King, Anthony Laurence
1974-01-01T23:59:59.000Z
. , Texas ASM University; Chairman of Advisory Committee: Dr. David M, Moehring In this study wood specific gravity values of 220 plantation grown slash pine (Pinus elliottii Engelm. ) trees growing in East Texas were calculated and related to tree... parameters. Also tree dry weight (DW) relationships with tree parameters were determined and dry weight tables calculated. Average specific gravity values of cores and disks at breast height and tree specific gravities respectively were 0. 457, 0. 493...
STATE OF CALIFORNIA AREA WEIGHTED AVERAGE CALCULATION WORKSHEET: RESIDENTIAL
of a building feature, material, or construction assembly occur in a building, a weighted average there is more than one level of floor, wall, or ceiling insulation in a building, or more than one type
Optimal Control with Weighted Average Costs and Temporal Logic Specifications
Murray, Richard M.
Optimal Control with Weighted Average Costs and Temporal Logic Specifications Eric M. Wolff Control and Dynamical Systems California Institute of Technology Pasadena, California 91125 Email: ewolff@caltech.edu Ufuk Topcu Control and Dynamical Systems California Institute of Technology Pasadena, California 91125
Sulfur Content, Weighted Average Refinery Crude Oil Input Qualities
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API Gravity Period: Monthly Annual Download Series History Download Series History Definitions, Sources & Notes Definitions,
POLYMER END-GROUP ANALYSIS: THE DETERMINATION OF AVERAGE MOLECULAR WEIGHT
Weston, Ken
POLYMER END-GROUP ANALYSIS: THE DETERMINATION OF AVERAGE MOLECULAR WEIGHT Background reading. 11. Skoog, West, Holler and Crouch, 7th ed., Chap. 14. Introduction Polymers Polymers are a special in this experiment, or may be of different types. Polymers are very important in biological systems. For example
Expansion and Growth of Structure Observables in a Macroscopic Gravity Averaged Universe
Wijenayake, Tharake
2015-01-01T23:59:59.000Z
We investigate the effect of averaging inhomogeneities on expansion and large-scale structure growth observables using the exact and covariant framework of Macroscopic Gravity (MG). It is well-known that applying the Einstein's equations and spatial averaging do not commute and lead to the averaging problem. For the MG formalism applied to the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric, this gives an extra dynamical term encapsulated as an averaging density parameter denoted $\\Omega_A$. An exact isotropic cosmological solution of MG for the flat FLRW metric is already known in the literature, we derive here an anisotropic exact solution. Using the isotropic solution, we compare the expansion history to current data of distances to supernovae, Baryon Acoustic Oscillations, CMB last scattering surface, and Hubble constant measurements, and find $-0.05 \\le \\Omega_A \\le 0.07$ (at the 95% CL). For the flat metric case this reduces to $-0.03 \\le \\Omega_A \\le 0.05$. We also find that the inclusion of this ter...
Kearns, Michael
in the fact that it does not require such cost predictions. VWAP vs. Arrival Price So how does arrival priceImplementation Shortfall Â One Objective, Many Algorithms VWAP (Volume Weighted Average Price) has year toward using decision price, or implementation shortfall, algorithms. ITGÂ®'s Hitesh Mittal
Rouhani, S. Zia (Idaho Falls, ID)
1996-01-01T23:59:59.000Z
In most electrochemical batteries which generate electricity through the reaction of a battery electrode with an electrolyte solution, the chemical composition, and thus the weight and density, of the electrode changes as the battery discharges. The invention measures a parameter of the battery which changes as the weight of the electrode changes as the battery discharges and relates that parameter to the value of the parameter when the battery is fully charged and when the battery is functionally discharged to determine the state-of-charge of the battery at the time the parameter is measured. In one embodiment, the weight of a battery electrode or electrode unit is measured to determine the state-of-charge. In other embodiments, where a battery electrode is located away from the geometrical center of the battery, the position of the center of gravity of the battery or shift in the position of the center of gravity of the battery is measured (the position of the center of gravity changes with the change in weight of the electrode) and indicates the state-of-charge of the battery.
Rouhani, S.Z.
1996-12-03T23:59:59.000Z
In most electrochemical batteries which generate electricity through the reaction of a battery electrode with an electrolyte solution, the chemical composition, and thus the weight and density, of the electrode changes as the battery discharges. The invention measures a parameter of the battery which changes as the weight of the electrode changes as the battery discharges and relates that parameter to the value of the parameter when the battery is fully charged and when the battery is functionally discharged to determine the state-of-charge of the battery at the time the parameter is measured. In one embodiment, the weight of a battery electrode or electrode unit is measured to determine the state-of-charge. In other embodiments, where a battery electrode is located away from the geometrical center of the battery, the position of the center of gravity of the battery or shift in the position of the center of gravity of the battery is measured (the position of the center of gravity changes with the change in weight of the electrode) and indicates the state-of-charge of the battery. 35 figs.
Meynet, Georges; Georgy, Cyril
2015-01-01T23:59:59.000Z
(abridged) The flux-weighted gravity-luminosity relationship (FGLR) of blue supergiant stars (BSG) links their absolute magnitude to the spectroscopically determined flux-weighted gravity log g = Teff^4. BSG are the brightest stars in the universe at visual light and the application of the FGLR has become a powerful tool to determine extragalactic distances. Observationally, the FGLR is a tight relationship with only small scatter. It is, therefore, ideal to be used as a constraint for stellar evolution models. The goal of this work is to investigate whether stellar evolution can reproduce the observed FGLR and to develop an improved foundation of the FGLR as an extragalactic distance indicator. We use different grids of stellar models for initial masses between 9 and 40 Msun, for metallicities between Z = 0.002 and 0.014, with and without rotation, computed with various mass loss rates during the red supergiant phase. For each of these models we discuss the details of post-main sequence evolution and constru...
average state iq: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
6 STATE OF CALIFORNIA AREA WEIGHTED AVERAGE CALCULATION WORKSHEET: RESIDENTIAL Energy Storage, Conversion and Utilization Websites Summary: STATE OF CALIFORNIA AREA...
Light weight phosphate cements
Wagh, Arun S. (Naperville, IL); Natarajan, Ramkumar, (Woodridge, IL); Kahn, David (Miami, FL)
2010-03-09T23:59:59.000Z
A sealant having a specific gravity in the range of from about 0.7 to about 1.6 for heavy oil and/or coal bed methane fields is disclosed. The sealant has a binder including an oxide or hydroxide of Al or of Fe and a phosphoric acid solution. The binder may have MgO or an oxide of Fe and/or an acid phosphate. The binder is present from about 20 to about 50% by weight of the sealant with a lightweight additive present in the range of from about 1 to about 10% by weight of said sealant, a filler, and water sufficient to provide chemically bound water present in the range of from about 9 to about 36% by weight of the sealant when set. A porous ceramic is also disclosed.
Distributed Average Consensus with Time-Varying Metropolis Weights
computing; Metropolis algorithm. 1 Introduction We consider a set of interconnected processes (nodes falls into a broader class of distributed con- sensus or agreement problems in multi-agent coordina,17,24,10,15,18]. In gen- eral consensus or agreement problems, the asymptotic values of xi(t) must be the same for all i
Al-Haji, A.; Al-Omair, A.
2010-01-01T23:59:59.000Z
Green-weight is a novel system designed to supply a high-rise building with all its needs of electricity using wind energy and to supplement its lighting needs with natural sunlight. David Fisher has proposed an ingenious method to harness the wind...
Is nonrelativistic gravity possible?
Kocharyan, A. A. [School of Mathematical Sciences, Monash University, Clayton 3800 (Australia)
2009-07-15T23:59:59.000Z
We study nonrelativistic gravity using the Hamiltonian formalism. For the dynamics of general relativity (relativistic gravity) the formalism is well known and called the Arnowitt-Deser-Misner (ADM) formalism. We show that if the lapse function is constrained correctly, then nonrelativistic gravity is described by a consistent Hamiltonian system. Surprisingly, nonrelativistic gravity can have solutions identical to relativistic gravity ones. In particular, (anti-)de Sitter black holes of Einstein gravity and IR limit of Horava gravity are locally identical.
B. L. Hu
1999-02-22T23:59:59.000Z
We give a summary of the status of current research in stochastic semiclassical gravity and suggest directions for further investigations. This theory generalizes the semiclassical Einstein equation to an Einstein-Langevin equation with a stochastic source term arising from the fluctuations of the energy-momentum tensor of quantum fields. We mention recent efforts in applying this theory to the study of black hole fluctuations and backreaction problems, linear response of hot flat space, and structure formation in inflationary cosmology. To explore the physical meaning and implications of this stochastic regime in relation to both classical and quantum gravity, we find it useful to take the view that semiclassical gravity is mesoscopic physics and that general relativity is the hydrodynamic limit of certain spacetime quantum substructures. Three basic issues - stochasticity, collectivity, correlations- and three processes - dissipation, fluctuations, decoherence- underscore the transformation from quantum micro structure and interaction to the emergence of classical macro structure and dynamics. We discuss ways to probe into the high energy activity from below and make two suggestions: via effective field theory and the correlation hierarchy. We discuss how stochastic behavior at low energy in an effective theory and how correlation noise associated with coarse-grained higher correlation functions in an interacting quantum field could carry nontrivial information about the high energy sector. Finally we describe processes deemed important at the Planck scale, including tunneling and pair creation, wave scattering in random geometry, growth of fluctuations and forms, Planck scale resonance states, and spacetime foams.
Quantum Field Theory & Gravity
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Quantum Field Theory & Gravity Quantum Field Theory & Gravity Understanding discoveries at the Energy, Intensity, and Cosmic Frontiers Get Expertise Rajan Gupta (505) 667-7664...
Molecular weight and molecular weight distribution of kraft lignins
Schmidl, W.; Dong, D.; Fricke, A.L. (Univ. of Florida, Gainesville, FL (United States))
1990-01-01T23:59:59.000Z
Kraft lignins are the lignin degradation products from kraft pulping. They are complex, heterogeneous polymers with some polar character. The molecular weight of kraft lignins greatly affect the physical properties of black liquors, and are of primary importance in separation from black liquor and in evaluating potential uses. Several purified kraft lignins from slash pine were analyzed for number average molecular weight by vapor pressure osmometry (VPO), for weight average molecular weight by low angle laser light scattering (LALLS), and for the molecular weight distribution by high temperature size exclusion chromatography (SEC). The lignins were run in tetrahydrofuran (THF), N,N-dimethyl formamide (DMF), DMF with 0.1M LiBr, and pyridine at conditions above the Theta temperature. Experimental methods are discussed. The results show that VPO may be used to determine M[sub n] for kraft lignins if the purity of the lignins and the identity of the impurities are known. LALLS can be used to determine M[sub w] for kraft lignins if measurements are made at or above the Theta temperature of the lignin-solvent pair. SEC should be used at temperatures at, or above, the Theta temperature of the lignin-solvent pair. Size separation is highly dependent on the solvent used, and DMF is a much better solvent than THF for high temperature SEC. Future work using moment resolution procedures to derive an accurate calibration curve are also discussed.
Chapter 11Chapter 11 Estimating the Weighted
Schubart, Christoph
Chapter 11Chapter 11 Estimating the Weighted Average Cost of Capital DES Chapter 11 1 #12;U i th C.xls for shortfor short. DES Chapter 11 2 #12;S i l i hSteps to estimate value using the Corporate Valuation stockholders DES Chapter 11 7 #12;Estimating Target Weights Page 223: To calculate WACC, we need to estimate
Averaging Hypotheses in Newtonian Cosmology
T. Buchert
1995-12-20T23:59:59.000Z
Average properties of general inhomogeneous cosmological models are discussed in the Newtonian framework. It is shown under which circumstances the average flow reduces to a member of the standard Friedmann--Lema\\^\\i tre cosmologies. Possible choices of global boundary conditions of inhomogeneous cosmologies as well as consequences for the interpretation of cosmological parameters are put into perspective.
Mining Weighted Association Rules without Preassigned Weights
Bai, Fengshan
Mining Weighted Association Rules without Preassigned Weights Ke Sun and Fengshan Bai Abstract--Association rule mining is a key issue in data mining. However, the classical models ignore the difference between the transactions, and the weighted association rule mining does not work on databases with only binary attributes
Paris-Sud XI, Université de
weaned like those of Group A. Skim milk was acidified by adding 0.15 p. 100 acetic acid. Live weight of feeding acidified skim milk from 5 to 10 weeks of age (group 11) was compared to weaning with fermented rate. Key words : Teat feeding, kid, wenning, milk replacer, fermented ntilk. The use of starch
Chiral gravity, log gravity, and extremal CFT
Maloney, Alexander [Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada); Song Wei [Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, 100190 (China); Center for the Fundamental Laws of Nature Jefferson Physical Laboratory, Harvard University, Cambridge, Massachusetts 02138 (United States); Strominger, Andrew [Center for the Fundamental Laws of Nature Jefferson Physical Laboratory, Harvard University, Cambridge, Massachusetts 02138 (United States)
2010-03-15T23:59:59.000Z
We show that the linearization of all exact solutions of classical chiral gravity around the AdS{sub 3} vacuum have positive energy. Nonchiral and negative-energy solutions of the linearized equations are infrared divergent at second order, and so are removed from the spectrum. In other words, chirality is confined and the equations of motion have linearization instabilities. We prove that the only stationary, axially symmetric solutions of chiral gravity are BTZ black holes, which have positive energy. It is further shown that classical log gravity--the theory with logarithmically relaxed boundary conditions--has finite asymptotic symmetry generators but is not chiral and hence may be dual at the quantum level to a logarithmic conformal field theories (CFT). Moreover we show that log gravity contains chiral gravity within it as a decoupled charge superselection sector. We formally evaluate the Euclidean sum over geometries of chiral gravity and show that it gives precisely the holomorphic extremal CFT partition function. The modular invariance and integrality of the expansion coefficients of this partition function are consistent with the existence of an exact quantum theory of chiral gravity. We argue that the problem of quantizing chiral gravity is the holographic dual of the problem of constructing an extremal CFT, while quantizing log gravity is dual to the problem of constructing a logarithmic extremal CFT.
Average transverse momentum quantities approaching the lightfront
Daniel Boer
2014-09-29T23:59:59.000Z
In this contribution to Light Cone 2014, three average transverse momentum quantities are discussed: the Sivers shift, the dijet imbalance, and the $p_T$ broadening. The definitions of these quantities involve integrals over all transverse momenta that are overly sensitive to the region of large transverse momenta, which conveys little information about the transverse momentum distributions of quarks and gluons inside hadrons. TMD factorization naturally suggests alternative definitions of such integrated quantities, using Bessel-weighting and rapidity cut-offs, with the conventional definitions as limiting cases. The regularized quantities are given in terms of integrals over the TMDs of interest that are well-defined and moreover have the advantage of being amenable to lattice evaluations.
Evaluations of average level spacings
Liou, H.I.
1980-01-01T23:59:59.000Z
The average level spacing for highly excited nuclei is a key parameter in cross section formulas based on statistical nuclear models, and also plays an important role in determining many physics quantities. Various methods to evaluate average level spacings are reviewed. Because of the finite experimental resolution, to detect a complete sequence of levels without mixing other parities is extremely difficult, if not totally impossible. Most methods derive the average level spacings by applying a fit, with different degrees of generality, to the truncated Porter-Thomas distribution for reduced neutron widths. A method that tests both distributions of level widths and positions is discussed extensivey with an example of /sup 168/Er data. 19 figures, 2 tables.
The Frame Potential, on Average
Ingemar Bengtsson; Helena Granstrom
2008-10-24T23:59:59.000Z
A SIC consists of N^2 equiangular unit vectors in an N dimensional Hilbert space. The frame potential is a function of N^2 unit vectors. It has a unique global minimum if the vectors form a SIC, and this property has been made use of in numerical searches for SICs. When the vectors form an orbit of the Heisenberg group the frame potential becomes a function of a single fiducial vector. We analytically compute the average of this function over Hilbert space. We also compute averages when the fiducial vector is placed in certain special subspaces defined by the Clifford group.
4, 22832300, 2004 Hemispheric average
Paris-Sud XI, Université de
ACPD 4, 22832300, 2004 Hemispheric average Cl atom concentration U. Platt et al. Title Page U. Platt1 , W. Allen2 , and D. Lowe2 1 Institut f¨ur Umweltphysik, University of Heidelberg, INF 229 February 2004 Accepted: 9 March 2004 Published: 4 May 2004 Correspondence to: U. Platt (ulrich.platt
Multispecies weighted Hurwitz numbers
Harnad, J
2015-01-01T23:59:59.000Z
The construction of hypergeometric 2D Toda $\\tau$-functions as generating functions for weighted Hurwitz numbers is extended to multispecies families. Both the enumerative geometrical significance of multispecies weighted Hurwitz numbers as weighted enumerations of branched coverings of the Riemann sphere and their combinatorial significance in terms of weighted paths in the Cayley graph of $S_n$ are derived. The particular case of multispecies quantum weighted Hurwitz numbers is studied in detail.
Seasonal Average Temperature - Hanford Site
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol HomeFacebook TwitterSearch-Comments Sign In About | CareersAverage Temperature
Einstein Gravity, Massive Gravity, Multi-Gravity and Nonlinear Realizations
Garrett Goon; Kurt Hinterbichler; Austin Joyce; Mark Trodden
2014-12-18T23:59:59.000Z
The existence of a ghost free theory of massive gravity begs for an interpretation as a Higgs phase of General Relativity. We revisit the study of massive gravity as a Higgs phase. Absent a compelling microphysical model of spontaneous symmetry breaking in gravity, we approach this problem from the viewpoint of nonlinear realizations. We employ the coset construction to search for the most restrictive symmetry breaking pattern whose low energy theory will both admit the de Rham--Gabadadze--Tolley (dRGT) potentials and nonlinearly realize every symmetry of General Relativity, thereby providing a new perspective from which to build theories of massive gravity. In addition to the known ghost-free terms, we find a novel parity violating interaction which preserves the constraint structure of the theory, but which vanishes on the normal branch of the theory. Finally, the procedure is extended to the cases of bi-gravity and multi-vielbein theories. Analogous parity violating interactions exist here, too, and may be non-trivial for certain classes of multi-metric theories.
Particle Dynamics And Emergent Gravity
Amir H. Fatollahi
2008-05-08T23:59:59.000Z
The emergent gravity proposal is examined within the framework of noncommutative QED/gravity correspondence from particle dynamics point of view.
Dec 7, 2013 ... As soon as the brakes of a railroad car in West Lafayette are released, the car will roll down under the force of gravity. It will accelerate, then ...
,"Sulfur Content, Weighted Average Refinery Crude Oil Input Qualities"
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National and Regional Data; Row: NAICS Codes; Column: Energy Sources andPlant Liquids,+ LeasePrice Sold to Electric Power
Optimization Online - Dual Averaging Methods for Regularized ...
Lin Xiao
2010-04-15T23:59:59.000Z
Apr 15, 2010 ... ... simple minimization problem that involves the running average of all past subgradients of the loss function and the whole regularization term, ...
Time Gravity and Quantum Mechanics
W. G. Unruh
1993-12-17T23:59:59.000Z
Time plays different roles in quantum mechanics and gravity. These roles are examined and the problems that the conflict in the roles presents for quantum gravity are briefly summarised.
Al-Radhi, Adhi Omar
1974-01-01T23:59:59.000Z
) 50 3-10 Defects per Unit Control Charts (Sudden Increase in Number of Defects) 51 3-11 Defects per Unit Control Charts (Slow Increase in Number of Defects) 52 3-12 O. C. Curves of Fraction Defectives Control Charts. 54 3-13 O. C. Curves.... The exponential smoothing principle was introduced to quality control field in 1959. It was first adapted in the mean control chart [25]. Through this control system, the most recent information is weighted and combined with the weighted past observations. 10...
Averages in vector spaces over finite fields
Wright J.; Carbery A.; Stones B.
2008-01-01T23:59:59.000Z
We study the analogues of the problems of averages and maximal averages over a surface in R-n when the euclidean structure is replaced by that of a vector space over a finite field, and obtain optimal results in a number ...
MESOSCALE AVERAGING OF NUCLEATION AND GROWTH MODELS
Burger, Martin
MESOSCALE AVERAGING OF NUCLEATION AND GROWTH MODELS MARTIN BURGER , VINCENZO CAPASSO , AND LIVIO-Kolmogorov relations for the degree of crystallinity. By relating the computation of expected values to mesoscale averaging, we obtain a suitable description of the process at the mesoscale. We show how the variance
Ensemble bayesian model averaging using markov chain Monte Carlo sampling
Vrugt, Jasper A [Los Alamos National Laboratory; Diks, Cees G H [NON LANL; Clark, Martyn P [NON LANL
2008-01-01T23:59:59.000Z
Bayesian model averaging (BMA) has recently been proposed as a statistical method to calibrate forecast ensembles from numerical weather models. Successful implementation of BMA however, requires accurate estimates of the weights and variances of the individual competing models in the ensemble. In their seminal paper (Raftery etal. Mon Weather Rev 133: 1155-1174, 2(05)) has recommended the Expectation-Maximization (EM) algorithm for BMA model training, even though global convergence of this algorithm cannot be guaranteed. In this paper, we compare the performance of the EM algorithm and the recently developed Differential Evolution Adaptive Metropolis (DREAM) Markov Chain Monte Carlo (MCMC) algorithm for estimating the BMA weights and variances. Simulation experiments using 48-hour ensemble data of surface temperature and multi-model stream-flow forecasts show that both methods produce similar results, and that their performance is unaffected by the length of the training data set. However, MCMC simulation with DREAM is capable of efficiently handling a wide variety of BMA predictive distributions, and provides useful information about the uncertainty associated with the estimated BMA weights and variances.
Prodić, Aleksandar
Weight 0 1 2 3 1. Leadership 33% Has not demonstrated impact through a leadership role Has held a leadership role in one or more organizations and demonstrated impact Has held an organization-wide leadership role in one or more
Thermal ghost imaging with averaged speckle patterns
Shapiro, Jeffrey H.
We present theoretical and experimental results showing that a thermal ghost imaging system can produce images of high quality even when it uses detectors so slow that they respond only to intensity-averaged (that is, ...
STAFF FORECAST: AVERAGE RETAIL ELECTRICITY PRICES
CALIFORNIA ENERGY COMMISSION STAFF FORECAST: AVERAGE RETAIL ELECTRICITY PRICES 2005 TO 2018 Mignon Marks Principal Author Mignon Marks Project Manager David Ashuckian Manager ELECTRICITY ANALYSIS OFFICE Sylvia Bender Acting Deputy Director ELECTRICITY SUPPLY DIVISION B.B. Blevins Executive Director
Selling Geothermal Systems The "Average" Contractor
Selling Geothermal Systems #12;The "Average" Contractor · History of sales procedures · Manufacturer Driven Procedures · What makes geothermal technology any harder to sell? #12;"It's difficult to sell a geothermal system." · It should
Distributed Averaging Via Lifted Markov Chains
Jung, Kyomin
Motivated by applications of distributed linear estimation, distributed control, and distributed optimization, we consider the question of designing linear iterative algorithms for computing the average of numbers in a ...
Self-averaging characteristics of spectral fluctuations
Petr Braun; Fritz Haake
2014-10-20T23:59:59.000Z
The spectral form factor as well as the two-point correlator of the density of (quasi-)energy levels of individual quantum dynamics are not self-averaging. Only suitable smoothing turns them into useful characteristics of spectra. We present numerical data for a fully chaotic kicked top, employing two types of smoothing: one involves primitives of the spectral correlator, the second a small imaginary part of the quasi-energy. Self-averaging universal (like the CUE average) behavior is found for the smoothed correlator, apart from noise which shrinks like $1\\over\\sqrt N$ as the dimension $N$ of the quantum Hilbert space grows. There are periodically repeated quasi-energy windows of correlation decay and revival wherein the smoothed correlation remains finite as $N\\to\\infty$ such that the noise is negligible. In between those windows (where the CUE averaged correlator takes on values of the order ${1\\over N^2}$) the noise becomes dominant and self-averaging is lost. We conclude that the noise forbids distinction of CUE and GUE type behavior. Surprisingly, the underlying smoothed generating function does not enjoy any self-averaging outside the range of its variables relevant for determining the two-point correlator (and certain higher-order ones). --- We corroborate our numerical findings for the noise by analytically determining the CUE variance of the smoothed single-matrix correlator.
Is Average Run Length to False Alarm Always an Informative Criterion?
Mei, Yajun
applications, including statistical process control (SPC), industrial quality control, target or signal- point detection. A partial list includes cumulative sum (CUSUM), Shewhart's control chart, exponentially-weighted moving average (EWMA) charts, Shiyayev-Roberts proce- dures, window-limited control charts, and scan
Gravity on Conformal Superspace
Bryan Kelleher
2003-11-11T23:59:59.000Z
The configuration space of general relativity is superspace - the space of all Riemannian 3-metrics modulo diffeomorphisms. However, it has been argued that the configuration space for gravity should be conformal superspace - the space of all Riemannian 3-metrics modulo diffeomorphisms and conformal transformations. Taking this conformal nature seriously leads to a new theory of gravity which although very similar to general relativity has some very different features particularly in cosmology and quantisation. It should reproduce the standard tests of general relativity. The cosmology is studied in some detail. The theory is incredibly restrictive and as a result admits an extremely limited number of possible solutions. The problems of the standard cosmology are addressed and most remarkably the cosmological constant problem is resolved in a natural way. The theory also has several attractive features with regard to quantisation particularly regarding the problem of time.
Gravity, Dimension, Equilibrium, & Thermodynamics
Jerome Perez
2006-03-30T23:59:59.000Z
Is it actually possible to interpret gravitation as space's property in a pure classical way. Then, we note that extended self-gravitating system equilibrium depends directly on the number of dimension of the space in which it evolves. Given those precisions, we review the principal thermodynamical knowledge in the context of classical gravity with arbitrary dimension of space. Stability analyses for bounded 3D systems, namely the Antonov instability paradigm, are then rapproched to some amazing properties of globular clusters and galaxies.
Iver Brevik
2012-11-23T23:59:59.000Z
A bulk viscosity is introduced in the formalism of modified gravity. It is shown that, on the basis of a natural scaling law for the viscosity, a simple solution can be found for quantities such as the Hubble parameter and the energy density. These solutions may incorporate a viscosity-induced Big Rip singularity. By introducing a phase transition in the cosmic fluid, the future singularity can nevertheless in principle be avoided.
Lie algebraic noncommutative gravity
Banerjee, Rabin; Samanta, Saurav [S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata-700098 (India); Mukherjee, Pradip [Presidency College, 86/1 College Street, Kolkata-700073, West-Bengal (India)
2007-06-15T23:59:59.000Z
We exploit the Seiberg-Witten map technique to formulate the theory of gravity defined on a Lie algebraic noncommutative space-time. Detailed expressions of the Seiberg-Witten maps for the gauge parameters, gauge potentials, and the field strengths have been worked out. Our results demonstrate that notwithstanding the introduction of more general noncommutative structure there is no first order correction, exactly as happens for a canonical (i.e. constant) noncommutativity.
Koyama, Kazuya
2015-01-01T23:59:59.000Z
Einstein's theory of General Relativity (GR) is tested accurately within the local universe i.e., the Solar System, but this leaves open the possibility that it is not a good description at the largest scales in the Universe. The standard model of cosmology assumes GR as the theory to describe gravity on all scales. In 1998, astronomers made the surprising discovery that the expansion of the Universe is accelerating, not slowing down. This late-time acceleration of the Universe has become the most challenging problem in theoretical physics. Within the framework of GR, the acceleration would originate from an unknown dark energy. Alternatively, it could be that there is no dark energy and GR itself is in error on cosmological scales. The standard model of cosmology is based on a huge extrapolation of our limited knowledge of gravity. This discovery of the late time acceleration of the Universe may require us to revise the theory of gravity and the standard model of cosmology based on GR. We will review recent ...
Average System Cost Methodology : Administrator's Record of Decision.
United States. Bonneville Power Administration.
1984-06-01T23:59:59.000Z
Significant features of average system cost (ASC) methodology adopted are: retention of the jurisdictional approach where retail rate orders of regulartory agencies provide primary data for computing the ASC for utilities participating in the residential exchange; inclusion of transmission costs; exclusion of construction work in progress; use of a utility's weighted cost of debt securities; exclusion of income taxes; simplification of separation procedures for subsidized generation and transmission accounts from other accounts; clarification of ASC methodology rules; more generous review timetable for individual filings; phase-in of reformed methodology; and each exchanging utility must file under the new methodology within 20 days of implementation by the Federal Energy Regulatory Commission of the ten major participating utilities, the revised ASC will substantially only affect three. (PSB)
Boisberranger, Jérémie Du; Ponty, Yann
2012-01-01T23:59:59.000Z
Motivated by applications in bioinformatics, we consider the word collector problem, i.e. the expected number of calls to a random weighted generator of words of length $n$ before the full collection is obtained. The originality of this instance of the non-uniform coupon collector lies in the, potentially large, multiplicity of the words/coupons of a given probability/composition. We obtain a general theorem that gives an asymptotic equivalent for the expected waiting time of a general version of the Coupon Collector. This theorem is especially well-suited for classes of coupons featuring high multiplicities. Its application to a given language essentially necessitates some knowledge on the number of words of a given composition/probability. We illustrate the application of our theorem, in a step-by-step fashion, on three exemplary languages, revealing asymptotic regimes in $\\Theta(\\mu(n)\\cdot n)$ and $\\Theta(\\mu(n)\\cdot \\log n)$, where $\\mu(n)$ is the sum of weights over words of length $n$.
Predicting objective function weights from patient anatomy in prostate IMRT treatment planning
Lee, Taewoo, E-mail: taewoo.lee@utoronto.ca; Hammad, Muhannad [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario M5S 3G8 (Canada)] [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario M5S 3G8 (Canada); Chan, Timothy C. Y. [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario M5S 3G8, Canada and Techna Institute for the Advancement of Technology for Health, 124-100 College Street, Toronto, Ontario M5G 1P5 (Canada)] [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario M5S 3G8, Canada and Techna Institute for the Advancement of Technology for Health, 124-100 College Street, Toronto, Ontario M5G 1P5 (Canada); Craig, Tim [Radiation Medicine Program, UHN Princess Margaret Cancer Centre, 610 University Avenue, Toronto, Ontario M5T 2M9, Canada and Department of Radiation Oncology, University of Toronto, 148-150 College Street, Toronto, Ontario M5S 3S2 (Canada)] [Radiation Medicine Program, UHN Princess Margaret Cancer Centre, 610 University Avenue, Toronto, Ontario M5T 2M9, Canada and Department of Radiation Oncology, University of Toronto, 148-150 College Street, Toronto, Ontario M5S 3S2 (Canada); Sharpe, Michael B. [Radiation Medicine Program, UHN Princess Margaret Cancer Centre, 610 University Avenue, Toronto, Ontario M5T 2M9 (Canada) [Radiation Medicine Program, UHN Princess Margaret Cancer Centre, 610 University Avenue, Toronto, Ontario M5T 2M9 (Canada); Department of Radiation Oncology, University of Toronto, 148-150 College Street, Toronto, Ontario M5S 3S2 (Canada); Techna Institute for the Advancement of Technology for Health, 124-100 College Street Toronto, Ontario M5G 1P5 (Canada)
2013-12-15T23:59:59.000Z
Purpose: Intensity-modulated radiation therapy (IMRT) treatment planning typically combines multiple criteria into a single objective function by taking a weighted sum. The authors propose a statistical model that predicts objective function weights from patient anatomy for prostate IMRT treatment planning. This study provides a proof of concept for geometry-driven weight determination. Methods: A previously developed inverse optimization method (IOM) was used to generate optimal objective function weights for 24 patients using their historical treatment plans (i.e., dose distributions). These IOM weights were around 1% for each of the femoral heads, while bladder and rectum weights varied greatly between patients. A regression model was developed to predict a patient's rectum weight using the ratio of the overlap volume of the rectum and bladder with the planning target volume at a 1 cm expansion as the independent variable. The femoral head weights were fixed to 1% each and the bladder weight was calculated as one minus the rectum and femoral head weights. The model was validated using leave-one-out cross validation. Objective values and dose distributions generated through inverse planning using the predicted weights were compared to those generated using the original IOM weights, as well as an average of the IOM weights across all patients. Results: The IOM weight vectors were on average six times closer to the predicted weight vectors than to the average weight vector, usingl{sub 2} distance. Likewise, the bladder and rectum objective values achieved by the predicted weights were more similar to the objective values achieved by the IOM weights. The difference in objective value performance between the predicted and average weights was statistically significant according to a one-sided sign test. For all patients, the difference in rectum V54.3 Gy, rectum V70.0 Gy, bladder V54.3 Gy, and bladder V70.0 Gy values between the dose distributions generated by the predicted weights and IOM weights was less than 5 percentage points. Similarly, the difference in femoral head V54.3 Gy values between the two dose distributions was less than 5 percentage points for all but one patient. Conclusions: This study demonstrates a proof of concept that patient anatomy can be used to predict appropriate objective function weights for treatment planning. In the long term, such geometry-driven weights may serve as a starting point for iterative treatment plan design or may provide information about the most clinically relevant region of the Pareto surface to explore.
