instance, relaxing one of the energy conditions on the stress energy tensor sourcing the black hole. Some regular black hole solutions were found in the context of non-linear electrodynamics, the Bardeen black hole being the first one proposed. In this paper, we consider a planar massless scalar wave scattered by a Bardeen black hole. We compare the scattering cross section computed using a partial-wave description with the classical geodesic scattering of a stream of null geodesics, as well as with the semi-classical glory approximation. We obtain that, for some values of the corresponding black hole charge, the scattering cross section of a Bardeen black hole has a similar interference pattern of a Reissner-Nordstr\\"om black hole.

  10. Scattering by regular black holes: Planar massless scalar waves impinging upon a Bardeen black hole

    E-Print Network [OSTI]

    Caio F. B. Macedo; Ednilton S. de Oliveira; Luís C. B. Crispino

    2015-06-26

    Singularities are common features of general relativity black holes. However, within general relativity, one can construct black holes that present no singularities. These regular black hole solutions can be achieved by, for instance, relaxing one of the energy conditions on the stress energy tensor sourcing the black hole. Some regular black hole solutions were found in the context of non-linear electrodynamics, the Bardeen black hole being the first one proposed. In this paper, we consider a planar massless scalar wave scattered by a Bardeen black hole. We compare the scattering cross section computed using a partial-wave description with the classical geodesic scattering of a stream of null geodesics, as well as with the semi-classical glory approximation. We obtain that, for some values of the corresponding black hole charge, the scattering cross section of a Bardeen black hole has a similar interference pattern of a Reissner-Nordstr\\"om black hole.

  11. New approaches to black holes Eric Gourgoulhon

    E-Print Network [OSTI]

    Gourgoulhon, Eric

    References Eric Gourgoulhon (LUTH) New approaches to black holes Okinawa Nat. Col. Tech., 17 Aug 2008 2 / 36 Gourgoulhon (LUTH) New approaches to black holes Okinawa Nat. Col. Tech., 17 Aug 2008 3 / 36 #12;Local (2006)] Eric Gourgoulhon (LUTH) New approaches to black holes Okinawa Nat. Col. Tech., 17 Aug 2008 4

  12. High precision, rapid laser hole drilling

    DOE Patents [OSTI]

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

    2013-04-02

    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  13. High precision, rapid laser hole drilling

    DOE Patents [OSTI]

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

    2005-03-08

    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  14. High precision, rapid laser hole drilling

    DOE Patents [OSTI]

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

    2007-03-20

    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  15. Fast Hybrid and Monolithic CMOS Imagers in Multi-Frame Radiography...

    Office of Scientific and Technical Information (OSTI)

    Conference: Fast Hybrid and Monolithic CMOS Imagers in Multi-Frame Radiography Citation Details In-Document Search Title: Fast Hybrid and Monolithic CMOS Imagers in Multi-Frame...

  16. Conflicting Frames : the dispute over the meaning of rolezinhos in Brazilian media

    E-Print Network [OSTI]

    Goncalves, Alexandre A

    2014-01-01

    This research analyzes the battle of frames in the controversy surrounding rolezinhos- flashmobs organized by low-income youth in Brazilian shopping malls. To analyze the framing of these events, a corpus of 4,523 online ...

  17. Probing the puncture for black hole simulations

    E-Print Network [OSTI]

    J. David Brown

    2009-10-23

    With the puncture method for black hole simulations, the second infinity of a wormhole geometry is compactified to a single "puncture point" on the computational grid. The region surrounding the puncture quickly evolves to a trumpet geometry. The computational grid covers only a portion of the trumpet throat. It ends at a boundary whose location depends on resolution. This raises the possibility that perturbations in the trumpet geometry could propagate down the trumpet throat, reflect from the puncture boundary, and return to the black hole exterior with a resolution--dependent time delay. Such pathological behavior is not observed. This is explained by the observation that some perturbative modes propagate in the conformal geometry, others propagate in the physical geometry. The puncture boundary exists only in the physical geometry. The modes that propagate in the physical geometry are always directed away from the computational domain at the puncture boundary. The finite difference stencils ensure that these modes are advected through the boundary with no coupling to the modes that propagate in the conformal geometry. These results are supported by numerical experiments with a code that evolves spherically symmetric gravitational fields with standard Cartesian finite difference stencils. The code uses the Baumgarte--Shapiro--Shibata--Nakamura formulation of Einstein's equations with 1+log slicing and gamma--driver shift conditions.

  18. From Pinholes to Black Holes

    SciTech Connect (OSTI)

    Fenimore, Edward E.

    2014-10-06

    Pinhole photography has made major contributions to astrophysics through the use of “coded apertures”. Coded apertures were instrumental in locating gamma-ray bursts and proving that they originate in faraway galaxies, some from the birth of black holes from the first stars that formed just after the big bang.

  19. Black hole free energy during charged collapse: a numerical study

    E-Print Network [OSTI]

    Hugues Beauchesne; Ariel Edery

    2012-05-19

    We perform a numerical investigation of the thermodynamics during the collapse of a charged (complex) scalar field to a Reissner-Nordstr\\"om (RN) black hole in isotropic coordinates. Numerical work on gravitational collapse in isotropic coordinates has recently shown that the negative of the total Lagrangian approaches the Helmholtz free energy F= E-TS of a Schwarzschild black hole at late times of the collapse (where E is the black hole mass, T the temperature and S the entropy). The relevant thermodynamic potential for the RN black hole is the Gibbs free energy G=E-TS-$\\Phi_H$ Q where Q is the charge and $\\Phi_H$ the electrostatic potential at the outer horizon. In charged collapse, there is a large outgoing matter wave which prevents the exterior from settling quickly to a static state. However, the interior region is not affected significantly by the wave. We find numerically that the interior contribution to the Gibbs free energy is entirely gravitational and accumulates in a thin shell just inside the horizon. The entropy is gravitational in origin and one observes dynamically that it resides on the horizon. We also compare the numerical value of the interior Lagrangian to the expected analytical value of the interior Gibbs free energy for different initial states and we find that they agree to within 10-13%. The two values are approaching each other so that their difference decreases with more evolution time.

  20. The framing of seventeenth-century men-of-war in England and other northern European countries 

    E-Print Network [OSTI]

    Batchvarov, Kroum Nickolaev

    2002-01-01

    . . . . . . 77 VI ARCHAEOLOGICAL EVIDENCE FROM SEVENTEENTH-CENTURY SHIPWRECKS . . 91 VII DUTCH SHIPBUILDING. . . . . 106 VIII FRENCH, DANISH AND SWEDISH SHIPBUILDING. . . . . . . . . 123 IX TIMBER SHORTAGF, AND THE DOUBLE FRAME. . . . . . . . . 147 CHAPTER... of the Stuart Royal family ? Prince Rupert of the Palatinate, one of the most experienced naval commanders and seamen of the time. The King, who was the driving power behind the expansion and growing professionalism of the navy, should be given much...

  1. State-of-the-Art Highly Insulating Window Frames - Research and Market Review

    E-Print Network [OSTI]

    Gustavsen, Arild

    2008-01-01

    frames, Solar Energy Materials and Solar Cells, Vol. 25, pp.glazed windows, Solar Energy Materials & Solar Cells, Vol.

  2. Constraining the formation of black-holes in short-period Black-Hole Low-Mass X-ray Binaries

    E-Print Network [OSTI]

    Repetto, Serena

    2015-01-01

    The formation of stellar mass black holes is still very uncertain. Two main uncertainties are the amount of mass ejected in the supernova event (if any) and the magnitude of the natal kick the black hole receives at birth (if any). Repetto et al. (2012), studying the position of Galactic X-ray binaries containing black holes, found evidence for black holes receiving high natal kicks at birth. In this Paper we extend that study, taking into account the previous binary evolution of the sources as well. The seven short-period black-hole X-ray binaries that we use, are compact binaries consisting of a low-mass star orbiting a black hole in a period less than $1$ day. We trace their binary evolution backwards in time, from the current observed state of mass-transfer, to the moment the black hole was formed, and we add the extra information on the kinematics of the binaries. We find that several systems could be explained by no natal kick, just mass ejection, while for two systems (and possibly more) a high kick is...

  3. Two-hole bound states from a systematic low-energy effective field theory for magnons and holes in an antiferromagnet

    SciTech Connect (OSTI)

    Bruegger, C.; Kaempfer, F.; Moser, M.; Wiese, U.-J.; Pepe, M.

    2006-12-01

    Identifying the correct low-energy effective theory for magnons and holes in an antiferromagnet has remained an open problem for a long time. In analogy to the effective theory for pions and nucleons in QCD, based on a symmetry analysis of Hubbard and t-J-type models, we construct a systematic low-energy effective field theory for magnons and holes located inside pockets centered at lattice momenta ({+-}({pi}/2a),{+-}({pi}/2a)). The effective theory is based on a nonlinear realization of the spontaneously broken spin symmetry and makes model-independent universal predictions for the entire class of lightly doped antiferromagnetic precursors of high-temperature superconductors. The predictions of the effective theory are exact, order by order in a systematic low-energy expansion. We derive the one-magnon exchange potentials between two holes in an otherwise undoped system. Remarkably, in some cases the corresponding two-hole Schroedinger equations can even be solved analytically. The resulting bound states have d-wave characteristics. The ground state wave function of two holes residing in different hole pockets has a d{sub x{sup 2}-y{sup 2}}-like symmetry, while for two holes in the same pocket the symmetry resembles d{sub xy}.

  4. Extremal Higher Spin Black Holes

    E-Print Network [OSTI]

    Máximo Bañados; Alejandra Castro; Alberto Faraggi; Juan I. Jottar

    2015-11-30

    The gauge sector of three-dimensional higher spin gravities can be formulated as a Chern-Simons theory. In this context, a higher spin black hole corresponds to a flat connection with suitable holonomy (smoothness) conditions which are consistent with the properties of a generalized thermal ensemble. Building on these ideas, we discuss a definition of black hole extremality which is appropriate to the topological character of 3d higher spin theories. Our definition can be phrased in terms of the Jordan class of the holonomy around a non-contractible (angular) cycle, and we show that it is compatible with the zero-temperature limit of smooth black hole solutions. While this notion of extremality does not require nor implies the existence of supersymmetry, we exemplify its consequences in the context of sl(3|2) + sl(3|2) Chern-Simons theory. Remarkably, while as usual not all extremal solutions preserve supersymmetries, we find that the higher spin setup allows for non-extremal supersymmetric black hole solutions as well. Furthermore, we discuss our results from the perspective of the holographic duality between sl(3|2) + sl(3|2) Chern-Simons theory and two-dimensional CFTs with W_{(3|2)} symmetry, the simplest higher spin extension of the N=2 super-Virasoro algebra. In particular, we compute W_{(3|2)} BPS bounds at the full quantum level, and relate their semiclassical limit to extremal black hole or conical defect solutions in the 3d bulk. Along the way, we discuss the role of the spectral flow automorphism and provide a conjecture for the form of the semiclassical BPS bounds in general N=2 two-dimensional CFTs with extended symmetry algebras.

  5. Cooling air recycling for gas turbine transition duct end frame and related method

    DOE Patents [OSTI]

    Cromer, Robert Harold (Johnstown, NY); Bechtel, William Theodore (Scotia, NY); Sutcu, Maz (Niskayuna, NY)

    2002-01-01

    A method of cooling a transition duct end frame in a gas turbine includes the steps of a) directing cooling air into the end frame from a region external of the transition duct and the impingement cooling sleeve; and b) redirecting the cooling air from the end frame into the annulus between the transition duct and the impingement cooling sleeve.

  6. Elastomeric Network Models for the Frame and Viscid Silks from the Orb Web

    E-Print Network [OSTI]

    Denny, Mark

    Chapter 27 Elastomeric Network Models for the Frame and Viscid Silks from the Orb Web of the Spider of these networks. This paper presents an analysis of frame silk and viscid silk from the orb web of the spider is produced by the major ampullate gland and is used to form the frame of the orb web, as well as the radii

  7. SPARSE FUSION FRAMES: EXISTENCE AND CONSTRUCTION ROBERT CALDERBANK, PETER G. CASAZZA, ANDREAS HEINECKE, GITTA KUTYNIOK,

    E-Print Network [OSTI]

    Kutyniok, Gitta

    SPARSE FUSION FRAMES: EXISTENCE AND CONSTRUCTION ROBERT CALDERBANK, PETER G. CASAZZA, ANDREAS HEINECKE, GITTA KUTYNIOK, AND ALI PEZESHKI Abstract. Fusion frame theory is an emerging mathematical theory that provides a natural framework for performing hierarchical data processing. A fusion frame can be regarded

  8. Journal of Embedded Computing 2 (2006) 93102 93 Frame packing algorithms for automotive

    E-Print Network [OSTI]

    Navet, Nicolas

    2006-01-01

    Journal of Embedded Computing 2 (2006) 93­102 93 IOS Press Frame packing algorithms for automotive Vandoeuvre-l `es-Nancy, France Abstract. The set of frames exchanged in automotive applications must meet two proposes algorithms for building off-line the set of frames in automotive communica- tions with the two

  9. Green-Frag: Energy-Efficient Frame Fragmentation Scheme for Wireless Sensor Networks

    E-Print Network [OSTI]

    Shihada, Basem

    Green-Frag: Energy-Efficient Frame Fragmentation Scheme for Wireless Sensor Networks Anas that frame fragmenta- tion also helps to reduce energy consumption. In this paper we propose Green-Frag, a new energy-efficient protocol based on efficient frame fragmentation technique. Green-Frag allows

  10. On coupling impedances of pumping holes

    SciTech Connect (OSTI)

    Kurennoy, S.

    1993-04-01

    Coupling impedances of a single small hole in vacuum-chamber walls have been calculated at low frequencies. To generalize these results for higher frequencies and/or larger holes one needs to solve coupled integral equations for the effective currents. These equations are solved for two specific hole shapes. The effects of many holes at high frequencies where the impedances are not additive are studied using a perturbation-theory method. The periodic versus random distributions of the pumping holes in the Superconducting Super Collider liner are compared.

  11. Does syntactic priming in children persist across significant time periods? 

    E-Print Network [OSTI]

    Hill, Louisa

    2013-07-02

    Using a ‘snap’ paradigm, we investigated the time course effects of syntactic priming in both adults and children. The research was done over a one week time frame in order to see whether priming is a long lived effect and ...

  12. Quantum chaos and order based on classically moving reference frames

    SciTech Connect (OSTI)

    Hai Wenhua [Department of Physics, Hunan Normal University, Changsha 410081 (China); Department of Physics, Jishou University, Jishou 416000, Hunan (China); Xie Qiongtao; Fang Jianshu [Department of Physics, Hunan Normal University, Changsha 410081 (China)

    2005-07-15

    We develop a mathematically consistent approach for treating the quantum systems based on moving classical reference frames. The classical and quantum exact solutions show excellently classical-quantum correspondence, in which the quantum chaotic coherent states correspond to the classically chaotic motions. Applying the approach to the periodically driven linear and nonlinear oscillators, the regular and chaotic quantum states and quantum levels, and the quantum chaotic regions are evidenced. The results indicate that chaos may cause the collapse of matter wave packets and suppress the quantum effect of energy.

  13. A two-frame sampling survey: the Edwards Plateau study 

    E-Print Network [OSTI]

    Burcham, George William

    1970-01-01

    1970 Ba?820 ABSTRACT A T?o-Frame Samoling Survey: The Ed?aids Plateau Study. (January 1970) C orge V. Bu;cham, B. S. , East Texas State University; Directed by: Dr. R. J. Freund This research deals wi th problems that akd se in the estimation... the variance component arising throuah the stratified sub-sampling of the n tracts. Since A (given by (4)) is the standard stratified estimate of the population total A (given by (3)) wc have from standard stratified sampling formulas 32 2 v (A) = (EP) zn...

  14. Molecular-Frame Angular Distributions of Resonant Auger Electrons

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGEMissionStress Molecular MimicryMolecular-Frame Angular

  15. Molecular-Frame Angular Distributions of Resonant Auger Electrons

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGEMissionStress Molecular MimicryMolecular-Frame

  16. Molecular-Frame Angular Distributions of Resonant Auger Electrons

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGEMissionStress MolecularMolecular-Frame Angular

  17. SolarFrameWorks Co | Open Energy Information

    Open Energy Info (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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EA EIS ReportEurope GmbH JumpSloughInfra IncInformationSolarFrameWorks

  18. Department of Energy Quadrennial Technology Review Framing Document

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

    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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i Framing Document http://energy.gov/QTR 3/14/2011 U.S. Department of

  19. Black hole mimickers: Regular versus singular behavior

    SciTech Connect (OSTI)

    Lemos, Jose P. S.; Zaslavskii, Oleg B.

    2008-07-15

    Black hole mimickers are possible alternatives to black holes; they would look observationally almost like black holes but would have no horizon. The properties in the near-horizon region where gravity is strong can be quite different for both types of objects, but at infinity it could be difficult to discern black holes from their mimickers. To disentangle this possible confusion, we examine the near-horizon properties, and their connection with far away asymptotic properties, of some candidates to black mimickers. We study spherically symmetric uncharged or charged but nonextremal objects, as well as spherically symmetric charged extremal objects. Within the uncharged or charged but nonextremal black hole mimickers, we study nonextremal {epsilon}-wormholes on the threshold of the formation of an event horizon, of which a subclass are called black foils, and gravastars. Within the charged extremal black hole mimickers we study extremal {epsilon}-wormholes on the threshold of the formation of an event horizon, quasi-black holes, and wormholes on the basis of quasi-black holes from Bonnor stars. We elucidate whether or not the objects belonging to these two classes remain regular in the near-horizon limit. The requirement of full regularity, i.e., finite curvature and absence of naked behavior, up to an arbitrary neighborhood of the gravitational radius of the object enables one to rule out potential mimickers in most of the cases. A list ranking the best black hole mimickers up to the worst, both nonextremal and extremal, is as follows: wormholes on the basis of extremal black holes or on the basis of quasi-black holes, quasi-black holes, wormholes on the basis of nonextremal black holes (black foils), and gravastars. Since in observational astrophysics it is difficult to find extremal configurations (the best mimickers in the ranking), whereas nonextremal configurations are really bad mimickers, the task of distinguishing black holes from their mimickers seems to be less difficult than one could think of it.

  20. AAC R17-1-102 Licensing Time Frames | Open Energy Information

    Open Energy Info (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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EAand Dalton JumpProgram |RecentSulfonate as aEnergy1 Jump

  1. Detecting small holes in packages

    DOE Patents [OSTI]

    Kronberg, James W. (Aiken, SC); Cadieux, James R. (Aiken, SC)

    1996-01-01

    A package containing a tracer gas, and a method for determining the presence of a hole in the package by sensing the presence of the gas outside the package. The preferred tracer gas, especially for food packaging, is sulfur hexafluoride. A quantity of the gas is added to the package and the package is closed. The concentration of the gas in the atmosphere outside the package is measured and compared to a predetermined value of the concentration of the gas in the absence of the package. A measured concentration greater than the predetermined value indicates the presence of a hole in the package. Measuring may be done in a chamber having a lower pressure than that in the package.

  2. Detecting small holes in packages

    DOE Patents [OSTI]

    Kronberg, J.W.; Cadieux, J.R.

    1996-03-19

    A package containing a tracer gas, and a method for determining the presence of a hole in the package by sensing the presence of the gas outside the package are disclosed. The preferred tracer gas, especially for food packaging, is sulfur hexafluoride. A quantity of the gas is added to the package and the package is closed. The concentration of the gas in the atmosphere outside the package is measured and compared to a predetermined value of the concentration of the gas in the absence of the package. A measured concentration greater than the predetermined value indicates the presence of a hole in the package. Measuring may be done in a chamber having a lower pressure than that in the package. 3 figs.

  3. Horizon of quantum black holes in various dimensions

    E-Print Network [OSTI]

    Casadio, Roberto; Giugno, Andrea; Mureika, Jonas

    2015-01-01

    We adapt the horizon wave-function formalism to describe massive static spherically symmetric sources in a general $(1+D)$-dimensional space-time, for $D>3$ and including the $D=1$ case. We find that the probability $P_{\\rm BH} $ that such objects are (quantum) black holes behaves similarly to the probability in the $(3+1)$ framework for $D> 3$. In fact, for $D\\ge 3$, the probability increases towards unity as the mass grows above the relevant $D$-dimensional Planck scale $m_D$, the faster the larger $D$. In contrast, for $D=1$, we find the probability is comparably larger for smaller masses, but $P_{\\rm BH} < 0.5$, suggesting that such lower dimensional black holes are purely quantum and not classical objects. This result is consistent with recent observations that sub-Planckian black holes are governed by an effective two-dimensional gravitation theory. Lastly, we derive Generalised Uncertainty Principle relations for the black holes under consideration, and for all cases find a minimum length scale $L_D...

  4. Quantum chaos inside Black Holes

    E-Print Network [OSTI]

    Addazi, Andrea

    2015-01-01

    We show how semiclassical black holes can be reinterpreted as an effective geometry, composed of a large ensamble of horizonless naked singularities (eventually smoothed at the Planck scale). We call this new items {\\it frizzyballs}, which can be rigorously defined by euclidean path integral approach. This has interesting implications regarding information paradoxes. We demonstrate that infalling information will chaotically propagate inside this system before going to the full quantum gravity regime (Planck scale).

  5. Quantum chaos inside Black Holes

    E-Print Network [OSTI]

    Andrea Addazi

    2015-08-30

    We show how semiclassical black holes can be reinterpreted as an effective geometry, composed of a large ensamble of horizonless naked singularities (eventually smoothed at the Planck scale). We call this new items {\\it frizzyballs}, which can be rigorously defined by euclidean path integral approach. This has interesting implications regarding information paradoxes. We demonstrate that infalling information will chaotically propagate inside this system before going to the full quantum gravity regime (Planck scale).

  6. Classical Black Holes Are Hot

    E-Print Network [OSTI]

    Erik Curiel

    2014-11-09

    In the early 1970s it is was realized that there is a striking formal analogy between the Laws of black-hole mechanics and the Laws of classical thermodynamics. Before the discovery of Hawking radiation, however, it was generally thought that the analogy was only formal, and did not reflect a deep connection between gravitational and thermodynamical phenomena. It is still commonly held that the surface gravity of a stationary black hole can be construed as a true physical temperature and its area as a true entropy only when quantum effects are taken into account; in the context of classical general relativity alone, one cannot cogently construe them so. Does the use of quantum field theory in curved spacetime offer the only hope for taking the analogy seriously? I think the answer is `no'. To attempt to justify that answer, I shall begin by arguing that the standard argument to the contrary is not physically well founded, and in any event begs the question. Looking at the various ways that the ideas of "temperature" and "entropy" enter classical thermodynamics then will suggest arguments that, I claim, show the analogy between classical black-hole mechanics and classical thermodynamics should be taken more seriously, without the need to rely on or invoke quantum mechanics. In particular, I construct an analogue of a Carnot cycle in which a black hole "couples" with an ordinary thermodynamical system in such a way that its surface gravity plays the role of temperature and its area that of entropy. Thus, the connection between classical general relativity and classical thermodynamics on their own is already deep and physically significant, independent of quantum mechanics.

  7. Down hole periodic seismic generator

    DOE Patents [OSTI]

    Hardee, Harry C. (Albuquerque, NM); Hills, Richard G. (Las Cruces, NM); Striker, Richard P. (Albuquerque, NM)

    1989-01-01

    A down hole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

  8. Black hole lightning due to particle acceleration at subhorizon scales

    E-Print Network [OSTI]

    Aleksi?, J; Antonelli, L A; Antoranz, P; Babic, A; Bangale, P; Barrio, J A; González, J Becerra; Bednarek, W; Bernardini, E; Biasuzzi, B; Biland, A; Blanch, O; Bonnefoy, S; Bonnoli, G; Borracci, F; Bretz, T; Carmona, E; Carosi, A; Colin, P; Colombo, E; Contreras, J L; Cortina, J; Covino, S; Da Vela, P; Dazzi, F; De Angelis, A; De Caneva, G; De Lotto, B; Wilhelmi, E de Oña; Mendez, C Delgado; Prester, D Dominis; Dorner, D; Doro, M; Einecke, S; Eisenacher, D; Elsaesser, D; Fonseca, M V; Font, L; Frantzen, K; Fruck, C; Galindo, D; López, R J García; Garczarczyk, M; Terrats, D Garrido; Gaug, M; Godinovi?, N; Muñoz, A González; Gozzini, S R; Hadasch, D; Hanabata, Y; Hayashida, M; Herrera, J; Hildebrand, D; Hose, J; Hrupec, D; Idec, W; Kadenius, V; Kellermann, H; Kodani, K; Konno, Y; Krause, J; Kubo, H; Kushida, J; La Barbera, A; Lelas, D; Lewandowska, N; Lindfors, E; Lombardi, S; Longo, F; López, M; López-Coto, R; López-Oramas, A; Lorenz, E; Lozano, I; Makariev, M; Mallot, K; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Marcote, B; Mariotti, M; Martínez, M; Mazin, D; Menzel, U; Miranda, J M; Mirzoyan, R; Moralejo, A; Munar-Adrover, P; Nakajima, D; Niedzwiecki, A; Nilsson, K; Nishijima, K; Noda, K; Orito, R; Overkemping, A; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, J M; Paredes-Fortuny, X; Persic, M; Poutanen, J; Moroni, P G Prada; Prandini, E; Puljak, I; Reinthal, R; Rhode, W; Ribó, M; Rico, J; Garcia, J Rodriguez; Rügamer, S; Saito, T; Saito, K; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schweizer, T; Shore, S N; Sillanpää, A; Sitarek, J; Snidaric, I; Sobczynska, D; Spanier, F; Stamatescu, V; Stamerra, A; Steinbring, T; Storz, J; Strzys, M; Takalo, L; Takami, H; Tavecchio, F; Temnikov, P; Terzi?, T; Tescaro, D; Teshima, M; Thaele, J; Tibolla, O; Torres, D F; Toyama, T; Treves, A; Uellenbeck, M; Vogler, P; Zanin, R; Kadler, M; Schulz, R; Ros, E; Bach, U; Krauß, F; Wilms, J

    2014-01-01

    Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry, but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here, we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC telescopes revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20\\% of the gravitational radius of its central black hole. We suggest that the emission is associated with pulsar-like particle acceleration by the electric field across a magnetospheric gap at the base of the radio jet.

  9. Submicron patterned metal hole etching

    DOE Patents [OSTI]

    McCarthy, Anthony M. (Menlo Park, CA); Contolini, Robert J. (Lake Oswego, OR); Liberman, Vladimir (Needham, MA); Morse, Jeffrey (Martinez, CA)

    2000-01-01

    A wet chemical process for etching submicron patterned holes in thin metal layers using electrochemical etching with the aid of a wetting agent. In this process, the processed wafer to be etched is immersed in a wetting agent, such as methanol, for a few seconds prior to inserting the processed wafer into an electrochemical etching setup, with the wafer maintained horizontal during transfer to maintain a film of methanol covering the patterned areas. The electrochemical etching setup includes a tube which seals the edges of the wafer preventing loss of the methanol. An electrolyte composed of 4:1 water: sulfuric is poured into the tube and the electrolyte replaces the wetting agent in the patterned holes. A working electrode is attached to a metal layer of the wafer, with reference and counter electrodes inserted in the electrolyte with all electrodes connected to a potentiostat. A single pulse on the counter electrode, such as a 100 ms pulse at +10.2 volts, is used to excite the electrochemical circuit and perform the etch. The process produces uniform etching of the patterned holes in the metal layers, such as chromium and molybdenum of the wafer without adversely effecting the patterned mask.

  10. Massive vector particles tunneling from Kerr and Kerr-Newman black holes

    E-Print Network [OSTI]

    Li, Xiang-Qian

    2015-01-01

    In this paper, we investigate the Hawking radiation of massive spin-1 particles from 4-dimensional Kerr and Kerr-Newman black holes. By applying the Hamilton-Jacobi ansatz and the WKB approximation to the field equations of the massive bosons in Kerr and Kerr-Newman space-time, the quantum tunneling method is successfully implemented. As a result, we obtain the tunneling rate of the emitted vector particles and recover the standard Hawking temperature of both the two black holes.

  11. Massive vector particles tunneling from Kerr and Kerr-Newman black holes

    E-Print Network [OSTI]

    Xiang-Qian Li; Ge-Rui Chen

    2015-07-13

    In this paper, we investigate the Hawking radiation of massive spin-1 particles from 4-dimensional Kerr and Kerr-Newman black holes. By applying the Hamilton-Jacobi ansatz and the WKB approximation to the field equations of the massive bosons in Kerr and Kerr-Newman space-time, the quantum tunneling method is successfully implemented. As a result, we obtain the tunneling rate of the emitted vector particles and recover the standard Hawking temperature of both the two black holes.

  12. Chemical aspects of cylinder corrosion and a scenario for hole development

    SciTech Connect (OSTI)

    Barber, E.J. [Martin Marietta Energy Systems, Oak Ridge, TN (United States)

    1991-12-31

    In June 1990, two cylinders in the depleted UF{sub 6} cylinder storage yards at Portsmouth were discovered to have holes in their walls at the valve-end stiffening ring at a point below the level of the gas-solid interface of the UF{sub 6}. The cylinder with the larger hole, which extended under the stiffening ring, was stacked in a top row 13 years ago. The cylinder with the smaller hole had been stacked in a bottom row 4 years ago. The lifting lugs of the adjacent cylinders pointed directly at the holes. A Cylinder Investigating Committee was appointed to determine the cause or causes of the holes and to assess the implications of these findings. This report contains a listing of the chemically related facts established by the Investigating Committee with the cooperation of the Operations and Technical Support Divisions at the Portsmouth Gaseous Diffusion Plant, the scenario developed to explain these findings and some implications of this scenario. In summary, the interrelated reactions of water, solid UF{sub 6} and iron presented by R. L. Ritter are used to develop a scenario which explains the observations and deductions made during the investigation. The chemical processes are intimately related to the course of the last three of the four stages of hole development. A simple model is proposed which permits semiquantitative prediction of such information as the HF loss rates as a function of time, the rate of hole enlargement, the time to hydrolyze a cylinder of UF{sub 6} and the approximate size of the hole. The scenario suggests that the environmental consequences associated with a developing hole in a depleted UF{sub 6} cylinder are minimal for the first several years but will become significant if too many years pass before detection. The overall environmental picture is presented in more detail elsewhere.

  13. Jets from Tidal Disruptions of Stars by Black Holes

    E-Print Network [OSTI]

    Julian H. Krolik; Tsvi Piran

    2012-02-07

    Tidal disruption of main sequence stars by black holes has generally been thought to lead to a signal dominated by UV emission. If, however, the black hole spins rapidly and the poloidal magnetic field intensity on the black hole horizon is comparable to the inner accretion disk pressure, a powerful jet may form whose luminosity can easily exceed the thermal UV luminosity. When the jet beam points at Earth, its non-thermal luminosity can dominate the emitted spectrum. The thermal and non-thermal components decay differently with time. In particular, the thermal emission should remain roughly constant for a significant time after the period of maximum accretion, beginning to diminish only after a delay, whereas after the peak accretion rate, the non-thermal jet emission decays, but then reaches a plateau. Both transitions are tied to a characteristic timescale $t_{\\rm Edd}$ at which the accretion rate falls below Eddington. Making use of this timescale in a new parameter-inference formalism for tidal disruption events with significant emission from a jet, we analyze the recent flare source Swift J2058. It is consistent with an event in which a main sequence solar-type staris disrupted by a black hole of mass $\\sim 4 \\times 10^7 M_{\\odot}$. The beginning of the flat phase in the non-thermal emission from this source can possibly be seen in the late-time lightcurve. Optical photometry over the first $\\simeq 40$ d of this flare is also consistent with this picture, but is only weakly constraining because the bolometric correction is very uncertain. We suggest that future searches for main sequence tidal disruptions use methods sensitive to jet radiation as well as to thermal UV radiation.

  14. Gauge Gravity and Space-Time

    E-Print Network [OSTI]

    Ning Wu

    2012-07-11

    When we discuss problems on gravity, we can not avoid some fundamental physical problems, such as space-time, inertia, and inertial reference frame. The goal of this paper is to discuss the logic system of gravity theory and the problems of space-time, inertia, and inertial reference frame. The goal of this paper is to set up the theory on space-time in gauge theory of gravity. Based on this theory, it is possible for human kind to manipulate physical space-time on earth, and produce a machine which can physically prolong human's lifetime.

  15. Preferred-Frame and CP-Violation Tests with Polarized Electrons

    E-Print Network [OSTI]

    B. R. Heckel; E. G. Adelberger; C. E. Cramer; T. S. Cook; S. Schlamminger; U. Schmidt

    2008-08-20

    We used a torsion pendulum containing $\\approx 10^{23}$ polarized electrons to search new interactions that couple to electron spin. We limit CP-violating interactions between the pendulum's electrons and unpolarized matter in the earth or the sun, test for rotation and boost-dependent preferred-frame effects using the earth's rotation and velocity with respect to the entire cosmos, and search for exotic velocity-dependent potentials between polarized electrons and unpolarized matter in the sun and moon. Finally, we find that the gravitational mass of an electron spinning toward the galactic center differs by less than about 1 part in $10^{21}$ from an electron spinning in the opposite direction. As a byproduct of this work, the density of polarized electrons in Sm$ $Co$_5$ was measured to be $(4.19\\pm 0.19)\\times 10^{22} {\\rm cm}^{-3}$ at a field of 9.6 kG.

  16. Development of a dual MCP framing camera for high energy x-rays

    SciTech Connect (OSTI)

    Izumi, N., E-mail: izumi2@llnl.gov; Hall, G. N.; Carpenter, A. C.; Allen, F. V.; Cruz, J. G.; Felker, B.; Hargrove, D.; Holder, J.; Lumbard, A.; Montesanti, R.; Palmer, N. E.; Piston, K.; Stone, G.; Thao, M.; Vern, R.; Zacharias, R.; Landen, O. L.; Tommasini, R.; Bradley, D. K.; Bell, P. M. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

    2014-11-15

    Recently developed diagnostic techniques at LLNL require recording backlit images of extremely dense imploded plasmas using hard x-rays, and demand the detector to be sensitive to photons with energies higher than 50 keV [R. Tommasini et al., Phys. Phys. Plasmas 18, 056309 (2011); G. N. Hall et al., “AXIS: An instrument for imaging Compton radiographs using ARC on the NIF,” Rev. Sci. Instrum. (these proceedings)]. To increase the sensitivity in the high energy region, we propose to use a combination of two MCPs. The first MCP is operated in a low gain regime and works as a thick photocathode, and the second MCP works as a high gain electron multiplier. We tested the concept of this dual MCP configuration and succeeded in obtaining a detective quantum efficiency of 4.5% for 59 keV x-rays, 3 times larger than with a single plate of the thickness typically used in NIF framing cameras.

  17. Relationship of Black Holes to Bulges

    E-Print Network [OSTI]

    David Merritt; Laura Ferrarese

    2001-07-08

    Supermassive black holes appear to be uniquely associated with galactic bulges. The mean ratio of black hole mass to bulge mass was until recently very uncertain, with ground based, stellar kinematical data giving a value roughly an order of magnitude larger than other techniques. The discrepancy was resolved with the discovery of the M-sigma relation, which simultaneously established a tight corrrelation between black hole mass and bulge velocity dispersion, and confirmed that the stellar kinematical mass estimates were systematically too large due to failure to resolve the black hole's sphere of influence. There is now excellent agreement between the various techniques for estimating the mean black hole mass, including dynamical mass estimation in quiescent galaxies; reverberation mapping in active galaxies and quasars; and computation of the mean density of compact objects based on integrated quasar light. Implications of the M-sigma relation for the formation of black holes are discussed.

  18. Innermost stable circular orbit near dirty black holes in magnetic field and ultra-high energy particle collisions

    E-Print Network [OSTI]

    O. B. Zaslavskii

    2015-09-06

    We consider the behavior of the innermost stable circular orbit (ISCO) in the magnetic field near "dirty" (surrounded by matter) axially-symmetric black holes. The cases of near-extremal, extremal and nonextremal black holes are analyzed. For nonrotating black holes, in the strong magnetic field ISCO approaches the horizon (when backreaction of the field on geometry is neglected). Rotation destroys this phenomenon. The angular momentum and radius of ISCO look model-independent in the main approximation. We also study the collisions between two particles that results in the ultra-high energy $E_{c.m.}$ in the centre of mass frame. Two scenarios are considered - when one particle moves on the near-horizon ISCO or when collision occurs on the horizon, one particle having the energy and angular momentum typical of ISCO. If the magnetic field is strong enough and a black hole is slow rotating, $E_{c.m.}$ can become arbitrarily large. Kinematics of high-energy collision is discussed. As an example, we consider the magnetized Schwarzschild black hole for an arbitrary strength of the field (the Ernst solution). It is shown that backreaction of the magnetic field on the geometry can bound the growth of $E_{c.m.}$.

  19. Progressive Collapse Mechanisms of Brittle and Ductile Framed Structures

    E-Print Network [OSTI]

    Enrico Masoero; Falk K. Wittel; Hans J. Herrmann; B. M. Chiaia

    2015-09-07

    In this paper, we study the progressive collapse of 3D framed structures made of reinforced concrete after the sudden loss of a column. The structures are represented by elasto-plastic Euler Bernoulli beams with elongation-rotation failure threshold. We performed simulations using the Discrete Element Method considering inelastic collisions between the structural elements. The results show what collapse initiation and impact-driven propagation mechanisms are activated in structures with different geometric and mechanical features. Namely, we investigate the influence of the cross sectional size and reinforcement $\\alpha$ and of the plastic capacity $\\beta$ of the structural elements. We also study the final collapse extent and the fragment size distribution and their relation to $\\alpha$, $\\beta$ and to the observed collapse mechanisms. Finally, we compare the damage response of structures with symmetric and asymmetric reinforcement in the beams.

  20. "Meissner effect" and Blandford-Znajek mechanism in conductive black hole magnetospheres

    E-Print Network [OSTI]

    S. S. Komissarov; J. C. McKinney

    2007-02-14

    The expulsion of axisymmetric magnetic field from the event horizons of rapidly rotating black holes has been seen as an astrophysically important effect that may significantly reduce or even nullify the efficiency of the Blandford-Znajek mechanism of powering the relativistic jets in Active Galactic Nuclei and Gamma Ray Bursts. However, this Meissner-like effect is seen in vacuum solutions of black hole electrodynamics whereas the Blandford-Znajek mechanism is concerned with plasma-filled magnetospheres. In this paper we argue that conductivity dramatically changes the properties of axisymmetric electromagnetic solutions -- even for a maximally rotating Kerr black hole the magnetic field is pulled inside the event horizon. Moreover, the conditions resulting in outgoing Poynting flux in the Blandford-Znajek mechanism exist not on the event horizon but everywhere within the black hole ergosphere. Thus, the Meissner effect is unlikely to be of interest in astrophysics of black holes, at least not in the way this has been suggested so far. These conclusions are supported by the results of time-dependent numerical simulations with three different computer codes. The test problems involve black holes with the rotation parameter ranging from $a=0.999$ to $a=1$. The pure electrodynamic simulations deal with the structure of conductive magnetospheres of black holes placed in a uniform-at-infinity magnetic field (Wald's problem) and the magnetohydrodynamic simulations are used to study the magnetospheres arising in the problem of disk accretion.

  1. Temperature, Energy, and Heat Capacity of Asymptotically Anti-De Sitter Black Holes

    E-Print Network [OSTI]

    J. D. Brown; J. Creighton; R. B. Mann

    1994-05-03

    We investigate the thermodynamical properties of black holes in (3+1) and (2+1) dimensional Einstein gravity with a negative cosmological constant. In each case, the thermodynamic internal energy is computed for a finite spatial region that contains the black hole. The temperature at the boundary of this region is defined by differentiating the energy with respect to entropy, and is equal to the product of the surface gravity (divided by~$2\\pi$) and the Tolman redshift factor for temperature in a stationary gravitational field. We also compute the thermodynamic surface pressure and, in the case of the (2+1) black hole, show that the chemical potential conjugate to angular momentum is equal to the proper angular velocity of the black hole with respect to observers who are at rest in the stationary time slices. In (3+1) dimensions, a calculation of the heat capacity reveals the existence of a thermodynamically stable black hole solution and a negative heat capacity instanton. This result holds in the limit that the spatial boundary tends to infinity only if the comological constant is negative; if the cosmological constant vanishes, the stable black hole solution is lost. In (2+1) dimensions, a calculation of the heat capacity reveals the existence of a thermodynamically stable black hole solution, but no negative heat capacity instanton.

  2. Supermassive Black Hole Growth and Merger Rates from Cosmological N-body Simulations

    E-Print Network [OSTI]

    Miroslav Micic; Kelly Holley-Bockelmann; Steinn Sigurdsson; Tom Abel

    2007-03-20

    Understanding how seed black holes grow into intermediate and supermassive black holes (IMBHs and SMBHs, respectively) has important implications for the duty-cycle of active galactic nuclei (AGN), galaxy evolution, and gravitational wave astronomy. Most studies of the cosmological growth and merger history of black holes have used semianalytic models and have concentrated on SMBH growth in luminous galaxies. Using high resolution cosmological N-body simulations, we track the assembly of black holes over a large range of final masses -- from seed black holes to SMBHs -- over widely varying dynamical histories. We used the dynamics of dark matter halos to track the evolution of seed black holes in three different gas accretion scenarios. We have found that growth of Sagittarius A* - size SMBH reaches its maximum mass M_{SMBH}~10^6Msun at z~6 through early gaseous accretion episodes, after which it stays at near constant mass. At the same redshift, the duty-cycle of the host AGN ends, hence redshift z=6 marks the transition from an AGN to a starburst galaxy which eventually becomes the Milky Way. By tracking black hole growth as a function of time and mass, we estimate that the IMBH merger rate reaches a maximum of R_{max}=55 yr^-1 at z=11. From IMBH merger rates we calculate N_{ULX}=7 per Milky Way type galaxy per redshift in redshift range 2

  3. The role of stellar relaxation in the formation and evolution of the first massive black holes

    E-Print Network [OSTI]

    Yajima, Hidenobu

    2015-01-01

    We present calculations on the formation of massive black holes with 10^5 Msun at z > 6 that can be the seeds of supermassive black holes at z > 6. Under the assumption of compact star cluster formation in merging galaxies, star clusters in haloes of 10^8 ~ 10^9 Msun undergo rapid core-collapse leading to the formation of very massive stars (VMSs) with ~1000 Msun which directly collapse into black holes with similar masses. Star clusters in halos of > 10^9 Msun experience type-II supernovae before the formation of VMSs due to long core-collapse time scales. We also model the subsequent growth of black holes via accretion of residual stars in clusters. 2-body relaxation efficiently re-fills the loss cones of stellar orbits at larger radii and resonant relaxation at small radii is the main driver for accretion of stars onto black holes. As a result, more than ninety percent of stars in the initial cluster are swallowed by the central black holes before z=6. Using dark matter merger trees we derive black hole ma...

  4. Boson shells harboring charged black holes

    SciTech Connect (OSTI)

    Kleihaus, Burkhard; Kunz, Jutta; Laemmerzahl, Claus; List, Meike

    2010-11-15

    We consider boson shells in scalar electrodynamics coupled to Einstein gravity. The interior of the shells can be empty space, or harbor a black hole or a naked singularity. We analyze the properties of these types of solutions and determine their domains of existence. We investigate the energy conditions and present mass formulae for the composite black hole-boson shell systems. We demonstrate that these types of solutions violate black hole uniqueness.

  5. Black Holes in Galaxy Mergers: Evolution of Quasars

    E-Print Network [OSTI]

    Philip F. Hopkins; Lars Hernquist; Thomas J. Cox; Tiziana Di Matteo; Paul Martini; Brant Robertson; Volker Springel

    2005-06-13

    Based on numerical simulations of gas-rich galaxy mergers, we discuss a model in which quasar activity is tied to the self-regulated growth of supermassive black holes in galaxies. Nuclear inflow of gas attending a galaxy collision triggers a starburst and feeds black hole growth, but for most of the duration of the starburst, the black hole is heavily obscured by surrounding gas and dust which limits the visibility of the quasar, especially at optical and UV wavelengths. Eventually, feedback energy from accretion heats the gas and expels it in a powerful wind, leaving a 'dead quasar'. Between buried and dead phases there is a window during which the galaxy would be seen as a luminous quasar. Because the black hole mass, radiative output, and distribution of obscuring gas and dust all evolve strongly with time, the duration of this phase of observable quasar activity depends on both the waveband and imposed luminosity threshold. We determine the observed and intrinsic lifetimes as a function of luminosity and frequency, and calculate observable lifetimes ~10 Myr for bright quasars in the optical B-band, in good agreement with empirical estimates and much smaller than the black hole growth timescales ~100 Myr, naturally producing a substantial population of 'buried' quasars. However, observed and intrinsic energy outputs converge in the IR and hard X-ray bands as attenuation becomes weaker and chances of observation greatly increase. We obtain the distribution of column densities along sightlines in which the quasar is seen above a given luminosity, and find that our result agrees remarkably well with observed estimates of the column density distribution from the SDSS for appropriate luminosity thresholds. (Abridged)

  6. Lower Dimensional Black Holes: Inside and Out

    E-Print Network [OSTI]

    R. B. Mann

    1995-01-27

    I survey the physics of black holes in two and three spacetime dimensions, with special attention given to an understanding of their exterior and interior properties.

  7. Black Holes: from Speculations to Observations

    E-Print Network [OSTI]

    Thomas W. Baumgarte

    2006-04-13

    This paper provides a brief review of the history of our understanding and knowledge of black holes. Starting with early speculations on ``dark stars'' I discuss the Schwarzschild "black hole" solution to Einstein's field equations and the development of its interpretation from "physically meaningless" to describing the perhaps most exotic and yet "most perfect" macroscopic object in the universe. I describe different astrophysical black hole populations and discuss some of their observational evidence. Finally I close by speculating about future observations of black holes with the new generation of gravitational wave detectors.

  8. Core Holes | Open Energy Information

    Open Energy Info (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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTIONRobertsdale, Alabama (Utility Company)| Open(Evans,Oregon: EnergyInformationOpen1988)|Holes Jump

  9. Smart Frame Grabber : : A Hardware Accelerated Computer Vision Framework

    E-Print Network [OSTI]

    Jacobsen, Matthew Daniel

    2014-01-01

    automation this requirement can be several thousand times a second. For example, many factory production lines

  10. Construction and physical properties of Kerr black holes with scalar hair

    E-Print Network [OSTI]

    Carlos Herdeiro; Eugen Radu

    2015-05-04

    Kerr black holes with scalar hair are solutions of the Einstein-Klein-Gordon field equations describing regular (on and outside an event horizon), asymptotically flat black holes with scalar hair (arXiv:1403.2757). These black holes interpolate continuously between the Kerr solution and rotating boson stars in D=4 spacetime dimensions. Here we provide details on their construction, discussing properties of the ansatz, the field equations, the boundary conditions and the numerical strategy. Then, we present an overview of the parameter space of the solutions, and describe in detail the space-time structure of the black holes exterior geometry and of the scalar field for a sample of reference solutions. Phenomenological properties of potential astrophysical interest are also discussed, and the stability properties and possible generalizations are commented on. As supplementary material to this paper we make available numerical data files for the sample of reference solutions discussed, for public use.

  11. Three-Charge Black Holes and Quarter BPS States in Little String Theory

    E-Print Network [OSTI]

    Giveon, Amit; Kutasov, David; Lee, Sungjay

    2015-01-01

    We show that the system of $k$ NS5-branes wrapping $\\mathbb{T}^4\\times S^1$ has non-trivial vacuum structure. Different vacua have different spectra of 1/4 BPS states that carry momentum and winding around the $S^1$. In one vacuum, such states are described by black holes; in another, they can be thought of as perturbative BPS states in Double Scaled Little String Theory. In general, both kinds of states are present. We compute the degeneracy of perturbative BPS states exactly, and show that it differs from that of the corresponding black holes. We comment on the implication of our results to the black hole microstate program, UV/IR mixing in Little String Theory, string thermodynamics, the string/black hole transition, and other issues.