Entropic Gravity in Rindler Space
Edi Halyo
2011-04-13T23:59:59.000Z
We show that Rindler horizons are entropic screens and gravity is an entropic force in Rindler space by deriving the Verlinde entropy formula from the focusing of light due to a mass close to the horizon. Consequently, gravity is also entropic in the near horizon regions of Schwarzschild and de Sitter space-times. In different limits, the entropic nature of gravity in Rindler space leads to the Bekenstein entropy bound and the uncertainty principle.
Polarized electron beams at milliampere average current
Poelker, Matthew [JLAB
2013-11-01T23:59:59.000Z
This contribution describes some of the challenges associated with developing a polarized electron source capable of uninterrupted days-long operation at milliAmpere average beam current with polarization greater than 80%. Challenges will be presented in the context of assessing the required level of extrapolation beyond the performance of today's CEBAF polarized source operating at ~ 200 uA average current. Estimates of performance at higher current will be based on hours-long demonstrations at 1 and 4 mA. Particular attention will be paid to beam-related lifetime-limiting mechanisms, and strategies to construct a photogun that operate reliably at bias voltage > 350kV.
Lifshitz Gravity for Lifshitz Holography
Tom Griffin; Petr Horava; Charles M. Melby-Thompson
2012-11-20T23:59:59.000Z
We argue that Horava-Lifshitz (HL) gravity provides the minimal holographic dual for Lifshitz-type field theories with anisotropic scaling and dynamical exponent z. First we show that Lifshitz spacetimes are vacuum solutions of HL gravity, without need for additional matter. Then we perform holographic renormalization of HL gravity, and show how it reproduces the full structure of the z=2 anisotropic Weyl anomaly in dual field theories in 2+1 dimensions, while its minimal relativistic gravity counterpart yields only one of two independent central charges in the anomaly.
Extracting gluon condensate from the average plaquette
Lee, Taekoon
2015-01-01T23:59:59.000Z
The perturbative contribution in the average plaquette is subtracted using Borel summation and the remnant of the plaquette is shown to scale as a dim-4 condensate. A critical review is presented of the renormalon subtraction scheme that claimed a dim-2 condensate. The extracted gluon condensate is compared with the latest result employing high order (35-loop) calculation in the stochastic perturbation theory.
Three-dimensional gravity modeling and focusing inversion using rectangular meshes.
Commer, M.
2011-03-01T23:59:59.000Z
Rectangular grid cells are commonly used for the geophysical modeling of gravity anomalies, owing to their flexibility in constructing complex models. The straightforward handling of cubic cells in gravity inversion algorithms allows for a flexible imposition of model regularization constraints, which are generally essential in the inversion of static potential field data. The first part of this paper provides a review of commonly used expressions for calculating the gravity of a right polygonal prism, both for gravity and gradiometry, where the formulas of Plouff and Forsberg are adapted. The formulas can be cast into general forms practical for implementation. In the second part, a weighting scheme for resolution enhancement at depth is presented. Modelling the earth using highly digitized meshes, depth weighting schemes are typically applied to the model objective functional, subject to minimizing the data misfit. The scheme proposed here involves a non-linear conjugate gradient inversion scheme with a weighting function applied to the non-linear conjugate gradient scheme's gradient vector of the objective functional. The low depth resolution due to the quick decay of the gravity kernel functions is counteracted by suppressing the search directions in the parameter space that would lead to near-surface concentrations of gravity anomalies. Further, a density parameter transformation function enabling the imposition of lower and upper bounding constraints is employed. Using synthetic data from models of varying complexity and a field data set, it is demonstrated that, given an adequate depth weighting function, the gravity inversion in the transform space can recover geologically meaningful models requiring a minimum of prior information and user interaction.
Ivan Dimitrijevic; Branko Dragovich; Jelena Grujic; Zoran Rakic
2012-04-09T23:59:59.000Z
We consider some aspects of nonlocal modified gravity, where nonlocality is of the type $R \\mathcal{F}(\\Box) R$. In particular, using ansatz of the form $\\Box R = c R^\\gamma,$ we find a few $R(t)$ solutions for the spatially flat FLRW metric. There are singular and nonsingular bounce solutions. For late cosmic time, scalar curvature R(t) is in low regime and scale factor a(t) is decelerated. R (t) = 0 satisfies all equations when k = -1.
Ning Wu
2005-10-01T23:59:59.000Z
It is well-known that energy-momentum is the source of gravitational field. For a long time, it is generally believed that only stars with huge masses can generate strong gravitational field. Based on the unified theory of gravitational interactions and electromagnetic interactions, a new mechanism of the generation of gravitational field is studied. According to this mechanism, in some special conditions, electromagnetic energy can be directly converted into gravitational energy, and strong gravitational field can be generated without massive stars. Gravity impulse found in experiments is generated by this mechanism.
Bergshoeff, Eric A.; Rosseel, Jan [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Hohm, Olaf [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Townsend, Paul K. [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)
2011-05-15T23:59:59.000Z
The physical modes of a recently proposed D-dimensional 'critical gravity', linearized about its anti-de Sitter vacuum, are investigated. All 'log mode' solutions, which we categorize as 'spin-2' or 'Proca', arise as limits of the massive spin-2 modes of the noncritical theory. The linearized Einstein tensor of a spin-2 log mode is itself a 'nongauge' solution of the linearized Einstein equations whereas the linearized Einstein tensor of a Proca mode takes the form of a linearized general coordinate transformation. Our results suggest the existence of a holographically dual logarithmic conformal field theory.
Reduced models for quantum gravity
T. Thiemann
1999-10-04T23:59:59.000Z
The preceding talks given at this conference have dealt mainly with general ideas for, main problems of and techniques for the task of quantizing gravity canonically. Since one of the major motivations to arrange for this meeting was that it should serve as a beginner's introduction to canonical quantum gravity, we regard it as important to demonstrate the usefulness of the formalism by means of applying it to simplified models of quantum gravity, here formulated in terms of Ashtekar's new variables. From the various, completely solvable, models that have been discussed in the literature we choose those that we consider as most suitable for our pedagogical reasons, namely 2+1 gravity and the spherically symmetric model. The former model arises from a dimensional, the latter from a Killing reduction of full 3+1 gravity. While 2+1 gravity is usually treated in terms of closed topologies without boundary of the initial data hypersurface, the toplogy for the spherically symmetric system is chosen to be asymptotically flat. Finally, 2+1 gravity is more suitably quantized using the loop representation while spherically symmetric gravity is easier to quantize via the self-dual representation. Accordingly, both types of reductions, both types of topologies and both types of representations that are mainly employed in the literature in the context of the new variables come into practice. What makes the discussion especially clear is the fact that for both models the reduced phase space turns out to be finitely dimensional.
Canonical Analysis of Unimodular Gravity
J. Kluson
2014-10-07T23:59:59.000Z
This short note is devoted to the Hamiltonian analysis of the Unimodular Gravity.We treat the unimodular gravity as General Relativity action with the unimodular constraint imposed with the help of Lagrange multiplier. We perform the canonical analysis of the resulting theory and determine its constraint structure.
Polarized electron beams at milliampere average current
Poelker, M. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)
2013-11-07T23:59:59.000Z
This contribution describes some of the challenges associated with developing a polarized electron source capable of uninterrupted days-long operation at milliAmpere average beam current with polarization greater than 80%. Challenges will be presented in the context of assessing the required level of extrapolation beyond the performance of today’s CEBAF polarized source operating at ? 200 uA average current. Estimates of performance at higher current will be based on hours-long demonstrations at 1 and 4 mA. Particular attention will be paid to beam-related lifetime-limiting mechanisms, and strategies to construct a photogun that operate reliably at bias voltage > 350kV.
Table 7.1 Average Prices of Purchased Energy Sources, 2002
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012, 2011, 2010,Jersey"RhodeVirginia"West Average Prices of
Table 7.1 Average Prices of Purchased Energy Sources, 2010
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012, 2011, 2010,Jersey"RhodeVirginia"West Average Prices of
Table 7.2 Average Prices of Purchased Energy Sources, 2002
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012, 2011, 2010,Jersey"RhodeVirginia"West Average Prices of002
Table 7.2 Average Prices of Purchased Energy Sources, 2010;
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012, 2011, 2010,Jersey"RhodeVirginia"West Average Prices of002
Table 7.3 Average Prices of Purchased Electricity, Natural Gas, and Steam, 20
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012, 2011, 2010,Jersey"RhodeVirginia"West Average Prices of0023
Table 7.3 Average Prices of Purchased Electricity, Natural Gas, and Steam, 2010;
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012, 2011, 2010,Jersey"RhodeVirginia"West Average Prices
Table 7.4 Average Prices of Selected Purchased Energy Sources, 2002
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012, 2011, 2010,Jersey"RhodeVirginia"West Average Prices4
Table 7.4 Average Prices of Selected Purchased Energy Sources, 2010;
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012, 2011, 2010,Jersey"RhodeVirginia"West Average Prices44
Table 7.5 Average Prices of Selected Purchased Energy Sources, 2002
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012, 2011, 2010,Jersey"RhodeVirginia"West Average Prices445
Table 8. Retail sales, revenue, and average retail price by sector, 1990 through
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012, 2011, 2010,Jersey"RhodeVirginia"West AverageMexico"
The averaging process in permeability estimation from well-test data
Oliver, D.S. (Saudi Aramco (SA))
1990-09-01T23:59:59.000Z
Permeability estimates from the pressure derivative or the slope of the semilog plot usually are considered to be averages of some large ill-defined reservoir volume. This paper presents results of a study of the averaging process, including identification of the region of the reservoir that influences permeability estimates, and a specification of the relative contribution of the permeability of various regions to the estimate of average permeability. The diffusion equation for the pressure response of a well situated in an infinite reservoir where permeability is an arbitrary function of position was solved for the case of small variations from a mean value. Permeability estimates from the slope of the plot of pressure vs. the logarithm of drawdown time are shown to be weighted averages of the permeabilities within an inner and outer radius of investigation.
AdS Chern-Simons Gravity induces Conformal Gravity
Rodrigo Aros; Danilo E. Diaz
2013-12-25T23:59:59.000Z
The leitmotif of this paper is the question of whether four- and higher even-dimensional Conformal Gravities do have a Chern-Simons pedigree. We show that Weyl gravity can be obtained as dimensional reduction of a five-dimensional Chern-Simons action for a suitable (gauged-fixed, tractor-like) five-dimensional AdS connection. The gauge-fixing and dimensional reduction program admits a readily generalization to higher dimensions for the case of certain conformal gravities obtained by contractions of the Weyl tensor.
Some interrelationships of weights of beef calves from birth to weaning and to maturity
Jones, John Willoughby
1957-01-01T23:59:59.000Z
i . . . . . . . ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 21 6, Average weight curves from 15 to 210 days of age for 5/8 Hereford-3/8 Brahman calves in 15 calf crops at Lufkin ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 22 70 Average weight curves... The author expresses his appreciation to Professor J, K. Higgs for his assistance in planning and in directing this study, to Mr. H. W. Franke for his cooperation in weighing the cows and calves at College Station, to Mr~ E, K. Crouch for his assistance...
Some interrelationships of weights of beef calves from birth to weaning and to maturity
Jones, John Willoughby
1957-01-01T23:59:59.000Z
i . . . . . . . ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 21 6, Average weight curves from 15 to 210 days of age for 5/8 Hereford-3/8 Brahman calves in 15 calf crops at Lufkin ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 22 70 Average weight curves... The author expresses his appreciation to Professor J, K. Higgs for his assistance in planning and in directing this study, to Mr. H. W. Franke for his cooperation in weighing the cows and calves at College Station, to Mr~ E, K. Crouch for his assistance...
Is dark energy an effect of averaging?
Nan Li; Marina Seikel; Dominik J. Schwarz
2008-01-22T23:59:59.000Z
The present standard model of cosmology states that the known particles carry only a tiny fraction of total mass and energy of the Universe. Rather, unknown dark matter and dark energy are the dominant contributions to the cosmic energy budget. We review the logic that leads to the postulated dark energy and present an alternative point of view, in which the puzzle may be solved by properly taking into account the influence of cosmic structures on global observables. We illustrate the effect of averaging on the measurement of the Hubble constant.
M. G. Romania; N. C. Tsamis; R. P. Woodard
2014-12-05T23:59:59.000Z
We review some perturbative results obtained in quantum gravity in an accelerating cosmological background. We then describe a class of non-local, purely gravitational models which have the correct structure to reproduce the leading infrared logarithms of quantum gravitational back-reaction during the inflationary regime. These models end inflation in a distinctive phase of oscillations with slight and short violations of the weak energy condition and should, when coupled to matter, lead to rapid reheating. By elaborating this class of models we exhibit one that has the same behaviour during inflation, goes quiescent until the onset of matter domination, and induces a small, positive cosmological constant of about the right size thereafter. We also briefly comment on the primordial density perturbations that this class of models predict.
Henneaux, Marc; Teitelboim, Claudio [Physique Theorique et Mathematique and International Solvay Institutes, Universite Libre de Bruxelles, Campus Plaine C. P. 231, B-1050 Brussels (Belgium) and Centro de Estudios Cientificos (CECS), Valdivia (Chile); Centro de Estudios Cientificos (CECS), Valdivia (Chile)
2005-01-15T23:59:59.000Z
We show that duality transformations of linearized gravity in four dimensions, i.e., rotations of the linearized Riemann tensor and its dual into each other, can be extended to the dynamical fields of the theory so as to be symmetries of the action and not just symmetries of the equations of motion. Our approach relies on the introduction of two superpotentials, one for the spatial components of the spin-2 field and the other for their canonically conjugate momenta. These superpotentials are two-index, symmetric tensors. They can be taken to be the basic dynamical fields and appear locally in the action. They are simply rotated into each other under duality. In terms of the superpotentials, the canonical generator of duality rotations is found to have a Chern-Simons-like structure, as in the Maxwell case.
Kay, Bernard S
2015-01-01T23:59:59.000Z
We give an account of the matter-gravity entanglement hypothesis which, unlike the standard approach to entropy based on coarse-graining, offers a definition for the entropy of a closed system as a real and objective quantity. We explain how this new approach offers an explanation for the Second Law of Thermodynamics in general and a non-paradoxical understanding of information loss during black hole formation and evaporation in particular. We also very briefly review some recent related work on the nature of equilibrium states involving quantum black holes and point out how it promises to resolve some puzzling issues in the current version of the string theory approach to black hole entropy.
Renormalization, averaging, conservation laws and AdS (in)stability
Ben Craps; Oleg Evnin; Joris Vanhoof
2015-01-19T23:59:59.000Z
We continue our analytic investigations of non-linear spherically symmetric perturbations around the anti-de Sitter background in gravity-scalar field systems, and focus on conservation laws restricting the (perturbatively) slow drift of energy between the different normal modes due to non-linearities. We discover two conservation laws in addition to the energy conservation previously discussed in relation to AdS instability. A similar set of three conservation laws was previously noted for a self-interacting scalar field in a non-dynamical AdS background, and we highlight the similarities of this system to the fully dynamical case of gravitational instability. The nature of these conservation laws is best understood through an appeal to averaging methods which allow one to derive an effective Lagrangian or Hamiltonian description of the slow energy transfer between the normal modes. The conservation laws in question then follow from explicit symmetries of this averaged effective theory.
Natural Inflation and Quantum Gravity
Anton de la Fuente; Prashant Saraswat; Raman Sundrum
2015-01-29T23:59:59.000Z
Cosmic Inflation provides an attractive framework for understanding the early universe and the cosmic microwave background. It can readily involve energies close to the scale at which Quantum Gravity effects become important. General considerations of black hole quantum mechanics suggest nontrivial constraints on any effective field theory model of inflation that emerges as a low-energy limit of quantum gravity, in particular the constraint of the Weak Gravity Conjecture. We show that higher-dimensional gauge and gravitational dynamics can elegantly satisfy these constraints and lead to a viable, theoretically-controlled and predictive class of Natural Inflation models.
Riding Gravity Away from Doomsday
Sen, Ashoke
2015-01-01T23:59:59.000Z
The discovery that most of the energy density in the universe is stored in the form of dark energy has profound consequences for our future. In particular our current limited understanding of quantum theory of gravity indicates that some time in the future our universe will undergo a phase transition that will destroy us and everything else around us instantaneously. However the laws of gravity also suggest a way out -- some of our descendants could survive this catastrophe by riding gravity away from the danger. In this essay I describe the tale of this escape from doomsday.
Riding Gravity Away from Doomsday
Ashoke Sen
2015-03-27T23:59:59.000Z
The discovery that most of the energy density in the universe is stored in the form of dark energy has profound consequences for our future. In particular our current limited understanding of quantum theory of gravity indicates that some time in the future our universe will undergo a phase transition that will destroy us and everything else around us instantaneously. However the laws of gravity also suggest a way out -- some of our descendants could survive this catastrophe by riding gravity away from the danger. In this essay I describe the tale of this escape from doomsday.
Critical Gravity in Four Dimensions
Lue, H. [China Economics and Management Academy, Central University of Finance and Economics, Beijing 100081 (China); Institute for Advanced Study, Shenzhen University, Nanhai Avenue 3688, Shenzhen 518060 (China); Pope, C. N. [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, College Station, Texas 77843 (United States); DAMTP, Centre for Mathematical Sciences, Cambridge University, Wilberforce Road, Cambridge CB3 OWA (United Kingdom)
2011-05-06T23:59:59.000Z
We study four-dimensional gravity theories that are rendered renormalizable by the inclusion of curvature-squared terms to the usual Einstein action with a cosmological constant. By choosing the parameters appropriately, the massive scalar mode can be eliminated and the massive spin-2 mode can become massless. This ''critical'' theory may be viewed as a four-dimensional analogue of chiral topologically massive gravity, or of critical 'new massive gravity' with a cosmological constant, in three dimensions. We find that the on-shell energy for the remaining massless gravitons vanishes. There are also logarithmic spin-2 modes, which have positive energy. The mass and entropy of standard Schwarzschild-type black holes vanish. The critical theory might provide a consistent toy model for quantum gravity in four dimensions.
Fact #870: April 27, 2015 Corporate Average Fuel Economy Progress...
Office of Environmental Management (EM)
Fact 870: April 27, 2015 Corporate Average Fuel Economy Progress, 1978-2014 Fact 870: April 27, 2015 Corporate Average Fuel Economy Progress, 1978-2014 The Corporate Average Fuel...
Quantum Gravity: Motivations and Alternatives
Reiner Hedrich
2009-08-03T23:59:59.000Z
The mutual conceptual incompatibility between GR and QM/QFT is generally seen as the most essential motivation for the development of a theory of Quantum Gravity (QG). It leads to the insight that, if gravity is a fundamental interaction and QM is universally valid, the gravitational field will have to be quantized, not at least because of the inconsistency of semi-classical theories of gravity. If this means to quantize GR, its identification of the gravitational field with the spacetime metric has to be taken into account. And the resulting quantum theory has to be background-independent. This can not be achieved by means of quantum field theoretical procedures. More sophisticated strategies have to be applied. One of the basic requirements for such a quantization strategy is that the resulting quantum theory has GR as a classical limit. - However, should gravity not be a fundamental, but an residual, emergent interaction, it could very well be an intrinsically classical phenomenon. Should QM be nonetheless universally valid, we had to assume a quantum substrate from which gravity would result as an emergent classical phenomenon. And there would be no conflict with the arguments against semi-classical theories, because there would be no gravity at all on the substrate level. The gravitational field would not have any quantum properties, and a quantization of GR would not lead to any fundamental theory. The objective of a theory of 'QG' would instead be the identification of the quantum substrate from which gravity results. - The paper tries to give an overview over the main options for theory construction in the field of QG. Because of the still unclear status of gravity and spacetime, it pleads for the necessity of a plurality of conceptually different approaches to QG.
Fact #693: September 19, 2011 Average Vehicle Footprint for Cars...
and the average track width of the vehicle. The upcoming Corporate Average Fuel Economy (CAFE) Standards have fuel economy targets based on the vehicle footprint. The...
average atom model: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
(chemical potential, average ionic charge, free electron density, bound and continuum wave-functions and occupation numbers) are obtained from the average-atom model. The...
Principal facts for gravity stations of the Broadwater geothermal area, Montana
Bankey, V.; Paton, J.; Kleinkopf, M.D.
1981-01-01T23:59:59.000Z
Two complete Bouguer anomaly values were calculated for each of the 67 stations assuming average rock densities of 2.67 g/cm/sup 3/ and 2.45 g/cm/sup 3/. The corrections and anomaly values are listed. A hand contoured Bouguer gravity map is included.
APPENDIX A: MONTHLY AVERAGED DATA In many instances monthly averaged data are
Oregon, University of
for solar energy and climatic applications. Click on the buttons on the left to find out more about the lab for preliminary estimates of solar system performance. This section provides a summary of monthly averaged data for all sites in watt hours/meter2 per hour or day. For each site and each solar measurement the data
Conformal Lifshitz Gravity from Holography
Tom Griffin; Petr Horava; Charles M. Melby-Thompson
2012-04-03T23:59:59.000Z
We show that holographic renormalization of relativistic gravity in asymptotically Lifshitz spacetimes naturally reproduces the structure of gravity with anisotropic scaling: The holographic counterterms induced near anisotropic infinity take the form of the action for gravity at a Lifshitz point, with the appropriate value of the dynamical critical exponent $z$. In the particular case of 3+1 bulk dimensions and $z=2$ asymptotic scaling near infinity, we find a logarithmic counterterm, related to anisotropic Weyl anomaly of the dual CFT, and show that this counterterm reproduces precisely the action of conformal gravity at a $z=2$ Lifshitz point in 2+1 dimensions, which enjoys anisotropic local Weyl invariance and satisfies the detailed balance condition. We explain how the detailed balance is a consequence of relations among holographic counterterms, and point out that a similar relation holds in the relativistic case of holography in $AdS_5$. Upon analytic continuation, analogous to the relativistic case studied recently by Maldacena, the action of conformal gravity at the $z=2$ Lifshitz point features in the ground-state wavefunction of a gravitational system with an interesting type of spatial anisotropy.
Calculator program optimizes bit weight, rotary speed, reducing drilling cost
Simpson, M.A.
1984-04-23T23:59:59.000Z
Bit selection, bit weight, and rotary speed have repeatedly proven to be the most important and commonly overlooked alterable factors which control penetration rate, footage, and overall drilling cost. This is particularly true in offshore operations where drilling costs are highest and the greatest cost savings stand to be achieved through implementation of proven optimization techniques. The myth that bit weights and rotary speeds cannot be optimized in directional holes has hindered the industry from using this virtually cost-free method for reducing drilling cost. The use of optimized bit weights and rotary speeds in conjunction with minimum cost bit programs based on cost per foot analysis of previous bit runs in the area was implemented on a five-well platform in the Grand Isle Block 20 field, offshore Louisiana. Each of the directional wells was drilled substantially faster and cheaper than the discovery well, which was a straight hole. Average reductions in footage cost of 31.3%, based on daily operating cost of $30,000/day, and increase in average daily footage drilled of 45.2% were effected by ''collectively optimizing'' drilling performance. The ''Optimizer'' program is an HP-41CV adaptation of the Bourgoyne and Young drilling model. It was used to calculate the optimum bit weights and rotary speeds based on field drilling tests; historical bit and bearing wear data; and current operating conditions, cost, and constraints.
Gauge Theory of Quantum Gravity
J. W. Moffat
1994-01-04T23:59:59.000Z
A gauge theory of quantum gravity is formulated, in which an internal, field dependent metric is introduced which non-linearly realizes the gauge fields on the non-compact group $SL(2,C)$, while linearly realizing them on $SU(2)$. Einstein's $SL(2,C)$ invariant theory of gravity emerges at low energies, since the extra degrees of freedom associated with the quadratic curvature and the internal metric only dominate at high energies. In a fixed internal metric gauge, only the the $SU(2)$ gauge symmetry is satisfied, the particle spectrum is identified and the Hamiltonian is shown to be bounded from below. Although Lorentz invariance is broken in this gauge, it is satisfied in general. The theory is quantized in this fixed, broken symmetry gauge as an $SU(2)$ gauge theory on a lattice with a lattice spacing equal to the Planck length. This produces a unitary and finite theory of quantum gravity.
Energy bounds in designer gravity
Amsel, Aaron J.; Marolf, Donald [Physics Department, UCSB, Santa Barbara, California 93106 (United States)
2006-09-15T23:59:59.000Z
We consider asymptotically anti-de Sitter gravity coupled to tachyonic scalar fields with mass at or slightly above the Breitenlohner-Freedman bound in d{>=}4 spacetime dimensions. The boundary conditions in these ''designer gravity'' theories are defined in terms of an arbitrary function W. We give a general argument that the Hamiltonian generators of asymptotic symmetries for such systems will be finite, and proceed to construct these generators using the covariant phase space method. The direct calculation confirms that the generators are finite and shows that they take the form of the pure gravity result plus additional contributions from the scalar fields. By comparing the generators to the spinor charge, we derive a lower bound on the gravitational energy when W has a global minimum and the Breitenlohner-Freedman bound is not saturated.
Counterterms, critical gravity and holography
Kallol Sen; Aninda Sinha; Nemani V. Suryanarayana
2012-05-18T23:59:59.000Z
We consider counterterms for odd dimensional holographic CFTs. These counterterms are derived by demanding cut-off independence of the CFT partition function on $S^d$ and $S^1 \\times S^{d-1}$. The same choice of counterterms leads to a cut-off independent Schwarzschild black hole entropy. When treated as independent actions, these counterterm actions resemble critical theories of gravity, i.e., higher curvature gravity theories where the additional massive spin-2 modes become massless. Equivalently, in the context of AdS/CFT, these are theories where at least one of the central charges associated with the trace anomaly vanishes. Connections between these theories and logarithmic CFTs are discussed. For a specific choice of parameters, the theories arising from counterterms are non-dynamical and resemble a DBI generalization of gravity. For even dimensional CFTs, analogous counterterms cancel log-independent cut-off dependence.
Fluid Gravity Engineering Rocket motor flow analysis
Anand, Mahesh
Fluid Gravity Engineering Capability Â· Rocket motor flow analysis -Internal (performance) -External (plume / contamination) Â· Effect on landing site (surface alteration) -In-depth flow through porous young scientists/engineers Fluid Gravity Engineering Ltd #12;
Weighted Watson-Crick automata
Tamrin, Mohd Izzuddin Mohd [Department of Information System, Kulliyyah of Information and Communication Technology, International Islamic University Malaysia, 50728 Gombak, Selangor (Malaysia); Turaev, Sherzod; Sembok, Tengku Mohd Tengku [Department of Computer Science, Kulliyyah of Information and Communication Technology, International Islamic University Malaysia, 50728 Gombak, Selangor (Malaysia)
2014-07-10T23:59:59.000Z
There are tremendous works in biotechnology especially in area of DNA molecules. The computer society is attempting to develop smaller computing devices through computational models which are based on the operations performed on the DNA molecules. A Watson-Crick automaton, a theoretical model for DNA based computation, has two reading heads, and works on double-stranded sequences of the input related by a complementarity relation similar with the Watson-Crick complementarity of DNA nucleotides. Over the time, several variants of Watson-Crick automata have been introduced and investigated. However, they cannot be used as suitable DNA based computational models for molecular stochastic processes and fuzzy processes that are related to important practical problems such as molecular parsing, gene disease detection, and food authentication. In this paper we define new variants of Watson-Crick automata, called weighted Watson-Crick automata, developing theoretical models for molecular stochastic and fuzzy processes. We define weighted Watson-Crick automata adapting weight restriction mechanisms associated with formal grammars and automata. We also study the generative capacities of weighted Watson-Crick automata, including probabilistic and fuzzy variants. We show that weighted variants of Watson-Crick automata increase their generative power.
Molecular Weight & Energy Transport 7 September 2011
Militzer, Burkhard
't transport the bulk of the energy in the sun. #12;Molecular Weight & Energy Transport 7 September 2011 Goals · Review mean molecular weight this intuitively before looking back at your quantitative results. #12;molecular weight & energy transport 2 Energy
Tian, David Wenjie
2015-01-01T23:59:59.000Z
According to Lovelock's theorem, the Hilbert-Einstein and the Lovelock actions are indistinguishable from their field equations. However, they have different scalar-tensor counterparts, which correspond to the Brans-Dicke and the \\emph{Lovelock-Brans-Dicke} (LBD) gravities, respectively. In this paper the LBD model of alternative gravity with the Lagrangian density $\\mathscr{L}_{\\text{LBD}}=\\frac{1}{16\\pi}\\left[\\phi\\left(R+\\frac{a}{\\sqrt{-g}}{}^*RR + b\\mathcal{G}\\right)-\\frac{\\omega_{\\text L}}{\\phi}\
David Wenjie Tian; Ivan Booth
2015-03-02T23:59:59.000Z
According to Lovelock's theorem, the Hilbert-Einstein and the Lovelock actions are indistinguishable from their field equations. However, they have different scalar-tensor counterparts, which correspond to the Brans-Dicke and the \\emph{Lovelock-Brans-Dicke} (LBD) gravities, respectively. In this paper the LBD model of alternative gravity with the Lagrangian density $\\mathscr{L}_{\\text{LBD}}=\\frac{1}{16\\pi}[\\phi(R+\\frac{a}{\\sqrt{-g}}{}^*RR + b\\mathcal{G})-\\frac{\\omega_{\\text L}}{\\phi}\
Characterization and analysis of the molecular weight of lignin for biorefining studies
Tolbert, Allison [Georgia Institute of Technology, Atlanta] [Georgia Institute of Technology, Atlanta; Akinosho, Hannah [Georgia Institute of Technology, Atlanta] [Georgia Institute of Technology, Atlanta; Khunsupat, Taya Ratayakorn [ORNL] [ORNL; Naskar, Amit K [ORNL] [ORNL; Ragauskas, Arthur [Georgia Institute of Technology, Atlanta] [Georgia Institute of Technology, Atlanta
2014-01-01T23:59:59.000Z
The molecular weight of lignin is a fundamental property that infl uences the recalcitrance of biomass and the valorization of lignin. The determination of the molecular weight of lignin in native biomass is dependent on the bioresources used and the isolation and purifi cation procedures employed. The three most commonly employed isolation methods are milled wood lignin (MWL), cellulolytic enzyme lignin (CEL), and enzymatic mild acidolysis lignin (EMAL). Common characterization techniques for determining the molecular weight of lignin will be addressed, with an emphasis on gel permeation chromatography (GPC). This review also examines the mechanisms behind several biological, physical, and chemical pre-treatments and their impact on the molecular weight of lignin. The number average molecular weight (Mn), weight average molecular weight (Mw) and polydispersity index (D) all vary in magnitude depending on the biomass source, pre-treatment conditions, and isolation method. Additionally, there is a growing body of literature that supports changes in the molecular weight of lignin in response to genetic modifi cations in the lignin biosynthetic pathways. This review summarizes different procedures for obtaining the molecular weight of lignin that have been used in recent years and highlight future opportunities for applications of lignin.