  12. The scattering matrix approach for the quantum black hole, an overview

    E-Print Network [OSTI]

    G. 't Hooft

    1996-07-09

    If one assumes the validity of conventional quantum field theory in the vicinity of the horizon of a black hole, one does not find a quantum mechanical description of the entire black hole that even remotely resembles that of conventional forms of matter; in contrast with matter made out of ordinary particles one finds that, even if embedded in a finite volume, a black hole would be predicted to have a strictly continuous spectrum. Dissatisfied with such a result, which indeed hinges on assumptions concerning the horizon that may well be wrong, various investigators have now tried to formulate alternative approaches to the problem of ``quantizing" the black hole. We here review the approach based on the assumption of quantum mechanical purity and unitarity as a starting point, as has been advocated by the present author for some time, concentrating on the physics of the states that should live on a black hole horizon. The approach is shown to be powerful in not only producing promising models for the quantum black hole, but also new insights concerning the dynamics of physical degrees of freedom in ordinary flat space-time.

  13. Can black holes and naked singularities be detected in accelerators?

    E-Print Network [OSTI]

    R. Casadio; B. Harms

    2002-01-07

    We study the conditions for the existence of black holes that can be produced in colliders at TeV-scale if the space-time is higher dimensional. On employing the microcanonical picture, we find that their life-times strongly depend on the details of the model. If the extra dimensions are compact (ADD model), microcanonical deviations from thermality are in general significant near the fundamental TeV mass and tiny black holes decay more slowly than predicted by the canonical expression, but still fast enough to disappear almost instantaneously. However, with one warped extra dimension (RS model), microcanonical corrections are much larger and tiny black holes appear to be (meta)stable. Further, if the total charge is not zero, we argue that naked singularities do not occur provided the electromagnetic field is strictly confined on an infinitely thin brane. However, they might be produced in colliders if the effective thickness of the brane is of the order of the fundamental length scale (~1/TeV).

  14. Supersymmetric black holes and attractors in gauged supergravity with hypermultiplets

    E-Print Network [OSTI]

    Samuele Chimento; Dietmar Klemm; Nicolò Petri

    2015-04-13

    We consider four-dimensional $N=2$ supergravity coupled to vector- and hypermultiplets, where abelian isometries of the quaternionic K\\"ahler hypermultiplet scalar manifold are gauged. Using the recipe given by Meessen and Ort\\'{\\i}n in arXiv:1204.0493, we analytically construct a supersymmetric black hole solution for the case of just one vector multiplet with prepotential ${\\cal F}=-i\\chi^0\\chi^1$, and the universal hypermultiplet. This solution has a running dilaton, and it interpolates between $\\text{AdS}_2\\times\\text{H}^2$ at the horizon and a hyperscaling-violating type geometry at infinity, conformal to $\\text{AdS}_2\\times\\text{H}^2$. It carries two magnetic charges that are completely fixed in terms of the parameters that appear in the Killing vector used for the gauging. In the second part of the paper, we extend the work of Bellucci et al. on black hole attractors in gauged supergravity to the case where also hypermultiplets are present. The attractors are shown to be governed by an effective potential $V_{\\text{eff}}$, which is extremized on the horizon by all the scalar fields of the theory. Moreover, the entropy is given by the critical value of $V_{\\text{eff}}$. In the limit of vanishing scalar potential, $V_{\\text{eff}}$ reduces (up to a prefactor) to the usual black hole potential.

  15. From the New Ecological Paradigm to Total Liberation: The Emergence of a Social Movement Frame

    E-Print Network [OSTI]

    Pellow, DN; Brehm, HN

    2015-01-01

    radical ecological movements and social justice movements ismany other social movements, social change organizations,Framing Processes and Social Movements: An Overview and

  16. Performance of an LPD prototype detector at MHz frame rates under...

    Office of Scientific and Technical Information (OSTI)

    at MHz frame rates under Synchrotron and FEL radiation Authors: Koch, Andreas ; Hart, Matthew ; Nicholls, Tim ; Angelsen, Christian ; Coughlan, John ; French, Marcus ;...

  17. Key Elements of and Materials Performance Targets for Highly Insulating Window Frames

    E-Print Network [OSTI]

    Gustavsen, Arild

    2012-01-01

    can calculate radiation heat transfer using view factors orcould reduce radiation heat transfer in frame cavities. Wethe radiation portion of the surface heat transfer is

  18. State-of-the-Art Highly Insulating Window Frames - Research and Market Review

    E-Print Network [OSTI]

    Gustavsen, Arild

    2008-01-01

    to calculate the radiation heat transfer effects (Finlaysonfor frame cavity radiation heat transfer. Research has shownheat transfer for projecting fenestration products: Using Radiation

  19. Citizenship Porn within the Frame: Visualizing Techniques, Cyberspace, and the Production of “Undocumented”

    E-Print Network [OSTI]

    Moran, Erin

    2007-01-01

    Citizenship Porn within the Frame: Visualizing Techniques,pornographic fantasy that I call “citizenship porn”. Let mewhat I mean by “citizenship porn”; I will then raise several

  20. Method and architecture design for motion compensated frame interpolation in high-definition video processing

    E-Print Network [OSTI]

    Lee, Yen-Lin

    2009-01-01

    7.3 Proposed Architecture Design for High Frame RateAnalysis and Efficient Architecture Design for VC-1 OverlapProposed Deblocking Filter Architecture and Implementation

  1. Asymptotically flat black holes with scalar hair: a review

    E-Print Network [OSTI]

    Herdeiro, Carlos A R

    2015-01-01

    We consider the status of black hole solutions with non-trivial scalar fields but no gauge fields, in four dimensional asymptotically flat space-times, reviewing both classical results and recent developments. We start by providing a simple illustration on the physical difference between black holes in electro-vacuum and scalar-vacuum. Next, we review no-scalar-hair theorems. In particular, we detail an influential theorem by Bekenstein and stress three key assumptions: 1) the type of scalar field equation; 2) the spacetime symmetry inheritance by the scalar field; 3) an energy condition. Then, we list regular (on and outside the horizon), asymptotically flat BH solutions with scalar hair, organizing them by the assumption which is violated in each case and distinguishing primary from secondary hair. We provide a table summary of the state of the art.

  2. Asymptotically flat black holes with scalar hair: a review

    E-Print Network [OSTI]

    Carlos A. R. Herdeiro; Eugen Radu

    2015-04-30

    We consider the status of black hole solutions with non-trivial scalar fields but no gauge fields, in four dimensional asymptotically flat space-times, reviewing both classical results and recent developments. We start by providing a simple illustration on the physical difference between black holes in electro-vacuum and scalar-vacuum. Next, we review no-scalar-hair theorems. In particular, we detail an influential theorem by Bekenstein and stress three key assumptions: 1) the type of scalar field equation; 2) the spacetime symmetry inheritance by the scalar field; 3) an energy condition. Then, we list regular (on and outside the horizon), asymptotically flat BH solutions with scalar hair, organizing them by the assumption which is violated in each case and distinguishing primary from secondary hair. We provide a table summary of the state of the art.

  3. Satellite observations of thought experiments close to a black hole

    E-Print Network [OSTI]

    S. K. Chakrabarti

    2000-07-18

    Since black holes are `black', methods of their identification must necessarily be indirect. Due to very special boundary condition on the horizon, the advective flow behaves in a particular way, which includes formation of centrifugal pressure dominated boundary layer or CENBOL where much of the infall energy is released and outflows are generated. The observational aspects of black holes must depend on the steady and time-dependent properties of this boundary layer. Several observational results are written down in this review which seem to support the predictions of thought experiments based on this advective accretion/outflow model. In future, when gravitational waves are detected, some other predictions of this model could be tested as well.

  4. CP Violation and Baryogenesis in the Presence of Black Holes

    E-Print Network [OSTI]

    Tom Banks; Willy Fischler

    2015-05-16

    In a recent paper[1] Kundu and one of the present authors showed that there were transient but observable CP violating effects in the decay of classical currents on the horizon of a black hole, if the Lagrangian of the Maxwell field contained a CP violating angle {\\theta}. In this paper we demonstrate that a similar effect can be seen in the quantum mechanics of QED: a non-trivial Berry phase in the QED wave function is produced by in-falling electric charges. We also investigate whether CP violation, of this or any other type, might be used to produce the baryon asymmetry of the universe, in models where primordial black hole decay contributes to the matter content of the present universe. This can happen both in a variety of hybrid inflation models, and in the Holographic Space-time (HST) model of inflation[2].

  5. Short distance signatures in Cosmology: Why not in Black Holes?

    E-Print Network [OSTI]

    Roberto Casadio; Laura Mersini

    2002-08-07

    Current theoretical investigations seem to indicate the possibility of observing signatures of short distance physics in the Cosmic Microwave Background spectrum. We try to gain a deeper understanding on why all information about this regime is lost in the case of Black Hole radiation but not necessarily so in a cosmological setting by using the moving mirror as a toy model for both backgrounds. The different responses of the Hawking and Cosmic Microwave Background spectra to short distance physics are derived in the appropriate limit when the moving mirror mimics a Black Hole background or an expanding universe. The different sensitivities to new physics, displayed by both backgrounds, are clarified through an averaging prescription that accounts for the intrinsic uncertainty in their quantum fluctuations. We then proceed to interpret the physical significance of our findings for time-dependent backgrounds in the light of nonlocal string theory.

  6. Class Transitions in Black Holes

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    2005-01-14

    A black hole spectrum is known to change from the hard state to the soft state when the energy spectral index $\\alpha$ ($F_E \\propto E^{-\\alpha}$) in, say, 2-20 keV range changes from $\\alpha \\sim 0.5$ to $\\sim 1.5$. However, this `classical' definition which characterizes black holes like Cyg X-1, becomes less useful for many objects such as GRS 1915+105 in which the spectral slope is seen to vary from one to the other in a matter of seconds and depending on whether or not winds form, the spectral slope also changes. The light curves and the colour-colour diagrams may look completely different on different days depending on the frequency and mode of switching from one spectral state to the other. Though RXTE observations have yielded wealth of information on such `variability classes' in GRS 1915+105, very rarely one has been able to observe how the object goes from one class to the other. In the present review, we discuss possible origins of the class transition and present several examples of such transitions. In this context, we use mostly the results of the Indian X-ray Astronomy Experiment (IXAE) which observed GRS 1915+105 more regularly.

  7. Viscous-Fluid-Spring Damper Retrofit of a Steel Moment Frame Structure

    SciTech Connect (OSTI)

    Hussain, Saif; Van Benschoten, Paul; Al Satari, Mohamed; Lin, Silian

    2008-07-08

    The subject building is a peculiar pre-Northridge steel moment resisting frame building. Upon investigating the existing lateral resisting system, numerous significant deficiencies were identified; inherent lack of redundancy, poor geometry and inadequate stiffness of the lateral resisting system. All of which resulted in an extremely soft 5-story structure with a primary torsional mode of vibration at T{sub 1} = 5.46 s. Significant structural modifications were deemed necessary to meet the 'life-safety' performance objective as outlined in rehabilitation standards such as ASCE 41. Both increased stiffness and damping were required to adequately retrofit the building. Furthermore, adjacent building separation as well as deformation compatibility issues needed to be addressed and resolved. A three-dimensional computer model of the building was created using ETABS mathematically simulating the building's dynamic characteristics in its current condition. Multiple seismic retrofit systems were investigated such as Buckling Restrained Braced Frames (BRBF's). However, based on the performance effectiveness and constructability of the retrofit schemes studied, the Viscous-Fluid-Spring Damper (VFSD) system was proposed as the 'optimum' solution for the building. The VFSD, was chosen because it combines the relatively compact size and minimally invasive constructability with the required properties (an elastomeric spring in parallel with a nonlinear velocity dependent viscous damper). A site-specific response spectrum was developed for the Design Basis Earthquake (DBE, 475 year return period) event, and three pairs of representative earthquake horizontal ground motion time-histories were scaled to match this DBE. The proposed scheme reduced the building maximum inter-story drift ratio from 5.4% to about 1%. Similarly, the maximum roof displacement was reduced by about 70% (23'' to 7'')

  8. An electromagnetic black hole made of metamaterials

    E-Print Network [OSTI]

    Qiang Cheng; Tie Jun Cui; Wei Xiang Jiang; Ben Geng Cai

    2010-04-30

    Traditionally, a black hole is a region of space with huge gravitational field, which absorbs everything hitting it. In history, the black hole was first discussed by Laplace under the Newton mechanics, whose event horizon radius is the same as the Schwarzschild's solution of the Einstein's vacuum field equations. If all those objects having such an event horizon radius but different gravitational fields are called as black holes, then one can simulate certain properties of the black holes using electromagnetic fields and metamaterials due to the similar propagation behaviours of electromagnetic waves in curved space and in inhomogeneous metamaterials. In a recent theoretical work by Narimanov and Kildishev, an optical black hole has been proposed based on metamaterials, in which the theoretical analysis and numerical simulations showed that all electromagnetic waves hitting it are trapped and absorbed. Here we report the first experimental demonstration of such an electromagnetic black hole in the microwave frequencies. The proposed black hole is composed of non-resonant and resonant metamaterial structures, which can trap and absorb electromagnetic waves coming from all directions spirally inwards without any reflections due to the local control of electromagnetic fields and the event horizon corresponding to the device boundary. It is shown that the absorption rate can reach 99% in the microwave frequencies. We expect that the electromagnetic black hole could be used as the thermal emitting source and to harvest the solar light.

  9. Black holes cannot support conformal scalar hair

    E-Print Network [OSTI]

    T. Zannias

    1994-09-14

    It is shown that the only static asymptotically flat non-extrema black hole solution of the Einstein-conformally invariant scalar field equations having the scalar field bounded on the horizon, is the Schwarzschild one. Thus black holes cannot be endowed with conformal scalar hair of finite length.

  10. Quantum Entropy of Charged Rotating Black Holes

    E-Print Network [OSTI]

    R. B. Mann

    1996-07-10

    I discuss a method for obtaining the one-loop quantum corrections to the tree-level entropy for a charged Kerr black hole. Divergences which appear can be removed by renormalization of couplings in the tree-level gravitational action in a manner similar to that for a static black hole.

  11. Primordial black holes and asteroid danger

    E-Print Network [OSTI]

    Alexander Shatskiy

    2008-02-21

    Probability for a primordial black hole to invade the Kuiper belt was calculated. We showed that primordial black holes of certain masses can significantly change asteroids' orbits. These events may result in disasters, local for our solar system and global for the Earth (like the Tunguska meteorite). We also estimated how often such events occur.

  12. Fractal Statistics and Quantum Black Hole Entropy

    E-Print Network [OSTI]

    Wellington da Cruz

    2000-11-18

    Simple considerations about the fractal characteristic of the quantum-mechanical path give us the opportunity to derive the quantum black hole entropy in connection with the concept of fractal statistics. We show the geometrical origin of the numerical factor of four of the quantum black hole entropy expression and the statistics weight appears as a counting of the quanta of geometry.

  13. Thermal Gradient Holes At Northern Basin & Range Region (Pritchett...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Northern Basin & Range Region (Pritchett, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes...

  14. Slim Holes At Blue Mountain Geothermal Area (Fairbank Engineering...

    Open Energy Info (EERE)

    Slim Holes At Blue Mountain Geothermal Area (Fairbank Engineering Ltd, 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Blue...

  15. Effective theories and black hole production in warped compactificatio...

    Office of Scientific and Technical Information (OSTI)

    Effective theories and black hole production in warped compactifications Citation Details In-Document Search Title: Effective theories and black hole production in warped...

  16. Thermal Gradient Holes At Upper Hot Creek Ranch Area (Benoit...

    Open Energy Info (EERE)

    gradient holes up to 500' deep were initially planned but higher than anticipated drilling and permitting costs within a fixed budget reduced the number of holes to five....

  17. Brookhaven National Laboratory - Sr90 - Chemical Holes | Department...

    Office of Environmental Management (EM)

    - Chemical Holes Brookhaven National Laboratory - Sr90 - Chemical Holes January 1, 2014 - 12:00pm Addthis US Department of Energy Groundwater Database Groundwater Master Report...

  18. Nonthermal correction to black hole spectroscopy

    E-Print Network [OSTI]

    Wen-Yu Wen

    2014-11-14

    Area spectrum of black holes have been obtained via various methods such as quasinormal modes, adiabatic invariance and angular momentum. Among those methods, calculations were done by assuming black holes in thermal equilibrium. Nevertheless, black holes in the asymptotically flat space usually have negative specific heat and therefore tend to stay away from thermal equilibrium. Even for those black holes with positive specific heat, temperature may still not be well defined in the process of radiation, due to the back reaction of decreasing mass. Respect to these facts, it is very likely that Hawking radiation is nonthermal and the area spectrum is no longer equidistant. In this note, we would like to illustrate how the area spectrum of black holes is corrected by this nonthermal effect.

  19. Fourier Analysis of the BTZ Black Hole

    E-Print Network [OSTI]

    Ian M. Tolfree

    2009-11-11

    In this paper we extend our previous work regarding the role of the Fourier transformation in bulk to boundary mappings to include the BTZ black hole. We follow standard procedures for modifying Fourier Transformations to accommodate quotient spaces and arrive at a bulk to boundary mapping in a black hole background. We show that this mapping is consistent with known results and lends a new insight into the AdS/CFT duality. We find that the micro-states corresponding to the entropy of a bulk scalar field are the Fourier coefficients on the boundary, which transform under the principal series representation of $SL(2,R)$. Building upon this we present a toy model to analyze the implications of this for the origin of black hole entropy. We find that the black hole micro-states live on the boundary and correspond to the possible emission modes of the black hole

  20. Evidence for the Black Hole Event Horizon

    E-Print Network [OSTI]

    Ramesh Narayan

    2003-10-23

    Astronomers have discovered many candidate black holes in X-ray binaries and in the nuclei of galaxies. The candidate objects are too massive to be neutron stars, and for this reason they are considered to be black holes. While the evidence based on mass is certainly strong, there is no proof yet that any of the objects possesses the defining characteristic of a black hole, namely an event horizon. Type I X-ray bursts, which are the result of thermonuclear explosions when gas accretes onto the surface of a compact star, may provide important evidence in this regard. Type I bursts are commonly observed in accreting neutron stars, which have surfaces, but have never been seen in accreting black hole candidates. It is argued that the lack of bursts in black hole candidates is compelling evidence that these objects do not have surfaces. The objects must therefore possess event horizons.

  1. How fast can a black hole rotate?

    E-Print Network [OSTI]

    Herdeiro, Carlos A R

    2015-01-01

    Kerr black holes have their angular momentum, $J$, bounded by their mass, $M$: $Jc\\leqslant GM^2$. There are, however, known black hole solutions violating this Kerr bound. We propose a very simple universal bound on the rotation, rather than on the angular momentum, of four-dimensional, stationary and axisymmetric, asymptotically flat black holes, given in terms of an appropriately defined horizon linear velocity, $v_H$. The $v_H$ bound is simply that $v_H$ cannot exceed the velocity of light. We verify the $v_H$ bound for known black hole solutions, including some that violate the Kerr bound, and conjecture that only extremal Kerr black holes saturate the $v_H$ bound.

  2. External Insulation of Masonry Walls and Wood Framed Walls

    SciTech Connect (OSTI)

    Baker, P.

    2013-01-01

    The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1" to 1 1/2"), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

  3. External Insulation of Masonry Walls and Wood Framed Walls

    SciTech Connect (OSTI)

    Baker, P.

    2013-01-01

    The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1” to 1 ½”), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

  4. Extended phase space thermodynamics and P-V criticality: Brans-Dicke-Born-Infeld vs Einstein-BI-dilaton black holes

    E-Print Network [OSTI]

    S. H. Hendi; R. Moradi; Z. Armanfard

    2015-11-25

    Following interesting resemblance between black holes and Van der Waals liquid/gas system, in this paper, we study $P-V$ criticality of both dilatonic Born-Infeld black holes and their conformal solutions, the so-called Brans-Dicke-Born-Infeld solutions. At first, we regard spherically symmetric nonlinearly charged black hole solutions in both Einstein and Jordan frames and calculate related conserved and thermodynamic quantities. Then, we take into account the cosmological constant proportional to thermodynamical pressure to extend the phase space. After that we obtain critical values of thermodynamic coordinates to plot proper $P-V$ and $G-T$ diagrams. Investigation of the mentioned diagrams helps us to study the possibility of the thermodynamical phase transition.

  5. Extended phase space thermodynamics and P-V criticality: Brans-Dicke-Born-Infeld vs Einstein-BI-dilaton black holes

    E-Print Network [OSTI]

    Hendi, S H; Armanfard, Z

    2015-01-01

    Following interesting resemblance between black holes and Van der Waals liquid/gas system, in this paper, we study $P-V$ criticality of both dilatonic Born-Infeld black holes and their conformal solutions, the so-called Brans-Dicke-Born-Infeld solutions. At first, we regard spherically symmetric nonlinearly charged black hole solutions in both Einstein and Jordan frames and calculate related conserved and thermodynamic quantities. Then, we take into account the cosmological constant proportional to thermodynamical pressure to extend the phase space. After that we obtain critical values of thermodynamic coordinates to plot proper $P-V$ and $G-T$ diagrams. Investigation of the mentioned diagrams helps us to study the possibility of the thermodynamical phase transition.

  6. Extended phase space thermodynamics and P-V criticality: Brans-Dicke-Born-Infeld vs Einstein-BI-dilaton black holes

    E-Print Network [OSTI]

    S. H. Hendi; R. Moradi; Z. Armanfard

    2015-10-23

    Following interesting resemblance between black holes and Van der Waals liquid/gas system, in this paper, we study $P-V$ criticality of both dilatonic Born-Infeld black holes and their conformal solutions, the so-called Brans-Dicke-Born-Infeld solutions. At first, we regard spherically symmetric nonlinearly charged black hole solutions in both Einstein and Jordan frames and calculate related conserved and thermodynamic quantities. Then, we take into account the cosmological constant proportional to thermodynamical pressure to extend the phase space. After that we obtain critical values of thermodynamic coordinates to plot proper $P-V$ and $G-T$ diagrams. Investigation of the mentioned diagrams helps us to study the possibility of the thermodynamical phase transition.

  7. Dependence of polar hole density on magnetic and solar conditions

    SciTech Connect (OSTI)

    Hoegy, W.R.; Grebowsky, J.M. (NASA Goddard Space Flight Center, Greenbelt, MD (USA))

    1991-04-01

    The dependence of electron density in the polar F region ionization hole on solar activity, universal time (UT), magnetic activity, season, and hemisphere is studied using data from the Langmuir probes on Atmosphere Explorer C and Dynamics Explorer 2. The AE-C data were obtained during solar minimum when the 3-month average 10.7-cm solar flux index varied from 70 to 140; the DE 2 data were obtained near solar maximum when 10.7-cm solar flux index varied from 120 to 220. The polar hole is a region on the nightside of the polar cap where reduced ionization exists because of the long transport time of ionization from the dayside across the polar cap. The behavior of this region as a function of 10.7-cm solar flux (F10.7), UT, and Kp is statistically modeled for equinox, summer, and winter conditions for each hemisphere separately. The strongest dependencies are observed in F10.7 and UT; the Kp dependence is weak because it poorly represents the complexities of convection across the polar cap. A strong hemispherical difference due to the offset of the magnetic poles from the Earth's rotation axis is observed in the UT dependence of the ionization hole: there is a density minimum at about 20.3 hours UT in the south and at about 4.8 hours UT in the north; the minimum to maximum UT density variation is about a factor of 8.9 in the south and about a factor of 2.1 in the north. There is a seasonal variation in the dependence of ion density (N{sub i}) on solar flux (F10.7). Use of the relationship (N{sub i}{approximately}F10.7{sup D}) yields values of D of approximately unity (1.) in the summer polar hole and about 2.1 during equinox. There is an overall asymmetry in the density level between hemispheres; it was found that the winter hole density is about a factor of 10 greater in the north than in the south. The Utah State University time dependent ionosphere model gives similar UT behavior to that found in the AE-C and DE 2 data.

  8. Time Machine at the LHC

    E-Print Network [OSTI]

    I. Ya. Aref'eva; I. V. Volovich

    2007-10-25

    Recently, black hole and brane production at CERN's Large Hadron Collider (LHC) has been widely discussed. We suggest that there is a possibility to test causality at the LHC. We argue that if the scale of quantum gravity is of the order of few TeVs, proton-proton collisions at the LHC could lead to the formation of time machines (spacetime regions with closed timelike curves) which violate causality. One model for the time machine is a traversable wormhole. We argue that the traversable wormhole production cross section at the LHC is of the same order as the cross section for the black hole production. Traversable wormholes assume violation of the null energy condition (NEC) and an exotic matter similar to the dark energy is required. Decay of the wormholes/time machines and signatures of time machine events at the LHC are discussed.

  9. Damage Assessment of a Three-Story Infilled RC Frame Subjected to Seismic Base Excitations

    E-Print Network [OSTI]

    Hines, Eric

    1 Damage Assessment of a Three-Story Infilled RC Frame Subjected to Seismic Base Excitations Babak-NEES shake table to investigate the seismic performance of this type of construction. The frame was designed code provisions that do not meet current safety standards. They may also suffer from aging

  10. Comparison of Energy Needed to Heat Greenhouses and Insulated Frame Buildings Used in Aquaculture1

    E-Print Network [OSTI]

    Hill, Jeffrey E.

    initial cost. Building material costs for the structure can be as low as $1 per square foot, but plastic for this type of structure can be as low as $4 to $6 per square foot. Construction costs for wood or metal frameCIR1198 Comparison of Energy Needed to Heat Greenhouses and Insulated Frame Buildings Used

  11. VESSEL SEGMENTATION IN MEDICAL IMAGING USING A TIGHT-FRAME BASED ALGORITHM

    E-Print Network [OSTI]

    Chan, Raymond

    VESSEL SEGMENTATION IN MEDICAL IMAGING USING A TIGHT-FRAME BASED ALGORITHM XIAOHAO CAI, RAYMOND vessels in magnetic resonance angiography images. Our method iteratively refines a region that encloses the potential boundary of the vessels. At each iteration, we apply the tight-frame algorithm to denoise

  12. Gun Policy, Opinion, Tragedy, and Blame Attribution: The Conditional Influence of Issue of Frames

    E-Print Network [OSTI]

    Haider-Markel, Donald P.; Joslyn, Mark R.

    2001-01-01

    attention has been given to highly salient issues, such as gun policy, and the potential effect of framing on causal attributions of blame for tragic events. This study expands the framing research to include opinion on policies concerning guns as well...

  13. DAMAGE IDENTIFICATION IN A STEEL FRAME USING HIGH-FREQUENCY ELECTRO-MECHANICAL IMPEDANCE

    E-Print Network [OSTI]

    Wang, Ji

    411 DAMAGE IDENTIFICATION IN A STEEL FRAME USING HIGH-FREQUENCY ELECTRO-MECHANICAL IMPEDANCE presents an experimental investigation of damage detection of a steel frame using electro damage in structures. Damages are introduced by completely loosening bolts over several locations

  14. Sensory transformations and the use of multiple reference frames for reach planning

    E-Print Network [OSTI]

    Sabes, Philip

    Sensory transformations and the use of multiple reference frames for reach planning Leah M M McGuire & Philip N Sabes The sensory signals that drive movement planning arrive in a variety of `reference frames the sensory signals available for reach planning were varied. These results challenge the widely held ideas

  15. Page 1 of 6 Frame Coding: T = Training Available W = Instruction / Web Link P = Policy / Procedure

    E-Print Network [OSTI]

    Brierley, Andrew

    Page 1 of 6 Frame Coding: T = Training Available W = Instruction / Web Link P = Policy / Procedure within the University's web page section titled "Policy & Governance" and are part of the University://www.st-andrews.ac.uk/staff/policy/hr/Stafftravelsubsistenceandexpensespolicy/ W #12;Page 2 of 6 Frame Coding: T = Training Available W = Instruction / Web Link P = Policy

  16. A Tutorial on Multi-frame Computational Super-resolution using Statistical Methods

    E-Print Network [OSTI]

    Lübeck, Universität zu

    1 A Tutorial on Multi-frame Computational Super-resolution using Statistical Methods Alexandru Paul.e., multi-frame computational super-resolution). We start be describing the maximum likelihood (ML) solution about each wave). Here we concentrate on computational super-resolution, which includes methods

  17. SEISMIC PERFORMANCE EVALUATION FOR STEEL MOMENT FRAMES By Seung-Yul Yun1

    E-Print Network [OSTI]

    Sweetman, Bert

    SEISMIC PERFORMANCE EVALUATION FOR STEEL MOMENT FRAMES By Seung-Yul Yun1 , Ronald O. Hamburger2 , C than existing buildings designed and built with older technologies. Key words: seismic behavior; seismic performance evaluation; performance-based design; earthquake engineering; steel moment frame

  18. Seismic data restoration via data-driven tight frame Jingwei Liang1

    E-Print Network [OSTI]

    Zhang, Xiaoqun

    Seismic data restoration via data-driven tight frame Jingwei Liang1 , Jianwei Ma2 , and Xiaoqun Zhang3 ABSTRACT Restoration/interpolation of missing traces plays a crucial role in the seismic data regularization method for seismic data restoration. The main idea of the data-driven tight frame (TF

  19. BENDIX SYSTEMS DIVISION ANN ARIOR,MICH NO. ATM-Active Seismic Frame

    E-Print Network [OSTI]

    Rathbun, Julie A.

    BENDIX SYSTEMS DIVISION ANN ARIOR,MICH NO. ATM- 444 REV.NO. Active Seismic Frame Synchronization SYSTEMS DIVISION ANN ARIOR,MICH NOATM- 444 Active Seismic Frame Synchronization PAGE 2 REV.NO. OF 5 seismic mode of operation, maintaining this high density of sync bits to data bits is not feasible

  20. Developing Low-Conductance Window Frames: Capabilities and Limitations of Current Window Heat Transfer Design Tools

    E-Print Network [OSTI]

    on the total window heat transfer rates may be much larger. This effect is even greater in low on a literature review and an evaluation of current methods of modeling heat transfer through window frames, we evaluating heat transfer through the low-conductance frames. We conclude that the near-term priorities

  1. Superradiant instablility of charged regular black holes under charged scalar perturbations

    E-Print Network [OSTI]

    Huang, Yang; Li, Xin-Zhou

    2015-01-01

    We investigate the late-time behavior of charged scalar perturbations in the background of a charged regular black hole proposed by Ay\\'{o}n-Beato-Garc\\'{\\i}a. We find that, different from the neutral perturbations, the charged perturbation can lead to superradiance phenomenon, and moreover destabilize the charged regular black hole. By using careful time-domain analysis, we show that all the growing modes originate from superradiance mechanism, but not all the superradiant modes are unstable. Another interesting property of the instability is that, these unstable modes do not in the bound state and can escape to infinity which make the instability radically different from those reported previously.

  2. Detectability of Gravitational Radiation from Prompt and Delayed Star Collapse to a Black Hole

    E-Print Network [OSTI]

    Cristiano Palomba

    2001-01-31

    We consider the emission of gravitational waves in the two proposed models for the collapse of a massive star to a black hole: the prompt collapse, in which nearly all the star collapses to a black hole in a dynamical time scale, and the delayed collapse, in which a light black hole, or a neutron star, which subsequently accretes matter, forms due to the fall-back achieving, in the neutron star case, the critical mass for black hole formation. Recent simulations strongly support this last scenario. We show that, due to the slowness of fall-back, in the delayed collapse the main burst of gravitational radiation is emitted depending on the parameters, mass and angular momentum, of the initial, light, black hole. We estimate, under different assumptions, the detectability of the emitted gravitational waves showing that such kind of collapse is not particularly suited for detection by forthcoming interferometric detectors. Detectors with high sensitivity at frequencies greater than ~4-5 kHz would be well suited for this kind of sources. We calculate also the final mass distribution function of single black holes.

  3. Dynamics of Scalar Fields in the Background of Rotating Black Holes

    E-Print Network [OSTI]

    W. Krivan; P. Laguna; P. Papadopoulos

    1996-06-04

    A numerical study of the evolution of a massless scalar field in the background of rotating black holes is presented. First, solutions to the wave equation are obtained for slowly rotating black holes. In this approximation, the background geometry is treated as a perturbed Schwarzschild spacetime with the angular momentum per unit mass playing the role of a perturbative parameter. To first order in the angular momentum of the black hole, the scalar wave equation yields two coupled one-dimensional evolution equations for a function representing the scalar field in the Schwarzschild background and a second field that accounts for the rotation. Solutions to the wave equation are also obtained for rapidly rotating black holes. In this case, the wave equation does not admit complete separation of variables and yields a two-dimensional evolution equation. The study shows that, for rotating black holes, the late time dynamics of a massless scalar field exhibit the same power-law behavior as in the case of a Schwarzschild background independently of the angular momentum of the black hole.

  4. The Efficiency of Gravitational Bremsstrahlung Production in the Collision of Two Schwarzschild Black Holes

    E-Print Network [OSTI]

    R. F. Aranha; H. P. de Oliveira; I. Damião Soares; E. V. Tonini

    2008-04-22

    We examine the efficiency of gravitational bremsstrahlung production in the process of head-on collision of two boosted Schwarzschild black holes. We constructed initial data for the characteristic initial value problem in Robinson-Trautman spacetimes, that represent two instantaneously stationary Schwarzschild black holes in motion towards each other with the same velocity. The Robinson-Trautman equation was integrated for these initial data using a numerical code based on the Galerkin method. The final resulting configuration is a boosted black hole with Bondi mass greater than the sum of the individual mass of each initial black hole. Two relevant aspects of the process are presented. The first relates the efficiency $\\Delta$ of the energy extraction by gravitational wave emission to the mass of the final black hole. This relation is fitted by a distribution function of non-extensive thermostatistics with entropic parameter $q \\simeq 1/2$; the result extends and validates analysis based on the linearized theory of gravitational wave emission. The second is a typical bremsstrahlung angular pattern in the early period of emission at the wave zone, a consequence of the deceleration of the black holes as they coalesce; this pattern evolves to a quadrupole form for later times.

  5. Functional determinants, index theorems, and exact quantum black hole entropy

    E-Print Network [OSTI]

    Murthy, Sameer

    2015-01-01

    The exact quantum entropy of BPS black holes can be evaluated using localization in supergravity. An important ingredient in this program, that has been lacking so far, is the one-loop effect arising from the quadratic fluctuations of the exact deformation (the $Q\\mathcal{V}$ operator). We compute the fluctuation determinant for vector multiplets and hyper multiplets around $Q$-invariant off-shell configurations in four-dimensional $\\mathcal{N}=2$ supergravity with $AdS_{2} \\times S^{2}$ boundary conditions, using the Atiyah-Bott fixed-point index theorem and a subsequent zeta function regularization. Our results extend the large-charge on-shell entropy computations in the literature to a regime of finite charges. Based on our results, we present an exact formula for the quantum entropy of BPS black holes in $\\mathcal{N}=2$ supergravity. We explain cancellations concerning $\\frac18$-BPS black holes in $\\mathcal{N}=8$ supergravity that were observed previously. We also make comments about the interpretation of...

  6. Functional determinants, index theorems, and exact quantum black hole entropy

    E-Print Network [OSTI]

    Sameer Murthy; Valentin Reys

    2015-08-10

    The exact quantum entropy of BPS black holes can be evaluated using localization in supergravity. An important ingredient in this program, that has been lacking so far, is the one-loop effect arising from the quadratic fluctuations of the exact deformation (the $Q\\mathcal{V}$ operator). We compute the fluctuation determinant for vector multiplets and hyper multiplets around $Q$-invariant off-shell configurations in four-dimensional $\\mathcal{N}=2$ supergravity with $AdS_{2} \\times S^{2}$ boundary conditions, using the Atiyah-Bott fixed-point index theorem and a subsequent zeta function regularization. Our results extend the large-charge on-shell entropy computations in the literature to a regime of finite charges. Based on our results, we present an exact formula for the quantum entropy of BPS black holes in $\\mathcal{N}=2$ supergravity. We explain cancellations concerning $\\frac18$-BPS black holes in $\\mathcal{N}=8$ supergravity that were observed in arXiv:1111.1161. We also make comments about the interpretation of a logarithmic term in the topological string partition function in the low energy supergravity theory.

  7. Particle-hole duality, integrability, and Russian doll BCS model

    E-Print Network [OSTI]

    L. V. Bork; W. V. Pogosov

    2015-05-04

    We address a generalized Richardson model (Russian doll BCS model), which is characterized by the breaking of time-reversal symmetry. This model is known to be exactly solvable and integrable. We point out that the Russian doll BCS model, on the level of Hamiltonian, is also particle-hole symmetric. This implies that the same state can be expressed both in the particle and hole representations with two different sets of Bethe roots. We then derive exact relations between Bethe roots in the two representations, which can hardly be obtained staying on the level of Bethe equations. In a quasi-classical limit, similar identities for usual Richardson model, known from literature, are recovered from our results. We also show that these relations for Richardson roots take a remarkably simple form at half-filling and for a symmetric with respect to the middle of the interaction band distribution of one-body energy levels, since, in this special case, the rapidities in the particle and hole representations up to the translation satisfy the same system of equations.

  8. Three-dimensional black holes, gravitational solitons, kinks and wormholes for BHT massive gravity

    E-Print Network [OSTI]

    Julio Oliva; David Tempo; Ricardo Troncoso

    2009-07-03

    The theory of massive gravity in three dimensions recently proposed by Bergshoeff, Hohm and Townsend (BHT) is considered. At the special case when the theory admits a unique maximally symmetric solution, a conformally flat space that contains black holes and gravitational solitons for any value of the cosmological constant is found. For negative cosmological constant, the black hole is characterized in terms of the mass and the "gravitational hair" parameter, providing a lower bound for the mass. For negative mass parameter, the black hole acquires an inner horizon, and the entropy vanishes at the extremal case. Gravitational solitons and kinks, being regular everywhere, are obtained from a double Wick rotation of the black hole. A wormhole solution in vacuum that interpolates between two static universes of negative spatial curvature is obtained as a limiting case of the gravitational soliton with a suitable identification. The black hole and the gravitational soliton fit within a set of relaxed asymptotically AdS conditions as compared with the ones of Brown and Henneaux. In the case of positive cosmological constant the black hole possesses an event and a cosmological horizon, whose mass is bounded from above. Remarkably, the temperatures of the event and the cosmological horizons coincide, and at the extremal case one obtains the analogue of the Nariai solution, $dS_{2}\\times S^{1}$. A gravitational soliton is also obtained through a double Wick rotation of the black hole. The Euclidean continuation of these solutions describes instantons with vanishing Euclidean action. For vanishing cosmological constant the black hole and the gravitational soliton are asymptotically locally flat spacetimes. The rotating solutions can be obtained by boosting the previous ones in the $t-\\phi$ plane.

  9. The Hawking cascade from a black hole is extremely sparse

    E-Print Network [OSTI]

    Gray, Finnian; Van-Brunt, Alexander; Visser, Matt

    2015-01-01

    The Hawking flux from a black hole, (at least as seen from large distances), is extremely sparse and thin, with the average time between emission of successive Hawking quanta being hundreds of times larger than the natural timescale set by the energies of the emitted quanta. Some aspects of this result have been known for over 30 years, but have been largely forgotten, possibly because authors focussed mainly on the late-time high-temperature regime. We shall instead focus on the early-stage low-temperature regime, and shall both quantify and significantly extend these observations in a number of different ways. First we shall identify several natural dimensionless figures of merit, and thereby compare the mean time between emission of successive Hawking quanta to several quite natural timescales that can be associated with the emitted quanta, demonstrating that ratios of 300 or more are typical for emission of photons or gravitons from a Schwarzschild black hole. Furthermore these ratios are independent of t...

  10. Radion clouds around evaporating black holes

    E-Print Network [OSTI]

    J. R. Morris

    2009-09-03

    A Kaluza-Klein model, with a matter source associated with Hawking radiation from an evaporating black hole, is used to obtain a simple form for the radion effective potential. The environmental effect generally causes a matter-induced shift of the radion vacuum, resulting in the formation of a radion cloud around the hole. There is an albedo due to the radion cloud, with an energy dependent reflection coefficient that depends upon the size of the extra dimensions and the temperature of the hole.

  11. Testing black hole candidates with electromagnetic radiation

    E-Print Network [OSTI]

    Bambi, Cosimo

    2015-01-01

    Astrophysical black hole candidates are thought to be the Kerr black holes of general relativity, but there is currently no direct observational evidence that the spacetime geometry around these objects is described by the Kerr solution. The study of the properties of the electromagnetic radiation emitted by gas or stars orbiting these objects can potentially test the Kerr black hole hypothesis. In this paper, I review the state of the art of this research field, describing the possible approaches to test the Kerr metric with current and future observational facilities and discussing current constraints.

  12. Quasinormal Modes of Dirty Black Holes

    E-Print Network [OSTI]

    P. T. Leung; Y. T. Liu; W. -M. Suen; C. Y. Tam; K. Young

    1999-03-08

    Quasinormal mode (QNM) gravitational radiation from black holes is expected to be observed in a few years. A perturbative formula is derived for the shifts in both the real and the imaginary part of the QNM frequencies away from those of an idealized isolated black hole. The formulation provides a tool for understanding how the astrophysical environment surrounding a black hole, e.g., a massive accretion disk, affects the QNM spectrum of gravitational waves. We show, in a simple model, that the perturbed QNM spectrum can have interesting features.

  13. Black hole microstates in AdS

    E-Print Network [OSTI]

    Shaghoulian, Edgar

    2015-01-01

    We extend a recently derived higher-dimensional Cardy formula to include angular momenta, which we use to obtain the Bekensten-Hawking entropy of AdS black branes, compactified rotating branes, and large Schwarzschild/Kerr black holes. This is the natural generalization of Strominger's microscopic derivation of the BTZ black hole entropy to higher dimensions. We propose an extension to include $U(1)$ charge, which agrees with the Bekenstein-Hawking entropy of large Reissner-Nordstrom/Kerr-Newman black holes at high temperature. We extend the results to arbitrary hyperscaling violation exponent (this captures the case of black D$p$-branes as a subclass) and reproduce logarithmic corrections.

  14. Thermodynamics of Dyonic Lifshitz Black Holes

    E-Print Network [OSTI]

    Tobias Zingg

    2011-07-15

    Black holes with asymptotic anisotropic scaling are conjectured to be gravity duals of condensed matter system close to quantum critical points with non-trivial dynamical exponent z at finite temperature. A holographic renormalization procedure is presented that allows thermodynamic potentials to be defined for objects with both electric and magnetic charge in such a way that standard thermodynamic relations hold. Black holes in asymptotic Lifshitz spacetimes can exhibit paramagnetic behavior at low temperature limit for certain values of the critical exponent z, whereas the behavior of AdS black holes is always diamagnetic.

  15. Scalar Perturbations of Charged Dilaton Black Holes

    E-Print Network [OSTI]

    Sharmanthie Fernando; Keith Arnold

    2015-08-01

    We have studied the scalar perturbation of static charged dilaton black holes in 3+1 dimensions. The black hole considered here is a solution to the low-energy string theory in 3+1 dimensions. The quasinormal modes for the scalar perturbations are calculated using the third order WKB method. The dilaton coupling constant has a considerable effect on the values of quasi normal modes. It is also observed that there is a linear relation between the quasi normal modes and the temperature for large black holes.

  16. Black Hole Spectral States and Physical Connections

    E-Print Network [OSTI]

    John A. Tomsick

    2005-09-06

    The dramatic changes seen in the X-ray spectral and timing properties of accreting black hole candidates (BHCs) provide important clues about the accretion and jet formation processes that occur in these systems. Dividing the different source behaviors into spectral states provides a framework for studying BHCs. To date, there have been three main classification schemes with Luminosity-based, Component-based, or Transition-based criteria. The canonical, Luminosity-based criteria and physical models that are based on this concept do not provide clear explanations for several phenomena, including hysteresis of spectral states and the presence of jets. I discuss the re-definitions of states, focusing on an application of the Component-based states to more than 400 RXTE observations of the recurrent BHC 4U 1630-47. We compare the X-ray properties for the recent 2002-2004 outburst to those of an earlier (1998) outburst, during which radio jets were observed. The results suggest a connection between hysteresis of states and major jet ejections, and it is possible that both of these are related to the evolution of the inner radius of the optically thick accretion disk.

  17. Gödel black hole, closed timelike horizon, and the study of particle emissions

    E-Print Network [OSTI]

    Sourav Bhattacharya; Anirban Saha

    2010-07-22

    We show that a particle, with positive orbital angular momentum, following an outgoing null/timelike geodesic, shall never reach the closed timelike horizon (CTH) present in the $(4+1)$-dimensional rotating G\\"{o}del black hole space-time. Therefore a large part of this space-time remains inaccessible to a large class of geodesic observers, depending on the conserved quantities associated with them. We discuss how this fact and the existence of the closed timelike curves present in the asymptotic region make the quantum field theoretic study of the Hawking radiation, where the asymptotic observer states are a pre-requisite, unclear. However, the semiclassical approach provides an alternative to verify the Smarr formula derived recently for the rotating G\\"{o}del black hole. We present a systematic analysis of particle emissions, specifically for scalars, charged Dirac spinors and vectors, from this black hole via the semiclassical complex path method.

  18. Energy of 4-Dimensional Black Hole, etc

    E-Print Network [OSTI]

    Dmitriy Palatnik

    2011-07-18

    In this letter I suggest possible redefinition of mass density, not depending on speed of the mass element, which leads to a more simple stress-energy for an object. I calculate energy of black hole.

  19. Horizon Operator Approach to Black Hole Quantization

    E-Print Network [OSTI]

    G. 't Hooft

    1994-02-21

    The $S$-matrix Ansatz for the construction of a quantum theory of black holes is further exploited. We first note that treating the metric tensor $g_{\\m\

  20. Radiation transport around Kerr black holes

    E-Print Network [OSTI]

    Schnittman, Jeremy David

    2005-01-01

    This Thesis describes the basic framework of a relativistic ray-tracing code for analyzing accretion processes around Kerr black holes. We begin in Chapter 1 with a brief historical summary of the major advances in black ...

  1. Evidence for the Black Hole Event Horizon

    E-Print Network [OSTI]

    Ramesh Narayan; Jeremy S. Heyl

    2002-04-26

    Roughly a dozen X-ray binaries are presently known in which the compact accreting primary stars are too massive to be neutron stars. These primaries are identified as black holes, though there is as yet no definite proof that any of the candidate black holes actually possesses an event horizon. We discuss how Type I X-ray bursts may be used to verify the presence of the event horizon in these objects. Type I bursts are caused by thermonuclear explosions when gas accretes onto a compact star. The bursts are commonly seen in many neutron star X-ray binaries, but they have never been seen in any black hole X-ray binary. Our model calculations indicate that black hole candidates ought to burst frequently if they have surfaces. Based on this, we argue that the lack of bursts constitutes strong evidence for the presence of event horizons in these objects.

  2. Black Hole Thermodynamics in Modified Gravity

    E-Print Network [OSTI]

    Jonas R. Mureika; John W. Moffat; Mir Faizal

    2015-03-03

    We analyze the thermodynamics of a non-rotating and rotating black hole in a modified theory of gravity that includes scalar and vector modifications to general relativity, which results in a modified gravitational constant $G = G_N(1+\\alpha)$ and a new gravitational charge $Q = \\sqrt{\\alpha G_N}M$. The influence of the parameter $\\alpha$ alters the non-rotating black hole's lifetime, temperature and entropy profiles from the standard Schwarzschild case. The thermodynamics of a rotating black hole is analyzed and it is shown to possess stable, cold remnants. The thermodynamic properties of a vacuum solution regular at $r=0$ are investigated and the solution without a horizon called a "gray hole" is not expected to possess an information loss problem.

  3. CHARYBDIS: A Black hole event generator.

    E-Print Network [OSTI]

    Harris, Chris M.; Richardson, P.; Webber, Bryan R.

    CHARYBDIS is an event generator which simulates the production and decay of miniature black holes at hadronic colliders as might be possible in certain extra dimension models. It interfaces via the Les Houches accord to general purpose Monte...