Intrusive gravity currents in two-layer
Flynn, Morris R.
Intrusive gravity currents in two-layer stratified media Morris R. Flynn & Paul F. Linden Dept.avalanche.org/pictures #12;· `Microbursts' pose a non-trivial threat to airplane safety Introduction Impacts on human health;· Whereas gravity currents travel along a solid boundary, intrusive gravity currents or intrusions propagate
Buckling in polymer monolayers: Molecular-weight dependence
Srivastava, S.; Basu, J.K.; (IIS)
2010-11-12T23:59:59.000Z
We present systematic investigations of buckling in Langmuir monolayers of polyvinyl acetate formed at the air-water interface. On compression the polymer monolayers are converted to a continuous membrane with a thickness of {approx}2-3 nm of well-defined periodicity, {lambda}{sub b}. Above a certain surface concentration the membrane undergoes a morphological transition buckling, leading to the formation of striped patterns. The periodicity seems to depend on molecular weight as per the predictions of the gravity-bending buckling formalism of Milner et al. for fluidlike films on water. However anomalously low values of bending rigidity and Young's modulus are obtained using this formalism. Hence we have considered an alternative model of buckling-based solidlike films on viscoelastic substrates. The values of bending rigidity and Young's modulus obtained by this method, although lower than expected, are closer to the bulk values. Remarkably, no buckling is found to occur above a certain molecular weight. We have tried to explain the observed molecular-weight dependence in terms of the variation in isothermal compressive modulus of the monolayers with surface concentration as well as provided possible explanations for the obtained low values of mechanical properties similar to that observed for ultrathin polymer films.
Quantum Gravity and Precision Tests
C. P. Burgess
2006-06-24T23:59:59.000Z
This article provides a cartoon of the quantization of General Relativity using the ideas of effective field theory. These ideas underpin the use of General Relativity as a theory from which precise predictions are possible, since they show why quantum corrections to standard classical calculations are small. Quantum corrections can be computed controllably provided they are made for the weakly-curved geometries associated with precision tests of General Relativity, such as within the solar system or for binary pulsars. They also bring gravity back into the mainstream of physics, by showing that its quantization (at low energies) exactly parallels the quantization of other, better understood, non-renormalizable field theories which arise elsewhere in physics. Of course effective field theory techniques do not solve the fundamental problems of quantum gravity discussed elsewhere in these pages, but they do helpfully show that these problems are specific to applications on very small distance scales. They also show why we may safely reject any proposals to modify gravity at long distances if these involve low-energy problems (like ghosts or instabilities), since such problems are unlikely to be removed by the details of the ultimate understanding of gravity at microscopic scales.
Thomas Rauch
2006-07-11T23:59:59.000Z
NLTE spectral analyses of high-gravity central stars by means of state-of-the-art model atmosphere techniques provide information about the precursor AGB stars. The hydrogen-deficient post-AGB stars allow investigations on the intershell matter which is apparently exhibited at the stellar surface. We summarize recent results from imaging, spectroscopy, and spectropolarimetry.
Antimatter, the SME, and Gravity
Jay D. Tasson
2012-12-07T23:59:59.000Z
A general field-theoretic framework for the analysis of CPT and Lorentz violation is provided by the Standard-Model Extension (SME). This work discusses a number of SME-based proposals for tests of CPT and Lorentz symmetry, including antihydrogen spectroscopy and antimatter gravity tests.
Antimatter, the SME, and Gravity
Tasson, Jay D
2012-01-01T23:59:59.000Z
A general field-theoretic framework for the analysis of CPT and Lorentz violation is provided by the Standard-Model Extension (SME). This work discusses a number of SME-based proposals for tests of CPT and Lorentz symmetry, including antihydrogen spectroscopy and antimatter gravity tests.
Liouville quantum gravity and KPZ
Duplantier, Bertrand
Consider a bounded planar domain D, an instance h of the Gaussian free field on D, with Dirichlet energy ... and a constant 0[less than or equal to]?<2. The Liouville quantum gravity measure on D is the weak limit as ...
Fact #624: May 24, 2010 Corporate Average Fuel Economy Standards...
4: May 24, 2010 Corporate Average Fuel Economy Standards, Model Years 2012-2016 Fact 624: May 24, 2010 Corporate Average Fuel Economy Standards, Model Years 2012-2016 The final...
Fact #870: April 27, 2015 Corporate Average Fuel Economy Progress...
70: April 27, 2015 Corporate Average Fuel Economy Progress, 1978-2014 - Dataset Fact 870: April 27, 2015 Corporate Average Fuel Economy Progress, 1978-2014 - Dataset Excel file...
Fact #849: December 1, 2014 Midsize Hybrid Cars Averaged 51%...
Broader source: Energy.gov (indexed) [DOE]
For the 2014 model year, midsize hybrid cars averaged 43.4 miles per gallon (mpg) while midsize non-hybrid cars averaged 28.7 mpg; the difference between the two has narrowed due...
Effects of dairy intake on weight maintenance
Zemel, Michael B.; Donnelly, Joseph E.; Smith, Bryan K.; Sullivan, Debra K.; Richards, Joanna; Morgan-Hanusa, Danielle; Mayo, Matthew S.; Sun, Xiaocun; Cook-Wiens, Galen; Bailey, Bruce W.; Van Walleghen, Emily L.; Washburn, Richard A.
2008-10-24T23:59:59.000Z
. However, weight maintenance following successful weight loss is a critical component to the successful management of obesity, and although there are animal data to support the concept of calcium and dairy attenuation of weight and fat regain [23... or components of body composition. The premise of this investigation was that correction of dietary calcium and dairy insufficiency may attenuate weight regain following successful weight loss. Accord- ingly, it was important to have a clear comparison of inad...
Gravity Control produced by a Thermoionic Current through the Air at Very Low Pressure
Fran De Aquino
2006-10-23T23:59:59.000Z
It was observed that samples hung above a thermoionic current exhibit a weight decrease directly proportional to the intensity of the current. The observed phenomenon appears to be absolutely new and unprecedented in the literature and can not be understood in the framework of the general relativity. It is pointed out the possibility that this unexpected effect is connected with a possible correlation between gravity and electromagnetism.
Axions in gravity with torsion
Oscar Castillo-Felisola; Cristobal Corral; Sergey Kovalenko; Ivan Schmidt; Valery E. Lyubovitskij
2015-04-13T23:59:59.000Z
We study a scenario allowing a solution of the strong charge parity problem via the Peccei-Quinn mechanism, implemented in gravity with torsion. In this framework there appears a torsion-related pseudoscalar field known as Kalb-Ramond axion. We compare it with the so-called Barbero-Immirzi axion recently proposed in the literature also in the context of the gravity with torsion. We show that they are equivalent from the viewpoint of the effective theory. The phenomenology of these torsion-descended axions is completely determined by the Planck scale without any additional model parameters. These axions are very light and very weakly interacting with ordinary matter. We briefly comment on their astrophysical and cosmological implications in view of the recent BICEP2 and Planck data.
Axions in gravity with torsion
Castillo-Felisola, Oscar; Kovalenko, Sergey; Schmidt, Ivan; Lyubovitskij, Valery E
2015-01-01T23:59:59.000Z
We study a scenario allowing a solution of the strong CP-problem via the Peccei-Quinn mechanism, implemented in gravity with torsion. In this framework there appears a torsion-related pseudoscalar field known as Kalb-Ramond axion. We compare it with the so called Barbero-Immirzi axion recently proposed in the literature also in the context of the gravity with torsion. We show that they are equivalent from the view point of the effective theory. The phenomenology of these torsion-descended axions is completely determined by the Planck scale without any additional model parameters. These axions are very light and very weakly interacting with ordinary matter. We briefly comment on their astrophysical and cosmological implications in view of the recent BICEP2 and Planck data.
Black holes in massive gravity
Babichev, Eugeny
2015-01-01T23:59:59.000Z
We review the black hole solutions of the ghost-free massive gravity theory and its bimetric extension and outline the main results on the stability of these solutions against small perturbations. Massive (bi)-gravity accommodates exact black hole solutions, analogous to those of General Relativity. In addition to these solutions, hairy black holes -- solutions with no correspondent in General Relativity -- have been found numerically, whose existence is a natural consequence of the absence of the Birkhoff's theorem in these theories. The existence of extra propagating degrees of freedom, makes the stability properties of these black holes richer and more complex than those of General Relativity. In particular, the bi-Schwarzschild black hole exhibits an unstable spherically symmetric mode, while the bi-Kerr geometry is also generically unstable, both against the spherical mode and against superradiant instabilities. If astrophysical black holes are described by these solutions, the superradiant instability o...
Focal lengths and gravity waves
Doherty, Mary Jane
1985-01-01T23:59:59.000Z
Film is composed of tiny photographs which, when projected, sometimes look very much like people and things in the real world. Film, too, cannot be separated from its tools. Aesthetic criticism was, and still is, weighted ...
average power femtosecond: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Stirling refrigerator1 that abrupt changes in geometry are ubiquitous in Stirling engines, thermoacoustics, and res- piratory flows Smith, Barton L. 52 On the Peak-to-Average...
average power ratio: Topics by E-print Network
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Stirling refrigerator1 that abrupt changes in geometry are ubiquitous in Stirling engines, thermoacoustics, and res- piratory flows Smith, Barton L. 60 High average power,...
average power semiconductor: Topics by E-print Network
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Stirling refrigerator1 that abrupt changes in geometry are ubiquitous in Stirling engines, thermoacoustics, and res- piratory flows Smith, Barton L. 56 High average power,...
average resonance neutron: Topics by E-print Network
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Nader Haghighipour 1999-02-03 4 Average over energy effect of parity nonconservation in neutron scattering on heavy nuclei Nuclear Theory (arXiv) Summary: Using semiclassical...
LOW-HIGH VALUES FOR PETROLEUM AVERAGE INVENTORY RANGES (MILLION...
Gasoline and Diesel Fuel Update (EIA)
ENERGY INFORMATION ADMINISTRATION LOW-HIGH VALUES FOR PETROLEUM AVERAGE INVENTORY RANGES (MILLION BARRELS) FILE UPDATED April 2004 Line Month Low High Number Product Name Geography...
average daily traffic: Topics by E-print Network
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Next Page Last Page Topic Index 1 April 2014 Annual Average DailyTraffic (AADT) is a key input in operations and transportation planning Environmental Sciences and Ecology...
average wind shear: Topics by E-print Network
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by uncompensated voids. Maria Mattsson; Teppo Mattsson 2010-07-17 7 Probabilistic Wind Speed Forecasting using Ensembles and Bayesian Model Averaging Mathematics Websites Summary:...
average high energy: Topics by E-print Network
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averaged null (ANEC) energy conditions, and quantum inequality restrictions on negative energy for free massless scalar fields. In a two-dimensional compactified Minkowski...
average kinetic energy: Topics by E-print Network
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energy by kinetic averaging Pierre-Emmanuel Jabin Ecole Normale Sup-Landau energy for two dimensional divergence free fields ap- pearing in the gradient theory of...
average beta energy: Topics by E-print Network
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averaged null (ANEC) energy conditions, and quantum inequality restrictions on negative energy for free massless scalar fields. In a two-dimensional compactified Minkowski...
average power high: Topics by E-print Network
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Simultaneous Power Fluctuation and Average Power Minimization during Nano-CMOS Behavioral Synthesis Computer Technologies and Information Sciences Websites Summary: conversion 6....
Born-Infeld gravity in three dimensions
Alishahiha, Mohsen [School of physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Naseh, Ali [School of physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Department of Physics, Sharif University of Technology, P.O. Box 11365-9161, Tehran (Iran, Islamic Republic of); Soltanpanahi, Hesam [School of physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); School of Physics and Centre for Theoretical Physics, University of the Witwatersrand, WITS 2050 Johannesburg (South Africa)
2010-07-15T23:59:59.000Z
In this paper we explore different aspects of three dimensional Born-Infeld as well as Born-Infeld-Chern-Simons gravity. We show that the models have anti-de Sitter and anti-de Sitter wave vacuum solutions. Moreover, we observe that although Born-Infeld-Chern-Simons gravity admits a logarithmic solution, Born-Infeld gravity does not, though it has a limiting logarithmic solution as we approach the critical point.
Weighted Guidelines | Department of Energy
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2, 2015Visiting Strong, Smart,Department of EnergyEnergyWeighted
Supersymmetry and Gravity in Noncommutative Field Theories
Victor O. Rivelles
2003-05-14T23:59:59.000Z
We discuss the renormalization properties of noncommutative supersymmetric theories. We also discuss how the gauge field plays a role similar to gravity in noncommutative theories.
Can Gravity Probe B usefully constrain torsion gravity theories?
Flanagan, Eanna E.; Rosenthal, Eran [Center for Radiophysics and Space Research, Cornell University, Ithaca, New York, 14853 (United States)
2007-06-15T23:59:59.000Z
In most theories of gravity involving torsion, the source for torsion is the intrinsic spin of matter. Since the spins of fermions are normally randomly oriented in macroscopic bodies, the amount of torsion generated by macroscopic bodies is normally negligible. However, in a recent paper, Mao et al. (arXiv:gr-qc/0608121) point out that there is a class of theories, including the Hayashi-Shirafuji (1979) theory, in which the angular momentum of macroscopic spinning bodies generates a significant amount of torsion. They further argue that, by the principle of action equals reaction, one would expect the angular momentum of test bodies to couple to a background torsion field, and therefore the precession of the Gravity Probe B gyroscopes should be affected in these theories by the torsion generated by the Earth. We show that in fact the principle of action equals reaction does not apply to these theories, essentially because the torsion is not an independent dynamical degree of freedom. We examine in detail a generalization of the Hayashi-Shirafuji theory suggested by Mao et al. called Einstein-Hayashi-Shirafuji theory. There are a variety of different versions of this theory, depending on the precise form of the coupling to matter chosen for the torsion. We show that, for any coupling to matter that is compatible with the spin transport equation postulated by Mao et al., the theory has either ghosts or an ill-posed initial-value formulation. These theoretical problems can be avoided by specializing the parameters of the theory and in addition choosing the standard minimal coupling to matter of the torsion tensor. This yields a consistent theory, but one in which the action equals reaction principle is violated, and in which the angular momentum of the gyroscopes does not couple to the Earth's torsion field. Thus, the Einstein-Hayashi-Shirafuji theory does not predict a detectable torsion signal for Gravity Probe B. There may be other torsion theories which do.
Gravity modeling of Cenozoic extensional basins, offshore Vietnam
Mauri, Steven Joseph
1993-01-01T23:59:59.000Z
(Yinggehai) basins. Gravity modeling results provide important clues to the controversial tectonic development of Southeast Asia during the Tertiary. Combined Bouguer and free-air gravity maps and residual gravity anomaly maps were generated for the study...
Energy Aware Scheduling for Weighted Completion Time and Weighted Tardiness
Carrasco, Rodrigo A; Stein, Cliff
2011-01-01T23:59:59.000Z
The ever increasing adoption of mobile devices with limited energy storage capacity, on the one hand, and more awareness of the environmental impact of massive data centres and server pools, on the other hand, have both led to an increased interest in energy management algorithms. The main contribution of this paper is to present several new constant factor approximation algorithms for energy aware scheduling problems where the objective is to minimize weighted completion time plus the cost of the energy consumed, in the one machine non-preemptive setting, while allowing release dates and deadlines.Unlike previous known algorithms these new algorithms can handle general job-dependent energy cost functions, extending the application of these algorithms to settings outside the typical CPU-energy one. These new settings include problems where in addition, or instead, of energy costs we also have maintenance costs, wear and tear, replacement costs, etc., which in general depend on the speed at which the machine r...
On average sampling restoration of Piranashvilitype harmonizable processes
Paris-Sud XI, Université de
; time shifted sam- pling; Piranashvili, Lo`eve, Karhunen harmonizable stochastic process; weakly.olenko@latrobe.edu.au, poganj@pfri.hr Abstract: The harmonizable Piranashvili type stochastic pro- cesses are approximated stationary stochastic process; local averages; average sampling reconstruction. 1. Introduction
averaged energy minimization: Topics by E-print Network
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averaged energy minimization First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Averaged Energy...
THE AVERAGED CONTROL SYSTEM OF FAST OSCILLATING CONTROL SYSTEMS
Paris-Sud XI, Université de
, control systems, small control, optimal control, Finsler geometry. AMS subject classifications. 34C29, 34H used for design. The use of averaging in optimal control of oscillating systems [10, 13, 14, 7THE AVERAGED CONTROL SYSTEM OF FAST OSCILLATING CONTROL SYSTEMS ALEX BOMBRUN AND JEAN
Distributed Average Consensus in Sensor Networks with Random Link Failures
Moura, José
Distributed Average Consensus in Sensor Networks with Random Link Failures Soummya Kar Department: soummyakgandrew.cmu.edu Abstract We study the impact of the topology of a sensor network on distributed average in terms of a moment of the distribution of the norm of a function of the network graph Laplacian matrix L
The global warming signal is the average of
Jones, Peter JS
, uncertainty in the isopycnal diffusivity causes uncertainty of up to 50% in the global warming signalThe global warming signal is the average of years 70-80 in the increasing CO2 run minus the average represent significant uncertainty in the global warming signal (Fig. 5). The differences at high latitudes
Weighted Marshall-Olkin Bivariate Exponential Distribution
Kundu, Debasis
Weighted Marshall-Olkin Bivariate Exponential Distribution Ahad Jamalizadeh§ & Debasis Kundu of weighted Marshall-Olkin bivariate exponential distribu- tions. This new singular distribution has of this paper is to introduce a weighted Marshall-Olkin bivariate exponential (WMOBE) distribution, using
Negative mass solitons in gravity
Cebeci, Hakan; Sarioglu, Oezguer; Tekin, Bayram [Anadolu University, Department of Physics, Yunus Emre Campus, 26470, Eskisehir (Turkey); Department of Physics, Faculty of Arts and Sciences, Middle East Technical University, 06531, Ankara (Turkey)
2006-03-15T23:59:59.000Z
We first reconstruct the conserved (Abbott-Deser) charges in the spin-connection formalism of gravity for asymptotically (Anti)-de Sitter spaces, and then compute the masses of the AdS soliton and the recently found Eguchi-Hanson solitons in generic odd dimensions, unlike the previous result obtained for only five dimensions. These solutions have negative masses compared to the global AdS or AdS/Z{sub p} spacetimes. As a separate note, we also compute the masses of the recent even dimensional Taub-NUT-Reissner-Nordstroem metrics.
Ground Gravity Survey At Neal Hot Springs Geothermal Area (Colwell...
Technique Ground Gravity Survey Activity Date 2011 - 2011 Usefulness not indicated DOE-funding Unknown Exploration Basis Gravity surveys were conducted to gain a better...
airborne gravity survey: Topics by E-print Network
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Gravity CERN Preprints Summary: Modified gravity theories may provide an alternative to dark energy to explain cosmic acceleration. We argue that the observational program...
Scale of gravity and the cosmological constant within a landscape
Graesser, Michael L. [California Institute of Technology, Pasadena, California 91125 (United States); Department of Physics, Rutgers University, Piscataway, New Jersey 08540 (United States); Salem, Michael P. [California Institute of Technology, Pasadena, California 91125 (United States)
2007-08-15T23:59:59.000Z
It is possible that the scale of gravity, parametrized by the apparent Planck mass, may obtain different values within different universes in an encompassing multiverse. We investigate the range over which the Planck mass may scan while still satisfying anthropic constraints. The window for anthropically allowed values of the Planck mass may have important consequences for landscape predictions. For example, if the likelihood to observe some value of the Planck mass is weighted by the inflationary expansion factors of the universes that contain that value, then it appears extremely unlikely to observe the value of the Planck mass that is measured within our universe. This is another example of the runaway inflation problem discussed in recent literature. We also show that the window for the Planck mass significantly weakens the anthropic constraint on the cosmological constant when both are allowed to vary over a landscape.
Is Dark Energy Abnormally Weighting?
A. Fuzfa; J. -M. Alimi
2006-09-05T23:59:59.000Z
We present a new interpretation of dark energy in terms of an \\textit{Abnormally Weighting Energy} (AWE). This means that dark energy does not couple to gravitation in the same way as ordinary matter, yielding a violation of the weak and strong equivalence principles on cosmological scales. The resulting cosmological mechanism accounts for the Hubble diagram of type Ia supernovae in terms of both cosmic acceleration and variation of the gravitational constant while still accounting for the present tests of general relativity. This explanation allows to build dark energy models (i) without violation of the strong energy condition $p<-\\rho c^2/3$ (ii) with non-negligible direct couplings to gravitation and (iii) natural convergence mechanism toward general relativity.
Reconstruction of Einstein-Aether Gravity from other Modified Gravity Models
Chayan Ranjit; Ujjal Debnath
2014-09-08T23:59:59.000Z
We briefly describe the modified Friedmann equations for Einstein-Aether gravity theory and we find the effective density and pressure. The purpose of our present work is to reconstruction of Einstein-Aether Gravity from other modified gravities like $f(T)$, $f(R)$, $f(G)$, $f(R,T)$ and $f(R,G)$ and check its viability. The scale factor is chosen in power law form. The free function $F(K)$ for Einstein-Aether gravity (where $K$ is proportional to $H^{2}$) have been found in terms for $K$ by the correspondence between Einstein-Aether gravity and other modified gravities and the nature of $F(K)$ vs $K$ have been shown graphically for every cases. Finally, we analyzed the stability of each reconstructed Einstein-Aether gravity model.
Conserved charges in 3D gravity
Blagojevic, M.; Cvetkovic, B. [University of Belgrade, Institute of Physics, P. O. Box 57, 11001 Belgrade (Serbia)
2010-06-15T23:59:59.000Z
The covariant canonical expression for the conserved charges, proposed by Nester, is tested on several solutions in three-dimensional gravity with or without torsion and topologically massive gravity. In each of these cases, the calculated values of energy momentum and angular momentum are found to satisfy the first law of black hole thermodynamics.
The Superheavy Elements and Anti-Gravity
Anastasovski, Petar K. [Department of Physics, Faculty of Technology and Metallurgy, Saints Cyril and Methodius University, Skopje (Macedonia, The Former Yugoslav Republic of)
2004-02-04T23:59:59.000Z
The essence of any propulsion concept is to overcome gravity. Anti-gravity is a natural means to achieve this. Thus, the technology to pursue anti-gravity, by using superheavy elements, may provide a new propulsion paradigm. The theory of superluminal relativity provides a hypothesis for existence of elements with atomic number up to Z = 145, some of which may possess anti-gravity properties. Analysis results show that curved space-time exists demonstrating both gravitic and anti-gravitic properties not only around nuclei but inside the nuclei as well. Two groups of elements (Z < 64 and 63 < Z <145) exist that demonstrate these capabilities. The nuclei of the first group of elements have the masses with only the property of gravity. The nuclei of the elements of the second group have the masses with both properties: gravity and anti-gravity in two different ranges of curved space-time around the nuclei.. The hypothetical element with Z = 145 is the unique among all elements whose nucleus has only anti-gravity property. It is proposed that this element be named Hawking, in honour of Stephen W. Hawking.
Dual Accretion Disks in Alternate Gravity Theories
James S. Graber
1997-12-15T23:59:59.000Z
The interior of gravitationally collapsed objects in alternate theories of gravity in which event horizons and singularities do not occur in strong field gravity were generically investigated. These objects, called red holes, were found to contain dynamic configurations of matter, radiation and spacetime similar to inside out accretion disks well inside the photon orbit. Applications to astrophysical phenomena are briefly described.
Threat Mitigation: The Gravity Tractor
Russell Schweickart; Clark Chapman; Dan Durda; Piet Hut
2006-08-15T23:59:59.000Z
The Gravity Tractor (GT) is a fully controlled asteroid deflection concept using the mutual gravity between a robotic spacecraft and an asteroid to slowly accelerate the asteroid in the direction of the "hovering" spacecraft. Based on early warning, provided by ground tracking and orbit prediction, it would be deployed a decade or more prior to a potential impact. Ion engines would be utilized for both the rendezvous with the asteroid and the towing phase. Since the GT does not dock with or otherwise physically contact the asteroid during the deflection process there is no requirement for knowledge of the asteroid's shape, composition, rotation state or other "conventional" characteristics. The GT would first reduce the uncertainty in the orbit of the asteroid via Earth tracking of its radio transponder while station keeping with the asteroid. If, after analysis of the more precise asteroid orbit a deflection is indeed indicated, the GT would "hover" above the surface of the asteroid in the direction of the required acceleration vector for a duration adequate to achieve the desired velocity change. The orbit of the asteroid is continuously monitored throughout the deflection process and the end state is known in real time. The performance envelope for the GT includes most NEOs which experience close gravitational encounters prior to impact and those below 150-200 meters in diameter on a direct Earth impact trajectory.
Solar System constraints to nonminimally coupled gravity
Orfeu Bertolami; Riccardo March; Jorge Páramos
2013-06-05T23:59:59.000Z
We extend the analysis of Chiba, Smith and Erickcek \\cite{CSE} of Solar System constraints on $f(R)$ gravity to a class of nonminimally coupled (NMC) theories of gravity. These generalize $f(R)$ theories by replacing the action functional of General Relativity (GR) with a more general form involving two functions $f^1(R)$ and $f^2(R)$ of the Ricci scalar curvature $R$. While the function $f^1(R)$ is a nonlinear term in the action, analogous to $f(R)$ gravity, the function $f^2(R)$ yields a NMC between the matter Lagrangian density $\\LL_m$ and the scalar curvature. The developed method allows for obtaining constraints on the admissible classes of functions $f^1(R)$ and $f^2(R)$, by requiring that predictions of NMC gravity are compatible with Solar System tests of gravity. We apply this method to a NMC model which accounts for the observed accelerated expansion of the Universe.
average glandular dose: Topics by E-print Network
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doses and cancer rates to the workers m the first Soviet atom-bomb facility, near 2 Chelyabinsk and 4,600 at the plutonium sep- aration plant. If we allow for an average work...
INDIVIDUAL REFORM ELEMENTS .63Average course exam score
Colorado at Boulder, University of
INDIVIDUAL REFORM ELEMENTS .63Average course exam score .11In class clicker score .02Lecture: · Correlations with effort/curricular elements are positive but not high, indicating no individual course reform
areally averaged heat: Topics by E-print Network
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Chulwoo Jung; Christoph Lehner 2014-02-18 56 The Fallacy of Averages University of Kansas - KU ScholarWorks Summary: of component variables as well, we found that ignoring...
Does anyone have access to 2012 average residential rates by...
Does anyone have access to 2012 average residential rates by utility company? I'm seeing an inconsistency between the OpenEI website and EIA 861 data set. Home > Groups > Utility...
From average case complexity to improper learning [Extended Abstract
Linial, Nathan "Nati"
is that the standard reduc- tions from NP-hard problems do not seem to apply in this context. There is essentially only.1145/2591796.2591820. Keywords Hardness of improper learning, DNFs, Halfspaces, Average Case complexity, CSP problems, Resolution
average neutronic properties: Topics by E-print Network
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M. H. van Kerkwijk 2004-03-20 2 Average over energy effect of parity nonconservation in neutron scattering on heavy nuclei Nuclear Theory (arXiv) Summary: Using semiclassical...
average power optical: Topics by E-print Network
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systems, Multiple Subcarrier Strohmer, Thomas 3 June 1, 2000 Vol. 25, No. 11 OPTICS LETTERS 859 16.2-W average power from a diode-pumped Materials Science Websites...
Fact #835: August 25, 2014 Average Annual Gasoline Pump Price...
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35: Average Annual Gasoline Pump Price, 1929-2013 fotw835web.xlsx More Documents & Publications Offshore Wind Market and Economic Analysis Report 2013 Response to several FOIA...
THE UNIVERSITY OF RHODE ISLAND FRINGE BENEFIT AVERAGE RATE
Rhode Island, University of
THE UNIVERSITY OF RHODE ISLAND FRINGE BENEFIT AVERAGE RATE FY 2015 Allocation Cost or Classified.2% URI Budget & Financial Planning Office 9.17.14 Office:fringebenefits:office of sponsored projects: FY2015 Allocation #12;
On the Choice of Average Solar Zenith Angle
Cronin, Timothy W.
Idealized climate modeling studies often choose to neglect spatiotemporal variations in solar radiation, but doing so comes with an important decision about how to average solar radiation in space and time. Since both ...
average neck flexion: Topics by E-print Network
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profiles including the singular isothermal sphere, the Navarro-Frenk-White... Retana-Montenegro, E; Baes, M 2012-01-01 13 Fast Averaging MIT - DSpace Summary: We are interested in...
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14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Relations between fusion cross sections and average angular momenta Nuclear Theory (arXiv) Summary: We study...
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14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Relations between fusion cross sections and average angular momenta Nuclear Theory (arXiv) Summary: We study...
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14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Relations between fusion cross sections and average angular momenta Nuclear Theory (arXiv) Summary: We study...
average effective dose: Topics by E-print Network
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field theory, Chern-Simons theory is discussed in detail. M. Reuter 1996-02-04 2 Is dark energy an effect of averaging? CERN Preprints Summary: The present standard model of...
Flavor Physics Data from the Heavy Flavor Averaging Group (HFAG)
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
The Heavy Flavor Averaging Group (HFAG) was established at the May 2002 Flavor Physics and CP Violation Conference in Philadelphia, and continues the LEP Heavy Flavor Steering Group's tradition of providing regular updates to the world averages of heavy flavor quantities. Data are provided by six subgroups that each focus on a different set of heavy flavor measurements: B lifetimes and oscillation parameters, Semi-leptonic B decays, Rare B decays, Unitarity triangle parameters, B decays to charm final states, and Charm Physics.
Partial Averaging Near a Resonance in Planetary Dynamics
Nader Haghighipour
1999-02-03T23:59:59.000Z
Following the general numerical analysis of Melita and Woolfson (1996), I showed in a recent paper that a restricted, planar, circular planetary system consisting of Sun, Jupiter and Saturn would be captured in a near (2:1) resonance when one would allow for frictional dissipation due to interplanetary medium (Haghighipour, 1998). In order to analytically explain this resonance phenomenon, the method of partial averaging near a resonance was utilized and the dynamics of the first-order partially averaged system at resonance was studied. Although in this manner, the finding that resonance lock occurs for all initial relative positions of Jupiter and Saturn was confirmed, the first-order partially averaged system at resonance did not provide a complete picture of the evolutionary dynamics of the system and the similarity between the dynamical behavior of the averaged system and the main planetary system held only for short time intervals. To overcome these limitations, the method of partial averaging near a resonance is extended to the second order of perturbation in this paper and a complete picture of dynamical behavior of the system at resonance is presented. I show in this study that the dynamics of the second-order partially averaged system at resonance resembles the dynamical evolution of the main system during the resonance lock in general, and I present analytical explanations for the evolution of the orbital elements of the main system while captured in resonance.
Table A44. Average Prices of Purchased Electricity and Steam
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013,Iowa"Dakota" ,"FullWestQuantity of2" "
atomic weights table: Topics by E-print Network
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stability, atomic weights and molecular weights V. Paar, Bijeniccka 32, 10000 Zagreb, Croatia Accepted 15 January 2002 Abstract A power law is introduced weights. The power law...
apparent molecular weight: Topics by E-print Network
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stability, atomic weights and molecular weights V. Paar, Bijeniccka 32, 10000 Zagreb, Croatia Accepted 15 January 2002 Abstract A power law is introduced weights. The power law...
atomic weights tables: Topics by E-print Network
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stability, atomic weights and molecular weights V. Paar, Bijeniccka 32, 10000 Zagreb, Croatia Accepted 15 January 2002 Abstract A power law is introduced weights. The power law...
assigning individual weights: Topics by E-print Network
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understeer, and cornering shifts weight to the opposite side, unloading the inside tires. But why does weight shift during these maneuvers? How can weight shift when...