  4. Spacetime constraints on accreting black holes

    SciTech Connect (OSTI)

    Garofalo, David [Jet Propulsion Laboratory, California Institute of Technology, Pasadena California 91109 (United States)

    2009-06-15

    We study the spin dependence of accretion onto rotating Kerr black holes using analytic techniques. In its linear regime, angular momentum transport in MHD turbulent accretion flow involves the generation of radial magnetic field connecting plasma in a differentially rotating flow. We take a first principles approach, highlighting the constraint that limits the generation and amplification of radial magnetic fields, stemming from the transfer of energy from mechanical to magnetic form. Because the energy transferred in magnetic form is ultimately constrained by gravitational potential energy or Killing energy, the spin dependence of the latter allows us to derive spin-dependent constraints on the success of the accreting plasma to expel its angular momentum. We find an inverse relationship between this ability and black hole spin. If this radial magnetic field generation forms the basis for angular momentum transfer in accretion flows, accretion rates involving Kerr black holes are expected to be lower as the black hole spin increases in the prograde sense.

  5. Thermodynamics and evaporation of the noncommutative black hole

    E-Print Network [OSTI]

    Yun Soo Myung; Yong-Wan Kim; Young-Jai Park

    2007-01-21

    We investigate the thermodynamics of the noncommutative black hole whose static picture is similar to that of the nonsingular black hole known as the de Sitter-Schwarzschild black hole. It turns out that the final remnant of extremal black hole is a thermodynamically stable object. We describe the evaporation process of this black hole by using the noncommutativity-corrected Vaidya metric. It is found that there exists a close relationship between thermodynamic approach and evaporation process.

  6. Classical and thermodynamic stability of black holes

    E-Print Network [OSTI]

    Monteiro, Ricardo

    2010-07-06

    Perturbations of the asymptotic charges . . . . . . . . . . . . . . . . 169 IV Conclusion 171 9 Conclusion and outlook 173 A Spectral numerical method 177 2 CONTENTS Part I Introduction 3 Chapter 1 Black holes Black holes are arguably the most interesting... to Newto- nian dynamics in the Solar system, and the indirect detection of gravitational waves from binary pulsars [1]. A crucial distinction from Newtonian gravity is that the “action-at-a-distance” is substituted by a built-in causality structure...

  7. Fractionated Branes and Black Hole Interiors

    E-Print Network [OSTI]

    Emil J. Martinec

    2015-05-20

    Combining a variety of results in string theory and general relativity, a picture of the black hole interior is developed wherein spacetime caps off at an inner horizon, and the inter-horizon region is occupied by a Hagedorn gas of a very low tension state of fractionated branes. This picture leads to natural resolutions of a variety of puzzles concerning quantum black holes. Gravity Research Foundation 2015 Fourth Prize Award for Essays on Gravitation.

  8. Minimum length, extra dimensions, modified gravity and black hole remnants

    SciTech Connect (OSTI)

    Maziashvili, Michael

    2013-03-01

    We construct a Hilbert space representation of minimum-length deformed uncertainty relation in presence of extra dimensions. Following this construction, we study corrections to the gravitational potential (back reaction on gravity) with the use of correspondingly modified propagator in presence of two (spatial) extra dimensions. Interestingly enough, for r?0 the gravitational force approaches zero and the horizon for modified Schwarzschild-Tangherlini space-time disappears when the mass approaches quantum-gravity energy scale. This result points out to the existence of zero-temperature black hole remnants in ADD brane-world model.

  9. Probing attosecond pulse structures by XUV-induced hole dynamics

    E-Print Network [OSTI]

    You, Jhih-An; Dahlström, Jan Marcus

    2015-01-01

    We investigate a two-photon ionization process in neon by an isolated attosecond pump pulse and two coherent extreme ultraviolet probe fields. The probe fields, tuned to the 2s-2p transition in the residual ion, allow for coherent control of the photoelectron via indirect interactions with the hole. We show that the photoelectron-ion coincidence signal contains an interference pattern that can be used to reconstruct the temporal structure of attosecond pump pulses. Our results are supported by simulations based on time-dependent configuration-interaction singles and lowest-order perturbation theory within second quantization.

  10. A complex state transition from the black hole candidate Swift J1753.5-0127

    E-Print Network [OSTI]

    Soleri, P; Motta, S; Belloni, T; Casella, P; Méndez, M; Altamirano, D; Linares, M; Wijnands, R; Fender, R; van der Klis, M

    2012-01-01

    We present our monitoring campaign of the outburst of the black-hole candidate Swift J1753.5-0127, observed with the Rossi X-ray Timing Explorer and the Swift satellites. After ~4.5 years since its discovery, the source had a transition to the hard intermediate state. We performed spectral and timing studies of the transition showing that, unlike the majority of the transient black holes, the system did not go to the soft states but it returned to the hard state after a few months. During this transition Swift J1753.5-0127 features properties which are similar to those displayed by the black hole Cygnus X-1. We compared Swift J1753.5-0127 to one dynamically confirmed black hole and two neutron stars showing that its power spectra are in agreement with the binary hosting a black hole. We also suggest that the prolonged period at low flux that followed the initial flare is reminiscent of that observed in other X-ray binaries, as well as in cataclysmic variables.

  11. Solar Wind Forecasting with Coronal Holes

    E-Print Network [OSTI]

    S. Robbins; C. J. Henney; J. W. Harvey

    2007-01-09

    An empirical model for forecasting solar wind speed related geomagnetic events is presented here. The model is based on the estimated location and size of solar coronal holes. This method differs from models that are based on photospheric magnetograms (e.g., Wang-Sheeley model) to estimate the open field line configuration. Rather than requiring the use of a full magnetic synoptic map, the method presented here can be used to forecast solar wind velocities and magnetic polarity from a single coronal hole image, along with a single magnetic full-disk image. The coronal hole parameters used in this study are estimated with Kitt Peak Vacuum Telescope He I 1083 nm spectrograms and photospheric magnetograms. Solar wind and coronal hole data for the period between May 1992 and September 2003 are investigated. The new model is found to be accurate to within 10% of observed solar wind measurements for its best one-month periods, and it has a linear correlation coefficient of ~0.38 for the full 11 years studied. Using a single estimated coronal hole map, the model can forecast the Earth directed solar wind velocity up to 8.5 days in advance. In addition, this method can be used with any source of coronal hole area and location data.

  12. The impact of cine EPID image acquisition frame rate on markerless soft-tissue tracking

    SciTech Connect (OSTI)

    Yip, Stephen Rottmann, Joerg; Berbeco, Ross

    2014-06-15

    Purpose: Although reduction of the cine electronic portal imaging device (EPID) acquisition frame rate through multiple frame averaging may reduce hardware memory burden and decrease image noise, it can hinder the continuity of soft-tissue motion leading to poor autotracking results. The impact of motion blurring and image noise on the tracking performance was investigated. Methods: Phantom and patient images were acquired at a frame rate of 12.87 Hz with an amorphous silicon portal imager (AS1000, Varian Medical Systems, Palo Alto, CA). The maximum frame rate of 12.87 Hz is imposed by the EPID. Low frame rate images were obtained by continuous frame averaging. A previously validated tracking algorithm was employed for autotracking. The difference between the programmed and autotracked positions of a Las Vegas phantom moving in the superior-inferior direction defined the tracking error (?). Motion blurring was assessed by measuring the area change of the circle with the greatest depth. Additionally, lung tumors on 1747 frames acquired at 11 field angles from four radiotherapy patients are manually and automatically tracked with varying frame averaging. ? was defined by the position difference of the two tracking methods. Image noise was defined as the standard deviation of the background intensity. Motion blurring and image noise are correlated with ? using Pearson correlation coefficient (R). Results: For both phantom and patient studies, the autotracking errors increased at frame rates lower than 4.29 Hz. Above 4.29 Hz, changes in errors were negligible with? < 1.60 mm. Motion blurring and image noise were observed to increase and decrease with frame averaging, respectively. Motion blurring and tracking errors were significantly correlated for the phantom (R = 0.94) and patient studies (R = 0.72). Moderate to poor correlation was found between image noise and tracking error with R ?0.58 and ?0.19 for both studies, respectively. Conclusions: Cine EPID image acquisition at the frame rate of at least 4.29 Hz is recommended. Motion blurring in the images with frame rates below 4.29 Hz can significantly reduce the accuracy of autotracking.

  13. Probing embryonic tissue mechanics with laser hole-drilling

    E-Print Network [OSTI]

    Ma, Xiaoyan; Scully, Peter C; Hutson, M Shane

    2008-01-01

    We have used laser hole-drilling to assess mechanical changes in an embryonic epithelium during development - in vivo and with subcellular resolution. This method uses a single laser pulse to ablate a cylindrical hole (1 micron in diameter, 5-7 micron tall) clean through the epithelium, and tracks the subsequent recoil of adjacent cells (with ms time resolution). We investigate dorsal closure in the fruit fly with emphasis on apical constriction of amnioserosa cells. We find that substantial in-plane tension is carried across each cell surface and not just along cell-cell interfaces. In early phases of constriction, the tension is 1.6-fold greater along cell-cell interfaces. Later, the two tensions are indistinguishable. Other changes associated with constriction include a decrease in the characteristic recoil times and an increased anisotropy. The smaller time constants imply a more solid-like tissue. The anisotropy matches changes in the underlying quasi-hexagonal cellular mesh. The results of these laser h...

  14. Introducing Abuse Frames for Analysing Security Requirements Luncheng Lin Bashar Nuseibeh Darrel Ince Michael Jackson Jonathan Moffett

    E-Print Network [OSTI]

    Nuseibeh, Bashar

    a focus for early security threat analysis. Traditional information security development methods haveIntroducing Abuse Frames for Analysing Security Requirements Luncheng Lin Bashar Nuseibeh Darrel using Jackson's Problem Frames to analyse security problems in order to determine security

  15. Rotating-frame relaxation as a noise spectrum analyzer of a superconducting qubit undergoing driven evolution

    E-Print Network [OSTI]

    F. Yan; S. Gustavsson; J. Bylander; X. Jin; F. Yoshihara; D. G. Cory; Y. Nakamura; T. P. Orlando; W. D. Oliver

    2015-08-26

    Gate operations in a quantum information processor are generally realized by tailoring specific periods of free and driven evolution of a quantum system. Unwanted environmental noise, which may in principle be distinct during these two periods, acts to decohere the system and increase the gate error rate. While there has been significant progress characterizing noise processes during free evolution, the corresponding driven-evolution case is more challenging as the noise being probed is also extant during the characterization protocol. Here we demonstrate the noise spectroscopy (0.1 - 200 MHz) of a superconducting flux qubit during driven evolution by using a robust spin-locking pulse sequence to measure relaxation (T1rho) in the rotating frame. In the case of flux noise, we resolve spectral features due to coherent fluctuators, and further identify a signature of the 1MHz defect in a time-domain spin-echo experiment. The driven-evolution noise spectroscopy complements free-evolution methods, enabling the means to characterize and distinguish various noise processes relevant for universal quantum control.

  16. Calculation of Eddy Currents In the CTH Vacuum Vessel and Coil Frame

    SciTech Connect (OSTI)

    A. Zolfaghari, A. Brooks, A. Michaels, J. Hanson, and G. Hartwell

    2012-09-25

    Knowledge of eddy currents in the vacuum vessel walls and nearby conducting support structures can significantly contribute to the accuracy of Magnetohydrodynamics (MHD) equilibrium reconstruction in toroidal plasmas. Moreover, the magnetic fields produced by the eddy currents could generate error fields that may give rise to islands at rational surfaces or cause field lines to become chaotic. In the Compact Toroidal Hybrid (CTH) device (R0 = 0.75 m, a = 0.29 m, B ? 0.7 T), the primary driver of the eddy currents during the plasma discharge is the changing flux of the ohmic heating transformer. Electromagnetic simulations are used to calculate eddy current paths and profile in the vacuum vessel and in the coil frame pieces with known time dependent currents in the ohmic heating coils. MAXWELL and SPARK codes were used for the Electromagnetic modeling and simulation. MAXWELL code was used for detailed 3D finite-element analysis of the eddy currents in the structures. SPARK code was used to calculate the eddy currents in the structures as modeled with shell/surface elements, with each element representing a current loop. In both cases current filaments representing the eddy currents were prepared for input into VMEC code for MHD equilibrium reconstruction of the plasma discharge. __________________________________________________

  17. Using Pulsars to Detect Massive Black Hole Binaries via Gravitational Radiation: Sagittarius A* and Nearby Galaxies

    E-Print Network [OSTI]

    Andrea N. Lommen; Donald C. Backer

    2001-07-24

    Pulsar timing measurements can be used to detect gravitational radiation from massive black hole binaries. The ~106d quasi-periodic flux variations in Sagittarius A* at radio wavelengths reported by Zhao, Bower, & Goss (2001) may be due to binarity of the massive black hole that is presumed to be responsible for the radio emission. A 106d equal-mass binary black hole is unlikely based on its short inspiral lifetime and other arguments. Nevertheless the reported quasi-periodicity has led us to consider whether the long-wavelength gravitational waves from a conjectured binary might be detected in present or future precision timing of millisecond pulsars. While present timing cannot reach the level expected for an equal-mass binary, we estimate that future efforts could. This inquiry has led us to further consider the detection of binarity in the massive black holes now being found in nearby galaxies. For orbital periods of ~2000d where the pulsar timing measurements are most precise, we place upper limits on the mass ratio of binaries as small as 0.06.

  18. Navier-Stokes on Black Hole Horizons and DC Thermoelectric Conductivity

    E-Print Network [OSTI]

    Aristomenis Donos; Jerome P. Gauntlett

    2015-11-12

    Within the context of the AdS/CFT correspondence we show that the DC thermoelectric conductivity can be obtained by solving the linearised, time-independent and forced Navier-Stokes equations on the black hole horizon for an incompressible and charged fluid.

  19. Improving hole injection efficiency by manipulating the hole transport mechanism through

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    -emitting diodes (LEDs) for elec- tron overflow suppression. However, a typical EBL also reduces the hole injection to be the key to enhancing the hole injection efficiency. InGaN/ GaN LEDs with the proposed p-type AlGaN/GaN/AlGaN EBL have demonstrated substantially higher optical output power and external quantum efficiency

  20. Using reference frames and the Global Positioning System (GPS) to produce control networks for spatial data 

    E-Print Network [OSTI]

    Naismith, James Mozeney

    1998-01-01

    for setting base control points that cover very large areas. Data obtained from the International GPS Service for Geodynamics (IGS) is used in conjunction with the International Terrestrial Reference Frame (ITRF) to establish control points anywhere...

  1. Investigation of manufacturing techniques and prototyping of the Smartcities Citycar frame

    E-Print Network [OSTI]

    Rogers, Arin S

    2011-01-01

    A study was performed to analyze different methods of manufacturing a full scale car frame for the Smart Cities Citycar, a folding electric vehicle being designed at the MIT Media Lab, as well as a half-scale prototype for ...

  2. Quadrature Rotating-Frame Gradient Fields for Ultra-Low Field Nuclear Magnetic Resonance and Imaging

    E-Print Network [OSTI]

    Bouchard, Louis-Serge

    2005-01-01

    Frame Gradient Fields For Ultra-Low Field Nuclear Magneticslow, as in the limit of ultra-low ?elds. In the ?rst case,B. Slice selection in ultra-low ?elds We ?rst examine the

  3. Laser wakefield simulation using a speed-of-light frame envelope model

    E-Print Network [OSTI]

    Cowan, B.

    2010-01-01

    Laser wake?eld simulation using a speed-of-light frameAbstract. Simulation of laser wake?eld accelerator (LWFA)extend hundreds of laser wave- lengths transversely and many

  4. Rhetorical Response to the Homeless Movement: Adopting Discursive Units in Counter-Frames 

    E-Print Network [OSTI]

    Mathe, Kristin S.

    2010-07-14

    the causes of homelessness and characterize homeless people. I identify both the policy opportunities and limits created by the way interest groups talk about homelessness by weaving together framing theory with analysis of discursive units employed...

  5. On the relation of Thomas rotation and angular velocity of reference frames

    E-Print Network [OSTI]

    T. Matolcsi; M. Matolcsi; T. Tasnádi

    2006-11-19

    In the extensive literature dealing with the relativistic phenomenon of Thomas rotation several methods have been developed for calculating the Thomas rotation angle of a gyroscope along a circular world line. One of the most appealing concepts, introduced in \\cite{rindler}, is to consider a rotating reference frame co-moving with the gyroscope, and relate the precession of the gyroscope to the angular velocity of the reference frame. A recent paper \\cite{herrera}, however, applies this principle to three different co-moving rotating reference frames and arrives at three different Thomas rotation angles. The reason for this apparent paradox is that the principle of \\cite{rindler} is used for a situation to which it does not apply. In this paper we rigorously examine the theoretical background and limitations of applicability of the principle of \\cite{rindler}. Along the way we also establish some general properties of {\\it rotating reference frames}, which may be of independent interest.

  6. Converting Hybrid Wire-frames to B-rep Models Jie-Hui Gong

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Converting Hybrid Wire-frames to B-rep Models Jie-Hui Gong Dept. of Comp. Sci. and Technol of curved surfaces [Liu et al. 2001; Gong et al. 2006b]. The CSG oriented approach, however, is generally

  7. Shaking Table Tests on Deficient RC Frames Strengthened with FRPs and Pos-Tensioned

    E-Print Network [OSTI]

    Shaking Table Tests on Deficient RC Frames Strengthened with FRPs and Pos-Tensioned Metal Straps Dr Strengthened with FRPs and Pos-Tensioned Metal Straps Dr Iman Hajirasouliha Lecturer, Department of Civil

  8. Analytical Modeling of Wood Frame Shear Walls Subjected to Vertical Load 

    E-Print Network [OSTI]

    Nguyendinh, Hai

    2011-08-08

    A nonlinear automated parameter fitted analytical model that numerically predicts the load-displacement response of wood frame shear walls subjected to static monotonic loading with and without vertical load is presented. This analytical model...

  9. FULL ELECTROMAGNETIC FEL SIMULATION VIA THE LORENTZ-BOOSTED FRAME TRANSFORMATION

    E-Print Network [OSTI]

    Fawley, William

    2010-01-01

    FULL ELECTROMAGNETIC FEL SIMULATION VIA THE LORENTZ-BOOSTEDrest frame), the red-shifted FEL radiation and blue-shiftedper- mit direct study of FEL problems for which the eikonal

  10. Thermal properties of structural details in wood frame homes : analysis and recommendations

    E-Print Network [OSTI]

    Graybeal, Alexander Kung

    2010-01-01

    The wood platform frame home is the dominant design in the United States when it comes to single family housing. Introduced during the mid-nineteenth century, the scheme is a cheap, fast, and proven design that takes ...

  11. The Behaviour of Multi-storey Composite Steel Framed Structures in Response to Compartment Fires 

    E-Print Network [OSTI]

    Lamont, Susan

    For many years, the ability of highly redundant composite framed structure to resist the effect of a fire have been undervalued and misunderstood. A great deal of work on the behavior of composite steel-concrete structures ...

  12. The design of a frame for an all terrain, lever propelled wheelchair

    E-Print Network [OSTI]

    Walton, John Michael

    2011-01-01

    This thesis outlines the process of designing a frame for the Leveraged Freedom Chair (LFC) Prime, an all-terrain levered powered wheelchair designed to improve the mobility of disabled individuals. This design allows for ...

  13. Experimental and Numerical Examination of the Thermal Transmittance of High Performance Window Frames

    E-Print Network [OSTI]

    Gustavsen Ph.D., Arild

    2010-01-01

    windows are often called passive -house wind ows, as windowse window frames, like passive-house windows. In this p aperare supposed to satisfy the Passive house requirements of

  14. Rotating black hole thermodynamics with a particle probe

    SciTech Connect (OSTI)

    Gwak, Bogeun; Lee, Bum-Hoon

    2011-10-15

    The thermodynamics of Myers-Perry black holes in general dimensions are studied using a particle probe. When undergoing particle absorption, the changes of the entropy and irreducible mass are shown to be dependent on the particle radial momentum. The black hole thermodynamic behaviors are dependent on dimensionality for specific rotations. For a 4-dimensional Kerr black hole, its black hole properties are maintained for any particle absorption. 5-dimensional black holes can avoid a naked ring singularity by absorbing a particle in specific momenta ranges. Black holes over 6 dimensions become ultraspinning black holes through a specific form of particle absorption. The microscopical changes are interpreted in limited cases of Myers-Perry black holes using Kerr/CFT correspondence. We systematically describe the black hole properties changed by particle absorption in all dimensions.

  15. Time dependence of Hawking radiation entropy

    SciTech Connect (OSTI)

    Page, Don N., E-mail: profdonpage@gmail.com [Department of Physics, 4-181 CCIS, University of Alberta, Edmonton, Alberta T6G 2E1 (Canada)

    2013-09-01

    If a black hole starts in a pure quantum state and evaporates completely by a unitary process, the von Neumann entropy of the Hawking radiation initially increases and then decreases back to zero when the black hole has disappeared. Here numerical results are given for an approximation to the time dependence of the radiation entropy under an assumption of fast scrambling, for large nonrotating black holes that emit essentially only photons and gravitons. The maximum of the von Neumann entropy then occurs after about 53.81% of the evaporation time, when the black hole has lost about 40.25% of its original Bekenstein-Hawking (BH) entropy (an upper bound for its von Neumann entropy) and then has a BH entropy that equals the entropy in the radiation, which is about 59.75% of the original BH entropy 4?M{sub 0}{sup 2}, or about 7.509M{sub 0}{sup 2} ? 6.268 × 10{sup 76}(M{sub 0}/M{sub s}un){sup 2}, using my 1976 calculations that the photon and graviton emission process into empty space gives about 1.4847 times the BH entropy loss of the black hole. Results are also given for black holes in initially impure states. If the black hole starts in a maximally mixed state, the von Neumann entropy of the Hawking radiation increases from zero up to a maximum of about 119.51% of the original BH entropy, or about 15.018M{sub 0}{sup 2} ? 1.254 × 10{sup 77}(M{sub 0}/M{sub s}un){sup 2}, and then decreases back down to 4?M{sub 0}{sup 2} = 1.049 × 10{sup 77}(M{sub 0}/M{sub s}un){sup 2}.

  16. GLOBAL PLATE MOTION FRAMES: TOWARD A UNIFIED MODEL

    E-Print Network [OSTI]

    Torsvik, Trond Helge

    to a reference system such as the Earth's mantle, are still poorly understood. Accurate absolute plate motion magnetic dipole axis are not necessarily fixed to the mantle reference system. Absolute plate motion models and a paleomagnetic absolute plate reference system into a ``hybrid'' model for the time period from the assembly

  17. Supermassive Black Holes in Galactic Nuclei: Past, Present and Future Research

    E-Print Network [OSTI]

    Laura Ferrarese; Holland Ford

    2004-11-09

    This review discusses the current status of supermassive black hole research, as seen from a purely observational standpoint. Since the early '90s, rapid technological advances, most notably the launch of the Hubble Space Telescope, the commissioning of the VLBA and improvements in near-infrared speckle imaging techniques, have not only given us incontrovertible proof of the existence of supermassive black holes, but have unveiled fundamental connections between the mass of the central singularity and the global properties of the host galaxy. It is thanks to these observations that we are now, for the first time, in a position to understand the origin, evolution and cosmic relevance of these fascinating objects.

  18. Anomalous Flyby in the Non-Prefered Reference Frame of the Rotating Earth

    E-Print Network [OSTI]

    Walter Petry

    2011-09-27

    Several spacecrafts show an anomalous flyby. In a previous paper a non-prefered reference frame is studied moving uniformly relative to the prefered one. In this article the Doppler frequency residual is derived. The prefered reference frame is given by the isotropy of the CMB and the non-prefered one is the Earth. The resulting jump is much too small to explain the measured anomalous flybys of the different spacecrafts. Therefore, the transformations from the prefered frame to the non-prefered frame are replaced by the corresponding total differentials. A formula for the Doppler frequency residual is derived. It is applied to the prefered frame of the Earth and the non-prefered frame of the rotating Earth. The resulting Doppler residual depends on the direction of the velocity of the spacecraft and the position of the observer on the rotating Earth. It is similar to the experimental formula of Anderson et al. which is independent of the position of the observer.

  19. Key Elements of and Materials Performance Targets for Highly Insulating Window Frames

    SciTech Connect (OSTI)

    Gustavsen, Arild; Grynning, Steinar; Arasteh, Dariush; Jelle, Bjorn Petter; Goudey, Howdy

    2011-03-28

    The thermal performance of windows is important for energy efficient buildings. Windows typically account for about 30-50 percent of the transmission losses though the building envelope, even if their area fraction of the envelope is far less. The reason for this can be found by comparing the thermal transmittance (U-factor) of windows to the U-factor of their opaque counterparts (wall, roof and floor constructions). In well insulated buildings the U-factor of walls, roofs an floors can be between 0.1-0.2 W/(m2K). The best windows have U-values of about 0.7-1.0. It is therefore obvious that the U-factor of windows needs to be reduced, even though looking at the whole energy balance for windows (i.e. solar gains minus transmission losses) makes the picture more complex.In high performance windows the frame design and material use is of utmost importance, as the frame performance is usually the limiting factor for reducing the total window U-factor further. This paper describes simulation studies analyzing the effects on frame and edge-of-glass U-factors of different surface emissivities as well as frame material and spacer conductivities. The goal of this work is to define materials research targets for window frame components that will result in better frame thermal performance than is exhibited by the best products available on the market today.

  20. Applying compressive sensing to TEM video: A substantial frame rate increase on any camera

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

    Stevens, Andrew; Kovarik, Libor; Abellan, Patricia; Yuan, Xin; Carin, Lawrence; Browning, Nigel D.

    2015-08-13

    One of the main limitations of imaging at high spatial and temporal resolution during in-situ transmission electron microscopy (TEM) experiments is the frame rate of the camera being used to image the dynamic process. While the recent development of direct detectors has provided the hardware to achieve frame rates approaching 0.1 ms, the cameras are expensive and must replace existing detectors. In this paper, we examine the use of coded aperture compressive sensing (CS) methods to increase the frame rate of any camera with simple, low-cost hardware modifications. The coded aperture approach allows multiple sub-frames to be coded and integratedmore »into a single camera frame during the acquisition process, and then extracted upon readout using statistical CS inversion. Here we describe the background of CS and statistical methods in depth and simulate the frame rates and efficiencies for in-situ TEM experiments. Depending on the resolution and signal/noise of the image, it should be possible to increase the speed of any camera by more than an order of magnitude using this approach.« less

  1. X-ray Diffraction and Multi-Frame Phase Contrast Imaging Diagnostics for IMPULSE at the Advanced Photon Source

    SciTech Connect (OSTI)

    Iverson, Adam [National Security Technologies, LLC; Carlson, Carl [National Security Technologies, LLC; Young, Jason [National Security Technologies, LLC; Curtis, Alden [National Security Technologies, LLC; Jensen, Brian [Los Alamos National Laboratory; Ramos, Kyle [Los Alamos National Laboratory; Yeager, John [Los Alamos National Laboratory; Montgomery, David [Los Alamos National Laboratory; Fezza, Kamel [Argonne National Laboratory

    2013-07-08

    The diagnostic needs of any dynamic loading platform present unique technical challenges that must be addressed in order to accurately measure in situ material properties in an extreme environment. The IMPULSE platform (IMPact system for Ultrafast Synchrotron Experiments) at the Advanced Photon Source (APS) is no exception and, in fact, may be more challenging, as the imaging diagnostics must be synchronized to both the experiment and the 60 ps wide x-ray bunches produced at APS. The technical challenges of time-resolved x-ray diffraction imaging and high-resolution multi-frame phase contrast imaging (PCI) are described in this paper. Example data from recent IMPULSE experiments are shown to illustrate the advances and evolution of these diagnostics with a focus on comparing the performance of two intensified CCD cameras and their suitability for multi-frame PCI. The continued development of these diagnostics is fundamentally important to IMPULSE and many other loading platforms and will benefit future facilities such as the Dynamic Compression Sector at APS and MaRIE at Los Alamos National Laboratory.

  2. Holographic superconductor in the exact hairy black hole

    E-Print Network [OSTI]

    Yun Soo Myung; Chanyong Park

    2011-09-13

    We study the charged black hole of hyperbolic horizon with scalar hair (charged Martinez-Troncoso-Zanelli: CMTZ black hole) as a model of analytic hairy black hole for holographic superconductor. For this purpose, we investigate the second order phase transition between CMTZ and hyperbolic Reissner-Nordstr\\"om-AdS (HRNAdS) black holes. However, this transition unlikely occur. As an analytic treatment for holographic superconductor, we develop superconductor in the bulk and superfluidity on the boundary using the CMTZ black hole below the critical temperature. The presence of charge destroys the condensates around the zero temperature, which is in accord with the thermodynamic analysis of the CMTZ black hole.

  3. Supersymmetric black holes and attractors in gauged supergravity with hypermultiplets

    E-Print Network [OSTI]

    Chimento, Samuele; Petri, Nicolò

    2015-01-01

    We consider four-dimensional $N=2$ supergravity coupled to vector- and hypermultiplets, where abelian isometries of the quaternionic K\\"ahler hypermultiplet scalar manifold are gauged. Using the recipe given by Meessen and Ort\\'{\\i}n in arXiv:1204.0493, we analytically construct a supersymmetric black hole solution for the case of just one vector multiplet with prepotential ${\\cal F}=-i\\chi^0\\chi^1$, and the universal hypermultiplet. This solution has a running dilaton, and it interpolates between $\\text{AdS}_2\\times\\text{H}^2$ at the horizon and a hyperscaling-violating type geometry at infinity, conformal to $\\text{AdS}_2\\times\\text{H}^2$. It carries two magnetic charges that are completely fixed in terms of the parameters that appear in the Killing vector used for the gauging. In the second part of the paper, we extend the work of Bellucci et al. on black hole attractors in gauged supergravity to the case where also hypermultiplets are present. The attractors are shown to be governed by an effective potent...

  4. Electrically charged black hole with scalar hair

    E-Print Network [OSTI]

    Cristian Martinez; Ricardo Troncoso

    2006-06-16

    An electrically charged black hole solution with scalar hair in four dimensions is presented. The self-interacting scalar field is real and it is minimally coupled to gravity and electromagnetism. The event horizon is a surface of negative constant curvature and the asymptotic region is locally an AdS spacetime. The asymptotic fall-off of the fields is slower than the standard one. The scalar field is regular everywhere except at the origin, and is supported by the presence of electric charge which is bounded from above by the AdS radius. In turn, the presence of the real scalar field smooths the electromagnetic potential everywhere. Regardless the value of the electric charge, the black hole is massless and has a fixed temperature. The entropy follows the usual area law. It is shown that there is a nonvanishing probability for the decay of the hairy black hole into a charged black hole without scalar field. Furthermore, it is found that an extremal black hole without scalar field is likely to undergo a spontaneous dressing up with a nontrivial scalar field, provided the electric charge is below a critical value.

  5. The Environmental Impact of Supermassive Black Holes

    E-Print Network [OSTI]

    Abraham Loeb

    2004-08-10

    The supermassive black holes observed at the centers of almost all present-day galaxies, had a profound impact on their environment. I highlight the principle of self-regulation, by which supermassive black holes grow until they release sufficient energy to unbind the gas that feeds them from their host galaxy. This principle explains several observed facts, including the correlation between the mass of a central black hole and the depth of the gravitational potential well of its host galaxy, and the abundance and clustering properties of bright quasars in the redshift interval of z~2-6. At lower redshifts, quasars might have limited the maximum mass of galaxies through the suppression of cooling flows in X-ray clusters. The seeds of supermassive black holes were likely planted in dwarf galaxies at redshifts z>10, through the collapse of massive or supermassive stars. The minimum seed mass can be identified observationally through the detection of gravitational waves from black hole binaries by Advanced LIGO or LISA. Aside from shaping their host galaxies, quasar outflows filled the intergalactic medium with magnetic fields and heavy elements. Beyond the reach of these outflows, the brightest quasars at z>6 have ionized exceedingly large volumes of gas (tens of comoving Mpc) prior to global reionization, and must have suppressed the faint end of the galaxy luminosity function in these volumes before the same occurred through the rest of the universe.

  6. BLACK HOLE FORAGING: FEEDBACK DRIVES FEEDING

    SciTech Connect (OSTI)

    Dehnen, Walter; King, Andrew, E-mail: wd11@leicester.ac.uk, E-mail: ark@astro.le.ac.uk [Theoretical Astrophysics Group, University of Leicester, Leicester LE1 7RH (United Kingdom)] [Theoretical Astrophysics Group, University of Leicester, Leicester LE1 7RH (United Kingdom)

    2013-11-10

    We suggest a new picture of supermassive black hole (SMBH) growth in galaxy centers. Momentum-driven feedback from an accreting hole gives significant orbital energy, but little angular momentum to the surrounding gas. Once central accretion drops, the feedback weakens and swept-up gas falls back toward the SMBH on near-parabolic orbits. These intersect near the black hole with partially opposed specific angular momenta, causing further infall and ultimately the formation of a small-scale accretion disk. The feeding rates into the disk typically exceed Eddington by factors of a few, growing the hole on the Salpeter timescale and stimulating further feedback. Natural consequences of this picture include (1) the formation and maintenance of a roughly toroidal distribution of obscuring matter near the hole; (2) random orientations of successive accretion disk episodes; (3) the possibility of rapid SMBH growth; (4) tidal disruption of stars and close binaries formed from infalling gas, resulting in visible flares and ejection of hypervelocity stars; (5) super-solar abundances of the matter accreting on to the SMBH; and (6) a lower central dark-matter density, and hence annihilation signal, than adiabatic SMBH growth implies. We also suggest a simple subgrid recipe for implementing this process in numerical simulations.

  7. Perturbative String Thermodynamics near Black Hole Horizons

    E-Print Network [OSTI]

    Thomas G. Mertens; Henri Verschelde; Valentin I. Zakharov

    2015-07-01

    We provide further computations and ideas to the problem of near-Hagedorn string thermodynamics near (uncharged) black hole horizons, building upon our earlier work JHEP 1403 (2014) 086. The relevance of long strings to one-loop black hole thermodynamics is emphasized. We then provide an argument in favor of the absence of $\\alpha'$-corrections for the (quadratic) heterotic thermal scalar action in Rindler space. We also compute the large $k$ limit of the cigar orbifold partition functions (for both bosonic and type II superstrings) which allows a better comparison between the flat cones and the cigar cones. A discussion is made on the general McClain-Roth-O'Brien-Tan theorem and on the fact that different torus embeddings lead to different aspects of string thermodynamics. The black hole/string correspondence principle for the 2d black hole is discussed in terms of the thermal scalar. Finally, we present an argument to deal with arbitrary higher genus partition functions, suggesting the breakdown of string perturbation theory (in $g_s$) to compute thermodynamical quantities in black hole spacetimes.

  8. Black Hole Spin in AGN and GBHCs

    E-Print Network [OSTI]

    Christopher S. Reynolds; Laura W. Brenneman; David Garofalo

    2004-10-05

    We discuss constraints on black hole spin and spin-related astrophysics as derived from X-ray spectroscopy. After a brief discussion about the robustness with which X-ray spectroscopy can be used to probe strong gravity, we summarize how these techniques can constrain black hole spin. In particular, we highlight XMM-Newton studies of the Seyfert galaxy MCG-6-30-15 and the stellar-mass black hole GX339-4. The broad X-ray iron line profile, together with reasonable and general astrophysical assumptions, allow a non-rotating black hole to be rejected in both of these sources. If we make the stronger assertion of no emission from within the innermost stable circular orbit, the MCG-6-30-15 data constrain the dimensionless spin parameter to be a>0.93. Furthermore, these XMM-Newton data are already providing evidence for exotic spin-related astrophysics in the central regions of this object. We conclude with a discussion of the impact that Constellation-X will have on the study of strong gravity and black hole spin.

  9. Black Hole spin dependence of general relativistic multi-transonic accretion close to the horizon

    E-Print Network [OSTI]

    Tapas K. Das; Sankhasubhra Nag; Swathi Hegde; Sourav Bhattacharya; Ishita Maity; Bozena Czerny; Paramita Barai; Paul J. Wiita; Vladimir Karas; Tapan Naskar

    2014-12-31

    We introduce a novel formalism to investigate the role of the spin angular momentum of astrophysical black holes in influencing the behaviour of low angular momentum general relativistic accretion. We propose a metric independent analysis of axisymmetric general relativistic flow, and consequently formulate the space and time dependent equations describing the general relativistic hydrodynamic accretion flow in the Kerr metric. The associated stationary critical solutions for such flow equations are provided and the stability of the stationary transonic configuration is examined using an elegant linear perturbation technique. We examine the properties of infalling material for both prograde and retrograde accretion as a function of the Kerr parameter at extremely close proximity to the event horizon. Our formalism can be used to identify a new spectral signature of black hole spin, and has the potential of performing the black hole shadow imaging corresponding to the low angular momentum accretion flow.

  10. N = 4 Super-Yang-Mills on Conic Space as Hologram of STU Topological Black Hole

    E-Print Network [OSTI]

    Xing Huang; Yang Zhou

    2014-09-05

    We construct four-dimensional N=4 super-Yang-Mills theories on a conic sphere with various background R-symmetry gauge fields. We study free energy and supersymmetric Renyi entropy using heat kernel method as well as localization technique. We find that the universal contribution to the partition function in the free field limit is the same as that in the strong coupling limit, which implies that it may be protected by supersymmetry. Based on the fact that, the conic sphere can be conformally mapped to $S^1\\times H^3$ and the R-symmetry background fields can be supported by the R-charges of black hole, we propose that the holographic dual of these theories are five-dimensional, supersymmetric STU topological black holes. We demonstrate perfect agreement between N=4 super-Yang-Mills theories in the planar limit and the STU topological black holes.

  11. On Thermodynamics of AdS Black Holes in M-Theory

    E-Print Network [OSTI]

    A. Belhaj; M. Chabab; H. EL Moumni; K. Masmar; M. B. Sedra

    2015-09-07

    Motivated by a recent work on asymptotically AdS_4 black holes in M-theory, we investigate the thermodynamics and thermodynamical geometry of AdS black holes from M2 and M5-branes. Concretely, we consider AdS black holes in AdS_{p+2}\\times S^{11-p-2}, where p=2,5 by interpreting the number of M2 (and M5-branes) as a thermodynamical variable. We study the corresponding phase transition to examine their stabilities by calculating and discussing various thermodynamical quantities including the chemical potential. Then, we compute the thermodynamical curvatures from the Quevedo metric for M2 and M5-branes geometries to reconsider the stability of such black objects. The Quevedo metric singularities recover similar stability results provided by the phase transition program.

  12. Thermodynamic optimization of a Penrose process: an engineers' approach to black hole thermodynamics

    E-Print Network [OSTI]

    Bravetti, Alessandro; Lopez-Monsalvo, Cesar S

    2015-01-01

    In this work we present a new view on the thermodynamics of black holes introducing effects of irreversibility by employing thermodynamic optimization and finite-time thermodynamics. These questions are of importance both in physics and in engineering, combining standard thermodynamics with optimal control theory in order to find optimal protocols and bounds for realistic processes without assuming anything about the microphysics involved. We find general bounds on the maximum work and the efficiency of thermodynamic processes involving black holes that can be derived exclusively from the knowledge of thermodynamic relations at equilibrium. Since these new bounds consider the finite duration of the processes, they are more realistic and stringent than their reversible counterparts. To illustrate our arguments, we consider in detail the thermodynamic optimization of a Penrose process, i.e. the problem of finding the least dissipative process extracting all the angular momentum from a Kerr black hole in finite ...

  13. ISCO, Lyapunov exponent and Kolmogorov-Sinai entropy for Kerr-Newman Black hole

    E-Print Network [OSTI]

    Partha Pratim Pradhan

    2012-12-23

    We compute the principal Lyapunov exponent and Kolmogorov-Sinai(KS) entropy for Kerr-Newman black hole space-times and investigate the stability and instability of the equatorial circular geodesics via these exponents. We also show that the principal Lyapunov exponent and KS entropy can be expressed in terms of the radial equation of ISCO(innermost stable circular orbit) for timelike circular geodesics. The other aspect we have studied that among the all possible circular geodesics, which encircle the central black-hole, the timelike circular geodesics has the longest orbital period i.e. T_{timelike} > T_{photon}, than the null circular geodesics (photon sphere) as measured by asymptotic observers. Thus, the timelike circular geodesics provide the slowest way to circle the Kerr-Newman black-hole. In fact, any stable timelike circular geodesics other than the ISCO traverses more slowly than the null circular geodesics.

  14. Transition from adiabatic inspiral to plunge into a spinning black hole

    SciTech Connect (OSTI)

    Kesden, Michael

    2011-05-15

    A test particle of mass {mu} on a bound geodesic of a Kerr black hole of mass M>>{mu} will slowly inspiral as gravitational radiation extracts energy and angular momentum from its orbit. This inspiral can be considered adiabatic when the orbital period is much shorter than the time scale on which energy is radiated, and quasicircular when the radial velocity is much less than the azimuthal velocity. Although the inspiral always remains adiabatic provided {mu}<hole's spin changes following a test-particle merger, and can be extrapolated to help predict the mass and spin of the final black hole produced in finite-mass-ratio black-hole mergers. Our new contribution is particularly important for nearly maximally spinning black holes, as it can affect whether a merger produces a naked singularity.

  15. Black-hole quasinormal resonances: Wave analysis versus a geometric-optics approximation

    SciTech Connect (OSTI)

    Hod, Shahar [Ruppin Academic Center, Emeq Hefer 40250 (Israel) and Hadassah Institute, Jerusalem 91010 (Israel)

    2009-09-15

    It has long been known that null unstable geodesics are related to the characteristic modes of black holes--the so-called quasinormal resonances. The basic idea is to interpret the free oscillations of a black hole in the eikonal limit in terms of null particles trapped at the unstable circular orbit and slowly leaking out. The real part of the complex quasinormal resonances is related to the angular velocity at the unstable null geodesic. The imaginary part of the resonances is related to the instability time scale (or the inverse Lyapunov exponent) of the orbit. While this geometric-optics description of the black-hole quasinormal resonances in terms of perturbed null rays is very appealing and intuitive, it is still highly important to verify the validity of this approach by directly analyzing the Teukolsky wave equation which governs the dynamics of perturbation waves in the black-hole spacetime. This is the main goal of the present paper. We first use the geometric-optics technique of perturbing a bundle of unstable null rays to calculate the resonances of near-extremal Kerr black holes in the eikonal approximation. We then directly solve the Teukolsky wave equation (supplemented by the appropriate physical boundary conditions) and show that the resultant quasinormal spectrum obtained directly from the wave analysis is in accord with the spectrum obtained from the geometric-optics approximation of perturbed null rays.

  16. Cold black holes in the Harlow–Hayden approach to firewalls

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

    Ong, Yen Chin; McInnes, Brett; Chen, Pisin

    2014-12-31

    Firewalls are controversial principally because they seem to imply departures from general relativistic expectations in regions of spacetime where the curvature need not be particularly large. One of the virtues of the Harlow–Hayden approach to the firewall paradox, concerning the time available for decoding of Hawking radiation emanating from charged AdS black holes, is precisely that it operates in the context of cold black holes, which are not strongly curved outside the event horizon. Here we clarify this point. The approach is based on ideas borrowed from applications of the AdS/CFT correspondence to the quark–gluon plasma. Firewalls aside, our workmore »presents a detailed analysis of the thermodynamics and evolution of evaporating charged AdS black holes with flat event horizons. We show that, in one way or another, these black holes are always eventually destroyed in a time which, while long by normal standards, is short relative to the decoding time of Hawking radiation.« less

  17. Cold black holes in the Harlow–Hayden approach to firewalls

    SciTech Connect (OSTI)

    Ong, Yen Chin [Stockholm Univ., Stockholm (Sweden); National Taiwan Univ., Taipei (Taiwan); McInnes, Brett [National Univ. of Singapore (Singapore); Chen, Pisin [National Taiwan Univ., Taipei (Taiwan); SLAC National Accelerator Laboratory, Stanford, CA (United States)

    2014-12-31

    Firewalls are controversial principally because they seem to imply departures from general relativistic expectations in regions of spacetime where the curvature need not be particularly large. One of the virtues of the Harlow–Hayden approach to the firewall paradox, concerning the time available for decoding of Hawking radiation emanating from charged AdS black holes, is precisely that it operates in the context of cold black holes, which are not strongly curved outside the event horizon. Here we clarify this point. The approach is based on ideas borrowed from applications of the AdS/CFT correspondence to the quark–gluon plasma. Firewalls aside, our work presents a detailed analysis of the thermodynamics and evolution of evaporating charged AdS black holes with flat event horizons. We show that, in one way or another, these black holes are always eventually destroyed in a time which, while long by normal standards, is short relative to the decoding time of Hawking radiation.

  18. Neutrino Majorana Mass from Black Hole

    E-Print Network [OSTI]

    Yosuke Uehara

    2002-05-25

    We propose a new mechanism to generate the neutrino Majorana mass in TeV-scale gravity models. The black hole violates all non-gauged symmetries and can become the origin of lepton number violating processes. The fluctuation of higher-dimensional spacetime can result in the production of a black hole, which emits 2 neutrinos. If neutrinos are Majorana particles, this process is equivalent to the free propagation of a neutrino with the insertion of the black hole. From this fact, we derive the neutrino Majorana mass. The result is completely consistent with the recently observed evidence of neutrinoless double beta decay. And the obtained neutrino Majorana mass satisfies the constraint from the density of the neutrino dark matter, which affects the cosmic structure formation. Furthermore, we can explain the ultrahigh energy cosmic rays by the Z-burst scenario with it.

  19. No Supermassive Black Hole in M33?

    E-Print Network [OSTI]

    David Merritt; Laura Ferrarese; Charles L. Joseph

    2001-07-20

    We analyze optical long-slit spectroscopy of the nucleus of M33 obtained from the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope. Rather than the steep rise expected within the radius of influence of a supermassive black hole, the velocity dispersion drops significantly within the inner parsec. Dynamical modelling yields an estimated upper limit of 3000 solar masses for the mass of a central compact object. This upper limit is however consistent within the uncertainties with the mass predicted by the M-sigma relation, which is between 2000 and 20,000 solar masses. We therefore can not conclude that the presence of a massive black hole in the nucleus of M33 would require a different formation mechanism from that of the black holes detected in galaxies with more luminous bulges.

  20. Concepts Associated with Transferring Temporal and Spatial Boundary Conditions between Modules in the Framework for Risk Analysis in Multimedia Environmental Systems (FRAMES)

    SciTech Connect (OSTI)

    Whelan, Gene; Castleton, Karl J.; Pelton, Mitch A.

    2006-10-03

    This document describes concepts associated with transferring temporal and spatial boundary conditions between modules in FRAMES and how FRAMES might consider dynamic feedback.

  1. Walén test and de Hoffmann-Teller frame of interplanetary large-amplitude Alfvén waves

    SciTech Connect (OSTI)

    Chao, J. K.; Hsieh, Wen-Chieh; Lee, L. C. [Institute of Space Science, National Central University, Jhongli 320, Taiwan (China); Yang, L., E-mail: jkchaous@gmail.com [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2014-05-10

    In this study, three methods of analysis are compared to test the Walén relation. Method 1 requires a good de Hoffmann-Teller (HT) frame. Method 2 uses three components separately to find the frame that is slightly modified from Method 1. This method is intended to improve the accuracy of the HT frame and able to demonstrate the anisotropic property of the fluctuations. The better the relation is, the closer the slope of a regression fitting the data of plasma versus Alfvén velocities is to 1. However, this criterion is based on an average HT frame, and the fitted slope does not always work for the Walén test because the HT frame can change so fast in the high-speed streams. We propose Method 3 to check the Walén relation using a sequence of data generated by taking the difference of two consecutive values of plasma and Alfvén velocities, respectively. The difference data are independent of the HT frame. We suggest that the ratio of the variances between plasma and Alfvén velocities is a better parameter to qualify the Walén relation. Four cases in two solar wind streams are studied using these three methods. Our results show that when the solar wind HT frame remains stable, all three methods can predict Alfvénic fluctuations well, but Method 3 can better predict the Walén relation when solar wind contains structures with several small streams. A simulated case also demonstrates that Method 3 is better and more robust than Methods 1 and 2. These results are important for a better understanding of Alfvénic fluctuations and turbulence in the solar wind.