Emergent Horava gravity in graphene
G. E. Volovik; M. A. Zubkov
2013-07-07T23:59:59.000Z
First of all, we reconsider the tight - binding model of monolayer graphene, in which the variations of the hopping parameters are allowed. We demonstrate that the emergent 2D Weitzenbock geometry as well as the emergent U(1) gauge field appear. The emergent gauge field is equal to the linear combination of the components of the zweibein. Therefore, we actually deal with the gauge fixed version of the emergent 2+1 D teleparallel gravity. In particular, we work out the case, when the variations of the hopping parameters are due to the elastic deformations, and relate the elastic deformations with the emergent zweibein. Next, we investigate the tight - binding model with the varying intralayer hopping parameters for the multilayer graphene with the ABC stacking. In this case the emergent 2D Weitzenbock geometry and the emergent U(1) gauge field appear as well, the emergent low energy effective field theory has the anisotropic scaling.
Dimensional Reduction in Quantum Gravity
G. 't Hooft
2009-03-20T23:59:59.000Z
The requirement that physical phenomena associated with gravitational collapse should be duly reconciled with the postulates of quantum mechanics implies that at a Planckian scale our world is not 3+1 dimensional. Rather, the observable degrees of freedom can best be described as if they were Boolean variables defined on a two-dimensional lattice, evolving with time. This observation, deduced from not much more than unitarity, entropy and counting arguments, implies severe restrictions on possible models of quantum gravity. Using cellular automata as an example it is argued that this dimensional reduction implies more constraints than the freedom we have in constructing models. This is the main reason why so-far no completely consistent mathematical models of quantum black holes have been found. Essay dedicated to Abdus Salam.
Tom Fleming; Mark Gross; Ray Renken
1994-01-04T23:59:59.000Z
We define a simplified version of Regge quantum gravity where the link lengths can take on only two possible values, both always compatible with the triangle inequalities. This is therefore equivalent to a model of Ising spins living on the links of a regular lattice with somewhat complicated, yet local interactions. The measure corresponds to the natural sum over all 2^links configurations, and numerical simulations can be efficiently implemented by means of look-up tables. In three dimensions we find a peak in the ``curvature susceptibility'' which grows with increasing system size. However, the value of the corresponding critical exponent as well as the behavior of the curvature at the transition differ from that found by Hamber and Williams for the Regge theory with continuously varying link lengths.
Gravity-Induced Vacuum Dominance
Lima, William C. C.; Vanzella, Daniel A. T. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Caixa Postal 369, CEP 15980-900, Sao Carlos, SP (Brazil)
2010-04-23T23:59:59.000Z
It has been widely believed that, except in very extreme situations, the influence of gravity on quantum fields should amount to just small, subdominant contributions. This view seemed to be endorsed by the seminal results obtained over the last decades in the context of renormalization of quantum fields in curved spacetimes. Here, however, we argue that this belief is false by showing that there exist well-behaved spacetime evolutions where the vacuum energy density of free quantum fields is forced, by the very same background spacetime, to become dominant over any classical energy-density component. By estimating the time scale for the vacuum energy density to become dominant, and therefore for backreaction on the background spacetime to become important, we argue that this (infrared) vacuum dominance may bear unexpected astrophysical and cosmological implications.
Average Soil Water Retention Curves Measured by Neutron Radiography
Cheng, Chu-Lin [ORNL; Perfect, Edmund [University of Tennessee, Knoxville (UTK); Kang, Misun [ORNL; Voisin, Sophie [ORNL; Bilheux, Hassina Z [ORNL; Horita, Juske [Texas Tech University (TTU); Hussey, Dan [NIST Center for Neutron Research (NCRN), Gaithersburg, MD
2011-01-01T23:59:59.000Z
Water retention curves are essential for understanding the hydrologic behavior of partially-saturated porous media and modeling flow transport processes within the vadose zone. In this paper we report direct measurements of the main drying and wetting branches of the average water retention function obtained using 2-dimensional neutron radiography. Flint sand columns were saturated with water and then drained under quasi-equilibrium conditions using a hanging water column setup. Digital images (2048 x 2048 pixels) of the transmitted flux of neutrons were acquired at each imposed matric potential (~10-15 matric potential values per experiment) at the NCNR BT-2 neutron imaging beam line. Volumetric water contents were calculated on a pixel by pixel basis using Beer-Lambert s law after taking into account beam hardening and geometric corrections. To remove scattering effects at high water contents the volumetric water contents were normalized (to give relative saturations) by dividing the drying and wetting sequences of images by the images obtained at saturation and satiation, respectively. The resulting pixel values were then averaged and combined with information on the imposed basal matric potentials to give average water retention curves. The average relative saturations obtained by neutron radiography showed an approximate one-to-one relationship with the average values measured volumetrically using the hanging water column setup. There were no significant differences (at p < 0.05) between the parameters of the van Genuchten equation fitted to the average neutron radiography data and those estimated from replicated hanging water column data. Our results indicate that neutron imaging is a very effective tool for quantifying the average water retention curve.
Newtonian gravity, red shift, confinement, asymptotic freedom and quarks oscillations
G. Quznetsov
2008-10-18T23:59:59.000Z
Quarks oscillations give the Newtonian gravity law, the red shift, the confinement and the asymptotic freedom.
Loop Quantum Gravity 1. Classical framework : Ashtekar-Barbero connection
Sart, Remi
gravity Why Quantum Gravity ? Gravitation vs. Quantum Physics : the two infinities Gravitation : large Quantum Gravity ? Gravitation vs. Quantum Physics : the two infinities Gravitation : large scales-perturbative renormalization Gravity is not a fundamental theory but it is effective (law energy) Â· it has to be modified
Fractal Structure of Loop Quantum Gravity
Leonardo Modesto
2008-12-11T23:59:59.000Z
In this paper we have calculated the spectral dimension of loop quantum gravity (LQG) using simple arguments coming from the area spectrum at different length scales. We have obtained that the spectral dimension of the spatial section runs from 2 to 3, across a 1.5 phase, when the energy of a probe scalar field decrees from high to low energy. We have calculated the spectral dimension of the space-time also using results from spin-foam models, obtaining a 2-dimensional effective manifold at hight energy. Our result is consistent with other two approach to non perturbative quantum gravity: causal dynamical triangulation and asymptotic safety quantum gravity.
CDT meets Horava-Lifshitz gravity
J. Ambjorn; A. Gorlich; S. Jordan; J. Jurkiewicz; R. Loll
2010-04-06T23:59:59.000Z
The theory of causal dynamical triangulations (CDT) attempts to define a nonperturbative theory of quantum gravity as a sum over space-time geometries. One of the ingredients of the CDT framework is a global time foliation, which also plays a central role in the quantum gravity theory recently formulated by Ho\\v{r}ava. We show that the phase diagram of CDT bears a striking resemblance with the generic Lifshitz phase diagram appealed to by Ho\\v{r}ava. We argue that CDT might provide a unifying nonperturbative framework for anisotropic as well as isotropic theories of quantum gravity.
Ning Wu
2012-07-11T23:59:59.000Z
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.
"EIA-914 Production Weighted Response Rates, Percent"
U.S. Energy Information Administration (EIA) Indexed Site
EIA-914 Production Weighted Response Rates, Percent" "Areas",38353,38384,38412,38443,38473,38504,38534,38565,38596,38626,38657,38687,38718,38749,38777,"application...
Average and recommended half-life values for two neutrino double beta decay: Upgrade-2013
Barabash, A. S. [Institute of Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117218 Moscow (Russian Federation)
2013-12-30T23:59:59.000Z
All existing positive results on two neutrino double beta decay in different nuclei were analyzed. Using the procedure recommended by the Particle Data Group, weighted average values for half-lives of {sup 48}Ca, {sup 76}Ge, {sup 82}Se, {sup 96}Zr, {sup 100}Mo, {sup 100}Mo?{sup 100}Ru (0{sub 1}{sup +}), {sup 116}Cd, {sup 130}Te, {sup 136}Xe, {sup 150}Nd, {sup 150}Nd?{sup 150}Sm (0{sub 1}{sup +}) and {sup 238}U were obtained. Existing geochemical data were analyzed and recommended values for half-lives of {sup 128}Te and {sup 130}Ba are proposed. I recommend the use of these results as the most currently reliable values for half-lives.
Bounds on quantum communication via Newtonian gravity
D. Kafri; G. J. Milburn; J. M. Taylor
2014-10-08T23:59:59.000Z
Newtonian gravity yields specific observable consequences, the most striking of which is the emergence of a $1/r^2$ force. In so far as communication can arise via such interactions between distant particles, we can ask what would be expected for a theory of gravity that only allows classical communication. Many heuristic suggestions for gravity-induced decoherence have this restriction implicitly or explicitly in their construction. Here we show that communication via a $1/r^2$ force has a minimum noise induced in the system when the communication cannot convey quantum information, in a continuous time analogue to Bell's inequalities. Our derived noise bounds provide tight constraints from current experimental results on any theory of gravity that does not allow quantum communication.
Zhan, Lang; Yortsos, Yanis
2000-09-11T23:59:59.000Z
A new gravity finger model was proposed in this report in the absence of interfacial tension but in the presence of gravities. This model considered differences in density and viscosity of the two fluids. Thus, it was able to represent both stable and unstable displacements, and the finger development along either the upper or the bottom walls of a channel. This solution recovers the Saffman - Taylar solution if gravity is neglected. The results of the solution are very similar to the solutions proposed by Brener et al. for the gravity number up to 10. The solution provided in this work only has one free parameter while the solution of Brener et al. has three.
Gravity waves from vortex dipoles and jets
Wang, Shuguang
2009-05-15T23:59:59.000Z
The dissertation first investigates gravity wave generation and propagation from jets within idealized vortex dipoles using a nonhydrostatic mesoscale model. Several initially balanced and localized jets induced by vortex dipoles are examined here...
State sum models for quantum gravity
John W. Barrett
2000-10-12T23:59:59.000Z
This paper reviews the construction of quantum field theory on a 4-dimensional spacetime by combinatorial methods, and discusses the recent developments in the direction of a combinatorial construction of quantum gravity.
Energy conditions in f(R) gravity
Santos, J. [Universidade Federal do Rio Grande do Norte, Departamento de Fisica C.P. 1641, 59072-970 Natal-Rio Grande do Norte (Brazil); Departamento de Astronomia, Observatorio Nacional, 20921-400 Rio de Janeiro-Rio de Janeiro (Brazil); Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro-Rio de Janeiro (Brazil); Alcaniz, J. S.; Carvalho, F. C. [Departamento de Astronomia, Observatorio Nacional, 20921-400 Rio de Janeiro-Rio de Janeiro (Brazil); Reboucas, M. J. [Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro-Rio de Janeiro (Brazil)
2007-10-15T23:59:59.000Z
In order to shed some light on the current discussion about f(R)-gravity theories we derive and discuss the bounds imposed by the energy conditions on a general f(R) functional form. The null and strong energy conditions in this framework are derived from Raychaudhuri's equation along with the requirement that gravity is attractive, whereas the weak and dominant energy conditions are stated from a comparison with the energy conditions that can be obtained in a direct approach via an effective energy-momentum tensor for f(R) gravity. As a concrete application of the energy conditions to locally homogeneous and isotropic f(R) cosmology, the recent estimated values of the deceleration and jerk parameters are used to examine the bounds from the weak energy condition on the parameters of two families of f(R)-gravity theories.
Cosmology of modified (but second order) gravity
Tomi S. Koivisto
2009-10-21T23:59:59.000Z
This is a brief review of modified gravity cosmologies. Generically extensions of gravity action involve higher derivative terms, which can result in ghosts and instabilities. There are three ways to circumvent this: Chern-Simons terms, first order variational principle and nonlocality. We consider recent cosmological applications of these three classes of modified gravity models, in particular to the dark energy problem. The viable parameter spaces can be very efficiently constrained by taking into account cosmological data from all epochs in addition to Solar system tests and stability considerations. We make some new remarks concerning so called algebraic scalar-tensor theories, biscalar reformulation of nonlocal actions involving the inverse d'Alembertian, and a possible covariant formulation holographic cosmology with nonperturbative gravity.
Energy conditions in f(R)-gravity
J. Santos; J. S. Alcaniz; M. J. Reboucas; F. C. Carvalho
2007-09-06T23:59:59.000Z
In order to shed some light on the current discussion about f(R)-gravity theories we derive and discuss the bounds imposed by the energy conditions on a general f(R) functional form. The null and strong energy conditions in this framework are derived from the Raychaudhuri's equation along with the requirement that gravity is attractive, whereas the weak and dominant energy conditions are stated from a comparison with the energy conditions that can be obtained in a direct approach via an effective energy-momentum tensor for f(R)-gravity. As a concrete application of the energy conditions to locally homogeneous and isotropic f(R)-cosmology, the recent estimated values of the deceleration and jerk parameters are used to examine the bounds from the weak energy condition on the parameters of two families of f(R)-gravity theories.
Test particle motion in modified gravity theories
Mahmood Roshan
2013-02-05T23:59:59.000Z
We derive the equations of motion of an electrically neutral test particle for modified gravity theories in which the covariant divergence of the ordinary matter energy-momentum tensor dose not vanish (i.e. $\
A new vacuum for Loop Quantum Gravity
Bianca Dittrich; Marc Geiller
2015-05-05T23:59:59.000Z
We construct a new vacuum for loop quantum gravity, which is dual to the Ashtekar-Lewandowski vacuum. Because it is based on BF theory, this new vacuum is physical for $(2+1)$-dimensional gravity, and much closer to the spirit of spin foam quantization in general. To construct this new vacuum and the associated representation of quantum observables, we introduce a modified holonomy-flux algebra which is cylindrically consistent with respect to the notion of refinement by time evolution suggested in [1]. This supports the proposal for a construction of a physical vacuum made in [1,2], also for $(3+1)$-dimensional gravity. We expect that the vacuum introduced here will facilitate the extraction of large scale physics and cosmological predictions from loop quantum gravity.
Antimatter-Gravity Couplings, and Lorentz Symmetry
Tasson, Jay D
2015-01-01T23:59:59.000Z
Implications of possible CPT and Lorentz violation for antimatter-gravity experiments as well as other antimatter tests are considered in the context of the general field-theory-based framework of the Standard-Model Extension (SME).
Antimatter-Gravity Couplings, and Lorentz Symmetry
Jay D. Tasson
2015-01-27T23:59:59.000Z
Implications of possible CPT and Lorentz violation for antimatter-gravity experiments as well as other antimatter tests are considered in the context of the general field-theory-based framework of the Standard-Model Extension (SME).
Oblique reflections of internal gravity wave beams
Karimi, Hussain H. (Hussain Habibullah)
2012-01-01T23:59:59.000Z
We study nonlinear effects in reflections of internal gravity wave beams in a continuously stratified liquid which are incident upon a uniform slope at an oblique angle. Wave motion in a stratified fluid medium is unique ...
Gravity Recovery and Interior Laboratory (GRAIL) Launch
Gravity Recovery and Interior Laboratory (GRAIL) Launch Press Kit/AUGUst 2011 #12;http of its four channels to AC-3, making each channel's secondary audio MPEG 1 Layer II. For digital downlink
Anisotropic induced gravity and inflationary universe
W. F. Kao
2006-12-09T23:59:59.000Z
Existence and stability analysis of the Kantowski-Sachs type universe in a higher derivative induced gravity theory is studied in details. Existence of one stable mode and one unstable mode is shown to be in favor of the inflationary universe. As a result, the de Sitter background can be made to be stable against anisotropic perturbations with proper constraints imposed on the coupling constants of the induced gravity model.
Gravity waves from cosmic bubble collisions
Salem, Michael P.; Saraswat, Prashant; Shaghoulian, Edgar, E-mail: mpsalem@stanford.edu, E-mail: ps88@stanford.edu, E-mail: edgars@stanford.edu [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, California 94305 (United States)
2013-02-01T23:59:59.000Z
Our local Hubble volume might be contained within a bubble that nucleated in a false vacuum with only two large spatial dimensions. We study bubble collisions in this scenario and find that they generate gravity waves, which are made possible in this context by the reduced symmetry of the global geometry. These gravity waves would produce B-mode polarization in the cosmic microwave background, which could in principle dominate over the inflationary background.
Semiring Artificial Neural Networks and Weighted Automata
Hoelldobler, Steffen
Semiring Artificial Neural Networks and Weighted Automata And an Application to Digital Image neural networks and weighted automata. For this task, we introduce semiring artificial neural networks, that is, artificial neural networks which implement the addition and the multiplication of semirings. We
The shape dynamics description of gravity
Tim Koslowski
2015-01-13T23:59:59.000Z
Classical gravity can be described as a relational dynamical system without ever appealing to spacetime or its geometry. This description is the so-called shape dynamics description of gravity. The existence of relational first principles from which the shape dynamics description of gravity can be derived is a motivation to consider shape dynamics (rather than GR) as the fundamental description of gravity. Adopting this point of view leads to the question: What is the role of spacetime in the shape dynamics description of gravity? This question contains many aspects: Compatibility of shape dynamics with the description of gravity in terms of spacetime geometry, the role of local Minkowski space, universality of spacetime geometry and the nature of quantum particles, which can no longer be assumed to be irreducible representations of the Poincare group. In this contribution I derive effective spacetime structures by considering how matter fluctuations evolve along with shape dynamics. This evolution reveals an "experienced spacetime geometry." This leads (in an idealized approximation) to local Minkowski space and causal relations. The small scale structure of the emergent geometric picture depends on the specific probes used to experience spacetime, which limits the applicability of effective spacetime to describe shape dynamics. I conclude with discussing the nature of quantum fluctuations (particles) in shape dynamics and how local Minkowski spacetime emerges from the evolution of quantum particles.
Gravity as Quantum Foam In-Flow
Reginald T Cahill
2003-07-01T23:59:59.000Z
The new information-theoretic Process Physics provides an explanation of space as a quantum foam system in which gravity is an inhomogeneous flow of the quantum foam into matter. The older Newtonian and General Relativity theories for gravity are analysed. It is shown that Newtonian gravity may be written in the form of an in-flow. General Relativity is also analysed as an in-flow, for those cases where it has been tested. An analysis of various experimental data demonstrates that absolute motion relative to space has been observed by Michelson and Morley, Miller, Illingworth, Jaseja et al, Torr and Kolen, and by DeWitte. The Dayton Miller and Roland DeWitte data also reveal the in-flow of space into matter which manifests as gravity. The experimental data suggests that the in-flow is turbulent, which amounts to the observation of a gravitational wave phenomena. A new in-flow theory of gravity is proposed which passes all the tests that General Relativity was claimed to have passed, but as well the new theory suggests that the so-called spiral galaxy rotation-velocity anomaly may be explained without the need of `dark matter'. Various other gravitational anomalies also appear to be explainable. Newtonian gravity appears to be strictly valid only outside of spherically symmetric matter systems.
averaged lorentz dynamics: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
averaged lorentz dynamics First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Dynamics on Lorentz manifolds...
average energy losses: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
average energy losses First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Comparing energy loss...
HIGH AVERAGE POWER UV FREE ELECTRON LASER EXPERIMENTS AT JLAB
Douglas, David; Evtushenko, Pavel; Gubeli, Joseph; Hernandez-Garcia, Carlos; Legg, Robert; Neil, George; Powers, Thomas; Shinn, Michelle D; Tennant, Christopher
2012-07-01T23:59:59.000Z
Having produced 14 kW of average power at {approx}2 microns, JLAB has shifted its focus to the ultraviolet portion of the spectrum. This presentation will describe the JLab UV Demo FEL, present specifics of its driver ERL, and discuss the latest experimental results from FEL experiments and machine operations.
Probabilistic Wind Speed Forecasting Using Ensembles and Bayesian Model Averaging
Raftery, Adrian
the chance of winds high enough to pose dangers for boats or aircraft. In situations calling for a cost/loss analysis, the probabilities of different outcomes need to be known. For wind speed, this issue often arisesProbabilistic Wind Speed Forecasting Using Ensembles and Bayesian Model Averaging J. Mc
The Scientist : Surpassing the Law of Averages The Scientist
Heller, Eric
/8/2009 7:02:24 PM] #12;The Scientist : Surpassing the Law of Averages "Single-cell genomics appears to be the most straightforward, and at the moment the only way we can assemble the genomes of the uncultured and pushing technological limitations to bring their studies of genomics, genetics, RNA transcription
Navy Estimated Average Hourly Load Profile by Month (in MW)
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Navy Estimated Average Hourly Load Profile by Month (in MW) MONTH HE1 HE2 HE3 HE4 HE5 HE6 HE7 HE8 HE9 HE10 HE11 HE12 HE13 HE14 HE15 HE16 HE17 HE18 HE19 HE20 HE21 HE22 HE23 HE24...
Paleosecular variation and the average geomagnetic field at 20 latitude
Johnson, Catherine Louise
-averaged field (TAF) for a two-parameter longitudinally symmetric (zonal) model. Values for our model parameters rocks, and oceanic sediments, but consistent with that from reversed polarity continental and igneous to paleosecular variation (PSV). We examine PSV at ±20° using virtual geomagnetic pole (VGP) dispersion
Probabilistic Quantitative Precipitation Forecasting Using Bayesian Model Averaging
Washington at Seattle, University of
February 24, 2006 1J. McLean Sloughter is Graduate Research Assistant, Adrian E. Raftery is BlumsteinProbabilistic Quantitative Precipitation Forecasting Using Bayesian Model Averaging J. McLean Sloughter, Adrian E. Raftery and Tilmann Gneiting 1 Department of Statistics, University of Washington
Probabilistic Wind Vector Forecasting Using Ensembles and Bayesian Model Averaging
Raftery, Adrian
: J. McLean Sloughter, Department of Mathematics, Seattle University, 901 12th Ave., P.O. Box 222000Probabilistic Wind Vector Forecasting Using Ensembles and Bayesian Model Averaging J. MCLEAN SLOUGHTER Seattle University, Seattle, Washington TILMANN GNEITING Heidelberg University, Heidelberg
average specific absorption: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
average specific absorption First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Original Research Specific...
Using Brain Weight to Predict Gestation in Mammals Bivariate Fit of Gestation By Brain Weight
Carriquiry, Alicia
1 Using Brain Weight to Predict Gestation in Mammals Bivariate Fit of Gestation By Brain Weight 0 100 200 300 400 500 Gestation 0 500 1000 1500 BrainWgt Linear Fit (All 50 mammals) Predicted Gestation = 85.248543 + 0.299867 Brain Weight Summary of Fit RSquare 0.372483 RSquare Adj 0.35941 Root Mean
Quantum gravity and inventory accumulation
Scott Sheffield
2011-08-10T23:59:59.000Z
We begin by studying inventory accumulation at a LIFO (last-in-first-out) retailer with two products. In the simplest version, the following occur with equal probability at each time step: first product ordered, first product produced, second product ordered, second product produced. The inventory thus evolves as a simple random walk on Z^2. In more interesting versions, a p fraction of customers orders the "freshest available" product regardless of type. We show that the corresponding random walks scale to Brownian motions with diffusion matrices depending on p. We then turn our attention to the critical Fortuin-Kastelyn random planar map model, which gives, for each q>0, a probability measure on random (discretized) two-dimensional surfaces decorated by loops, related to the q-state Potts model. A longstanding open problem is to show that as the discretization gets finer, the surfaces converge in law to a limiting (loop-decorated) random surface. The limit is expected to be a Liouville quantum gravity surface decorated by a conformal loop ensemble, with parameters depending on q. Thanks to a bijection between decorated planar maps and inventory trajectories (closely related to bijections of Bernardi and Mullin), our results about the latter imply convergence of the former in a particular topology. A phase transition occurs at p = 1/2, q=4.
Encoding field theories into gravities
Aoki, Sinya; Onogi, Tetsuya
2015-01-01T23:59:59.000Z
We propose a method, which encodes the information of a $d$ dimensional quantum field theory into a $d+1$ dimensional gravity in the $1/N$ expansion. We first construct a $d+1$ dimensional field theory from the $d$ dimensional one via the gradient flow equation, whose flow time $t$ represents the energy scale of the system such that $t\\rightarrow 0$ corresponds to the ultra-violet (UV) while $t\\rightarrow\\infty$ to the infra-red (IR). We then define the induced metric from $d+1$ dimensional field operators. We show that the metric defined in this way becomes classical in the large $N$ limit, in a sense that quantum fluctuations of the metric are suppressed as $1/N$ due to the large $N$ factorization property. As a concrete example, we apply our method to the O(N) non-linear $\\sigma$ model in two dimensions. We calculate the induced metric in three dimensions, which is shown to describe De Sitter (dS) or Anti De Sitter (AdS) space in the massless limit, where the mass is dynamically generated in the O(N) non-l...
Universality of Gravity from Entanglement
Brian Swingle; Mark Van Raamsdonk
2014-05-12T23:59:59.000Z
The entanglement "first law" in conformal field theories relates the entanglement entropy for a ball-shaped region to an integral over the same region involving the expectation value of the CFT stress-energy tensor, for infinitesimal perturbations to the CFT vacuum state. In recent work, this was exploited at leading order in $N$ in the context of large N holographic CFTs to show that any geometry dual to a perturbed CFT state must satisfy Einstein's equations linearized about pure AdS. In this note, we investigate the implications of the leading 1/N correction to the exact CFT result. We show that these corrections give rise to the source term for the gravitational equations: for semiclassical bulk states, the expectation value of the bulk stress-energy tensor appears as a source in the linearized equations. In particular, the CFT first law leads to Newton's Law of gravitation and the fact that all sources of stress-energy source the gravitational field. In our derivation, this universality of gravity comes directly from the universality of entanglement (the fact that all degrees of freedom in a subsystem contribute to entanglement entropy).
Gravity and Anti-gravity of Fermions: the Unification of Dark Matter and Dark Energy
Chen, X S
2005-01-01T23:59:59.000Z
Massive gravity with second and fourth derivatives is shown to give both attractive and repulsive gravity between fermions. In contrast to the attractive gravity correlated with energy-momentum tensor, the repulsive gravity is proportional to the graviton mass. Therefore, weakly interacting fermions with energy smaller than the graviton mass are both dark matter and dark energy: Their overall gravity is attractive with normal matter but repulsive among themselves. Detailed analyses reveal that this unified dark scenario can properly account for the observed dark matter/energy phenomena: galaxy rotation curves, transition from early cosmic deceleration to recent acceleration; and naturally overcome other dark scenarios' difficulties: the substructure and cuspy core problems, the difference of dark halo distributions in galaxies and clusters, and the cosmic coincidence.
A Kinetic Theory Approach to Quantum Gravity
B. L. Hu
2002-04-22T23:59:59.000Z
We describe a kinetic theory approach to quantum gravity -- by which we mean a theory of the microscopic structure of spacetime, not a theory obtained by quantizing general relativity. A figurative conception of this program is like building a ladder with two knotted poles: quantum matter field on the right and spacetime on the left. Each rung connecting the corresponding knots represent a distinct level of structure. The lowest rung is hydrodynamics and general relativity; the next rung is semiclassical gravity, with the expectation value of quantum fields acting as source in the semiclassical Einstein equation. We recall how ideas from the statistical mechanics of interacting quantum fields helped us identify the existence of noise in the matter field and its effect on metric fluctuations, leading to the establishment of the third rung: stochastic gravity, described by the Einstein-Langevin equation. Our pathway from stochastic to quantum gravity is via the correlation hierarchy of noise and induced metric fluctuations. Three essential tasks beckon: 1) Deduce the correlations of metric fluctuations from correlation noise in the matter field; 2) Reconstituting quantum coherence -- this is the reverse of decoherence -- from these correlation functions 3) Use the Boltzmann-Langevin equations to identify distinct collective variables depicting recognizable metastable structures in the kinetic and hydrodynamic regimes of quantum matter fields and how they demand of their corresponding spacetime counterparts. This will give us a hierarchy of generalized stochastic equations -- call them the Boltzmann-Einstein hierarchy of quantum gravity -- for each level of spacetime structure, from the macroscopic (general relativity) through the mesoscopic (stochastic gravity) to the microscopic (quantum gravity).
An Anzatz about Gravity, Cosmology, and the Pioneer Anomaly
Murad, Paul [Morningstar Applied Physics Inc., LLC, Vienna, VA 22182 (Austria)
2010-01-28T23:59:59.000Z
The Pulsar 1913+16 binary system may represent a 'young' binary system where previously it is claimed that the dynamics are due to either a third body or a gravitational vortex. Usually a binary system's trajectory could reside in a single ellipse or circular orbit; the double ellipse implies that the 1913+16 system may be starting to degenerate into a single elliptical trajectory. This could be validated only after a considerably long time period. In a majority of binary star systems, the weights of both stars are claimed by analysis to be the same. It may be feasible that the trajectory of the primary spinning star could demonstrate repulsive gravitational effects where the neutron star's high spin rate induces a repulsive gravitational source term that compensates for inertia. If true, then it provides evidence that angular momentum may be translated into linear momentum as a repulsive source that has propulsion implications. This also suggests mass differences may dictate the neutron star's spin rate as an artifact of a natural gravitational process. Moreover, the reduced matter required by the 'dark' mass hypothesis may not exist but these effects could be due to repulsive gravity residing in rotating celestial bodies.The Pioneer anomaly observed on five different deep-space spacecraft, is the appearance of a constant gravitational force directed toward the sun. Pioneer spacecraft data reveals that a vortex-like magnetic field exists emanating from the sun. The spiral arms of the Sun's magnetic vortex field may be causal to this constant acceleration. This may profoundly provide a possible experimental verification on a cosmic scale of Gertsenshtein's principle relating gravity to electromagnetism. Furthermore, the anomalous acceleration may disappear once the spacecraft passes out into a magnetic spiral furrow, which is something that needs to be observed in the future. Other effects offer an explanation from space-time geometry to the Yarkovsky thermal effects are discussed.
Better than Average? - Green Building Certification in International Projects
Baumann, O.
2008-01-01T23:59:59.000Z
. An Enterprise of the Ebert-Consulting Group 1004 Pennsylvania Avenue, SE Washington, D.C. 20003, USA 00 12 02/ 6 08 - 13 34 o.baumann@eb-engineers.com Better than Average? - Green Building Certification in International Projects Green Building..., green building rating systems focus on sustainability for the entire life-cycle of buildings and therefore offer great opportunities for enhancing building operation, when applied and used appropriately. This presentation gives an overview...
Averaging cross section data so we can fit it
Brown, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). NNDC
2014-10-23T23:59:59.000Z
The ^{56}Fe cross section we are interested in have a lot of fluctuations. We would like to fit the average of the cross section with cross sections calculated within EMPIRE. EMPIRE is a Hauser-Feshbach theory based nuclear reaction code, requires cross sections to be smoothed using a Lorentzian profile. The plan is to fit EMPIRE to these cross sections in the fast region (say above 500 keV).
Estimate of average freeze-out volume in multifragmentation events
Piantelli, S; Borderie, B; Bougault, R; Chbihi, A; Dayras, R; Durand, D; Frankland, J D; Galíchet, E; Guinet, D; Lanzalone, G; Lautesse, P; Le Neindre, N; López, O; Pârlog, M; Rivet, M F; Rosato, E; Tamain, B; Vient, E; Vigilante, M; Volant, C; Wieleczko, J P
2005-01-01T23:59:59.000Z
An estimate of the average freeze-out volume for multifragmentation events is presented. Values of volumes are obtained by means of a simulation using the experimental charged product partitions measured by the 4pi multidetector INDRA for 129Xe central collisions on Sn at 32 AMeV incident energy. The input parameters of the simulation are tuned by means of the comparison between the experimental and simulated velocity (or energy) spectra of particles and fragments.
High Average Power, High Energy Short Pulse Fiber Laser System
Messerly, M J
2007-11-13T23:59:59.000Z
Recently continuous wave fiber laser systems with output powers in excess of 500W with good beam quality have been demonstrated [1]. High energy, ultrafast, chirped pulsed fiber laser systems have achieved record output energies of 1mJ [2]. However, these high-energy systems have not been scaled beyond a few watts of average output power. Fiber laser systems are attractive for many applications because they offer the promise of high efficiency, compact, robust systems that are turn key. Applications such as cutting, drilling and materials processing, front end systems for high energy pulsed lasers (such as petawatts) and laser based sources of high spatial coherence, high flux x-rays all require high energy short pulses and two of the three of these applications also require high average power. The challenge in creating a high energy chirped pulse fiber laser system is to find a way to scale the output energy while avoiding nonlinear effects and maintaining good beam quality in the amplifier fiber. To this end, our 3-year LDRD program sought to demonstrate a high energy, high average power fiber laser system. This work included exploring designs of large mode area optical fiber amplifiers for high energy systems as well as understanding the issues associated chirped pulse amplification in optical fiber amplifier systems.
Determination of the uncertainty in assembly average burnup
Cacciapouti, R.J.; Lam, G.M.; Theriault, P.A.; Delmolino, P.M.
1998-12-31T23:59:59.000Z
Pressurized water reactors maintain records of the assembly average burnup for each fuel assembly at the plant. The reactor records are currently used by commercial reactor operators and vendors for (a) special nuclear accountability, (b) placement of spent fuel in storage pools, and (c) dry storage cask design and analysis. A burnup credit methodology has been submitted to the US Nuclear Regulatory Commission (NRC) by the US Department of Energy. In order to support this application, utilities are requested to provide burnup uncertainty as part of their reactor records. The collected burnup data are used for the development of a plant correction to the cask vendor supplied burnup credit loading curve. The objective of this work is to identify a feasible methodology for determining the 95/95 uncertainty in the assembly average burnup. Reactor records are based on the core neutronic analysis coupled with measured in-core detector data. The uncertainty of particular burnup records depends mainly on the uncertainty associated with the methods used to develop the records. The methodology adopted for this analysis utilizes current neutronic codes for the determination of the uncertainty in assembly average burnup.
Region-based Dynamic Weighting Probabilistic Geocoding
Li, Zhongxia
2014-07-30T23:59:59.000Z
it extremely important that geocoding results be as accurate as possible. Existing global-weighting approaches to geocoding assume spatial stationarity of addressing systems and address data characteristic distributions across space, resulting in heuristics...
A Library for Locally Weighted Projection Regression
Klanke, Stefan; Vijayakumar, Sethu; Schaal, Stefan
2008-01-01T23:59:59.000Z
In this paper we introduce an improved implementation of locally weighted projection regression (LWPR), a supervised learning algorithm that is capable of handling high-dimensional input data. As the key features, our ...
Weight Perception Discrepancy Among Ethnically Diverse Youth
Cromwell, Kate Duncan
2012-10-19T23:59:59.000Z
not feel they are, may be at risk for negative health conditions. Social Comparison Theory may provide a tool for evaluating identified discrepancies. Given that minorities have higher obesity rates, it is hypothesized that weight perception discrepancy...
Gravity as Quantum Foam In-Flow
Cahill, R T
2003-01-01T23:59:59.000Z
The new information-theoretic Process Physics provides an explanation of space as a quantum foam system in which gravity is an inhomogeneous flow of the quantum foam into matter. The older Newtonian and General Relativity theories for gravity are analysed. It is shown that Newtonian gravity may be written in the form of an in-flow. General Relativity is also analysed as an in-flow, for those cases where it has been tested. An analysis of various experimental data demonstrates that absolute motion relative to space has been observed by Michelson and Morley, Miller, Illingworth, Jaseja et al, Torr and Kolen, and by DeWitte. The Dayton Miller and Roland DeWitte data also reveal the in-flow of space into matter which manifests as gravity. The experimental data suggests that the in-flow is turbulent, which amounts to the observation of a gravitational wave phenomena. A new in-flow theory of gravity is proposed which passes all the tests that General Relativity was claimed to have passed, but as well the new theory...
Ribak, Erez
Fig. 3. Averaged PSF of a whole eye without immersion (a), compared to average eye with corneal of the complete eye was calculated by the averaged Zernike coefficients measured on 532 eyes. All PSFs were). The PSFs were calculated by averaging Zernike coefficients measured from 228 eyes. Both PSFs were
Solar System Constraints on Disformal Gravity Theories
Hiu Yan Ip; Jeremy Sakstein; Fabian Schmidt
2015-07-02T23:59:59.000Z
Disformal theories of gravity are scalar-tensor theories where the scalar couples derivatively to matter via the Jordan frame metric. These models have recently attracted interest in the cosmological context since they admit accelerating solutions. We derive the solution for a static isolated mass in generic disformal gravity theories and transform it into the parameterised post-Newtonian form. This allows us to investigate constraints placed on such theories by local tests of gravity. The tightest constraints come from preferred-frame effects due to the motion of the Solar System with respect to the evolving cosmological background field. The constraints we obtain improve upon the previous solar system constraints by two orders of magnitude, and constrain the scale of the disformal coupling for generic models to $\\mathcal{M} \\gtrsim 100$ eV. These constraints render all disformal effects irrelevant for cosmology.
Quantum gravity effects in the Kerr spacetime
Reuter, M. [Institute of Physics, University of Mainz, Staudingerweg 7, D-55099 Mainz (Germany); Tuiran, E. [Departamento de Fisica, Universidad del Norte, Km 5 via a Puerto Colombia, AA-1569 Barranquilla (Colombia)
2011-02-15T23:59:59.000Z
We analyze the impact of the leading quantum gravity effects on the properties of black holes with nonzero angular momentum by performing a suitable renormalization group improvement of the classical Kerr metric within quantum Einstein gravity. In particular, we explore the structure of the horizons, the ergosphere, and the static limit surfaces as well as the phase space available for the Penrose process. The positivity properties of the effective vacuum energy-momentum tensor are also discussed and the 'dressing' of the black hole's mass and angular momentum are investigated by computing the corresponding Komar integrals. The pertinent Smarr formula turns out to retain its classical form. As for their thermodynamical properties, a modified first law of black-hole thermodynamics is found to be satisfied by the improved black holes (to second order in the angular momentum); the corresponding Bekenstein-Hawking temperature is not proportional to the surface gravity.
Holographic Superconductors in Quasi-topological Gravity
Xiao-Mei Kuang; Wei-Jia Li; Yi Ling
2010-12-05T23:59:59.000Z
In this paper we study (3+1) dimensional holographic superconductors in quasi-topological gravity which is recently proposed by R. Myers {\\it et.al.}. Through both analytical and numerical analysis, we find in general the condensation becomes harder with the increase of coupling parameters of higher curvature terms. In particular, comparing with those in ordinary Gauss-Bonnet gravity, we find that positive cubic corrections in quasi-topological gravity suppress the condensation while negative cubic terms make it easier. We also calculate the conductivity numerically for various coupling parameters. It turns out that the universal relation of $\\omega_g/T_c\\simeq 8$ is unstable and this ratio becomes larger with the increase of the coupling parameters. A brief discussion on the condensation from the CFT side is also presented.
Solar system constraints on alternative gravity theories
Sumanta Chakraborty; Soumitra Sengupta
2014-01-14T23:59:59.000Z
The perihelion precession of planetary orbits and the bending angle of null geodesics are estimated for different gravity theories in string-inspired models. It is shown that, for dilaton coupled gravity, the leading order measure in the angle of bending of light comes purely from vacuum expectation value of the dilaton field which may be interpreted as an indicator of a dominant stringy effect over the curvature effect. We arrive at similar results for spherically symmetric solution in quadratic gravity. We also present the perihelion shift and bending of light in the Einstein-Maxwell-Gauss-Bonnet theory with special reference to the Casimir effect and Damour-Polyakov mechanism. Numerical bounds to different coupling parameters in these models are estimated.
Gauge theory of gravity and supergravity
Kaul, Romesh K. [Institute of Mathematical Sciences, Chennai 600 113 (India)
2006-03-15T23:59:59.000Z
We present a formulation of gravity in terms of a theory based on complex SU(2) gauge fields with a general coordinate invariant action functional quadratic in the field strength. Self-duality or anti-self-duality of the field strength emerges as a constraint from the equations of motion of this theory. This in turn leads to Einstein gravity equations for a dilaton and an axion conformally coupled to gravity for the self-dual constraint. The analysis has also been extended to N=1 and 2 super Yang-Mills theory of complex SU(2) gauge fields. This leads to, besides other equations of motion, self-duality/anti-self-duality of generalized supercovariant field strengths. The self-dual case is then shown to yield as its solutions N=1, 2 supergravity equations, respectively.
Solar System Constraints on Disformal Gravity Theories
Ip, Hiu Yan; Schmidt, Fabian
2015-01-01T23:59:59.000Z
Disformal theories of gravity are scalar-tensor theories where the scalar couples derivatively to matter via the Jordan frame metric. These models have recently attracted interest in the cosmological context since they admit accelerating solutions. We derive the solution for a static isolated mass in generic disformal gravity theories and transform it into the parameterised post-Newtonian form. This allows us to investigate constraints placed on such theories by local tests of gravity. The tightest constraints come from preferred-frame effects due to the motion of the Solar System with respect to the evolving cosmological background field. The constraints we obtain improve upon the previous solar system constraints by two orders of magnitude, and constrain the scale of the disformal coupling for generic models to $\\mathcal{M} \\gtrsim 100$ eV. These constraints render all disformal effects irrelevant for cosmology.
Entropic force, noncommutative gravity, and ungravity
Nicolini, Piero [Frankfurt Institute for Advanced Studies (FIAS), Institut fuer Theoretische Physik, Johann Wolfgang Goethe-Universitaet, Ruth-Moufang-Strasse 1, 60438 Frankfurt am Main (Germany)
2010-08-15T23:59:59.000Z
After recalling the basic concepts of gravity as an emergent phenomenon, we analyze the recent derivation of Newton's law in terms of entropic force proposed by Verlinde. By reviewing some points of the procedure, we extend it to the case of a generic quantum gravity entropic correction to get compelling deviations to the Newton's law. More specifically, we study: (1) noncommutative geometry deviations and (2) ungraviton corrections. As a special result in the noncommutative case, we find that the noncommutative character of the manifold would be equivalent to the temperature of a thermodynamic system. Therefore, in analogy to the zero temperature configuration, the description of spacetime in terms of a differential manifold could be obtained only asymptotically. Finally, we extend the Verlinde's derivation to a general case, which includes all possible effects, noncommutativity, ungravity, asymptotically safe gravity, electrostatic energy, and extra dimensions, showing that the procedure is solid versus such modifications.
Emergence in Holographic Scenarios for Gravity
Dieks, Dennis; de Haro, Sebastian
2015-01-01T23:59:59.000Z
'Holographic' relations between theories have become an important theme in quantum gravity research. These relations entail that a theory without gravity is equivalent to a gravitational theory with an extra spatial dimension. The idea of holography was first proposed in 1993 by Gerard 't Hooft on the basis of his studies of evaporating black holes. Soon afterwards the holographic 'AdS/CFT' duality was introduced, which since has been intensively studied in the string theory community and beyond. Recently, Erik Verlinde has proposed that even Newton's law of gravitation can be related holographically to the 'thermodynamics of information' on screens. We discuss these scenarios, with special attention to the status of the holographic relation in them and to the question of whether they make gravity and spacetime emergent. We conclude that only Verlinde's scheme straightfowardly instantiates emergence. However, assuming a non-standard interpretation of AdS/CFT may create room for the emergence of spacetime and ...
Theoretical and experimental study of nonlinear internal gravity wave beams
Tabaei Befrouei, Ali, 1974-
2005-01-01T23:59:59.000Z
Continuously stratified fluids, like the atmosphere and the oceans, support internal gravity waves due to the effect of buoyancy. This type of wave motion is anisotropic since gravity provides a preferred direction. As a ...
Average Fe K-alpha emission from distant AGN
A. Corral; M. J. Page; F. J. Carrera; X. Barcons; S. Mateos; J. Ebrero; M. Krumpe; A. Schwope; J. A. Tedds; M. G. Watson
2008-10-02T23:59:59.000Z
One of the most important parameters in the XRB (X-ray background) synthesis models is the average efficiency of accretion onto SMBH (super-massive black holes). This can be inferred from the shape of broad relativistic Fe lines seen in X-ray spectra of AGN (active galactic nuclei). Several studies have tried to measure the mean Fe emission properties of AGN at different depths with very different results. We compute the mean Fe emission from a large and representative sample of AGN X-ray spectra up to redshift ~ 3.5. We developed a method of computing the rest-frame X-ray average spectrum and applied it to a large sample (more than 600 objects) of type 1 AGN from two complementary medium sensitivity surveys based on XMM-Newton data, the AXIS and XWAS samples. This method makes use of medium-to-low quality spectra without needing to fit complex models to the individual spectra but with computing a mean spectrum for the whole sample. Extensive quality tests were performed by comparing real to simulated data, and a significance for the detection of any feature over an underlying continuum was derived. We detect with a 99.9% significance an unresolved Fe K-alpha emission line around 6.4 keV with an EW ~ 90 eV, but we find no compelling evidence of any significant broad relativistic emission line in the final average spectrum. Deviations from a power law around the narrow line are best represented by a reflection component arising from cold or low-ionization material. We estimate an upper limit for the EW of any relativistic line of 400 eV at a 3 sigma confidence level. We also marginally detect the so-called Iwasawa-Taniguchi effect on the EW for the unresolved emission line, which appears weaker for higher luminosity AGN.
Exact solutions of three dimensional black holes: Einstein gravity vs F(R) gravity
S. H. Hendi; B. Eslam Panah; R. Saffari
2014-10-28T23:59:59.000Z
In this paper, we consider Einstein gravity in the presence of a class of nonlinear electrodynamics, called power Maxwell invariant (PMI). We take into account $(2+1)$-dimensional spacetime in Einstein-PMI gravity and obtain its black hole solutions. Then, we regard pure $F(R)$ gravity as well as $F(R)$-conformally invariant Maxwell theory to obtain exact solutions of the field equations with black hole interpretation. Finally, we investigate the conserved and thermodynamic quantities and discuss about the first law of thermodynamics for the mentioned gravitational models.
Table 14a. Average Electricity Prices, Projected vs. Actual
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro IndustriesTownDells,1Stocks Nov-14 Dec-14TableConferenceInstalled:a. Average Electricity
Table 14b. Average Electricity Prices, Projected vs. Actual
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro IndustriesTownDells,1Stocks Nov-14 Dec-14TableConferenceInstalled:a. Average Electricityb.
Table 14b. Average Electricity Prices, Projected vs. Actual
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro IndustriesTownDells,1Stocks Nov-14 Dec-14TableConferenceInstalled:a. Average
Table 17. Average Price of U.S. Coke Exports
Gasoline and Diesel Fuel Update (EIA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for On-Highway4,1,50022,3,,,,6,1,9,1,50022,3,,,,6,1,Decade Year-0E (2001) -heating oilAll Tables133,477 133,5910. Average3.5.6.7.
Table 19. Average Price of U.S. Coal Imports
Gasoline and Diesel Fuel Update (EIA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for On-Highway4,1,50022,3,,,,6,1,9,1,50022,3,,,,6,1,Decade Year-0E (2001) -heating oilAll Tables133,477 133,5910.9. Average Price
Table 22. Average Price of U.S. Coke Imports
Gasoline and Diesel Fuel Update (EIA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for On-Highway4,1,50022,3,,,,6,1,9,1,50022,3,,,,6,1,Decade Year-0E (2001) -heating oilAll Tables133,477 133,5910.9. Average1.2.
Testing a Dilaton Gravity Model using Nucleosynthesis
Sibel Boran; Emre Onur Kahya
2014-09-05T23:59:59.000Z
Big Bang Nucleosynthesis (BBN) offers one of the most strict evidences for the Lambda-CDM cosmology at present, as well as the Cosmic Microwave Background (CMB) radiation. In this work, our main aim is to present the outcomes of our calculations related to primordial abundances of light elements, in the context of higher dimensional steady-state universe model in the dilaton gravity. Our results show that abundances of light elements (primordial D, 3He, 4He, T, 7Li) are significantly different for some cases, and a comparison is given between a particular dilaton gravity model and Lambda-CDM in the light of the astrophysical observations.
Energy Distribution in f(R) Gravity
M. Sharif; M. Farasat Shamir
2009-12-18T23:59:59.000Z
The well-known energy problem is discussed in f(R) theory of gravity. We use the generalized Landau-Lifshitz energy-momentum complex in the framework of metric f(R) gravity to evaluate the energy density of plane symmetric solutions for some general f(R) models. In particular, this quantity is found for some popular choices of f(R) models. The constant scalar curvature condition and the stability condition for these models are also discussed. Further, we investigate the energy distribution of cosmic string spacetime.
Multidimensional Gravity on the Principal Bundles
V. D. Dzhunushaliev
1997-11-10T23:59:59.000Z
The multidimensional gravity on the total space of principal bundle is considered. In this theory the gauge fields arise as nondiagonal components of multidimensional metric. The spherically symmetric and cosmology solutions for gravity on SU(2) principal bundle are obtained. The static spherically symmetric solution is wormhole-like solution located between two null surfaces, in contrast to 4D Einstein-Yang-Mills theory where corresponding solution (black hole) located outside of event horizon. Cosmology solution (at least locally) has the bouncing off effect for spatial dimensions. In spirit of Einstein these solutions are vacuum solutions without matter.
Violation of Energy Bounds in Designer Gravity
Thomas Hertog
2006-07-31T23:59:59.000Z
We continue our study of the stability of designer gravity theories, where one considers anti-de Sitter gravity coupled to certain tachyonic scalars with boundary conditions defined by a smooth function W. It has recently been argued there is a lower bound on the conserved energy in terms of the global minimum of W, if the scalar potential arises from a superpotential P and the scalar reaches an extremum of P at infinity. We show, however, there are superpotentials for which these bounds do not hold.
Weak Gravity Conjecture for Noncommutative Field Theory
Qing-Guo Huang; Jian-Huang She
2006-11-20T23:59:59.000Z
We investigate the weak gravity bounds on the U(1) gauge theory and scalar field theories in various dimensional noncommutative space. Many results are obtained, such as the upper bound on the noncommutative scale $g_{YM}M_p$ for four dimensional noncommutative U(1) gauge theory. We also discuss the weak gravity bounds on their commutative counterparts. For example, our result on 4 dimensional noncommutative U(1) gauge theory reduces in certain limit to its commutative counterpart suggested by Arkani-Hamed et.al at least at tree-level.
Holographic superconductors from the massive gravity
Hua Bi Zeng; Jian-Pin Wu
2014-09-24T23:59:59.000Z
A holographic superconductor is constructed in the background of a massive gravity theory. In the normal state without condensation, the conductivity exhibits a Drude peak that approaches a delta function in the massless gravity limit as studied by David Vegh. In the superconducting state, besides the infinite DC conductivity, the AC conductivity has Drude behavior at low frequency followed by a power law-fall. These results are in agreement with that found earlier by Horowitz and Santos, who studied a holographic superconductor with an implicit periodic potential beyond the probe limit. The results also agree with measurements on some cuprates.
One Loop Beta Functions in Topologically Massive Gravity
R. Percacci; E. Sezgin
2010-02-15T23:59:59.000Z
We calculate the running of the three coupling constants in cosmological, topologically massive 3d gravity. We find that \
HoravaLifshitz gravity Victoria University of Wellington
Visser, Matt
Abstract HoravaÂLifshitz gravity Victoria University of Wellington Te Whare WÂŻananga o te ÂŻUpoko o Vancouver Tuesday 25 August 2009 Matt Visser Who's afraid of Lorentz symmetry breaking? #12;Abstract HoravaÂLifshitz gravity HoravaÂLifshitz gravity: As of 23 August 2009 Spires reports that this topic has generated: 3
Nordstrom's scalar theory of gravity and the equivalence principle
Nathalie Deruelle
2011-04-24T23:59:59.000Z
Nordstrom's theory of gravity, which describes gravity by a scalar field in flat spacetime, is observationally ruled out. It is however the only theory of gravity with General Relativity to obey the strong equivalence principle. I show in this paper that this remarkable property is true beyond post-newtonian level and can be related to the existence of a 'Nordstrom-Katz' superpotential.
Observing ocean heat content using satellite gravity and altimetry
Jayne, Steven
: ocean heat content, altimetry, satellite gravity, steric height, remote sensing Citation: Jayne, S. RObserving ocean heat content using satellite gravity and altimetry Steven R. Jayne1,2 and John M with satellite measurements of the Earth's time-varying gravity to give improved estimates of the ocean's heat
Conformal gravity from the AdS/CFT mechanism
Aros, Rodrigo; Romo, Mauricio; Zamorano, Nelson [Departamento de Ciencias Fisicas, Universidad Andres Bello, Av. Republica 252, Santiago (Chile); Departamento de Fisica, Facultad de Ciencias Fisicas y Matematicas, Universidad de Chile, Avda Blanco Encalada 2008, Santiago (Chile)
2007-03-15T23:59:59.000Z
We explicitly calculate the induced gravity theory at the boundary of an asymptotically anti-de Sitter five dimensional Einstein gravity. We also display the action that encodes the dynamics of radial diffeomorphisms. It is found that the induced theory is a four dimensional conformal gravity plus a scalar field. This calculation confirms some previous results found by a different approach.
Quantum Gravity in Three Dimensions from Higher-Spin Holography
Tan, Hai Siong
2013-01-01T23:59:59.000Z
Higher Spin Anti-de Sitter Gravity,” JHEP 1012, 007 (2010)gravity in three dimensions from the per- spective of higher-spin holography in anti-gravity in three dimen- sions in the framework of higher-spin holography in anti-
Plasma dynamics and a significant error of macroscopic averaging
Marek A. Szalek
2005-05-22T23:59:59.000Z
The methods of macroscopic averaging used to derive the macroscopic Maxwell equations from electron theory are methodologically incorrect and lead in some cases to a substantial error. For instance, these methods do not take into account the existence of a macroscopic electromagnetic field EB, HB generated by carriers of electric charge moving in a thin layer adjacent to the boundary of the physical region containing these carriers. If this boundary is impenetrable for charged particles, then in its immediate vicinity all carriers are accelerated towards the inside of the region. The existence of the privileged direction of acceleration results in the generation of the macroscopic field EB, HB. The contributions to this field from individual accelerated particles are described with a sufficient accuracy by the Lienard-Wiechert formulas. In some cases the intensity of the field EB, HB is significant not only for deuteron plasma prepared for a controlled thermonuclear fusion reaction but also for electron plasma in conductors at room temperatures. The corrected procedures of macroscopic averaging will induce some changes in the present form of plasma dynamics equations. The modified equations will help to design improved systems of plasma confinement.
Average Fe K-alpha emission from distant AGN
Corral, A; Carrera, F J; Barcons, X; Mateos, S; Ebrero, J; Krumpe, M; Schwope, A; Tedds, J A; Watson, M G
2008-01-01T23:59:59.000Z
One of the most important parameters in the XRB (X-ray background) synthesis models is the average efficiency of accretion onto SMBH (super-massive black holes). This can be inferred from the shape of broad relativistic Fe lines seen in X-ray spectra of AGN (active galactic nuclei). Several studies have tried to measure the mean Fe emission properties of AGN at different depths with very different results. We compute the mean Fe emission from a large and representative sample of AGN X-ray spectra up to redshift ~ 3.5. We developed a method of computing the rest-frame X-ray average spectrum and applied it to a large sample (more than 600 objects) of type 1 AGN from two complementary medium sensitivity surveys based on XMM-Newton data, the AXIS and XWAS samples. This method makes use of medium-to-low quality spectra without needing to fit complex models to the individual spectra but with computing a mean spectrum for the whole sample. Extensive quality tests were performed by comparing real to simulated data, a...
Yearly average performance of the principal solar collector types
Rabl, A.
1981-01-01T23:59:59.000Z
The results of hour-by-hour simulations for 26 meteorological stations are used to derive universal correlations for the yearly total energy that can be delivered by the principal solar collector types: flat plate, evacuated tubes, CPC, single- and dual-axis tracking collectors, and central receiver. The correlations are first- and second-order polynomials in yearly average insolation, latitude, and threshold (= heat loss/optical efficiency). With these correlations, the yearly collectible energy can be found by multiplying the coordinates of a single graph by the collector parameters, which reproduces the results of hour-by-hour simulations with an accuracy (rms error) of 2% for flat plates and 2% to 4% for concentrators. This method can be applied to collectors that operate year-around in such a way that no collected energy is discarded, including photovoltaic systems, solar-augmented industrial process heat systems, and solar thermal power systems. The method is also recommended for rating collectors of different type or manufacturer by yearly average performance, evaluating the effects of collector degradation, the benefits of collector cleaning, and the gains from collector improvements (due to enhanced optical efficiency or decreased heat loss per absorber surface). For most of these applications, the method is accurate enough to replace a system simulation.
The Mars Gravity Biosatellite as an innovative partial gravity research platform
Fulford-Jones, Thaddeus R. F
2008-01-01T23:59:59.000Z
The Mars Gravity Biosatellite is an unprecedented independent spaceflight platform for gravitational biology research. With a projected first launch after 2010, the low Earth orbit satellite will support a cohort of fifteen ...
Webb, Spahr C.
, Petrologic and Seismic Expedition (GLIMPSE) study area from seismic refraction data R. Chadwick Holmes,1, Intraplate Melting, Petrologic and Seismic Expedition (GLIMPSE) experiment investigated the velocity in the Gravity Lineations, Intraplate Melting, Petrologic and Seismic Expedition (GLIMPSE) study area from
Infrared fixed point in quantum Einstein gravity
S. Nagy; J. Krizsan; K. Sailer
2012-06-28T23:59:59.000Z
We performed the renormalization group analysis of the quantum Einstein gravity in the deep infrared regime for different types of extensions of the model. It is shown that an attractive infrared point exists in the broken symmetric phase of the model. It is also shown that due to the Gaussian fixed point the IR critical exponent $\
A New Model of Nonlocal Modified Gravity
Ivan Dimitrijevic; Branko Dragovich; Jelena Grujic; Zoran Rakic
2014-11-18T23:59:59.000Z
We consider a new modified gravity model with nonlocal term of the form $R^{-1} \\mathcal{F}(\\Box) R. $ This kind of nonlocality is motivated by investigation of applicability of a few unusual ans\\"atze to obtain some exact cosmological solutions. In particular, we find attractive and useful quadratic ansatz $\\Box R = q R^{2}.$
Energy definition for quadratic curvature gravities
Ahmet Baykal
2012-12-03T23:59:59.000Z
A conserved current for generic quadratic curvature gravitational models is defined, and it is shown that, at the linearized level, it corresponds to the Deser-Tekin charges. An explicit expression for the charge for new massive gravity in three dimensions is given. Some implications of the linearized equations are discussed.
Ultrasonic hydrometer. [Specific gravity of electrolyte
Swoboda, C.A.
1982-03-09T23:59:59.000Z
The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time t between the initial and returning impulses. Considering the distance d between the spaced sonic surfaces and the measured time t, the sonic velocity V is calculated with the equation V = 2d/t. The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0 and 40/sup 0/C and for specific gravity values between 1.05 and 1.30. Upon knowing two parameters (the calculated sonic velocity and the measured temperature), the third parameter (specific gravity) can be uniquely found in the database. The hydrometer utilizes a microprocessor for data storage and manipulation.
Topological Black Holes in Quantum Gravity
J. Kowalski-Glikman; D. Nowak-Szczepaniak
2000-07-31T23:59:59.000Z
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.
Schwarzschild solution in extended teleparallel gravity
Nashed, G G L
2015-01-01T23:59:59.000Z
Tetrad field, with two unknown functions of radial coordinate and an angle $\\Phi$ which is the polar angle $\\phi$ times a function of the redial coordinate, is applied to the field equation of modified theory of gravity. Exact vacuum solution is derived whose scalar torsion, $T ={T^\\alpha}_{\\mu \
Constraining torsion with Gravity Probe B
Mao Yi; Guth, Alan H.; Cabi, Serkan [Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Tegmark, Max [Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); MIT Kavli Institute for Astrophysics and Space Research, Cambridge, Massachusetts 02139 (United States)
2007-11-15T23:59:59.000Z
It is well-entrenched folklore that all torsion gravity theories predict observationally negligible torsion in the solar system, since torsion (if it exists) couples only to the intrinsic spin of elementary particles, not to rotational angular momentum. We argue that this assumption has a logical loophole which can and should be tested experimentally, and consider nonstandard torsion theories in which torsion can be generated by macroscopic rotating objects. In the spirit of action=reaction, if a rotating mass like a planet can generate torsion, then a gyroscope would be expected to feel torsion. An experiment with a gyroscope (without nuclear spin) such as Gravity Probe B (GPB) can test theories where this is the case. Using symmetry arguments, we show that to lowest order, any torsion field around a uniformly rotating spherical mass is determined by seven dimensionless parameters. These parameters effectively generalize the parametrized post-Newtonian formalism and provide a concrete framework for further testing Einstein's general theory of relativity (GR). We construct a parametrized Lagrangian that includes both standard torsion-free GR and Hayashi-Shirafuji maximal torsion gravity as special cases. We demonstrate that classic solar system tests rule out the latter and constrain two observable parameters. We show that Gravity Probe B is an ideal experiment for further constraining nonstandard torsion theories, and work out the most general torsion-induced precession of its gyroscope in terms of our torsion parameters.
Scale invariance, unimodular gravity and dark energy
Mikhail Shaposhnikov; Daniel Zenhausern
2008-12-16T23:59:59.000Z
We demonstrate that the combination of the ideas of unimodular gravity, scale invariance, and the existence of an exactly massless dilaton leads to the evolution of the universe supported by present observations: inflation in the past, followed by the radiation and matter dominated stages and accelerated expansion at present. All mass scales in this type of theories come from one and the same source.
Topology in 4D simplicial quantum gravity
S. Bilke; Z. Burda; B. Petersson
1996-11-22T23:59:59.000Z
We simulate 4d simplicial gravity for three topologis S4, S3xS1, (S1)^4 and show that the free energy for these three fixed topology ensembles is the same in the thermodynamic limit. We show, that the next-to-leading order corrections, at least away from the critical point, can be described by kinematic sources.
Schwarzschild solution in extended teleparallel gravity
G. G. L. Nashed
2015-01-05T23:59:59.000Z
Tetrad field, with two unknown functions of radial coordinate and an angle $\\Phi$ which is the polar angle $\\phi$ times a function of the redial coordinate, is applied to the field equation of modified theory of gravity. Exact vacuum solution is derived whose scalar torsion, $T ={T^\\alpha}_{\\mu \
The diffeomorphism algebra approach to quantum gravity
T. A. Larsson
1999-09-13T23:59:59.000Z
The representation theory of non-centrally extended Lie algebras of Noether symmetries, including spacetime diffeomorphisms and reparametrizations of the observer's trajectory, has recently been developped. It naturally solves some long-standing problems in quantum gravity, e.g. the role of diffeomorphisms and the causal structure, but some new questions also arise.
Running Coupling Constants in 2D Gravity
Christof Schmidhuber
1993-08-26T23:59:59.000Z
The renormalization group flow in two--dimensional field theories that are coupled to gravity is discussed at the example of the sine-Gordon model. In order to derive the phase diagram in agreement with the matrix model results, it is necessary to generalize the theory of David, Distler and Kawai.
Explicit versus Spontaneous Diffeomorphism Breaking in Gravity
Robert Bluhm
2015-04-02T23:59:59.000Z
Gravitational theories with fixed background fields break local Lorentz and diffeomorphism invariance either explicitly or spontaneously. In the case of explicit breaking it is known that conflicts can arise between the dynamics and geometrical constraints, while spontaneous breaking evades this problem. It is for this reason that in the gravity sector of the Standard-Model Extension (SME) it is assumed that the background fields (SME coefficients) originate from spontaneous symmetry breaking. However, in other examples, such as Chern-Simons gravity and massive gravity, diffeomorphism invariance is explicitly broken by the background fields, and the potential conflicts between the dynamics and geometry can be avoided in most cases. An analysis of how this occurs is given, and the conditions that are placed on the metric tensor and gravitational structure as a result of the presence of an explicit-breaking background are described. The gravity sector of the SME is then considered for the case of explicit breaking. However, it is found that a useful post-Newtonian limit is only obtained when the symmetry breaking is spontaneous.
Second order noncommutative corrections to gravity
Calmet, Xavier [Universite Libre de Bruxelles, Service de Physique Theorique, CP225 Boulevard du Triomphe (Campus plaine), B-1050 Brussels (Belgium); Kobakhidze, Archil [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States)
2006-08-15T23:59:59.000Z
In this work, we calculate the leading order corrections to general relativity formulated on a canonical noncommutative spacetime. These corrections appear in the second order of the expansion in theta. First order corrections can only appear in the gravity-matter interactions. Some implications are briefly discussed.