  2. The rest mass of a system of two photons in different inertial reference frames: 0+0=0 and 0+0>0

    E-Print Network [OSTI]

    Berhard Rothenstein; Doru P?unescu; ?tefan Popescu

    2007-08-31

    We show that the rest mass of a system consisting of two photons is a relativistic invariant having the same magnitude in all inertial reference frames in relative motion. A scenario which starts with two photons where theirs frequencies are equal to each other the magnitude of the rest mass of the system depends on the angle made by the momentums of the two photons. The behavior of the photons when detected from two inertial reference frames is illustrated using a relativistic diagram which displays in true values the physical quantities (scalar and vector) introduced in order to characterize the dynamical properties of the photon. We consider that the obtained results should be taken in the discussions, some time fierce, between those who ban the concept of relativistic mass and those who consider that its use is harmless.

  3. Microhole Coiled Tubing Bottom Hole Assemblies

    SciTech Connect (OSTI)

    Don Macune

    2008-06-30

    The original objective of the project, to deliver an integrated 3 1/8-inch diameter Measurement While Drilling (MWD) and Logging While Drilling (LWD) system for drilling small boreholes using coiled tubing drilling, has been achieved. Two prototype systems have been assembled and tested in the lab. One of the systems has been successfully tested downhole in a conventional rotary drilling environment. Development of the 3 1/8-inch system has also lead to development and commercialization of a slightly larger 3.5-inch diameter system. We are presently filling customer orders for the 3.5-inch system while continuing with commercialization of the 3 1/8-inch system. The equipment developed by this project will be offered for sale to multiple service providers around the world, enabling the more rapid expansion of both coiled tubing drilling and conventional small diameter drilling. The project was based on the reuse of existing technology whenever possible in order to minimize development costs, time, and risks. The project was begun initially by Ultima Labs, at the time a small company ({approx}12 employees) which had successfully developed a number of products for larger oil well service companies. In September, 2006, approximately 20 months after inception of the project, Ultima Labs was acquired by Sondex plc, a worldwide manufacturer of downhole instrumentation for cased hole and drilling applications. The acquisition provided access to proven technology for mud pulse telemetry, downhole directional and natural gamma ray measurements, and surface data acquisition and processing, as well as a global sales and support network. The acquisition accelerated commercialization through existing Sondex customers. Customer demand resulted in changes to the product specification to support hotter (150 C) and deeper drilling (20,000 psi pressure) than originally proposed. The Sondex acquisition resulted in some project delays as the resistivity collar was interfaced to a different MWD system and also as the mechanical design was revised for the new pressure requirements. However, the Sondex acquisition has resulted in a more robust system, secure funding for completion of the project, and more rapid commercialization.

  4. From Vacuum Fluctuations to Radiation: Accelerated Detectors and Black Holes

    E-Print Network [OSTI]

    S. Massar; R. Parentani

    1994-06-03

    The vacuum fluctuations that induce the transitions and the thermalisation of a uniformly accelerated two level atom are studied in detail. Their energy content is revealed through the weak measurement formalism of Aharonov et al. It is shown that each time the detector makes a transition it radiates a Minkowski photon. The same analysis is then applied to the conversion of vacuum fluctuations into real quanta in the context of black hole radiation. Initially these fluctuations are located around the light like geodesic that shall generate the horizon and carry zero total energy. However upon exiting from the star they break up into two pieces one of which gradually acquires positive energy and becomes a Hawking quantum, the other, its ''partner", ends up in the singularity. As time goes by the vacuum fluctuations generating Hawking quanta have exponentially large energy densities. This implies that back reaction effects are large.

  5. CHARYBDIS: A Black Hole Event Generator

    E-Print Network [OSTI]

    C. M. Harris; P. Richardson; B. R. Webber

    2003-07-29

    CHARYBDIS is an event generator which simulates the production and decay of miniature black holes at hadronic colliders as might be possible in certain extra dimension models. It interfaces via the Les Houches accord to general purpose Monte Carlo programs like HERWIG and PYTHIA which then perform the parton evolution and hadronization. The event generator includes the extra-dimensional `grey-body' effects as well as the change in the temperature of the black hole as the decay progresses. Various options for modelling the Planck-scale terminal decay are provided.

  6. Vacuum polarization for lukewarm black holes

    E-Print Network [OSTI]

    Elizabeth Winstanley; Phil M. Young

    2007-12-20

    We compute the renormalized expectation value of the square of a quantum scalar field on a Reissner-Nordstrom-de Sitter black hole in which the temperatures of the event and cosmological horizons are equal (`lukewarm' black hole). Our numerical calculations for a thermal state at the same temperature as the two horizons indicate that this renormalized expectation value is regular on both the event and cosmological horizons. We are able to show analytically, using an approximation for the field modes near the horizons, that this is indeed the case.

  7. Thermal stability of radiant black holes

    E-Print Network [OSTI]

    Parthasarathi Majumdar

    2006-04-06

    Beginning with a brief sketch of the derivation of Hawking's theorem of horizon area increase, based on the Raychaudhuri equation, we go on to discuss the issue as to whether generic black holes, undergoing Hawking radiation, can ever remain in stable thermal equilibrium with that radiation. We derive a universal criterion for such a stability, which relates the black hole mass and microcanonical entropy, both of which are well-defined within the context of the Isolated Horizon, and in principle calculable within Loop Quantum Gravity. The criterion is argued to hold even when thermal fluctuations of electric charge are considered, within a {\\it grand} canonical ensemble.

  8. Black Hole Thermodynamics and Statistical Mechanics

    E-Print Network [OSTI]

    Steven Carlip

    2008-07-28

    We have known for more than thirty years that black holes behave as thermodynamic systems, radiating as black bodies with characteristic temperatures and entropies. This behavior is not only interesting in its own right; it could also, through a statistical mechanical description, cast light on some of the deep problems of quantizing gravity. In these lectures, I review what we currently know about black hole thermodynamics and statistical mechanics, suggest a rather speculative "universal" characterization of the underlying states, and describe some key open questions.

  9. Dynamics of galaxy cores and supermassive black holes

    E-Print Network [OSTI]

    David Merritt

    2006-05-02

    Recent work on the dynamical evolution of galactic nuclei containing supermassive black holes is reviewed. Topics include galaxy structural properties; collisionless and collisional equilibria; loss-cone dynamics; and dynamics of binary and multiple supermassive black holes.

  10. Black hole Meissner effect and Blandford-Znajek jets

    E-Print Network [OSTI]

    Penna, Robert

    Spinning black holes tend to expel magnetic fields. In this way they are similar to superconductors. It has been a persistent concern that this black hole “Meissner effect” could quench jet power at high spins. This would ...

  11. Entropy and Area of Black Holes in Loop Quantum Gravity

    E-Print Network [OSTI]

    I. B. Khriplovich

    2002-03-31

    Simple arguments related to the entropy of black holes strongly constrain the spectrum of the area operator for a Schwarzschild black hole in loop quantum gravity. In particular, this spectrum is fixed completely by the assumption that the black hole entropy is maximum. Within the approach discussed, one arrives in loop quantum gravity at a quantization rule with integer quantum numbers $n$ for the entropy and area of a black hole.

  12. SEARCH FOR SUPERMASSIVE BLACK HOLE BINARIES IN THE SLOAN DIGITAL...

    Office of Scientific and Technical Information (OSTI)

    ASTROPHYSICS; BLACK HOLES; COMPARATIVE EVALUATIONS; CORRELATIONS; COSMOLOGY; GALAXIES; GALAXY NUCLEI; NONLUMINOUS MATTER; OSCILLATIONS; QUASARS; VELOCITY Word Cloud More Like This...

  13. Testing the Kerr-nature of stellar-mass black hole candidates by combining the continuum-fitting method and the power estimate of transient ballistic jets

    E-Print Network [OSTI]

    Cosimo Bambi

    2012-01-25

    Astrophysical black hole candidates are thought to be the Kerr black holes predicted by General Relativity, as these objects cannot be explained otherwise without introducing new physics. However, there is no observational evidence that the space-time around them is really described by the Kerr solution. The Kerr black hole hypothesis can be tested with the already available X-ray data by extending the continuum-fitting method, a technique currently used by astronomers to estimate the spins of stellar-mass black hole candidates. In general, we cannot put a constraint on possible deviations from the Kerr geometry, but only on some combination between these deviations and the spin. The measurement of the radio power of transient jets in black hole binaries can potentially break this degeneracy, thus allowing for testing the Kerr-nature of these objects.

  14. Unified Field Theory From Enlarged Transformation Group. The Covariant Derivative for Conservative Coordinate Transformations and Local Frame Transformations

    E-Print Network [OSTI]

    Edward Lee Green

    2009-08-25

    Pandres has developed a theory in which the geometrical structure of a real four-dimensional space-time is expressed by a real orthonormal tetrad, and the group of diffeomorphisms is replaced by a larger group called the conservation group. This paper extends the geometrical foundation for Pandres' theory by developing an appropriate covariant derivative which is covariant under all local Lorentz (frame) transformations, including complex Lorentz transformations, as well as conservative transformations. After defining this extended covariant derivative, an appropriate Lagrangian and its resulting field equations are derived. As in Pandres' theory, these field equations result in a stress-energy tensor that has terms which may automatically represent the electroweak field. Finally, the theory is extended to include 2-spinors and 4-spinors.

  15. High-frame rate, fast neutron imaging of two-phase flow in a thin rectangular channel

    E-Print Network [OSTI]

    Zboray, R; Dangendorf, V; Stark, M; Tittelmeier, K; Cortesi, M; Adams, R

    2015-01-01

    We have demonstrated the feasibility of performing high-frame-rate, fast neutron radiography of air-water two-phase flows in a thin channel with rectangular cross section. The experiments have been carried out at the accelerator facility of the Physikalisch-Technische Bundesanstalt. A polychromatic, high-intensity fast neutron beam with average energy of 6 MeV was produced by 11.5 MeV deuterons hitting a thick Be target. Image sequences down to 10 millisecond exposure times were obtained using a fast-neutron imaging detector developed in the context of fast-neutron resonance imaging. Different two-phase flow regimes such as bubbly slug and churn flows have been examined. Two phase flow parameters like the volumetric gas fraction, bubble size and bubble velocities have been measured. The first results are promising, improvements for future experiments are also discussed.

  16. Thermal Impact of Fasteners in High-Performance Wood-Framed Walls: Preprint

    SciTech Connect (OSTI)

    Christensen, D.

    2011-01-01

    Buildings are heavy consumers of energy, and residential building design is rapidly addressing topics to maximize energy conservation en route to net-zero energy consumption. Annual energy analysis of a building informs the choice among disparate energy measures, for cost, durability, occupant comfort, and whole-house energy use. Physics-based and empirical models of elements of a building are used in such analyses. High-performance wood-framed walls enable builders to construct homes that use much less than 40% of the energy consumed by similar homes built to minimum code. Modeling for these walls has considered physical features such as framing factor, insulation and framing properties, roughness and convective effects, and air leakage. The thermal effects of fasteners used to construct these walls have not been fully evaluated, even though their thermal conductivity is orders of magnitudes higher than that of other building materials. Drywall screws and siding nails are considered in this finite element thermal conductivity analysis of wall sections that represent wood-framed walls that are often used in high-performance homes. Nails and screws reduce even the best walls' insulating performance by approximately 3% and become increasingly significant as the framing factor increases.

  17. MOTION OF ELECTRON-HOLE DROPS IN Ge

    E-Print Network [OSTI]

    Westervelt, R.M.

    2011-01-01

    MOTION OF ELECTRON-HOLE DROPS IN Ge R. M. Westervelt, J. C.MOTION OF ELECTRON-HOLE DROPS IN Ge R. M. Westervelt, J. C.OF ELECTRON-HOLE DROPS IN Ge R M Westervelt, J C Culbertson

  18. ANCHIALINE ECOSYSTEMS Microbial hotspots in anchialine blue holes

    E-Print Network [OSTI]

    Macalady, Jenn

    ANCHIALINE ECOSYSTEMS Microbial hotspots in anchialine blue holes: initial discoveries from+Business Media B.V. 2011 Abstract Inland blue holes of the Bahamas are anchialine ecosystems with distinct fresh and geomicrobiology exploration of blue holes are providing a first glimpse of the geochemistry and microbial life

  19. Light in tiny holes & T. W. Ebbesen1

    E-Print Network [OSTI]

    Turro, Nicholas J.

    REVIEWS Light in tiny holes C. Genet1 & T. W. Ebbesen1 The presence of tiny holes in an opaque metal film, with sizes smaller than the wavelength of incident light, leads to a wide variety of unexpected optical properties such as strongly enhanced transmission of light through the holes

  20. The Role of Primordial Kicks on Black Hole Merger Rates

    E-Print Network [OSTI]

    Miroslav Micic; Tom Abel; Steinn Sigurdsson

    2006-09-06

    Primordial stars are likely to be very massive $\\geq30\\Msun$, form in isolation, and will likely leave black holes as remnants in the centers of their host dark matter halos in the mass range $10^{6}-10^{10}\\Ms$. Such early black holes, at redshifts z$\\gtsim10$, could be the seed black holes for the many supermassive black holes found in galaxies in the local universe. If they exist, their mergers with nearby supermassive black holes may be a prime signal for long wavelength gravitational wave detectors. We simulate formation of black holes in the center of high redshift dark matter halos and explore implications of initial natal kick velocities conjectured by some formation models. The central concentration of early black holes in present day galaxies is reduced if they are born even with moderate kicks of tens of km/s. The modest kicks allow the black holes to leave their parent halo, which consequently leads to dynamical friction being less effective on the lower mass black holes as compared to those still embedded in their parent halos. Therefore, merger rates may be reduced by more than an order of magnitude. Using analytical and illustrative cosmological N--body simulations we quantify the role of natal kicks of black holes formed from massive metal free stars on their merger rates with supermassive black holes in present day galaxies. Our results also apply to black holes ejected by the gravitational slingshot mechanism.

  1. Charged fermions tunneling from accelerating and rotating black holes

    SciTech Connect (OSTI)

    Rehman, Mudassar; Saifullah, K., E-mail: mudassir051@yahoo.com, E-mail: saifullah@qau.edu.pk [Department of Mathematics, Quaid-i-Azam University, Islamabad (Pakistan)

    2011-03-01

    We study Hawking radiation of charged fermions from accelerating and rotating black holes with electric and magnetic charges. We calculate the tunneling probabilities of incoming and outgoing fermionic particles and find the Hawking temperature of these black holes. We also provide an explicit expression of the classical action for the massive and massless particles in the background of these black holes.

  2. The thermodynamics of time

    E-Print Network [OSTI]

    Dries Sels; Michiel Wouters

    2015-01-22

    The problem of time is a deep paradox in our physical description of the world. According to Aristotle's relational theory, time is a measure of change and does not exist on its own. In contrast, quantum mechanics, just like Newtonian mechanics, is equipped with a master clock that dictates the evolution of a system. This clock is infinitely precise and tacitly supplied free of charge from outside physics. Not only does this absolute time make it notoriously difficult to make a consistent theory of quantum gravity, it is also the underlying problem in establishing the second law. Indeed, contrary to our experience, the Wheeler-deWitt equation --a canonical quantization of general relativity-- predicts a static universe. Similarly, when simply concerned with the dynamics of a closed quantum system, there is no second law because the Von Neumann entropy is invariant under unitary transformations. Here we are mainly concerned with the latter problem and we show that it can be resolved by attributing a minimal amount of resources to the measurement of time. Although there is an absolute time in quantum mechanics, an observer can only establish a time by measuring a clock. For a local measurement, the minimal entropy production is equal to the number of ticks. This lower bound is attained by a black hole.

  3. Global Warming Hole 31 March 2015

    E-Print Network [OSTI]

    Hansen, James E.

    Global Warming Hole 31 March 2015 James Hansen Sorry to have disappeared for two months. I-thirds of North America know that global warming is really happening. In fact, 2015 should be the year that stifles discussion of a warming hiatus. A substantial developing El Nino will add to the global warming

  4. Brief review on higher spin black holes

    E-Print Network [OSTI]

    Alfredo Perez; David Tempo; Ricardo Troncoso

    2014-05-12

    We review some relevant results in the context of higher spin black holes in three-dimensional spacetimes, focusing on their asymptotic behaviour and thermodynamic properties. For simplicity, we mainly discuss the case of gravity nonminimally coupled to spin-3 fields, being nonperturbatively described by a Chern-Simons theory of two independent sl(3,R) gauge fields. Since the analysis is particularly transparent in the Hamiltonian formalism, we provide a concise discussion of their basic aspects in this context; and as a warming up exercise, we briefly analyze the asymptotic behaviour of pure gravity, as well as the BTZ black hole and its thermodynamics, exclusively in terms of gauge fields. The discussion is then extended to the case of black holes endowed with higher spin fields, briefly signaling the agreements and discrepancies found through different approaches. We conclude explaining how the puzzles become resolved once the fall off of the fields is precisely specified and extended to include chemical potentials, in a way that it is compatible with the asymptotic symmetries. Hence, the global charges become completely identified in an unambiguous way, so that different sets of asymptotic conditions turn out to contain inequivalent classes of black hole solutions being characterized by a different set of global charges.

  5. Flip-flopping binary black holes

    E-Print Network [OSTI]

    Carlos O. Lousto; James Healy

    2015-03-14

    We study binary spinning black holes to display the long term individual spin dynamics. We perform a full numerical simulation starting at an initial proper separation of $d\\approx25M$ between equal mass holes and evolve them down to merger for nearly 48 orbits, 3 precession cycles, and half of a flip-flop cycle. The simulation lasts for $t=20000M$ and displays a total change in the orientation of the spin of one of the black holes from initially aligned with the orbital angular momentum to a complete anti-alignment after half of a flip-flop cycle. We compare this evolution with an integration of the 3.5 Post-Newtonian equations of motion and spin evolution to show that this process continuously flip-flops the spin during the lifetime of the binary until merger. We also provide lower order analytic expressions for the maximum flip-flop angle and frequency. We discuss the effects this dynamics may have on spin growth in accreting binaries and on the observational consequences for galactic and supermassive binary black holes.

  6. Scalar Hairy Black Holes in General Dimensions

    E-Print Network [OSTI]

    Xing-Hui Feng; H. Lu; Qiang Wen

    2014-01-13

    We obtain a class of asymptotic flat or (A)dS hairy black holes in D-dimensional Einstein gravity coupled to a scalar with certain scalar potential. For a given mass, the theory admits both the Schwarzschild-Tangherlini and the hairy black holes with different temperature and entropy, but satisfying the same first law of thermodynamics. For some appropriate choice of parameters, the scalar potential can be expressed in terms of a super-potential and it can arise in gauged supergravities. In this case, the solutions develop a naked curvature singularity and become the spherical domain walls. Uplifting the solutions to D=11 or 10, we obtain solutions that can be viewed as spherical M-branes or D3-branes. We also add electric charges to these hairy black holes. All these solutions contain no scalar charges in that the first law of thermodynamics are unmodified. We also try to construct new AdS black holes carrying scalar charges, with some moderate success in that the charges are pre-fixed in the theory instead of being some continuous integration constants.

  7. Scalar Hairy Black Holes in General Dimensions

    E-Print Network [OSTI]

    Feng, Xing-Hui; Wen, Qiang

    2013-01-01

    We obtain a class of asymptotic flat or (A)dS hairy black holes in D-dimensional Einstein gravity coupled to a scalar with certain scalar potential. For a given mass, the theory admits both the Schwarzschild-Tangherlini and the hairy black holes with different temperature and entropy, but satisfying the same first law of thermodynamics. For some appropriate choice of parameters, the scalar potential can be expressed in terms of a super-potential and it can arise in gauged supergravities. In this case, the solutions develop a naked curvature singularity and become the spherical domain walls. Uplifting the solutions to D=11 or 10, we obtain solutions that can be viewed as spherical M-branes or D3-branes. We also add electric charges to these hairy black holes. All these solutions contain no scalar charges in that the first law of thermodynamics are unmodified. We also try to construct new AdS black holes carrying scalar charges, with some moderate success in that the charges are pre-fixed in the theory instead ...

  8. Remote down-hole well telemetry

    DOE Patents [OSTI]

    Briles, Scott D. (Los Alamos, NM); Neagley, Daniel L. (Albuquerque, NM); Coates, Don M. (Santa Fe, NM); Freund, Samuel M. (Los Alamos, NM)

    2004-07-20

    The present invention includes an apparatus and method for telemetry communication with oil-well monitoring and recording instruments located in the vicinity of the bottom of gas or oil recovery pipes. Such instruments are currently monitored using electrical cabling that is inserted into the pipes; cabling has a short life in this environment, and requires periodic replacement with the concomitant, costly shutdown of the well. Modulated reflectance, a wireless communication method that does not require signal transmission power from the telemetry package will provide a long-lived and reliable way to monitor down-hole conditions. Normal wireless technology is not practical since batteries and capacitors have to frequently be replaced or recharged, again with the well being removed from service. RF energy generated above ground can also be received, converted and stored down-hole without the use of wires, for actuating down-hole valves, as one example. Although modulated reflectance reduces or eliminates the loss of energy at the sensor package because energy is not consumed, during the transmission process, additional stored extra energy down-hole is needed.

  9. Lower-Dimensional Black Hole Chemistry

    E-Print Network [OSTI]

    Antonia M. Frassino; Robert B. Mann; Jonas R. Mureika

    2015-09-18

    The connection between black hole thermodynamics and chemistry is extended to the lower-dimensional regime by considering the rotating and charged BTZ metric in the $(2+1)$-D and a $(1+1)$-D limits of Einstein gravity. The Smarr relation is naturally upheld in both BTZ cases, where those with $Q \

  10. Strains and Jets in Black Hole Fields

    E-Print Network [OSTI]

    D. Bini; F. de Felice; A. Geralico

    2007-12-14

    We study the behaviour of an initially spherical bunch of particles emitted along trajectories parallel to the symmetry axis of a Kerr black hole. We show that, under suitable conditions, curvature and inertial strains compete to generate jet-like structures.

  11. Optical orientation of holes in strained nanostructures

    SciTech Connect (OSTI)

    Averkiev, N. S.; Sablina, N. I.

    2008-03-15

    A theory describing the optical orientation and Hanle effect for holes in quantum wells or quantum dots based on cubic semiconductors is developed. It is demonstrated that the presence of internal or external strain in quantum-confinement heterostructures leads to the dependence of the Hanle effect on the orientation of the magnetic field with respect to the heterostructure growth axis.

  12. Area products for black hole horizons

    E-Print Network [OSTI]

    Visser, Matt

    2013-01-01

    Area products for multi-horizon black holes often have intriguing properties, and are often independent of the mass of the black hole (depending only on various charges, angular momenta, and moduli). Such products are often formulated in terms of the areas of inner (Cauchy) horizons and event horizons, and often include the effects of unphysical "virtual'" horizons. For the Schwarzschild-de Sitter [Kottler] black hole in (3+1) dimensions it is shown by explicit exact calculation that the product of event horizon area and cosmological horizon area is not mass independent. (Including the effect of the third "virtual" horizon does not improve the situation.) Similarly, in the Reissner-Nordstrom-anti-de Sitter black hole in (3+1) dimensions the product of inner (Cauchy) horizon area and event horizon area is calculated (perturbatively), and is shown to be not mass independent. That is, the mass-independence of the product of physical horizon areas is not generic. In the generic situation, whenever the quasi-local...

  13. Ultra-Close Encounters of Stars With Massive Black Holes: Tidal Disruption Events With Prompt Hyperaccretion

    E-Print Network [OSTI]

    Christopher Evans; Pablo Laguna; Michael Eracleous

    2015-06-01

    A bright flare from a galactic nucleus followed at late times by a $t^{-5/3}$ decay in luminosity is often considered the signature of the complete tidal disruption of a star by a massive black hole. The flare and power-law decay are produced when the stream of bound debris returns to the black hole, self-intersects, and eventually forms an accretion disk or torus. In the canonical scenario of a solar-type star disrupted by a $10^{6}\\; M_\\odot$ black hole, the time between the disruption of the star and the formation of the accretion torus could be years. We present fully general relativistic simulations of a new class of tidal disruption events involving ultra-close encounters of solar-type stars with intermediate mass black holes. In these encounters, a thick disk forms promptly after disruption, on timescales of hours. After a brief initial flare, the accretion rate remains steady and highly super-Eddington for a few days at $\\sim 10^2\\,M_\\odot\\,{\\rm yr}^{-1}$.