Williams, Paul T.
2006-01-06T23:59:59.000Z
Background: Body weight increases with aging. Short-term,longitudinal exercise training studies suggest that increasing exerciseproduces acute weight loss, but it is not clear if the maintenance oflong-term, vigorous exercise attenuates age-related weight gain inproportion to the exercise dose. Methods: Prospective study of 6,119 maleand 2,221 female runners whose running distance changed less than 5 km/wkbetween their baseline and follow-up survey 7 years later. Results: Onaverage, men who ran modest (0-24 km/wk), intermediate (24-48 km/wk) orprolonged distances (>_48 km/wk) all gained weight throughage 64,however, those who ran ?48 km/wk had one-half the average annual weightgain of those who ran<24 km/wk. Age-related weight gain, and itsreduction by running, were both greater in younger than older men. Incontrast, men s gain in waist circumference with age, and its reductionby running, were the same in older and younger men. Women increased theirbody weight and waist and hip circumferences over time, regardless ofage, which was also reduced in proportion to running distance. In bothsexes, running did not attenuate weight gain uniformly, but ratherdisproportionately prevented more extreme increases. Conclusion: Men andwomen who remain vigorously active gain less weight as they age and thereduction is in proportion to the exercise dose.
Thouless, David
.8, and the standard deviation 14.2 1. Average 15.6, standard deviation 5.4 A glass bottle weighs 0.50 kg when empty are the volumes of the glass of which the bottle is made, and of the water inside the full bottle? The difference represent the weight of water displaced by the glass bottle. The volume of the glass must therefore be 0
PART I: JOB DESCRIPTION Weighted Job Questionnaire (WJQ) Custom
PART I: JOB DESCRIPTION Weighted Job Questionnaire (WJQ) Custom Department Name: Position Number WEIGHTED JOB QUESTIONNAIRE (WJQ) CUSTOM PARTI: JOB DESCRIPTION 1. POSITION IDENTIFICATION Department
Measuring the Earth's gravity field with cold atom interferometers
Carraz, Olivier; Massotti, Luca; Haagmans, Roger; Silvestrin, Pierluigi
2015-01-01T23:59:59.000Z
The scope of the paper is to propose different concepts for future space gravity missions using Cold Atom Interferometers (CAI) for measuring the diagonal elements of the gravity gradient tensor, the spacecraft angular velocity and the spacecraft acceleration. The aim is to achieve better performance than previous space gravity missions due to a very low white noise spectral behaviour of the CAI instrument and a very high common mode rejection, with the ultimate goals of determining the fine structures of the gravity field with higher accuracy than GOCE and detecting time-variable signals in the gravity field.
REVISITING THE SOLAR TACHOCLINE: AVERAGE PROPERTIES AND TEMPORAL VARIATIONS
Antia, H. M. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Basu, Sarbani, E-mail: antia@tifr.res.in, E-mail: sarbani.basu@yale.edu [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States)
2011-07-10T23:59:59.000Z
The tachocline is believed to be the region where the solar dynamo operates. With over a solar cycle's worth of data available from the Michelson Doppler Imager and Global Oscillation Network Group instruments, we are in a position to investigate not merely the average structure of the solar tachocline, but also its time variations. We determine the properties of the tachocline as a function of time by fitting a two-dimensional model that takes latitudinal variations of the tachocline properties into account. We confirm that if we consider the central position of the tachocline, it is prolate. Our results show that the tachocline is thicker at latitudes higher than the equator, making the overall shape of the tachocline more complex. Of the tachocline properties examined, the transition of the rotation rate across the tachocline, and to some extent the position of the tachocline, show some temporal variations.
Measurement strategies for estimating long-term average wind speeds
Ramsdell, J.V.; Houston, S.; Wegley, H.L.
1980-10-01T23:59:59.000Z
The uncertainty and bias in estimates of long-term average wind speeds inherent in continuous and intermittent measurement strategies are examined by simulating the application of the strategies to 40 data sets. Continuous strategies have smaller uncertainties for fixed duration measurement programs, but intermittent strategies make more efficient use of instruments and have smaller uncertainties for a fixed amount of instrument use. Continuous strategies tend to give biased estimates of the long-term annual mean speed unless an integral number of years' data is collected or the measurement program exceeds 3 years in duration. Intermittent strategies with three or more month-long measurement periods per year do not show any tendency toward bias.
Obesity & Weight Loss Therapy Krakauer and Krakauer, J Obes Weight Loss Ther 2014, 4:2
Krakauer, Nir Y.
Obesity & Weight Loss Therapy Krakauer and Krakauer, J Obes Weight Loss Ther 2014, 4:2 http the original author and source are credited. Keywords: Waist circumference; Body shape index; Obesity Introduction Obesity has historically been a sign of good health, except at the greatestexcess[1
A SEA FLOOR GRAVITY SURVEY OF THE SLEIPNER FIELD TO MONITOR CO2 MIGRATION
Mark Zumberge; Scott Nooner
2005-07-11T23:59:59.000Z
Since 1996, excess CO{sub 2} from the Sleipner natural gas field has been sequestered and injected underground into a porous saline aquifer 1000 m below the seafloor. In 2002, we carried out a high precision micro-gravity survey on the seafloor in order to monitor the injected CO{sub 2}. A repeatability of 5 {micro}Gal in the station averages was observed. This is considerably better than pre-survey expectations. These data will serve as the baseline for time-lapse gravity monitoring of the Sleipner CO{sub 2} injection site. A repeat survey has been scheduled for the summer of 2005. This report covers 9/19/04 to 3/18/05. During this time, gravity and pressure modeling were completed and work graduate student Scott Nooner began writing his Ph.D. dissertation, of which this work is a the major part. Improvements to the gravimeters are also underway that will hopefully increase the measurement precision.
The equilibrium of dense plasma in a gravity field
B. V. Vasiliev
2000-10-31T23:59:59.000Z
The equilibrium of dense plasma in a gravity field and problem of a gravity-induced electric polarization in this matter are discussed. The calculation for metals performed before shows that both - the gravity-induced compressive strain and the gravity-induced electric field - are inversely proportional to their Young moduli. The calculation for high dense plasma, where Young modulus is equal to zero, shows that there is another effect: each cell of this plasma inside a celestial body in own gravity field obtains the small positive electric charge. It happens as heavy ions sag on to light electron clouds. A celestial body stays electrically neutral as a whole, because the negative electric charge concentrates on its surface. The gravity-induced positive volume charge is very small, its order of magnitude equals to $10^{-18}e$ per atom only. But it is sufficient for the complete conterbalancing of the gravity force.
Spatiotemporal measurement of surfactant distribution on gravity-capillary waves
Strickland, Stephen L; Daniels, Karen E
2015-01-01T23:59:59.000Z
Materials adsorbed to the surface of a fluid -- for instance, crude oil, biogenic slicks, or industrial/medical surfactants -- will move in response to surface waves. Due to the difficulty of non-invasive measurement of the spatial distribution of a molecular monolayer, little is known about the dynamics that couple the surface waves and the evolving density field. Here, we report measurements of the spatiotemporal dynamics of the density field of an insoluble surfactant driven by gravity-capillary waves in a shallow cylindrical container. Standing Faraday waves and traveling waves generated by the meniscus are superimposed to create a non-trivial surfactant density field. We measure both the height field of the surface using moir\\'e-imaging, and the density field of the surfactant via the fluorescence of NBD-tagged phosphatidylcholine, a lipid. Through phase-averaging stroboscopically-acquired images of the density field, we determine that the surfactant accumulates on the leading edge of the traveling menis...
Andrei Lebed
2012-05-14T23:59:59.000Z
It is shown that weight operator of a composite quantum body in a weak external gravitational field in the post-Newtonian approximation of the General Relativity does not commute with its energy operator, taken in the absence of the field. Nevertheless, the weak equivalence between the expectations values of weight and energy is shown to survive at a macroscopic level for stationary quantum states for the simplest composite quantum body - a hydrogen atom. Breakdown of the weak equivalence between weight and energy at a microscopic level for stationary quantum states can be experimentally detected by studying unusual electromagnetic radiation, emitted by the atoms, supported and moved in the Earth gravitational field with constant velocity, using spacecraft or satellite. For superpositions of stationary quantum states, a breakdown of the above mentioned equivalence at a macroscopic level leads to time dependent oscillations of the expectation values of weight, where the equivalence restores after averaging over time procedure.
Weighted median of the data in solving least absolute
Scitovski, Rudolf
is illustrated by an example of hourly natural gas consumption forecast. Key words. median, weighted median
Manipulation of Weighted Voting Games and the Effect of Quota
Allan, Vicki H.
for measuring voters' power in weighted voting games. We consider two methods of manipulating weighted voting of manipulators to have more power over the outcomes of the games. We evaluate the extent of susceptibility, Weighted voting games, Manipulation, Annexation, Merging, Power indices. 1 Introduction Weighted voting
Dosimetry in Mammography: Average Glandular Dose Based on Homogeneous Phantom
Benevides, Luis A. [Naval Sea Systems Command,1333 Isaac Hull Avenue, Washington Navy Yard, DC 20376 (United States); Hintenlang, David E. [University of Florida, 202 Nuclear Sciences Center, P.O. Box 1183, Gainesville Florida 32611 (United States)
2011-05-05T23:59:59.000Z
The objective of this study was to demonstrate that a clinical dosimetry protocol that utilizes a dosimetric breast phantom series based on population anthropometric measurements can reliably predict the average glandular dose (AGD) imparted to the patient during a routine screening mammogram. AGD was calculated using entrance skin exposure and dose conversion factors based on fibroglandular content, compressed breast thickness, mammography unit parameters and modifying parameters for homogeneous phantom (phantom factor), compressed breast lateral dimensions (volume factor) and anatomical features (anatomical factor). The patient fibroglandular content was evaluated using a calibrated modified breast tissue equivalent homogeneous phantom series (BRTES-MOD) designed from anthropomorphic measurements of a screening mammography population and whose elemental composition was referenced to International Commission on Radiation Units and Measurements Report 44 and 46 tissues. The patient fibroglandular content, compressed breast thickness along with unit parameters and spectrum half-value layer were used to derive the currently used dose conversion factor (DgN). The study showed that the use of a homogeneous phantom, patient compressed breast lateral dimensions and patient anatomical features can affect AGD by as much as 12%, 3% and 1%, respectively. The protocol was found to be superior to existing methodologies. The clinical dosimetry protocol developed in this study can reliably predict the AGD imparted to an individual patient during a routine screening mammogram.
Long-term average performance benefits of parabolic trough improvements
Gee, R.; Gaul, H.W.; Kearney, D.; Rabl, A.
1980-03-01T23:59:59.000Z
Improved parabolic trough concentrating collectors will result from better design, improved fabrication techniques, and the development and utilization of improved materials. The difficulty of achieving these improvements varies as does their potential for increasing parabolic trough performance. The purpose of this analysis is to quantify the relative merit of various technology advancements in improving the long-term average performance of parabolic trough concentrating collectors. The performance benefits of improvements are determined as a function of operating temperature for north-south, east-west, and polar mounted parabolic troughs. The results are presented graphically to allow a quick determination of the performance merits of particular improvements. Substantial annual energy gains are shown to be attainable. Of the improvements evaluated, the development of stable back-silvered glass reflective surfaces offers the largest performance gain for operating temperatures below 150/sup 0/C. Above 150/sup 0/C, the development of trough receivers that can maintain a vacuum is the most significant potential improvement. The reduction of concentrator slope errors also has a substantial performance benefit at high operating temperatures.
High average power magnetic modulator for copper lasers
Cook, E.G.; Ball, D.G.; Birx, D.L.; Branum, J.D.; Peluso, S.E.; Langford, M.D.; Speer, R.D.; Sullivan, J.R.; Woods, P.G.
1991-06-14T23:59:59.000Z
Magnetic compression circuits show the promise of long life for operation at high average powers and high repetition rates. When the Atomic Vapor Laser Isotope Separation (AVLIS) Program at Lawrence Livermore National Laboratory needed new modulators to drive their higher power copper lasers in the Laser Demonstration Facility (LDF), existing technology using thyratron switched capacitor inversion circuits did not meet the goal for long lifetimes at the required power levels. We have demonstrated that magnetic compression circuits can achieve this goal. Improving thyratron lifetime is achieved by increasing the thyratron conduction time, thereby reducing the effect of cathode depletion. This paper describes a three stage magnetic modulator designed to provide a 60 kV pulse to a copper laser at a 4. 5 kHz repetition rate. This modulator operates at 34 kW input power and has exhibited MTBF of {approx}1000 hours when using thyratrons and even longer MTBFs with a series of stack of SCRs for the main switch. Within this paper, the electrical and mechanical designs for the magnetic compression circuits are discussed as are the important performance parameters of lifetime and jitter. Ancillary circuits such as the charge circuit and reset circuit are shown. 8 refs., 5 figs., 1 tab.
Gruben, David Christopher
1987-01-01T23:59:59.000Z
, is written as mx y Ab Sou 1hl zz mx x ? Ab?' S?? (3. 2) and we will now spend some time explaining its form. Write a = (1, ? P&) and assume an independent estimator of Z, S?, is avail- able. Fuller (1981) shows that maximizing the likelihood equations... ? z, + u? t = 1, 2, . . . , a?s' = 1, 2, 3, . . . , b? (2. 1c) The total number of observations, n, is equal to a?b?. The experimenter has available an instrumental variable for the unobservable ze =&a+sr&W, +re, t=1, 2, . . . , a?. (2. 1d...
Propagation of gravitational waves in multimetric gravity
Manuel Hohmann
2012-04-22T23:59:59.000Z
We discuss the propagation of gravitational waves in a recently discussed class of theories containing N >= 2 metric tensors and a corresponding number of standard model copies. Using the formalism of gauge-invariant linear perturbation theory we show that all gravitational waves propagate at the speed of light. We then employ the Newman-Penrose formalism to show that two to six polarizations of gravitational waves may exist, depending on the parameters entering the equations of motion. This corresponds to E(2) representations N_2, N_3, III_5 and II_6. We finally apply our general discussion to a recently presented concrete multimetric gravity model and show that it is of class N_2, i.e., it allows only two tensor polarizations, as it is the case for general relativity. Our results provide the theoretical background for tests of multimetric gravity theories using the upcoming gravitational wave experiments.
Hydrogen atom in Palatini theories of gravity
Gonzalo J. Olmo
2008-06-03T23:59:59.000Z
We study the effects that the gravitational interaction of $f(R)$ theories of gravity in Palatini formalism has on the stationary states of the Hydrogen atom. We show that the role of gravity in this system is very important for lagrangians $f(R)$ with terms that grow at low curvatures, which have been proposed to explain the accelerated expansion rate of the universe. We find that new gravitationally induced terms in the atomic Hamiltonian generate a strong backreaction that is incompatible with the very existence of bound states. In fact, in the 1/R model, Hydrogen disintegrates in less than two hours. The universe that we observe is, therefore, incompatible with that kind of gravitational interaction. Lagrangians with high curvature corrections do not lead to such instabilities.
Quantum Gravity models - brief conceptual summary
Jerzy Lukierski
2014-11-27T23:59:59.000Z
After short historical overview we describe the difficulties with application of standard QFT methods in quantum gravity (QG). The incompatibility of QG with the use of classical continuous space-time required conceptually new approach. We present briefly three proposals: loop quantum gravity (LQG), the field-theoretic framework on noncommutative space-time and QG models formulated on discretized (triangularized) space-time. We evaluate these models as realizing expected important properties of QG: background independence, consistent quantum diffeomorphisms, noncommutative or discrete structure of space-time at very short distances, finite/renormalizable QG corrections. We only briefly outline an important issue of embedding QG into larger geometric and dynamical frameworks (e.g. supergravity, (super)strings, p-branes, M-theory), with the aim to achieve full unification of all fundamental interactions.
Holographic studies of quasi-topological gravity
Robert C. Myers; Miguel F. Paulos; Aninda Sinha
2010-06-09T23:59:59.000Z
Quasi-topological gravity is a new gravitational theory including curvature-cubed interactions and for which exact black hole solutions were constructed. In a holographic framework, classical quasi-topological gravity can be thought to be dual to the large $N_c$ limit of some non-supersymmetric but conformal gauge theory. We establish various elements of the AdS/CFT dictionary for this duality. This allows us to infer physical constraints on the couplings in the gravitational theory. Further we use holography to investigate hydrodynamic aspects of the dual gauge theory. In particular, we find that the minimum value of the shear-viscosity-to-entropy-density ratio for this model is $\\eta/s \\simeq 0.4140/(4\\pi)$.
Black holes in Asymptotically Safe Gravity
Saueressig, Frank; D'Odorico, Giulio; Vidotto, Francesca
2015-01-01T23:59:59.000Z
Black holes are among the most fascinating objects populating our universe. Their characteristic features, encompassing spacetime singularities, event horizons, and black hole thermodynamics, provide a rich testing ground for quantum gravity ideas. In this note we observe that the renormalization group improved Schwarzschild black holes constructed by Bonanno and Reuter within Weinberg's asymptotic safety program constitute a prototypical example of a Hayward geometry used to model non-singular black holes within quantum gravity phenomenology. Moreover, they share many features of a Planck star: their effective geometry naturally incorporates the one-loop corrections found in the effective field theory framework, their Kretschmann scalar is bounded, and the black hole singularity is replaced by a regular de Sitter patch. The role of the cosmological constant in the renormalization group improvement process is briefly discussed.
Elliptic Genera and 3d Gravity
Benjamin, Nathan; Kachru, Shamit; Moore, Gregory W; Paquette, Natalie M
2015-01-01T23:59:59.000Z
We describe general constraints on the elliptic genus of a 2d supersymmetric conformal field theory which has a gravity dual with large radius in Planck units. We give examples of theories which do and do not satisfy the bounds we derive, by describing the elliptic genera of symmetric product orbifolds of $K3$, product manifolds, certain simple families of Calabi-Yau hypersurfaces, and symmetric products of the "Monster CFT." We discuss the distinction between theories with supergravity duals and those whose duals have strings at the scale set by the AdS curvature. Under natural assumptions we attempt to quantify the fraction of (2,2) supersymmetric conformal theories which admit a weakly curved gravity description, at large central charge.
Chaotic inflation in higher derivative gravity theories
Myrzakul, Shynaray; Sebastiani, Lorenzo
2015-01-01T23:59:59.000Z
In this paper, we investigate chaotic inflation from scalar field subjected to potential in the framework of $f(R^2, P, Q)$-gravity, where we add a correction to Einstein's gravity based on a function of the square of the Ricci scalar $R^2$, the contraction of the Ricci tensor $P$, and the contraction of the Riemann tensor $Q$. The Gauss-Bonnet case is also discussed. We give the general formalism of inflation, deriving the slow-roll parameters, the $e$-folds number, and the spectral indexes. Several explicit examples are furnished, namely we will consider the cases of massive scalar field and scalar field with quartic potential and some power-law function of the curvature invariants under investigation in the gravitational action of the theory. Viable inflation according with observations is analyzed.
Infrared modification of gravity from conformal symmetry
Gegenberg, Jack; Seahra, Sanjeev S
2015-01-01T23:59:59.000Z
We reconsider a gauge theory of gravity in which the gauge group is the conformal group SO(4,2) and the action is of the Yang-Mills form, quadratic in the curvature. The resulting gravitational theory exhibits local conformal symmetry and reduces to Weyl-squared gravity under certain conditions. When the theory is linearized about flat spacetime, we find that matter which couples to the generators of special conformal transformations reproduces Newton's inverse square law. Conversely, matter which couples to generators of translations induces a constant and possibly repulsive force far from the source, which may be relevant for explaining the late time acceleration of the universe. The coupling constant of theory is dimensionless, which means that it is potentially renormalizable.
Equivalence principle in scalar-tensor gravity
Dirk Puetzfeld; Yuri N. Obukhov
2015-05-06T23:59:59.000Z
We present a direct confirmation of the validity of the equivalence principle for unstructured test bodies in scalar tensor gravity. Our analysis is complementary to previous approaches and valid for a large class of scalar-tensor theories of gravitation. A covariant approach is used to derive the equations of motion in a systematic way and allows for the experimental test of scalar-tensor theories by means of extended test bodies.
Charged Cylindrical Black Holes in Conformal Gravity
Jackson Levi Said; Joseph Sultana; Kristian Zarb Adami
2013-01-04T23:59:59.000Z
Considering cylindrical topology we present the static solution for a charged black hole in conformal gravity. We show that unlike the general relativistic case there are two different solutions, both including a factor that when set to zero recovers the familiar static charged black string solution in Einstein's theory. This factor gives rise to a linear term in the potential that also features in the neutral case and may have significant ramifications for particle trajectories.
QPOs: Einstein's gravity non-linear resonances
Paola Rebusco; Marek A. Abramowicz
2006-01-30T23:59:59.000Z
There is strong evidence that the observed kHz Quasi Periodic Oscillations (QPOs) in the X-ray flux of neutron star and black hole sources in LMXRBs are linked to Einstein's General Relativity. Abramowicz&Klu\\'zniak (2001) suggested a non-linear resonance model to explain the QPOs origin: here we summarize their idea and the development of a mathematical toy-model which begins to throw light on the nature of Einstein's gravity non-linear oscillations.
Twisted covariant noncommutative self-dual gravity
Estrada-Jimenez, S.; Garcia-Compean, H.; Obregon, O.; Ramirez, C. [Centro de Estudios en Fisica y Matematicas Basicas y Aplicadas, Universidad Autonoma de Chiapas, Calle 4 Oriente Norte 1428, Tuxtla Gutierrez, Chiapas (Mexico); Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN, P.O. Box 14-740, 07000 Mexico D.F. (Mexico); Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Monterrey, PIIT, Via del Conocimiento 201, Autopista nueva al Aeropuerto km 9.5, 66600, Apodaca Nuevo Leon (Mexico); Instituto de Fisica de la Universidad de Guanajuato, P.O. Box E-143, 37150, Leon Gto. (Mexico); Facultad de Ciencias Fisico Matematicas, Universidad Autonoma de Puebla, P.O. Box 1364, 72000, Puebla (Mexico)
2008-12-15T23:59:59.000Z
A twisted covariant formulation of noncommutative self-dual gravity is presented. The formulation for constructing twisted noncommutative Yang-Mills theories is used. It is shown that the noncommutative torsion is solved at any order of the {theta} expansion in terms of the tetrad and some extra fields of the theory. In the process the first order expansion in {theta} for the Plebanski action is explicitly obtained.
Gravity and Yang-Mills amplitude relations
Bjerrum-Bohr, N. E. J.; Damgaard, Poul H.; Soendergaard, Thomas [Niels Bohr International Academy and Discovery Center, Niels Bohr Institute, Blegdamsvej 17, DK-2100, Copenhagen O (Denmark); FengBo [Center of Mathematical Science, Zhejiang University, Hangzhou (China)
2010-11-15T23:59:59.000Z
Using only general features of the S matrix and quantum field theory, we prove by induction the Kawai-Lewellen-Tye relations that link products of gauge theory amplitudes to gravity amplitudes at tree level. As a bonus of our analysis, we provide a novel and more symmetric form of these relations. We also establish an infinite tower of new identities between amplitudes in gauge theories.
Gravity controlled anti-reverse rotation device
Dickinson, Robert J. (Shaler Township, Allegheny County, PA); Wetherill, Todd M. (Lower Burrell, PA)
1983-01-01T23:59:59.000Z
A gravity assisted anti-reverse rotation device for preventing reverse rotation of pumps and the like. A horizontally mounted pawl is disposed to mesh with a fixed ratchet preventing reverse rotation when the pawl is advanced into intercourse with the ratchet by a vertically mounted lever having a lumped mass. Gravitation action on the lumped mass urges the pawl into mesh with the ratchet, while centrifugal force on the lumped mass during forward, allowed rotation retracts the pawl away from the ratchet.
Holographic Superconductors in Horava-Lifshitz Gravity
Kai Lin; Elcio Abdalla; Anzhong Wang
2014-06-18T23:59:59.000Z
We consider holographic superconductors related to the Schwarzschild black hole in the low energy limit of Ho\\v{r}ava-Lifshitz spacetime. The non-relativistic electromagnetic and scalar fields are introduced to construct a holographic superconductor model in Ho\\v{r}ava-Lifshitz gravity and the results show that the $\\alpha_2$ term plays an important role, modifying the conductivity curve line by means of an attenuation the conductivity.
Exact Gravity Dual of a Gapless Superconductor
George Koutsoumbas; Eleftherios Papantonopoulos; George Siopsis
2009-06-17T23:59:59.000Z
A model of an exact gravity dual of a gapless superconductor is presented in which the condensate is provided by a charged scalar field coupled to a bulk black hole of hyperbolic horizon in asymptotically AdS spacetime. Below a critical temperature, the black hole acquires its hair through a phase transition while an electromagnetic perturbation of the background Maxwell field determines the conductivity of the boundary theory.
Holographic Superconductivity with Gauss-Bonnet gravity
Ruth Gregory
2010-12-07T23:59:59.000Z
I review recent work on holographic superconductivity with Einstein-Gauss-Bonnet gravity, and show how the critical temperature of the superconductor depends on both gravitational backreaction and the Gauss-Bonnet parameter, using both analytic and numerical arguments. I also review computations of the conductivity, finding the energy gap, and demonstrating that there is no universal gap ratio, $\\omega_g/T_c$, for these superconductors.
Asbury, Mary Elizabeth
2011-04-20T23:59:59.000Z
The current study sought to expand social identity theory (Tajfel, 1978; Tajfel & Turner, 1979) to include the concept of weight. Previous research has shown that individuals have social identities associated with age ...
Nonlocal effective-average-action approach to crystalline phantom membranes
Hasselmann, N. [Max Planck Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart (Germany); International Institute of Physics, Universidade Federal do Rio Grande do Norte, 59072-970, Natal, RN (Brazil); Braghin, F. L. [International Institute of Physics, Universidade Federal do Rio Grande do Norte, 59072-970, Natal, RN (Brazil); Instituto de Fisica, Universidade Federal de Goias, P. B. 131, Campus II, 74001-970, Goiania, GO (Brazil)
2011-03-15T23:59:59.000Z
We investigate the properties of crystalline phantom membranes, at the crumpling transition and in the flat phase, using a nonperturbative renormalization group approach. We avoid a derivative expansion of the effective average action and instead analyze the full momentum dependence of the elastic coupling functions. This leads to a more accurate determination of the critical exponents and further yields the full momentum dependence of the correlation functions of the in-plane and out-of-plane fluctuation. The flow equations are solved numerically for D=2 dimensional membranes embedded in a d=3 dimensional space. Within our approach we find a crumpling transition of second order which is characterized by an anomalous exponent {eta}{sub c}{approx_equal}0.63(8) and the thermal exponent {nu}{approx_equal}0.69. Near the crumpling transition the order parameter of the flat phase vanishes with a critical exponent {beta}{approx_equal}0.22. The flat phase anomalous dimension is {eta}{sub f}{approx_equal}0.85 and the Poisson's ratio inside the flat phase is found to be {sigma}{sub f}{approx_equal}-1/3. At the crumpling transition we find a much larger negative value of the Poisson's ratio {sigma}{sub c}{approx_equal}-0.71(5). We discuss further in detail the different regimes of the momentum dependent fluctuations, both in the flat phase and in the vicinity of the crumpling transition, and extract the crossover momentum scales which separate them.
Replication regulates volume weighting in quantum cosmology
Hartle, James [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Hertog, Thomas [APC, UMR 7164 (CNRS, Universite Paris 7), 10 rue A.Domon et L.Duquet, 75205 Paris (France) and Intl Solvay Institutes, Boulevard du Triomphe, ULB-C.P. 231, 1050 Brussels (Belgium)
2009-09-15T23:59:59.000Z
Probabilities for observations in cosmology are conditioned both on the Universe's quantum state and on local data specifying the observational situation. We show the quantum state defines a measure for prediction through such conditional probabilities that is well-behaved for spatially large or infinite universes when the probabilities that our data are replicated are taken into account. In histories where our data are rare volume weighting connects top-down probabilities conditioned on both the data and the quantum state to the bottom-up probabilities conditioned on the quantum state alone. We apply these principles to a calculation of the number of inflationary e-folds in a homogeneous, isotropic minisuperspace model with a single scalar field moving in a quadratic potential. We find that volume weighting is justified and the top-down probabilities favor a large number of e-folds, hereby predicting the curvature of our Universe at the present time to be approximately zero.
Information weights of nucleotides in DNA sequences
M. R. Dudek; S. Cebrat; M. Kowalczuk; P. Mackiewicz; A. Nowicka; D. Mackiewicz; M. Dudkiewicz
2003-01-21T23:59:59.000Z
The coding sequence in DNA molecule is considered as a message to be transferred to receiver, the proteins, through a noisy information channel and each nucleotide is assigned a respective information weight. With the help of the nucleotide substitution matrix we estimated the lower bound of the amount of information carried out by nucleotides which is not subject of mutations. We used the calculated weights to reconstruct k-oligomers of genes from the Borrelia burgdorferi genome. We showed, that to this aim there is sufficient a simple rule, that the number of bits of the carried information cannot exceed some threshold value. The method introduced by us is general and applies to every genome.
Abelian-Higgs strings in Rastall gravity
Eugenio R. Bezerra de Mello; Julio C. Fabris; Betti Hartmann
2015-04-02T23:59:59.000Z
In this paper we analyze Abelian-Higgs strings in a phenomenological model that takes quantum effects in curved space-time into account. This model, first introduced by Rastall, cannot be derived from an action principle. We formulate phenomenological equations of motion under the guiding principle of minimal possible deformation of the standard equations. We construct string solutions that asymptote to a flat space-time with a deficit angle by solving the set of coupled non-linear ordinary differential equations numerically. Decreasing the Rastall parameter from its Einstein gravity value we find that the deficit angle of the space-time increases and becomes equal to $2\\pi$ at some critical value of this parameter that depends on the remaining couplings in the model. For smaller values the resulting solutions are supermassive string solutions possessing a singularity at a finite distance from the string core. Assuming the Higgs boson mass to be on the order of the gauge boson mass we find that also in Rastall gravity this happens only when the symmetry breaking scale is on the order of the Planck mass. We also observe that for specific values of the parameters in the model the energy per unit length becomes proportional to the winding number, i.e. the degree of the map $S^1 \\rightarrow S^1$. Unlike in the BPS limit in Einstein gravity, this is, however, not connect to an underlying mathematical structure, but rather constitutes a would-be-BPS bound.
Constraining Torsion with Gravity Probe B
Yi Mao; Max Tegmark; Alan Guth; Serkan Cabi
2007-10-05T23:59:59.000Z
It is well-entrenched folklore that torsion gravity theories predict observationally negligible torsion in the solar system, since torsion (if it exists) couples only to the intrinsic spin of elementary particles, not to rotational angular momentum. We argue that this assumption has a logical loophole which can and should be tested experimentally. In the spirit of action=reaction, if a rotating mass like a planet can generate torsion, then a gyroscope should also feel torsion. Using symmetry arguments, we show that to lowest order, the torsion field around a uniformly rotating spherical mass is determined by seven dimensionless parameters. These parameters effectively generalize the PPN formalism and provide a concrete framework for further testing GR. We construct a parametrized Lagrangian that includes both standard torsion-free GR and Hayashi- Shirafuji maximal torsion gravity as special cases. We demonstrate that classic solar system tests rule out the latter and constrain two observable parameters. We show that Gravity Probe B (GPB) is an ideal experiment for further constraining torsion theories, and work out the most general torsion-induced precession of its gyroscope in terms of our torsion parameters
Cooling, Gravity and Geometry: Flow-driven Massive Core Formation
Fabian Heitsch; Lee Hartmann; Adrianne D. Slyz; Julien E. G. Devriendt; Andreas Burkert
2007-09-15T23:59:59.000Z
We study numerically the formation of molecular clouds in large-scale colliding flows including self-gravity. The models emphasize the competition between the effects of gravity on global and local scales in an isolated cloud. Global gravity builds up large-scale filaments, while local gravity -- triggered by a combination of strong thermal and dynamical instabilities -- causes cores to form. The dynamical instabilities give rise to a local focusing of the colliding flows, facilitating the rapid formation of massive protostellar cores of a few 100 M$_\\odot$. The forming clouds do not reach an equilibrium state, though the motions within the clouds appear comparable to ``virial''. The self-similar core mass distributions derived from models with and without self-gravity indicate that the core mass distribution is set very early on during the cloud formation process, predominantly by a combination of thermal and dynamical instabilities rather than by self-gravity.
New Agegraphic Dark Energy in $f(R)$ Gravity
M. R. Setare
2009-08-03T23:59:59.000Z
In this paper we study cosmological application of new agegraphic dark energy density in the $f(R)$ gravity framework. We employ the new agegraphic model of dark energy to obtain the equation of state for the new agegraphic energy density in spatially flat universe. Our calculation show, taking $nnew agegraphic dark energy model in flat universe in the modified gravity cosmology framework. Also we develop a reconstruction scheme for the modified gravity with $f(R)$ action.
Solar System experiments do not yet veto modified gravity models
Valerio Faraoni
2006-07-05T23:59:59.000Z
The dynamical equivalence between modified and scalar-tensor gravity theories is revisited and it is concluded that it breaks down in the limit to general relativity. A gauge-independent analysis of cosmological perturbations in both classes of theories lends independent support to this conclusion. As a consequence, the PPN formalism of scalar-tensor gravity and Solar System experiments do not veto modified gravity, as previously thought.
AdS waves as exact solutions to quadratic gravity
Guellue, Ibrahim; Sisman, Tahsin Cagri; Tekin, Bayram [Department of Physics, Middle East Technical University, 06531 Ankara (Turkey); Guerses, Metin [Department of Mathematics, Faculty of Sciences Bilkent University, 06800 Ankara (Turkey)
2011-04-15T23:59:59.000Z
We give an exact solution of the quadratic gravity in D dimensions. The solution is a plane-fronted wave metric with a cosmological constant. This metric solves not only the full quadratic gravity field equations but also the linearized ones which include the linearized equations of the recently found critical gravity. A subset of the solutions change the asymptotic structure of the anti-de Sitter space due to their logarithmic behavior.
Analysis of faults using gravity methods in Mason County, Texas
Milligan, Michael Glen
1992-01-01T23:59:59.000Z
Committee: Dr. D. A. Fahlquist Dr. B. Johnson The objective of this study is to determine the applicability of gravity profiling methods for determining the location and throw of a series of faults related to a structural graben in northern Mason County... profiles. For two faults with the best geologic control, the best-fit gravity models compared favorably with the the geologic model constructed by Randolph (1991) on the basis of surface mapping, structural control and well control. The gravity models...
Gravity interpretation of the northern Overthrust Belt, Idaho and Wyoming
Silver, Wendy Ilene
1979-01-01T23:59:59.000Z
provide a potential source of information about the configuration of the sedimentary rock / Precambrian basement interface as well as the geometry of the overlying younger rocks. GRAVITY DA. A Regional Gravity The regional gravity field of Wyoming..., Jurassic and Lower Cretaceous units. It may therefore be concluded that the uplifts of the Precambrian basement were fomed after the deposition of those overly1ng sedimentary rocks. ACKNOWLEDGEMEWTS I w1sh to thank Dr, R. R. Berg, chairman of my...
The Role of Gravity Waves in the Formation and Organization of Clouds during TWPICE
Reeder, Michael J. [Monash University; Lane, Todd P. [University of Melbourne; Hankinson, Mai Chi Nguyen [Monash University
2013-09-27T23:59:59.000Z
All convective clouds emit gravity waves. While it is certain that convectively-generated waves play important parts in determining the climate, their precise roles remain uncertain and their effects are not (generally) represented in climate models. The work described here focuses mostly on observations and modeling of convectively-generated gravity waves, using the intensive observations from the DoE-sponsored Tropical Warm Pool International Cloud Experiment (TWP-ICE), which took place in Darwin, from 17 January to 13 February 2006. Among other things, the research has implications the part played by convectively-generated gravity waves in the formation of cirrus, in the initiation and organization of further convection, and in the subgrid-scale momentum transport and associated large-scale stresses imposed on the troposphere and stratosphere. The analysis shows two groups of inertia-gravity waves are detected: group L in the middle stratosphere during the suppressed monsoon period, and group S in the lower stratosphere during the monsoon break period. Waves belonging to group L propagate to the south-east with a mean intrinsic period of 35 h, and have vertical and horizontal wavelengths of about 5-6 km and 3000-6000 km, respectively. Ray tracing calculations indicate that these waves originate from a deep convective region near Indonesia. Waves belonging to group S propagate to the south-south-east with an intrinsic period, vertical wavelength and horizontal wavelength of about 45 h, 2 km and 2000-4000 km, respectively. These waves are shown to be associated with shallow convection in the oceanic area within about 1000 km of Darwin. The intrinsic periods of high-frequency waves are estimated to be between 20-40 minutes. The high-frequency wave activity in the stratosphere, defined by mass-weighted variance of the vertical motion of the sonde, has a maximum following the afternoon local convection indicating that these waves are generated by local convection. The wave activity is strongest in the lower stratosphere below 22 km and, during the suppressed monsoon period, is modulated with a 3-4-day period. The concentration of the wave activity in the lower stratosphere is consistent with the properties of the environment in which these waves propagate, whereas its 3-4-day modulation is explained by the variation of the convection activity in the TWP-ICE domain. At low rainfall intensity the wave activity increases as rainfall intensity increases. At high values of rainfall intensity, however, the wave activity associated with deep convective clouds is independent of the rainfall intensity. The convection and gravity waves observed during TWP-ICE are simulated with the Weather Research and Forecasting (WRF) Model. These simulations are compared with radiosonde observations described above and are used to determine some of the properties of convectively generated gravity waves. The gravity waves appear to be well simulated by the model. The model is used to explore the relationships between the convection, the gravity waves and cirrus.
Leider, H R
1981-06-01T23:59:59.000Z
Changes in molecular weight and nitrate ester content for cellulose nitrate (NC), either pure or as a constituent of PBX-9404, were determined as a function of time and temperature. Changes in the number-averaged molecular weight, M/sub n/, are described by the simple theory of random chain scission, and M/sub n/ is found to correlate well with nitrate ester loss. Significant differences are seen between NC aged in the isolated condition and aged as the binder in PBX-9404.
asymptotically safe gravity: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
at high energies. Elisa Manrique; Stefan Rechenberger; Frank Saueressig 2011-02-24 2 Fractal Spacetime Structure in Asymptotically Safe Gravity General Relativity & Quantum...
Ground Gravity Survey At Valles Caldera - Sulphur Springs Geothermal...
Survey Activity Date - 1986 Usefulness not indicated DOE-funding Unknown Notes A computer program capable of two-dimensional modeling of gravity data was used in interpreting...
Quantized gauge-affine gravity in the superfiber bundle approach
A. Meziane; M. Tahiri
2005-11-10T23:59:59.000Z
The quantization of gauge-affine gravity within the superfiber bundle formalism is proposed. By introducing an even pseudotensorial 1-superform over a principal superfibre bundle with superconnection, we obtain the geometrical Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST transformations of the fields occurring in such a theory. Reducing the four-dimensional general affine group double-covering to the Poincare group double-covering we also find the BRST and anti-BRST transformations of the fields present in Einstein's gravity. Furthermore, we give a prescription leading to the construction of both BRST-invariant gauge-fixing action for gauge-affine gravity and Einstein's gravity.
atmospheric gravity waves: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
gravity waves (AGWs). Satellite imagery shows evidence the characteristics of these waves. The favorable wave propagation conditions in 12;this region are illustrated 5...
Integration of Full Tensor Gravity and ZTEM Passive Low Frequency...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
and ZTEM Passive Low Frequency EM Instruments for Simultaneous Data Acquisition Integration of Full Tensor Gravity and ZTEM Passive Low Frequency EM Instruments for...
Ground Gravity Survey At Blue Mountain Geothermal Area (Fairbank...
Fairbank Engineering Ltd, 2003) Exploration Activity Details Location Blue Mountain Geothermal Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not...
Ground Gravity Survey At San Francisco Volcanic Field Area (Warpinski...
Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Northern Arizona University has re-assessed the existing exploration...
Exercise protocols during short-radius centrifugation for artificial gravity
Edmonds, Jessica Leigh
2008-01-01T23:59:59.000Z
Long-duration spaceflight results in severe physiological deconditioning, threatening the success of interplanetary travel. Exercise combined with artificial gravity provided by centrifugation may be the comprehensive ...
The f(R) Gravity Function of the Linde Quintessence
Sergei V. Ketov; Natsuki Watanabe
2014-10-20T23:59:59.000Z
We calculate the f(R) gravity function in the dual gravity description of the quintessence model with a quadratic (Linde) scalar potential and a positive cosmological constant. We find that in the large curvature regime relevant to chaotic inflation in early Universe, the dual f(R) gravity is well approximated by the (matter) loop-corrected Starobinsky inflationary model. In the small curvature regime relevant to dark energy in the present Universe, the f(R) gravity function reduces to the Einstein-Hilbert one with a positive cosmological constant.
Ground Gravity Survey At Lake City Hot Springs Area (Warpinski...
fault zones. The focus of Lake City Geothermal's current effort is on enhancing the site interpretation by re-evaluating the existing seismic data, conducting a detailed gravity...
Lessons in quantum gravity from quantum field theory
Berenstein, David [Department of Physics, University of California at Santa Barbara, CA 93106 (United States); Institute for Advanced Study, School of Natural Science, Princeton, NJ 08540 (United States)
2010-12-07T23:59:59.000Z
This paper reviews advances in the understanding of quantum gravity based on field theory calculations in the AdS/CFT correspondence.
Ground Gravity Survey At Dixie Valley Geothermal Area (Allis...
DOE-funding Unknown Exploration Basis Gravity surveys were conducted to monitor the evolution of the geothermal reservoir. Notes A 12 month long experiment was conducted using a...
Summary of Session A6: Alternative Theories of Gravity
R. B. Mann
1998-03-13T23:59:59.000Z
This is a summary of the workshop A.6 on Alternative Theories of Gravity, prepared for the proceedings for the GR15 conference.
Ground Gravity Survey At Long Valley Caldera Geothermal Area...
Battaglia, Et Al., 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Long Valley Caldera Geothermal Area (Battaglia,...
Strong and weak gravitational field in $R+?^4/R$ gravity
Kh. Saaidi; A. Vajdi; S. W. Rabiei; A. Aghamohammadi; H. Sheikhahmadi
2012-01-18T23:59:59.000Z
We introduce a new approach for investigating the weak field limit of vacuum field equations in $f(R)$ gravity and we find the weak field limit of $f(R)=R+\\mu ^4/R$ gravity. Furthermore, we study the strong gravity regime in $R+\\mu^{4}/R$ model of $f(R)$ gravity. We show the existence of strong gravitational field in vacuum for such model. We find out in the limit $\\mu\\rightarrow 0$, the weak field limit and the strong gravitational field can be regarded as a perturbed Schwarzschild metric.
Antonio Enea Romano
2007-01-27T23:59:59.000Z
We show that positive averaged acceleration obtained in LTB models through spatial averaging can require integration over a region beyond the event horizon of the central observer. We provide an example of a LTB model with positive averaged acceleration in which the luminosity distance does not contain information about the entire spatially averaged region, making the averaged acceleration unobservable. Since the cosmic acceleration is obtained from fitting the observed luminosity distance to a FRW model we conclude that in general a positive averaged acceleration in LTB models does not imply a positive FRW cosmic acceleration.
Romano, A E
2006-01-01T23:59:59.000Z
We show that positive averaged acceleration obtained in LTB models through spatial averaging can require integration over a region beyond the event horizon of the central observer. We provide an example of a LTB model with positive averaged acceleration in which the luminosity distance does not contain information about the entire spatially averaged region, making the averaged acceleration unobservable. Since the cosmic acceleration is obtained from fitting the observed luminosity distance to a FRW model we conclude that in general a positive averaged acceleration in LTB models does not imply a positive FRW cosmic acceleration.
Nutrition, Weight Control and Fast Food.
Sweeten, Mary K.
1980-01-01T23:59:59.000Z
Page in Original Bulletin] Nutrition, Weight Control and Fast Food Mary K. Sweeten* The Fast Food Trend More people are eating fewer meals at home and more snack-type meals at fast food ' restaurants. Fast food sales in 1978 in the United States... chain when eating out 60 percent of the time. This trend is a result of more women employed outside the home, a higher per capita disposable income and more leisure time. Although they may cost more than the same meals prepared at home, fast food res...
Light-weight analyzer for odor recognition
Vass, Arpad A; Wise, Marcus B
2014-05-20T23:59:59.000Z
The invention provides a light weight analyzer, e.g., detector, capable of locating clandestine graves. The detector utilizes the very specific and unique chemicals identified in the database of human decompositional odor. This detector, based on specific chemical compounds found relevant to human decomposition, is the next step forward in clandestine grave detection and will take the guess-work out of current methods using canines and ground-penetrating radar, which have historically been unreliable. The detector is self contained, portable and built for field use. Both visual and auditory cues are provided to the operator.
A new quasidilaton theory of massive gravity
Shinji Mukohyama
2014-10-08T23:59:59.000Z
We present a new quasidilaton theory of Poincare invariant massive gravity, based on the recently proposed framework of matter coupling that makes it possible for the kinetic energy of the quasidilaton scalar to couple to both physical and fiducial metrics simultaneously. We find a scaling-type exact solution that expresses a self-accelerating de Sitter universe, and then analyze linear perturbations around it. It is shown that in a range of parameters all physical degrees of freedom have non-vanishing quadratic kinetic terms and are stable in the subhorizon limit, while the effective Newton's constant for the background is kept positive.
Fractal Spacetime Structure in Asymptotically Safe Gravity
O. Lauscher; M. Reuter
2005-08-26T23:59:59.000Z
Four-dimensional Quantum Einstein Gravity (QEG) is likely to be an asymptotically safe theory which is applicable at arbitrarily small distance scales. On sub-Planckian distances it predicts that spacetime is a fractal with an effective dimensionality of 2. The original argument leading to this result was based upon the anomalous dimension of Newton's constant. In the present paper we demonstrate that also the spectral dimension equals 2 microscopically, while it is equal to 4 on macroscopic scales. This result is an exact consequence of asymptotic safety and does not rely on any truncation. Contact is made with recent Monte Carlo simulations.
Gamma Ray Burst Neutrinos Probing Quantum Gravity
M. C. Gonzalez-Garcia; F. Halzen
2006-11-28T23:59:59.000Z
Very high energy, short wavelength, neutrinos may interact with the space-time foam predicted by theories of quantum gravity. They would propagate like light through a crystal lattice and be delayed, with the delay depending on the energy. This will appear to the observer as a violation of Lorenz invariance. Back of the envelope calculations imply that observations of neutrinos produced by gamma ray bursts may reach Planck-scale sensitivity. We revisit the problem considering two essential complications: the imprecise timing of the neutrinos associated with their poorly understood production mechanism in the source and the indirect nature of their energy measurement made by high energy neutrino telescopes.
Dynamics of generalized Palatini theories of gravity
Vitagliano, Vincenzo; Liberati, Stefano [SISSA-International School for Advanced Studies, Via Bonomea 265, 34136 Trieste (Italy) and INFN sezione di Trieste, sezione di Trieste, via Valerio 2, 34127 Trieste (Italy); Sotiriou, Thomas P. [Department of Applied Mathematics and Theoretical Physics, Center for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)
2010-10-15T23:59:59.000Z
It is known that in f(R) theories of gravity with an independent connection which can be both nonmetric and nonsymmetric, this connection can always be algebraically eliminated in favor of the metric and the matter fields, so long as it is not coupled to the matter explicitly. We show here that this is a special characteristic of f(R) actions, and it is not true for actions that include other curvature invariants. This contradicts some recent claims in the literature. We clarify the reasons for this contradiction.
Modification of gravity due to torsion
Nair, V. P. [Physics Department, City College of the CUNY, New York, NY 10031 (United States); Nikiforova, V. [Physics Department, Mascow State University Moscow (Russian Federation); Randjbar-Daemi, S. [The Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Rubakov, V. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation)
2010-01-01T23:59:59.000Z
Modifications of general relativity have been considered as one of the possible ways of addressing some of the outstanding problems related to the large scale gravitational physics. In this contribution we review some of the recent results which are due to the inclusion of dynamical torsion. More specifically we shall discuss the propagation of massive spin-2 particles in flat and curved space times. We shall show that, contrary to what is generally believed, spinning matter is not the sole source of torsion field. A symmetric energy momentum tensor can also couple to torsion degrees of freedom. The massive and massless spin-2 particles mix giving rise to an infrared modification of gravity.
A high frequency resonance gravity gradiometer
Bagaev, S. N.; Kvashnin, N. L.; Skvortsov, M. N. [Laser Physics Institute SB RAS, Novosibirsc (Russian Federation); Bezrukov, L. B.; Krysanov, V. A. [Institute of Nuclear Physics RAS, Moscow (Russian Federation); Oreshkin, S. I.; Motylev, A. M.; Popov, S. M.; Samoilenko, A. A.; Yudin, I. S. [Lomonosov MSU, Sternberg Astronomical Institute, Moscow (Russian Federation); Rudenko, V. N. [Institute of Nuclear Physics RAS, Moscow (Russian Federation); Lomonosov MSU, Sternberg Astronomical Institute, Moscow (Russian Federation)
2014-06-15T23:59:59.000Z
A new setup OGRAN—the large scale opto-acoustical gravitational detector is described. As distinguished from known gravitational bar detectors it uses the optical interferometrical readout for registering weak variations of gravity gradient at the kilohetz frequency region. At room temperature, its sensitivity is limited only by the bar Brownian noise at the bandwidth close to 100 Hz. It is destined for a search for rare events—gravitational pulses coincident with signals of neutrino scintillator (BUST) in the deep underground of Baksan Neutrino Observatory of INR RAS.
Confronting Dilaton-exchange gravity with experiments
H. V. Klapdor-Kleingrothaus; H. Päs; U. Sarkar
2000-08-16T23:59:59.000Z
We study the experimental constraints on theories, where the equivalence principle is violated by dilaton-exchange contributions to the usual graviton-exchange gravity. We point out that in this case it is not possible to have any CPT violation and hence there is no constraint from the CPT violating measurements in the $K-$system. The most stringent bound is obtained from the $K_L - K_S$ mass difference. In contrast, neither neutrino oscillation experiments nor neutrinoless double beta decay imply significant constraints.
Wave Packets Propagation in Quantum Gravity
Kourosh Nozari; S. H. Mehdipour
2005-07-03T23:59:59.000Z
Wave packet broadening in usual quantum mechanics is a consequence of dispersion behavior of the medium which the wave propagates in it. In this paper, we consider the problem of wave packet broadening in the framework of Generalized Uncertainty Principle(GUP) of quantum gravity. New dispersion relations are derived in the context of GUP and it has been shown that there exists a gravitational induced dispersion which leads to more broadening of the wave packets. As a result of these dispersion relations, a generalized Klein-Gordon equation is obtained and its interpretation is given.
Anisotropic higher derivative gravity and inflationary universe
W. F. Kao
2006-05-21T23:59:59.000Z
Stability analysis of the Kantowski-Sachs type universe in pure higher derivative gravity theory is studied in details. The non-redundant generalized Friedmann equation of the system is derived by introducing a reduced one dimensional generalized KS type action. This method greatly reduces the labor in deriving field equations of any complicate models. Existence and stability of inflationary solution in the presence of higher derivative terms are also studied in details. Implications to the choice of physical theories are discussed in details in this paper.
Inflationary Universe in Higher Derivative Induced Gravity
W. F. Kao
2000-06-27T23:59:59.000Z
In an induced-gravity model, the stability condition of an inflationary slow-rollover solution is shown to be $\\phi_0 \\partial_{\\phi_0}V(\\phi_0)=4V(\\phi_0)$. The presence of higher derivative terms will, however, act against the stability of this expanding solution unless further constraints on the field parameters are imposed. We find that these models will acquire a non-vanishing cosmological constant at the end of inflation. Some models are analyzed for their implication to the early universe.
Loop Quantum Gravity: An Inside View
Thomas Thiemann
2006-08-29T23:59:59.000Z
This is a (relatively) non -- technical summary of the status of the quantum dynamics in Loop Quantum Gravity (LQG). We explain in detail the historical evolution of the subject and why the results obtained so far are non -- trivial. The present text can be viewed in part as a response to an article by Nicolai, Peeters and Zamaklar [hep-th/0501114]. We also explain why certain no go conclusions drawn from a mathematically correct calculation in a recent paper by Helling et al [hep-th/0409182] are physically incorrect.
Hall viscosity from gauge/gravity duality
Omid Saremi; Dam Thanh Son
2011-03-24T23:59:59.000Z
In (2+1)-dimensional systems with broken parity, there exists yet another transport coefficient, appearing at the same order as the shear viscosity in the hydrodynamic derivative expansion. In condensed matter physics, it is referred to as "Hall viscosity". We consider a simple holographic realization of a (2+1)-dimensional isotropic fluid with broken spatial parity. Using techniques of fluid/gravity correspondence, we uncover that the holographic fluid possesses a nonzero Hall viscosity, whose value only depends on the near-horizon region of the background. We also write down a Kubo's formula for the Hall viscosity. We confirm our results by directly computing the Hall viscosity using the formula.
Thermodynamics of 5D dilaton-gravity
Megias, E. [Institute for Theoretical Physics, University of Heidelberg (Germany); Instituto de Fisica Teorica CSIC-UAM, Universidad Autonoma de Madrid (Spain)
2011-05-23T23:59:59.000Z
We calculate the free energy, spatial string tension and Polyakov loop of the gluon plasma using the dilaton potential of Ref. [1] in the dilaton-gravity theory of AdS/QCD. The free energy is computed from the Black Hole solutions of the Einstein equations in two ways: first, from the Bekenstein-Hawking proportionality of the entropy with the area of the horizon, and secondly from the Page-Hawking computation of the free energy. The finite temperature behaviour of the spatial string tension and Polyakov loop follow from the corresponding string theory in AdS{sub 5}. Comparison with lattice data is made.
Holographic renormalization of new massive gravity
Alishahiha, Mohsen [School of Physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Naseh, Ali [School of Physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Department of Physics, Sharif University of Technology, P.O. Box 11365-9161, Tehran (Iran, Islamic Republic of)
2010-11-15T23:59:59.000Z
We study holographic renormalization for three-dimensional new massive gravity. By studying the general falloff conditions for the metric allowed by the model at infinity, we show that at the critical point where the central charges of the dual conformal field theory (CFT) are zero, it contains a leading logarithmic behavior. In the context of AdS/CFT correspondence it can be identified as a source for an irrelevant operator in the dual CFT. The presence of the logarithmic falloff may be interpreted as the fact that the dual CFT would be a logarithmic conformal field theory.
Gravity dual of spatially modulated phase
Nakamura, Shin [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Ooguri, Hirosi [California Institute of Technology, Pasadena, California 91125 (United States); IPMU, University of Tokyo, Kashiwa 277-8586 (Japan); Park, Chang-Soon [California Institute of Technology, Pasadena, California 91125 (United States)
2010-02-15T23:59:59.000Z
We show that the five-dimensional Maxwell theory with the Chern-Simons term is tachyonic in the presence of a constant electric field. When coupled to gravity, a sufficiently large Chern-Simons coupling causes instability of the Reissner-Nordstroem black holes in anti-de Sitter space. The instability happens only at nonvanishing momenta, suggesting a spatially modulated phase in the holographically dual quantum field theory in (3+1) dimensions, with spontaneous current generation in a helical configuration. The three-charge extremal black hole in the type IIB superstring theory on AdS{sub 5}xS{sup 5} barely satisfies the stability condition.
Apparent horizon in fluid-gravity duality
Booth, Ivan; Heller, Michal P.; Plewa, Grzegorz; Spalinski, Michal [Department of Mathematics and Statistics, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, A1C 5S7 (Canada); Instituut voor Theoretische Fysica, Universiteit van Amsterdam, Science Park 904, 1090 GL Amsterdam (Netherlands); Soltan Institute for Nuclear Studies, Hoza 69, 00-681 Warsaw (Poland); Soltan Institute for Nuclear Studies, Hoza 69, 00-681 Warsaw (Poland) and Physics Department, University of Bialystok, 15-424 Bialystok (Poland)
2011-05-15T23:59:59.000Z
This article develops a computational framework for determining the location of boundary-covariant apparent horizons in the geometry of conformal fluid-gravity duality in arbitrary dimensions. In particular, it is shown up to second order and conjectured to hold to all orders in the gradient expansion that there is a unique apparent horizon which is covariantly expressible in terms of fluid velocity, temperature, and boundary metric. This leads to the first explicit example of an entropy current defined by an apparent horizon and opens the possibility that in the near-equilibrium regime there is preferred foliation of apparent horizons for black holes in asymptotically anti-de Sitter spacetimes.
Seven-dimensional gravity with topological terms
Lue, H. [China Economics and Management Academy Central, University of Finance and Economics, Beijing 100081 (China); Institute for Advanced Study, Shenzhen University, Nanhai Ave 3688, Shenzhen 518060 (China); Pang Yi [Key Laboratory of Frontiers in Theoretical Physics Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China)
2010-04-15T23:59:59.000Z
We construct new seven-dimensional gravity by adding two topological terms to the Einstein-Hilbert action. For a certain choice of the coupling constants, these terms exist naturally in seven-dimensional gauged supergravity from the S{sup 4} reduction of eleven-dimensional supergravity with the R{sup 4} corrections. We derive the full set of the equations of motion. We find that the static spherically-symmetric black holes are unmodified by the topological terms. We obtain squashed AdS{sub 7}, and also squashed seven spheres and Q{sup 111} spaces in Euclidean signature.
Drag phenomena from holographic massive gravity
Matteo Baggioli; Daniel K. Brattan
2015-04-28T23:59:59.000Z
We consider the motion of point particles in a strongly coupled field theory with broken translation invariance. We obtain the energy and momentum loss rates and drag coefficients for a class of such particles by solving for the motion of classical strings in holographic massive gravity. At low temperatures compared to the graviton mass the behaviour of the string is controlled by the appearance of an exotic ground state with non-zero entropy at zero temperature. Additionally we find an upper bound on the diffusion constant for a collection of these particles which is saturated when the mass of the graviton goes to zero.
Drag phenomena from holographic massive gravity
Baggioli, Matteo
2015-01-01T23:59:59.000Z
We consider the motion of point particles in a strongly coupled field theory with broken translation invariance. We obtain the energy and momentum loss rates and drag coefficients for a class of such particles by solving for the motion of classical strings in holographic massive gravity. At low temperatures compared to the graviton mass the behaviour of the string is controlled by the appearance of an exotic ground state with non-zero entropy at zero temperature. Additionally we find an upper bound on the diffusion constant for a collection of these particles which is saturated when the mass of the graviton goes to zero.
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atomic weight values: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
a sample of 10 100 atoms. Sumei Huang; Girish S. Agarwal 2015-01-10 3 Power laws and fractal behavior in nuclear stability, atomic weights and molecular weights Physics Websites...
atomic weight determinations: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Power laws and fractal behavior in nuclear stability, atomic weights and molecular weights Physics Websites...
Written emotional expression: Effects on weight loss and maintenance
Hockemeyer, Jill Renee
2007-10-16T23:59:59.000Z
the negative effects of distress on weight loss and maintenance through improved emotional self-regulatory processes. This study examined the effects of expressive writing on weight regain, stress, and emotional eating among individuals who have recently lost...
PARTI: JOB DESCRIPTION Weighted Job Questionnaire (WJQ) Custom
PARTI: JOB DESCRIPTION Weighted Job Questionnaire (WJQ) Custom Meeting, Event and Conference UNIVERSITY & C.U.P.E., Local 3338 WEIGHTED JOB QUESTIONNAIRE (WJQ) CUSTOM PARTI: JOB DESCRIPTION 1. POSITION
A weighted iterative algorithm for neuromagnetic imaging
Gorodnitsky, I. (Los Alamos National Lab., NM (United States) California Univ., San Diego, La Jolla, CA (United States)); George, J.S.; Schlitt, H.A.; Lewis, P.S. (Los Alamos National Lab., NM (United States))
1992-01-01T23:59:59.000Z
The goal of neuromagnetic source reconstruction is high resolution 3-D mapping of the current distribution within the brain. However, the neuromagnetic inverse problem is ill-posed and typically underdetermined. The Moore-Penrose pseudoinverse provides a linear algebraic inverse calculation that simultaneously minimizes chisquare and the Euclidean norm of the component currents. Such minimum norm'' reconstructions tend to produce diffuse and superficial current distributions because voxels nearer the sensor array can account for more power in the data with less current than deeper voxels. We describe an algorithm that overcomes the bias of minimum norm procedures toward superficial solutions by using weights chosen to compensate for the distance dependence of magnetic signal strength. We also apply a Bayesian weighting strategy in an iterative pseudoinverse computation, to address the bias of the linear estimator procedure toward diffuse solutions. This strategy produces a progressively more focal current distribution while accomodating distributed current sources, and appears to effectively reduce the problems associated with the under-determined linear system.
A weighted iterative algorithm for neuromagnetic imaging
Gorodnitsky, I. [Los Alamos National Lab., NM (United States)]|[California Univ., San Diego, La Jolla, CA (United States); George, J.S.; Schlitt, H.A.; Lewis, P.S. [Los Alamos National Lab., NM (United States)
1992-09-01T23:59:59.000Z
The goal of neuromagnetic source reconstruction is high resolution 3-D mapping of the current distribution within the brain. However, the neuromagnetic inverse problem is ill-posed and typically underdetermined. The Moore-Penrose pseudoinverse provides a linear algebraic inverse calculation that simultaneously minimizes chisquare and the Euclidean norm of the component currents. Such ``minimum norm`` reconstructions tend to produce diffuse and superficial current distributions because voxels nearer the sensor array can account for more power in the data with less current than deeper voxels. We describe an algorithm that overcomes the bias of minimum norm procedures toward superficial solutions by using weights chosen to compensate for the distance dependence of magnetic signal strength. We also apply a Bayesian weighting strategy in an iterative pseudoinverse computation, to address the bias of the linear estimator procedure toward diffuse solutions. This strategy produces a progressively more focal current distribution while accomodating distributed current sources, and appears to effectively reduce the problems associated with the under-determined linear system.
Fact #638: August 30, 2010 Average Expenditure for a New Car...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
8: August 30, 2010 Average Expenditure for a New Car Declines in Relation to Family Earnings Fact 638: August 30, 2010 Average Expenditure for a New Car Declines in Relation to...
Moho topography beneath the Corinth Rift area (Greece) from inversion of gravity data
Demouchy, Sylvie
Moho topography beneath the Corinth Rift area (Greece) from inversion of gravity data C. Tiberi,1 to Miocene lithospheric instabilities. Key words: boudinage, continental rifts, gravity inversion, Greece
Gravity Control by means of Electromagnetic Field through Gas or Plasma at Ultra-Low Pressure
Fran De Aquino
2013-12-02T23:59:59.000Z
It is shown that the gravity acceleration just above a chamber filled with gas or plasma at ultra-low pressure can be strongly reduced by applying an Extra Low-Frequency (ELF) electromagnetic field across the gas or the plasma. This Gravitational Shielding Effect is related to recent discovery of quantum correlation between gravitational mass and inertial mass. According to the theory samples hung above the gas or the plasma should exhibit a weight decrease when the frequency of the electromagnetic field is decreased or when the intensity of the electromagnetic field is increased. This Gravitational Shielding Effect is unprecedented in the literature and can not be understood in the framework of the General Relativity. From the technical point of view, there are several applications for this discovery; possibly it will change the paradigms of energy generation, transportation and telecommunications.
GOALS, EXPECTATIONS, AND SATISFACTION IN THE MAINTENANCE OF WEIGHT LOSS
Chang, Olivia L.