  14. Effects of gravitational-wave recoil on the dynamics and growth of supermassive black holes

    E-Print Network [OSTI]

    Laura Blecha; Abraham Loeb

    2008-08-01

    Simulations of binary black hole mergers indicate that asymmetrical gravitational wave (GW) emission can cause black holes to recoil at speeds up to thousands of km/s. These GW recoil events can dramatically affect the coevolution of recoiling supermassive black holes (SMBHs) and their host galaxies. However, theoretical studies of SMBH-galaxy evolution almost always assume a stationary central black hole. In light of the numerical results on GW recoil velocities, we relax that assumption here and consider the consequences of recoil for SMBH evolution. We follow the trajectories of SMBHs ejected in a smooth background potential that includes both a stellar bulge and a multi-component gaseous disk. In addition, we calculate the accretion rate onto the SMBH as a function of time using a hybrid prescription of viscous (alpha-disk) and Bondi accretion. We find that recoil kicks between 100 km/s and the escape speed cause SMBHs to wander through the galaxy and halo for about 1 Myr - 1 Gyr before settling back to the galactic center. However, the mass accreted during this time is roughly constant at about 10% of the initial mass, independent of the recoil velocity. This indicates that while large recoils may disrupt active galactic nuclei feedback processes, recoil itself is an effective means of regulating SMBH growth. Recoiling SMBHs may be observable as spatially or kinematically offset quasars, but finding such systems could be challenging, because the largest offsets correspond to the shortest quasar lifetimes.

  15. Comparison of the Window-Frame RHIC-abort kicker with C-type Kicker

    SciTech Connect (OSTI)

    Tsoupas, N.; Hahn, H.; Meng, W.; Severance, Michael; McMahan, Brandon

    2014-08-26

    The high intensity proton bunches (~2.5x1011 p/bunch ) circulating in RHIC increase the temperature of the ferrite-made RHIC-abort-kickers above the Curie point; as a result, the kickers cannot provide the required field to abort the beam at the beam dump. A team of experts in the CAD department worked on modifying the design of the window-frame RHIC-abort kicker to minimize the hysteresis losses responsible for the increase of the ferrite’s temperature. In this technical note we report some results from the study of two possible modifications of the window-frame RHIC-abort kicker, and we compare these results with those of a propose C-type RHIC-abort kicker. We also include an Appendix where we describe a method which may further reduce the hysteresis losses of the window-frame kicker.

  16. Ultra-scale vehicle tracking in low spatial-resolution and low frame-rate overhead video

    SciTech Connect (OSTI)

    Carrano, C J

    2009-05-20

    Overhead persistent surveillance systems are becoming more capable at acquiring wide-field image sequences for long time-spans. The need to exploit this data is becoming ever greater. The ability to track a single vehicle of interest or to track all the observable vehicles, which may number in the thousands, over large, cluttered regions while they persist in the imagery either in real-time or quickly on-demand is very desirable. With this ability we can begin to answer a number of interesting questions such as, what are normal traffic patterns in a particular region or where did that truck come from? There are many challenges associated with processing this type of data, some of which we will address in the paper. Wide-field image sequences are very large with many thousands of pixels on a side and are characterized by lower resolutions (e.g. worse than 0.5 meters/pixel) and lower frame rates (e.g. a few Hz or less). The objects in the scenery can vary in size, density, and contrast with respect to the background. At the same time the background scenery provides a number of clutter sources both man-made and natural. We describe our current implementation of an ultrascale capable multiple-vehicle tracking algorithm for overhead persistent surveillance imagery as well as discuss the tracking and timing performance of the currently implemented algorithm which is aimed at utilizing grayscale electrooptical image sequences alone for the track segment generation.

  17. Implications of access hole size on tank waste retrieval system design and cost

    SciTech Connect (OSTI)

    Babcock, S.M.; Kwon, D.S.; Burks, B.L.; Stoughton, R.S.; Evans, M.S.

    1994-05-01

    The DOE Environmental Restoration and Waste Management Robotics Technology Development Program has been investigating the application of robotics technology to the retrieval of waste from single-shell storage tanks for several years. The use of a large, ``long-reach`` manipulator to position and orient a variety of tools and other equipment has been recommended. The objective of this study is to determine the appropriate access hole size for the tank waste retrieval system installation. Previous reports on the impact of access hole size on manipulator performance are summarized. In addition, the practical limitation for access hole size based on structural limitations of the waste storage tanks, the state-of-the-art size limitations for the installation of new risers, the radiation safety implications of various access hole sizes, and overall system cost implications are considered. Basic conclusions include: (1) overall cost of remediation will; be dominated by the costs of the balance of plant and time required to perform the task rather than the cost of manipulator hardware or the cost of installing a riser, (2) the most desirable solution from a manipulator controls point of view is to make the manipulator as stiff as possible and have as high as possible a natural frequency, which implies a large access hole diameter, (3) beyond some diameter; simple, uniform cross-section elements become less advantageous from a weight standpoint and alternative structures should be considered, and (4) additional shielding and contamination control measures would be required for larger holes. Parametric studies summarized in this report considered 3,790,000 1 (1,000,000 gal) tanks, while initial applications are likely to be for 2,840,000 1 (750,000 gal) tanks. Therefore, the calculations should be somewhat conservative, recognizing the limitations of the specific conditions considered.

  18. Sowing the seeds of massive black holes in small galaxies: Young clusters as the building blocks of ultracompact dwarf galaxies

    SciTech Connect (OSTI)

    Amaro-Seoane, Pau [Max Planck Institut für Gravitationsphysik (Albert-Einstein-Institut), D-14476 Potsdam (Germany); Konstantinidis, Symeon [Astronomisches Rechen-Institut, Zentrum für Astronomie, Universität Heidelberg, Mönchhofstraße 12-14, Heidelberg D-69120 (Germany); Freitag, Marc Dewi [Institute of Astronomy, Madingley Road, CB3 0HA Cambridge (United Kingdom); Coleman Miller, M. [Department of Astronomy and Joint Space-Science Institute, University of Maryland, College Park, MD 20742-2421 (United States); Rasio, Frederic A., E-mail: Pau.Amaro-Seoane@aei.mpg.de, E-mail: simos@ari.uni-heidelberg.de, E-mail: marc.freitag@gmail.com, E-mail: miller@astro.umd.edu, E-mail: rasio@northwestern.edu [Department of Physics and Astronomy, and Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Northwestern University, Evanston, IL 60208 (United States)

    2014-02-20

    Interacting galaxies often have complexes of hundreds of young stellar clusters of individual masses ?10{sup 4}-10{sup 6} M {sub ?} in regions that are a few hundred parsecs across. These cluster complexes interact dynamically, and their coalescence is a candidate for the origin of some ultracompact dwarf galaxies. Individual clusters with short relaxation times are candidates for the production of intermediate-mass black holes of a few hundred solar masses, via runaway stellar collisions prior to the first supernovae in a cluster. It is therefore possible that a cluster complex hosts multiple intermediate-mass black holes that may be ejected from their individual clusters due to mergers or binary processes, but bound to the complex as a whole. Here we explore the dynamical interaction between initially free-flying massive black holes and clusters in an evolving cluster complex. We find that, after hitting some clusters, it is plausible that the massive black hole will be captured in an ultracompact dwarf forming near the center of the complex. In the process, the hole typically triggers electromagnetic flares via stellar disruptions, and is also likely to be a prominent source of gravitational radiation for the advanced ground-based detectors LIGO and VIRGO. We also discuss other implications of this scenario, notably that the central black hole could be considerably larger than expected in other formation scenarios for ultracompact dwarfs.

  19. All 4-dimensional static, spherically symmetric, 2-charge abelian Kaluza-Klein black holes and their CFT duals

    E-Print Network [OSTI]

    Edwin Barnes; Diana Vaman; Chaolun Wu

    2009-10-26

    We derive the dual CFT Virasoro algebras from the algebra of conserved diffeomorphism charges, for a large class of abelian Kaluza-Klein black holes. Under certain conditions, such as non-vanishing electric and magnetic monopole charges, the Kaluza-Klein black holes have a Reissner-Nordstrom space-time structure. For the non-extremal charged Kaluza-Klein black holes, we use the uplifted 6d pure gravity solutions to construct a set of Killing horizon preserving diffeomorphisms. For the (non-supersymmetric) extremal black holes, we take the NENH limit, and construct a one-parameter family of diffeomorphisms which preserve the Hamiltonian constraints at spatial infinity. In each case we evaluate the algebra of conserved diffeomorphism charges following Barnich, Brandt and Compere, who used a cohomological approach, and Silva, who employed a covariant-Lagrangian formalism. At the Killing horizon, it is only Silva's algebra which acquires a central charge extension, and which enables us to recover the Bekenstein-Hawking black hole entropy from the Cardy formula. For the NENH geometry, the extremal black hole entropy is obtained only when the free parameter of the diffeomorphism generating vector fields is chosen such that the central terms of the two algebras are in agreement.

  20. Trumpet-puncture initial data for black holes

    SciTech Connect (OSTI)

    Immerman, Jason D.; Baumgarte, Thomas W.

    2009-09-15

    We propose a new approach, based on the puncture method, to construct black hole initial data in the so-called trumpet geometry, i.e. on slices that asymptote to a limiting surface of nonzero areal radius. Our approach is easy to implement numerically and, at least for nonspinning black holes, does not require any internal boundary conditions. We present numerical results, obtained with a uniform-grid finite-difference code, for boosted black holes and binary black holes. We also comment on generalizations of this method for spinning black holes.

  1. Dissipation in a rotating frame: Master equation, effective temperature, and Lamb shift

    SciTech Connect (OSTI)

    Verso, Alvise; Ankerhold, Joachim

    2010-02-15

    Motivated by recent realizations of microwave-driven nonlinear resonators in superconducting circuits, the impact of environmental degrees of freedom is analyzed as seen from a rotating frame. A system plus reservoir model is applied to consistently derive in the weak coupling limit the master equation for the reduced density in the moving frame and near the first bifurcation threshold. The concept of an effective temperature is introduced to analyze to what extent a detailed balance relation exists. Explicit expressions are also found for the Lamb-shift. Results for ohmic baths are in agreement with experimental findings, while for structured environments population inversion is predicted that may qualitatively explain recent observations.

  2. Particle rapidity distribution in proton-nucleus collisions using the proton-contributor reference frame

    E-Print Network [OSTI]

    Gines Martinez-Garcia

    2014-08-14

    I define the proton-contributor reference frame in proton nucleus (p--A) collisions as the center of mass of the system formed by the proton and the participant nucleons of the nucleus. Assuming that the rapidity distribution of produced particles is symmetric in the proton-contributor reference frame, several measurements in p-Pb collisions at $\\sqrt{s_{\\rm NN}} = 5.02 {\\rm TeV}$ can be described qualitatively. These include rapidity distributions of charged particles, $J/\\psi$ and Z bosons.

  3. Rotating-frame gradient fields for magnetic resonance imaging and nuclear magnetic resonance in low fields

    DOE Patents [OSTI]

    Bouchard, Louis-Serge; Pines, Alexander; Demas, Vasiliki

    2014-01-21

    A system and method for Fourier encoding a nuclear magnetic resonance (NMR) signal is disclosed. A static magnetic field B.sub.0 is provided along a first direction. An NMR signal from the sample is Fourier encoded by applying a rotating-frame gradient field B.sub.G superimposed on the B.sub.0, where the B.sub.G comprises a vector component rotating in a plane perpendicular to the first direction at an angular frequency .omega.in a laboratory frame. The Fourier-encoded NMR signal is detected.

  4. On naked singularities in higher dimensional Vaidya space-times

    E-Print Network [OSTI]

    S. G. Ghosh; Naresh Dadhich

    2001-05-28

    We investigate the end state of gravitational collapse of null fluid in higher dimensional space-times. Both naked singularities and black holes are shown to be developing as final outcome of the collapse. The naked singularity spectrum in collapsing Vaidya region (4D) gets covered with increase in dimensions and hence higher dimensions favor black hole in comparison to naked singularity. The Cosmic Censorship Conjecture will be fully respected for a space of infinite dimension.

  5. Acoustic clouds: standing sound waves around a black hole analogue

    E-Print Network [OSTI]

    Carolina L. Benone; Luis C. B. Crispino; Carlos Herdeiro; Eugen Radu

    2015-01-28

    Under certain conditions sound waves in fluids experience an acoustic horizon with analogue properties to those of a black hole event horizon. In particular, a draining bathtub-like model can give rise to a rotating acoustic horizon and hence a rotating black hole (acoustic) analogue. We show that sound waves, when enclosed in a cylindrical cavity, can form stationary waves around such rotating acoustic black holes. These acoustic perturbations display similar properties to the scalar clouds that have been studied around Kerr and Kerr-Newman black holes; thus they are dubbed acoustic clouds. We make the comparison between scalar clouds around Kerr black holes and acoustic clouds around the draining bathtub explicit by studying also the properties of scalar clouds around Kerr black holes enclosed in a cavity. Acoustic clouds suggest the possibility of testing, experimentally, the existence and properties of black hole clouds, using analog models.

  6. Thermodynamic Relations for Kiselev and Dilaton Black Hole

    E-Print Network [OSTI]

    Bushra Majeed; Mubasher Jamil; Parthapratim Pradhan

    2015-08-24

    We investigate the thermodynamics and phase transition for Kiselev black hole and dilaton black hole. Speci?cally we consider Reissner Nordstrom black hole surrounded by radiation and dust, and Schwarzschild black hole surrounded by quintessence, as special cases of Kiselev solution. We have calculated the products relating the surface gravities, surface temperatures, Komar energies, areas, entropies, horizon radii and the irreducible masses at the Cauchy and the event horizons. It is observed that the product of surface gravities, surface temperature product and product of Komar energies at the horizons are not universal quantities for the Kiselev solutions while products of areas and entropies at both the horizons are independent of mass of the above mentioned black holes (except for Schwarzschild black hole surrounded by quintessence). For charged dilaton black hole, all the products vanish. First law of thermodynamics is also veri?ed for Kiselev solutions. Heat capacities are calculated and phase transitions are observed, under certain conditions.

  7. Quantization of black holes by analogy with hydrogen atoms

    E-Print Network [OSTI]

    Chang Liu; Yan-Gang Miao; Yu-Mei Wu; Yu-Hao Zhang

    2015-11-16

    We suggest a proposal of quantization for black holes that is based on an analogy between a black hole and a hydrogen atom. A self-regular Schwarzschild-AdS black hole is investigated, where the mass density of the extreme black hole is given by the probability density of the ground state of hydrogen atoms and the mass densities of non-extreme black holes are chosen to be the probability densities of excited states with no angular momenta. Consequently, it is logical to accept quantization of mean radii of hydrogen atoms as that of black hole horizons. In this way, quantization of total black hole masses is deduced. Furthermore, the quantum hoop conjecture and the Correspondence Principle are discussed.

  8. Quantization of black holes by analogy with hydrogen atoms

    E-Print Network [OSTI]

    Liu, Chang; Wu, Yu-Mei; Zhang, Yu-Hao

    2015-01-01

    We suggest a proposal of quantization for black holes that is based on an analogy between a black hole and a hydrogen atom. A self-regular Schwarzschild-AdS black hole is investigated, where the mass density of the extreme black hole is given by the probability density of the ground state of hydrogen atoms and the mass densities of non-extreme black holes are chosen to be the probability densities of excited states with no angular momenta. Consequently, it is logical to accept quantization of mean radii of hydrogen atoms as that of black hole horizons. In this way, quantization of total black hole masses is deduced. Furthermore, the quantum hoop conjecture and the Correspondence Principle are discussed.

  9. Quantization of black holes by analogy with hydrogen atoms

    E-Print Network [OSTI]

    Chang Liu; Yan-Gang Miao; Yu-Mei Wu; Yu-Hao Zhang

    2015-11-23

    We suggest a proposal of quantization for black holes that is based on an analogy between a black hole and a hydrogen atom. A self-regular Schwarzschild-AdS black hole is investigated, where the mass density of the extreme black hole is given by the probability density of the ground state of hydrogen atoms and the mass densities of non-extreme black holes are chosen to be the probability densities of excited states with no angular momenta. Consequently, it is logical to accept quantization of mean radii of hydrogen atoms as that of black hole horizons. In this way, quantization of total black hole masses is deduced. Furthermore, the quantum hoop conjecture and the Correspondence Principle are discussed.

  10. Energy Extraction from Spinning Black Holes via Relativistic Jets

    E-Print Network [OSTI]

    Ramesh Narayan; Jeffrey E. McClintock; Alexander Tchekhovskoy

    2013-03-12

    It has for long been an article of faith among astrophysicists that black hole spin energy is responsible for powering the relativistic jets seen in accreting black holes. Two recent advances have strengthened the case. First, numerical general relativistic magnetohydrodynamic simulations of accreting spinning black holes show that relativistic jets form spontaneously. In at least some cases, there is unambiguous evidence that much of the jet energy comes from the black hole, not the disk. Second, spin parameters of a number of accreting stellar-mass black holes have been measured. For ballistic jets from these systems, it is found that the radio luminosity of the jet correlates with the spin of the black hole. This suggests a causal relationship between black hole spin and jet power, presumably due to a generalized Penrose process.

  11. Mass estimate of the XTE J1650-500 black hole from the Extended Orbital Resonance Model for high-frequency QPOs

    E-Print Network [OSTI]

    Petr Slany; Zdenek Stuchlik

    2008-10-01

    XTE J1650-500 is a Galactic black-hole binary system for which at least one high-frequency QPO at 250Hz was reported. Moreover there are indications that the system harbours a near-extreme Kerr black-hole with the spin near 0.998 and mass M0.9953, being analyzed in the locally non-rotating frames, reveals a hump near the marginally stable orbit. Further it was suggested that the hump could excite the epicyclic motion of particles near the ISCO with frequencies typical for high-frequency QPOs. Characteristic frequency of the hump-induced oscillations was defined as the maximal positive rate of change of the LNRF-related orbital velocity with the proper radial distance. If the characteristic "humpy frequency" and the radial epicyclic frequency are commensurable, strong resonant phenomena are expected. For the Kerr black hole with the spin a=0.9982 the "humpy frequency" and the radial epicyclic frequency are in ratio 1:3. Identifying the radial epicyclic frequency with the observed 250Hz QPO, we get the mass of the black hole in XTE J1650-500 near 5.1M_sun.

  12. The Role of Primordial Kicks on Black Hole Merger Rates

    E-Print Network [OSTI]

    Miroslav Micic; Tom Abel; Steinn Sigurdsson

    2006-09-15

    Primordial stars are likely to be very massive >30 Msun, form in isolation, and will likely leave black holes as remnants in the centers of their host dark matter halos. We expect primordial stars to form in halos in the mass range 10^6-10^10 Msun. Some of these early black holes, formed at redshifts z>10, could be the seed black hole for a significant fraction of the supermassive black holes found in galaxies in the local universe. If the black hole descendants of the primordial stars exist, their mergers with nearby supermassive black holes may be a prime candidate for long wavelength gravitational wave detectors. We simulate formation and evolution of dark matter halos in LambdaCDM universe. We seed high-redshift dark matter halos with early black holes, and explore the merger history of the host halos and the implications of black hole's kick velocities arising from their coalescence. The central concentration of low mass early black holes in present day galaxies is reduced if they experience even moderate kicks of tens of km/s. Even such modest kicks allow the black holes to leave their parent halo, which consequently leads to dynamical friction being less effective on the low mass black holes that were ejected, compared to those still embedded in their parent halos. Therefore, merger rates with central supermassive black holes in the largest halos may be reduced by more than an order of magnitude. Using analytical and illustrative cosmological N-body simulations, we quantify the role of kicks on the merger rates of black holes formed from massive metal free stars with supermassive black holes in present day galaxies.

  13. Effects of hyperbolic rotation in Minkowski space on the modeling of plasma accelerators in a Lorentz boosted frame

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    space resulting from the use of Lorentz boosted frames of calculation on laser propagation in plasmas in the plasma column in space-tim

  14. Building America Webinar: High-Performance Enclosure Strategies, Part I: Unvented Roof Systems and Innovative Advanced Framing Strategies

    Broader source: Energy.gov [DOE]

    This presentation was delivered at the February 12, 2015, Building America webinar, High-Performance Enclosure Strategies, Part I: Unvented Roof Systems and Innovative Advanced Framing Strategies.

  15. The Parkes Pulsar Timing Array

    E-Print Network [OSTI]

    R N Manchester

    2006-04-13

    Given sufficient sensitivity, pulsar timing observations can make a direct detection of gravitational waves passing over the Earth. Pulsar timing is most sensitive to gravitational waves with frequencies in the nanoHertz region, with the most likely astronomical sources being binary super-massive black holes in galaxy cores. The Parkes Pulsar Timing Array project uses the Parkes 64-m radio telescope to make precision timing observations of a sample of about 20 millisecond pulsars with a principal goal of making a direct detection of gravitational waves. Observations commenced about one year ago and so far sub-microsecond timing residuals have been achieved for more than half of these pulsars. New receiver and software systems are being developed with the aim of reducing these residuals to the level believed necessary for a positive detection of gravitational waves.

  16. Rotating analogue black holes: Quasinormal modes and tails, superresonance, and sonic bombs and plants in the draining bathtub acoustic hole

    E-Print Network [OSTI]

    José P. S. Lemos

    2013-12-27

    The analogy between sound wave propagation and light waves led to the study of acoustic holes, the acoustic analogues of black holes. Many black hole features have their counterparts in acoustic holes. The Kerr metric, the rotating metric for black holes in general relativity, has as analogue the draining bathtub metric, a metric for a rotating acoustic hole. Here we report on the progress that has been made in the understanding of features, such as quasinormal modes and tails, superresonance, and instabilities when the hole is surrounded by a reflected mirror, in the draining bathtub metric. Given then the right settings one can build up from these instabilities an apparatus that stores energy in the form of amplified sound waves. This can be put to wicked purposes as in a bomb, or to good profit as in a sonic plant.

  17. PERFORMANCE-BASED PLASTIC DESIGN METHOD FOR BUCKLING-RESTRAINED BRACED FRAMES

    E-Print Network [OSTI]

    Chao, Shih-Ho

    depends on the natural period of the structure, the modal properties, and the intended plastic drift ratioPERFORMANCE-BASED PLASTIC DESIGN METHOD FOR BUCKLING- RESTRAINED BRACED FRAMES D. R. Sahoo1 and S) by using the performance-based plastic design (PBPD) methodology. This method is based on energy

  18. The Impact of Transmit Buffer on EDCF with Frame-Bursting Option for Wireless Networks

    E-Print Network [OSTI]

    Selvadurai, Selvakennedy

    a single contention, an optional feature known as controlled frame- bursting (CFB) is introduced in its with the CFB option to quantify its performance gain. The impact of the MAC transmit buffer size is also duration limit. It is demonstrated that an optimized CFB configuration allows the MAC protocol to achieve

  19. Frame-Scheduling for Input-Queued Switches with Energy Reconfiguration Costs

    E-Print Network [OSTI]

    Frame-Scheduling for Input-Queued Switches with Energy Reconfiguration Costs Andrea Bianco, Paolo problems, mainly due to thermal issues that require complex cooling systems and to increasing energy costs scheduler determines a switching fabric configuration to transfer packets. We consider the energy

  20. Aalborg Universitet Control of parallel-connected bidirectional AC-DC converters in stationary frame for

    E-Print Network [OSTI]

    Kerekes, Tamas

    frame for microgrid application Lu, Xiaonan; Guerrero, Josep M.; Teodorescu, Remus; Kerekes, Tamas; Sun, Kai; Huang , Lipei Published in: Proceedings of the 3rd IEEE Energy Conversion Congress and Exposition for published version (APA): Lu, X., Guerrero, J. M., Teodorescu, R., Kerekes, T., Sun, K., & Huang , L. (2011