2009-08-19T23:59:59.000Z
......................................................................25 Satisfaction and Weight Loss 37 Measurement of Goals, Expectations, and Satisfaction with Weight Loss...............41 Goals, Expectations, and Satisfaction in the Treatment of Obesity 43 Limitations of Previous Research... of approximately 15-25% of initial weight in 2 to 4 months of treatment, but may also result in substantially greater weight regain than more conventional, calorie-restrictive diets (Wadden & Osei, 2002). Pharmacological interventions have been presented...
S86 JUNE 2006| above-average precipitation totals for the year, caus-
in Croatia and Bosnia-Herzegovina, but below average for June in Bulgaria. Rainfall totals in April and June
Gravity waves excited by jets: Propagation versus generation R. Plougonven
Plougonven, Riwal
Gravity waves excited by jets: Propagation versus generation R. Plougonven School of Mathematics imposed by the generation mechanism. In proceeding so, effects due to the propagation of the waves through simulations demonstrate that the propagation of inertia-gravity waves through horizontal deformation
Gravity Field and Internal Structure of Mercury from MESSENGER
Zuber, Maria
,5 Mark E. Perry,11 David D. Rowlands,5 Sander Goossens,12 James W. Head,13 Anthony H. Taylor14 RadioGravity Field and Internal Structure of Mercury from MESSENGER David E. Smith,1 Maria T. Zuber,1 tracking of the MESSENGER spacecraft has provided a model of Mercury's gravity field. In the northern
Wavelet based inversion of gravity data Fabio Boschetti
Boschetti, Fabio
1 Wavelet based inversion of gravity data Fabio Boschetti CSIRO Exploration & Mining and Australian Running Heading: Wavelet based inversion of gravity data #12;2 ABSTRACT The Green's function of the Poisson equation, and its spatial derivatives, lead to a family of wavelets specifically tailored
Cosmological evolutions of $F(R)$ nonlinear massive gravity
De-Jun Wu
2014-03-24T23:59:59.000Z
Recently a new extended nonlinear massive gravity model has been proposed which includes the $F(R)$ modifications to dRGT model.We follow the $F(R)$ nonlinear massive gravity and study its implications on cosmological evolutions. We derive the critical points of the cosmic system and study the corresponding kinetics by performing the phase-plane analysis.
Mapping crustal thickness using marine gravity data: Methods and uncertainties
Müller, Dietmar
of petroleum systems within passive margins. However, direct measurements of crustal thickness are sparse geophysical data, to estimate crustal thickness. We evaluated alternative gravity inversion methodol- ogies, but economic considerations make gravity modeling a more practical approach for mapping crustal thickness over
On coupling NEC-violating matter to gravity
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Chatterjee, Saugata; Parikh, Maulik; van der Schaar, Jan Pieter
2015-05-01T23:59:59.000Z
We show that effective theories of matter that classically violate the null energy condition cannot be minimally coupled to Einstein gravity without being inconsistent with both string theory and black hole thermodynamics. We argue however that they could still be either non-minimally coupled or coupled to higher-curvature theories of gravity.
Constrained Clustering with Minkowski Weighted Renato Cordeiro de Amorim
Amorim, Renato Cordeiro de
Constrained Clustering with Minkowski Weighted K-Means Renato Cordeiro de Amorim Department: renato@dcs.bbk.ac.uk Abstract--In this paper we introduce the Constrained Minkowski Weighted K-Means ratify the general superiority of using feature weighting in K-Means, particularly when applying
The Complexity of Weighted Boolean #CSP , Sangxia Huang2
Paris-Sud XI, Université de
The Complexity of Weighted Boolean #CSP Modulo k Heng Guo1 , Sangxia Huang2 , Pinyan Lu3@gmail.com Abstract We prove a complexity dichotomy theorem for counting weighted Boolean CSP modulo k for any similar to the one for the complex weighted Boolean #CSP, found by [Cai, Lu and Xia, STOC 2009]. Then we
-- Auto Tuning; Measurement Weights; Power System State Estimation; Random Error Variances. I is not always true. M is used for estimating measurement e1 Abstract--This paper describes an approach for choosing and updating measurement weights used
Dipole gravity waves from unbound quadrupoles
Felber, Franklin
2010-01-01T23:59:59.000Z
Dipole gravitational disturbances from gravitationally unbound mass quadrupoles propagate to the radiation zone with signal strength at least of quadrupole order if the quadrupoles are nonrelativistic, and of dipole order if relativistic. Angular distributions of parallel-polarized and transverse-polarized dipole power in the radiation zone are calculated for simple unbound quadrupoles, like a linear-oscillator/stress-wave pair and a particle storage ring. Laboratory tests of general relativity through measurements of dipole gravity waves in the source region are proposed. A NASA G2 flywheel module with a modified rotor can produce a post-Newtonian dc bias signal at a gradiometer up to 1 mE. At peak luminosity, the repulsive dipole impulses of proton bunches at the LHC can produce an rms velocity of a high-Q detector surface up to 4 micron/s. Far outside the source region, Newtonian lunar dipole gravity waves can produce a 1-cm displacement signal at LISA. Dipole signal strengths of astrophysical events invol...
Dipole gravity waves from unbound quadrupoles
Franklin Felber
2010-06-10T23:59:59.000Z
Dipole gravitational disturbances from gravitationally unbound mass quadrupoles propagate to the radiation zone with signal strength at least of quadrupole order if the quadrupoles are nonrelativistic, and of dipole order if relativistic. Angular distributions of parallel-polarized and transverse-polarized dipole power in the radiation zone are calculated for simple unbound quadrupoles, like a linear-oscillator/stress-wave pair and a particle storage ring. Laboratory tests of general relativity through measurements of dipole gravity waves in the source region are proposed. A NASA G2 flywheel module with a modified rotor can produce a post-Newtonian dc bias signal at a gradiometer up to 1 mE. At peak luminosity, the repulsive dipole impulses of proton bunches at the LHC can produce an rms velocity of a high-Q detector surface up to 4 micron/s. Far outside the source region, Newtonian lunar dipole gravity waves can produce a 1-cm displacement signal at LISA. Dipole signal strengths of astrophysical events involving unbound quadrupoles, like near collisions and neutron star kicks in core-collapse supernovae, are estimated.
A dynamical inconsistency of Horava gravity
Henneaux, Marc [Universite Libre de Bruxelles and International Solvay Institutes, ULB-Campus Plaine CP231, 1050 Brussels (Belgium); Centro de Estudios Cientificos (CECS), Casilla 1469, Valdivia (Chile); Kleinschmidt, Axel; Lucena Gomez, Gustavo [Universite Libre de Bruxelles and International Solvay Institutes, ULB-Campus Plaine CP231, 1050 Brussels (Belgium)
2010-03-15T23:59:59.000Z
The dynamical consistency of the nonprojectable version of Horava gravity is investigated by focusing on the asymptotically flat case. It is argued that for generic solutions of the constraint equations the lapse must vanish asymptotically. We then consider particular values of the coupling constants for which the equations are tractable and in that case we prove that the lapse must vanish everywhere--and not only at infinity. Put differently, the Hamiltonian constraints are generically all second-class. We then argue that the same feature holds for generic values of the couplings, thus revealing a physical inconsistency of the theory. In order to cure this pathology, one might want to introduce further constraints but the resulting theory would then lose much of the appeal of the original proposal by Horava. We also show that there is no contradiction with the time-reparametrization invariance of the action, as this invariance is shown to be a so-called 'trivial gauge symmetry' in Horava gravity, hence with no associated first-class constraints.
Spherically symmetric conformal gravity and "gravitational bubbles"
V. A. Berezin; V. I. Dokuchaev; Yu. N. Eroshenko
2014-12-09T23:59:59.000Z
The general structure of the spherically symmetric solutions in the Weyl conformal gravity is described. The corresponding Bach equation are derived for the special type of metrics, which can be considered as the representative of the general class. The complete set of the pure vacuum solutions is found. It consists of two classes. The first one contains the solutions with constant two-dimensional curvature scalar of our specific metrics, and the representatives are the famous Robertson-Walker metrics. One of them we called the "gravitational bubbles", which is compact and with zero Weyl tensor. The second class is more general, with varying curvature scalar. We found its representative as the one-parameter family. It appears that it can be conformally covered by the thee-parameter Mannheim-Kazanas solution. We also investigated the general structure of the energy-momentum tensor in the spherical conformal gravity and constructed the vectorial equation that reveals clearly the same features of non-vacuum solutions. One of them, the metrics a la Vaidya, is explicitly written.
Vacuum energy: quantum hydrodynamics vs quantum gravity
G. E. Volovik
2005-09-09T23:59:59.000Z
We compare quantum hydrodynamics and quantum gravity. They share many common features. In particular, both have quadratic divergences, and both lead to the problem of the vacuum energy, which in the quantum gravity transforms to the cosmological constant problem. We show that in quantum liquids the vacuum energy density is not determined by the quantum zero-point energy of the phonon modes. The energy density of the vacuum is much smaller and is determined by the classical macroscopic parameters of the liquid including the radius of the liquid droplet. In the same manner the cosmological constant is not determined by the zero-point energy of quantum fields. It is much smaller and is determined by the classical macroscopic parameters of the Universe dynamics: the Hubble radius, the Newton constant and the energy density of matter. The same may hold for the Higgs mass problem: the quadratically divergent quantum correction to the Higgs potential mass term is also cancelled by the microscopic (trans-Planckian) degrees of freedom due to thermodynamic stability of the whole quantum vacuum.
Bigravity and Lorentz-violating massive gravity
Blas, D.; Garriga, J. [ICC, Departament de Fisica Fonamental, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Deffayet, C. [APC, Batiment Condorcet, 10 rue Alice Domont et Leonie Duquet, 75205 Paris Cedex 13 (France); GReCO/IAP, 98 bis Boulevard Arago, 75014 Paris (France)
2007-11-15T23:59:59.000Z
Bigravity is a natural arena where a nonlinear theory of massive gravity can be formulated. If the interaction between the metrics f and g is nonderivative, spherically symmetric exact solutions can be found. At large distances from the origin, these are generically Lorentz-breaking bi-flat solutions (provided that the corresponding vacuum energies are adjusted appropriately). The spectrum of linearized perturbations around such backgrounds contains a massless as well as a massive graviton, with two physical polarizations each. There are no propagating vectors or scalars, and the theory is ghost free (as happens with certain massive gravities with explicit breaking of Lorentz invariance). At the linearized level, corrections to general relativity are proportional to the square of the graviton mass, and so there is no van Dam-Veltam-Zakharov discontinuity. Surprisingly, the solution of linear theory for a static spherically symmetric source does not agree with the linearization of any of the known exact solutions. The latter coincide with the standard Schwarzschild-(anti)-de Sitter solutions of general relativity, with no corrections at all. Another interesting class of solutions is obtained where f and g are proportional to each other. The case of bi-de Sitter solutions is analyzed in some detail.
Canonical Quantum Gravity on Noncommutative Spacetime
Martin Kober
2014-09-04T23:59:59.000Z
In this paper canonical quantum gravity on noncommutative space-time is considered. The corresponding generalized classical theory is formulated by using the moyal star product, which enables the representation of the field quantities depending on noncommuting coordinates by generalized quantities depending on usual coordinates. But not only the classical theory has to be generalized in analogy to other field theories. Besides, the necessity arises to replace the commutator between the gravitational field operator and its canonical conjugated quantity by a corresponding generalized expression on noncommutative space-time. Accordingly the transition to the quantum theory has also to be performed in a generalized way and leads to extended representations of the quantum theoretical operators. If the generalized representations of the operators are inserted to the generalized constraints, one obtains the corresponding generalized quantum constraints including the Hamiltonian constraint as dynamical constraint. After considering quantum geometrodynamics under incorporation of a coupling to matter fields, the theory is transferred to the Ashtekar formalism. The holonomy representation of the gravitational field as it is used in loop quantum gravity opens the possibility to calculate the corresponding generalized area operator.
Volume-weighted measure for eternal inflation
Winitzki, Sergei [Department of Physics, Ludwig-Maximilians University, Munich (Germany) and Yukawa Institute of Theoretical Physics, Kyoto University, Kyoto (Japan)
2008-08-15T23:59:59.000Z
I propose a new volume-weighted probability measure for cosmological 'multiverse' scenarios involving eternal inflation. The 'reheating-volume (RV) cutoff' calculates the distribution of observable quantities on a portion of the reheating hypersurface that is conditioned to be finite. The RV measure is gauge-invariant, does not suffer from the 'youngness paradox', and is independent of initial conditions at the beginning of inflation. In slow-roll inflationary models with a scalar inflaton, the RV-regulated probability distributions can be obtained by solving nonlinear diffusion equations. I discuss possible applications of the new measure to 'landscape' scenarios with bubble nucleation. As an illustration, I compute the predictions of the RV measure in a simple toy landscape.
Li-E Qiang; Peng Xu
2015-02-16T23:59:59.000Z
High precision Superconductivity Gravity Gradiometers (SGG) are powerful tools for relativistic experiments. In this paper, we work out the tidal signals in non-dynamical Chern-Simons modified gravity, which could be measured by orbiting SGGs around Earth. We find that, with proper orientations of multi-axes SGGs, the tidal signals from the Chern-Simons modification can be isolated in the combined data of different axes. Furthermore, for three-axes SGGs, such combined data is the trace of the total tidal matrix, which is invariant under the rotations of SGG axes and thus free from axis pointing errors. Following nearly circular orbits, the tests of the parity-violating Chern-Simons modification and the measurements of the gravitomagnetic sector in parity-conserving metric theories can be carried out independently in the same time. A first step analysis on noise sources is also included.
Qiang, Li-E
2015-01-01T23:59:59.000Z
High precision Superconductivity Gravity Gradiometers (SGG) are powerful tools for relativistic experiments. In this paper, we work out the tidal signals in non-dynamical Chern-Simons modified gravity, which could be measured by orbiting SGGs around Earth. We find that, with proper orientations of multi-axes SGGs, the tidal signals from the Chern-Simons modification can be isolated in the combined data of different axes. Furthermore, for three-axes SGGs, such combined data is the trace of the total tidal matrix, which is invariant under the rotations of SGG axes and thus free from axis pointing errors. Following nearly circular orbits, the tests of the parity-violating Chern-Simons modification and the measurements of the gravitomagnetic sector in parity-conserving metric theories can be carried out independently in the same time. A first step analysis on noise sources is also included.
Aharon Davidson; Tomer Ygael
2014-10-22T23:59:59.000Z
A gravity-anti-gravity (GaG) odd linear dilaton action offers an eternal inflation evolution governed by the unified (cosmological constant plus radiation) equation of state $\\rho-3P=4\\Lambda$. At the mini superspace level, a 'two-particle' variant of the no-boundary proposal, notably 'one-particle' energy dependent, is encountered. While a GaG-odd wave function can only host a weak Big Bang boundary condition, albeit for any $k$, a strong Big Bang boundary condition requires a GaG-even entangled wave function, and singles out $k=0$ flat space. The locally most probable values for the cosmological scale factor and the dilaton field form a grid $\\{a^2,a\\phi\\}\\sim\\sqrt{4n_1+1}\\pm\\sqrt{4n_2+1}$.
E. M. Sessolo; D. W. McKay
2008-11-18T23:59:59.000Z
We calculate low scale gravity effects on the cross section for neutrino-nucleon scattering at center of mass energies up to the Greisen-Zatsepin-Kuzmin (GZK) scale, in the eikonal approximation. We compare the cases of an infinitely thin brane embedded in n=5 compactified extra-dimensions, and of a brane with a physical tension M_{S}=1 TeV and M_{S}=10 TeV. The extra dimensional Planck scale M_{D} is set at 10^{3} GeV and 2\\times10^{3} GeV. We also compare our calculations with neutral current standard model calculations in the same energy range, and compare the thin brane eikonal cross section to its saddle point approximation. New physics effects enhance the cross section by orders of magnitude on average. They are quite sensitive to M_{S} and M_{D} choices, though much less sensitive to n.
Solar system tests of Ho?ava-Lifshitz gravity
Tiberiu Harko; Zoltan Kovács; Francisco S. N. Lobo
2010-10-28T23:59:59.000Z
Recently, a renormalizable gravity theory with higher spatial derivatives in four dimensions was proposed by Ho\\v{r}ava. The theory reduces to Einstein gravity with a non-vanishing cosmological constant in IR, but it has improved UV behaviors. The spherically symmetric black hole solutions for an arbitrary cosmological constant, which represent the generalization of the standard Schwarzschild-(A)dS solution, has also been obtained for the Ho\\v{r}ava-Lifshitz theory. The exact asymptotically flat Schwarzschild type solution of the gravitational field equations in Ho\\v{r}ava gravity contains a quadratic increasing term, as well as the square root of a fourth order polynomial in the radial coordinate, and it depends on one arbitrary integration constant. The IR modified Ho\\v{r}ava gravity seems to be consistent with the current observational data, but in order to test its viability more observational constraints are necessary. In the present paper we consider the possibility of observationally testing Ho\\v{r}ava gravity at the scale of the Solar System, by considering the classical tests of general relativity (perihelion precession of the planet Mercury, deflection of light by the Sun and the radar echo delay) for the spherically symmetric black hole solution of Ho\\v{r}ava-Lifshitz gravity. All these gravitational effects can be fully explained in the framework of the vacuum solution of the gravity. Moreover, the study of the classical general relativistic tests also constrain the free parameter of the solution.
Goedel-type universes in f(R) gravity
Reboucas, M. J. [Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro-RJ (Brazil); Santos, J. [Universidade Federal do Rio G. do Norte, Departamento de Fisica, 59072-970 Natal-RN (Brazil)
2009-09-15T23:59:59.000Z
The f(R) gravity theories provide an alternative way to explain the current cosmic acceleration without a dark energy matter component. If gravity is governed by a f(R) theory, a number of issues should be reexamined in this framework, including the violation of causality problem on nonlocal scale. We examine the question as to whether the f(R) gravity theories permit space-times in which the causality is violated. We show that the field equations of these f(R) gravity theories do not exclude solutions with breakdown of causality for a physically well-motivated perfect-fluid matter content. We demonstrate that every perfect-fluid Goedel-type solution of a generic f(R) gravity satisfying the condition df/dR>0 is necessarily isometric to the Goedel geometry, and therefore presents violation of causality. This result extends a theorem on Goedel-type models, which has been established in the context of general relativity. We also derive an expression for the critical radius r{sub c} (beyond which the causality is violated) for an arbitrary f(R) theory, making apparent that the violation of causality depends on both the f(R) gravity theory and the matter content. As an illustration, we concretely take a recent f(R) gravity theory that is free from singularities of the Ricci scalar and is cosmologically viable, and show that this theory accommodates noncausal as well as causal Goedel-type solutions.
On the condensed matter scheme for emergent gravity and interferometry
G. Jannes
2008-11-10T23:59:59.000Z
An increasingly popular approach to quantum gravity rests on the idea that gravity (and maybe electromagnetism and the other gauge fields) might be an 'emergent phenomenon', in the sense of representing a collective behaviour resulting from a very different microscopic physics. A prominent example of this approach is the condensed matter scheme for quantum gravity, which considers the possibility that gravity emerges as an effective low-energy phenomenon from the quantum vacuum in a way similar to the emergence of collective excitations in condensed matter systems. This condensed matter view of the quantum vacuum clearly hints that, while the term 'ether' has been discredited for about a century, quantum gravity holds many (if not all) of the characteristics that have led people in the past to label various hypothetical substances with the term 'ether'. Since the last burst of enthusiasm for an ether, at the end of the 19th century, was brought to the grave in part by the performance of a series of important experiments in interferometry, the suggestion then naturally arises that maybe interferometry could also play a role in the current discussion on quantum gravity. We will highlight some aspects of this suggestion in the context of the condensed matter scheme for emergent gravity.
Couch, Sean M.; Graziani, Carlo; Flocke, Norbert, E-mail: smc@flash.uchicago.edu [Flash Center for Computational Science, Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)
2013-12-01T23:59:59.000Z
Self-gravity computation by multipole expansion is a common approach in problems such as core-collapse and Type Ia supernovae, where single large condensations of mass must be treated. The standard formulation of multipole self-gravity in arbitrary coordinate systems suffers from two significant sources of error, which we correct in the formulation presented in this article. The first source of error is due to the numerical approximation that effectively places grid cell mass at the central point of the cell, then computes the gravitational potential at that point, resulting in a convergence failure of the multipole expansion. We describe a new scheme that avoids this problem by computing gravitational potential at cell faces. The second source of error is due to sub-optimal choice of location for the expansion center, which results in angular power at high multipole l values in the gravitational field, requiring a high—and expensive—value of multipole cutoff l {sub max}. By introducing a global measure of angular power in the gravitational field, we show that the optimal coordinate for the expansion is the square-density-weighted mean location. We subject our new multipole self-gravity algorithm, implemented in the FLASH simulation framework, to two rigorous test problems: MacLaurin spheroids for which exact analytic solutions are known, and core-collapse supernovae. We show that key observables of the core-collapse simulations, particularly shock expansion, proto-neutron star motion, and momentum conservation, are extremely sensitive to the accuracy of the multipole gravity, and the accuracy of their computation is greatly improved by our reformulated solver.
Black Hole Thermodynamics in Modified Gravity
Jonas R. Mureika; John W. Moffat; Mir Faizal
2015-03-03T23:59:59.000Z
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.
Quantum Mechanics, Gravity, and the Multiverse
Yasunori Nomura
2012-07-30T23:59:59.000Z
The discovery of accelerating expansion of the universe has led us to take the dramatic view that our universe may be one of the many universes in which low energy physical laws take different forms: the multiverse. I explain why/how this view is supported both observationally and theoretically, especially by string theory and eternal inflation. I then describe how quantum mechanics plays a crucial role in understanding the multiverse, even at the largest distance scales. The resulting picture leads to a revolutionary change of our view of spacetime and gravity, and completely unifies the paradigm of the eternally inflating multiverse with the many worlds interpretation of quantum mechanics. The picture also provides a solution to a long-standing problem in eternal inflation, called the measure problem, which I briefly describe.
Kinetic Gravity Braiding and axion inflation
Debaprasad Maity
2013-03-11T23:59:59.000Z
We constructed a new class of inflationary model with the higher derivative axion field which obeys constant shift symmetry. In the usual axion (natural) inflation, the axion decay constant is predicted to be in the super-Planckian regime which is believed to be incompatible with an effective field theory framework. With a novel mechanism originating from a higher derivative kinetic gravity braiding (KGB) of an axion field we found that there exist a huge parameter regime in our model where axion decay constant could be naturally sub-Planckian. Thanks to the KGB which effectively reduces the Planck constant. This effectively reduced Planck scale provides us the mechanism of further lowering down the speed of an axion field rolling down its potential without introducing super-Planckian axion decay constant. We also find that with that wide range of parameter values, our model induces almost scale invariant power spectrum as observed in CMB experiments.
A length operator for canonical quantum gravity
T. Thiemann
1996-06-29T23:59:59.000Z
We construct an operator that measures the length of a curve in four-dimensional Lorentzian vacuum quantum gravity. We work in a representation in which a $SU(2)$ connection is diagonal and it is therefore surprising that the operator obtained after regularization is densely defined, does not suffer from factor ordering singularities and does not require any renormalization. We show that the length operator admits self-adjoint extensions and compute part of its spectrum which like its companions, the volume and area operators already constructed in the literature, is purely discrete and roughly is quantized in units of the Planck length. The length operator contains full and direct information about all the components of the metric tensor which faciliates the construction of a new type of weave states which approximate a given classical 3-geometry.
Bi-metric Gravity and "Dark Matter"
I. T. Drummond
2000-08-18T23:59:59.000Z
We present a bi-metric theory of gravity containing a length scale of galactic size. For distances less than this scale the theory satisfies the standard tests of General Relativity. For distances greater than this scale the theory yields an effective gravitational constant much larger than the locally observed value of Newton's constant. The transition from one regime to the other through the galactic scale can explain the observed rotation curves of galaxies and hence the effects normally attributed to the presence of dark matter. Phenomena on an extragalactic scale such as galactic clusters and the expansion of the universe are controlled by the enhanced gravitational coupling. This provides an explanation of the missing matter normally invoked to account for the observed value of Hubble's constant in relation to observed matter.
QCD thermodynamics using five-dimensional gravity
Megias, E.; Veschgini, K. [Institute for Theoretical Physics, University of Heidelberg (Germany); Pirner, H. J. [Institute for Theoretical Physics, University of Heidelberg (Germany); Max Planck Institute for Nuclear Physics, Heidelberg (Germany)
2011-03-01T23:59:59.000Z
We calculate the critical temperature and free energy of the gluon plasma using the dilaton potential [B. Galow, E. Megias, J. Nian, and H. J. Pirner, Nucl. Phys. B834, 330 (2010).] in the gravity theory of anti-de Sitter/QCD. The finite temperature observables are calculated in two ways: first, from the Page-Hawking computation of the free energy, and secondly using the Bekenstein-Hawking proportionality of the entropy with the area of the horizon. Renormalization is well defined, because the T=0 theory has asymptotic freedom. We further investigate the change of the critical temperature with the number of flavors induced by the change of the running coupling constant in the quenched theory. The finite temperature behavior of the speed of sound, spatial string tension and vacuum expectation value of the Polyakov loop follow from the corresponding string theory in AdS{sub 5}.
Bergshoeff, Eric A.; Hohm, Olaf [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Townsend, Paul K. [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)
2009-06-15T23:59:59.000Z
We explore the space of static solutions of the recently discovered three-dimensional 'new massive gravity' (NMG), allowing for either sign of the Einstein-Hilbert term and a cosmological term parametrized by a dimensionless constant {lambda}. For {lambda}=-1 we find black hole solutions asymptotic (but not isometric) to the unique (anti) de Sitter [(A)dS] vacuum, including extremal black holes that interpolate between this vacuum and (A)dS{sub 2}xS{sup 1}. We also investigate unitarity of linearized NMG in (A)dS vacua. We find unitary theories for some dS vacua, but (bulk) unitarity in AdS implies negative central charge of the dual conformal field theories (CFT), except for {lambda}=3 where the central charge vanishes and the bulk gravitons are replaced by 'massive photons'. A similar phenomenon is found in the massless limit of NMG, for which the linearized equations become equivalent to Maxwell's equations.
Gravity dual of metastable dynamical supersymmetry breaking
DeWolfe, Oliver [Department of Physics, 390 UCB, University of Colorado, Boulder, Colorado 80309 (United States); Kachru, Shamit; Mulligan, Michael [Department of Physics and SLAC, Stanford University, Stanford, California 94305/94309 (United States)
2008-03-15T23:59:59.000Z
Metastable, supersymmetry-breaking configurations can be created in flux geometries by placing antibranes in warped throats. Via gauge/gravity duality, such configurations should have an interpretation as supersymmetry-breaking states in the dual field theory. In this paper, we perturbatively determine the asymptotic supergravity solutions corresponding to D3-brane probes placed at the tip of the cascading warped deformed conifold geometry, which is dual to an SU(N+M)xSU(N) gauge theory. The backreaction of the antibranes has the effect of introducing imaginary anti-self-dual flux, squashing the compact part of the space and forcing the dilaton to run. Using the generalization of holographic renormalization to cascading geometries, we determine the expectation values of operators in the dual field theory in terms of the asymptotic values of the supergravity fields.
Brane f(R) gravity cosmologies
Balcerzak, Adam; DaPbrowski, Mariusz P. [Institute of Physics, University of Szczecin, Wielkopolska 15, 70-451 Szczecin (Poland)
2010-06-15T23:59:59.000Z
By the application of the generalized Israel junction conditions we derive cosmological equations for the fourth-order f(R) brane gravity and study their cosmological solutions. We show that there exists a nonstatic solution which describes a four-dimensional de Sitter (dS{sub 4}) brane embedded in a five-dimensional anti-de Sitter (AdS{sub 5}) bulk for a vanishing Weyl tensor contribution. On the other hand, for the case of a nonvanishing Weyl tensor contribution, there exists a static brane solution only. We claim that in order to get some more general nonstatic f(R) brane configurations, one needs to admit a dynamical matter energy-momentum tensor in the bulk rather than just a bulk cosmological constant.
Bending of light in conformal Weyl gravity
Sultana, Joseph; Kazanas, Demosthenes [Astrophysics Science Division, NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States) and Department of Mathematics, University of Malta, Msida (Malta); Astrophysics Science Division, NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)
2010-06-15T23:59:59.000Z
We reexamine the bending of light issue associated with the metric of the static, spherically symmetric solution of Weyl gravity discovered by Mannheim and Kazanas (1989). To this end we employ the procedure used recently by Rindler and Ishak to obtain the bending angle of light by a centrally concentrated spherically symmetric matter distribution in a Schwarzschild-de Sitter background. In earlier studies the term {gamma}r in the metric led to the paradoxical result of a bending angle proportional to the photon impact parameter, when using the usual formalism appropriate to asymptotically flat space-times. However, employing the approach of light bending of Rindler and Ishak we show that the effects of this term are in fact insignificant, with the discrepancy between the two procedures attributed to the definition of the bending angle between the asymptotically flat and nonflat spaces.
The dynamics of metric-affine gravity
Vitagliano, Vincenzo, E-mail: vitaglia@sissa.it [SISSA-International School for Advanced Studies, Via Bonomea 265, 34136 Trieste (Italy); INFN, Sez. di Trieste, Via Valerio 2, 34127 Trieste (Italy); Sotiriou, Thomas P., E-mail: T.Sotiriou@damtp.cam.ac.uk [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom); Liberati, Stefano, E-mail: liberati@sissa.it [SISSA-International School for Advanced Studies, Via Bonomea 265, 34136 Trieste (Italy); INFN, Sez. di Trieste, Via Valerio 2, 34127 Trieste (Italy)
2011-05-15T23:59:59.000Z
Highlights: > The role and the dynamics of the connection in metric-affine theories is explored. > The most general second order action does not lead to a dynamical connection. > Including higher order invariants excites new degrees of freedom in the connection. > f(R) actions are also discussed and shown to be a non- representative class. - Abstract: Metric-affine theories of gravity provide an interesting alternative to general relativity: in such an approach, the metric and the affine (not necessarily symmetric) connection are independent quantities. Furthermore, the action should include covariant derivatives of the matter fields, with the covariant derivative naturally defined using the independent connection. As a result, in metric-affine theories a direct coupling involving matter and connection is also present. The role and the dynamics of the connection in such theories is explored. We employ power counting in order to construct the action and search for the minimal requirements it should satisfy for the connection to be dynamical. We find that for the most general action containing lower order invariants of the curvature and the torsion the independent connection does not carry any dynamics. It actually reduces to the role of an auxiliary field and can be completely eliminated algebraically in favour of the metric and the matter field, introducing extra interactions with respect to general relativity. However, we also show that including higher order terms in the action radically changes this picture and excites new degrees of freedom in the connection, making it (or parts of it) dynamical. Constructing actions that constitute exceptions to this rule requires significant fine tuned and/or extra a priori constraints on the connection. We also consider f(R) actions as a particular example in order to show that they constitute a distinct class of metric-affine theories with special properties, and as such they cannot be used as representative toy theories to study the properties of metric-affine gravity.
Simulations of Solar System observations in alternative theories of gravity
A. Hees; B. Lamine; S. Reynaud; M. -T. Jaekel; C. Le Poncin-Lafitte; V. Lainey; A. Füzfa; J. -M. Courty; V. Dehant; P. Wolf
2013-02-27T23:59:59.000Z
In this communication, we focus on the possibility to test General Relativity (GR) with radioscience experiments. We present simulations of observables performed in alternative theories of gravity using a software that simulates Range/Doppler signals directly from the space time metric. This software allows one to get the order of magnitude and the signature of the modifications induced by an alternative theory of gravity on radioscience signals. As examples, we present some simulations for the Cassini mission in Post-Einsteinian gravity (PEG) and with Standard Model Extension (SME).
Particles on a Circle in Canonical Lineal Gravity
R. B. Mann
2001-05-02T23:59:59.000Z
A description of the canonical formulation of lineal gravity minimally coupled to N point particles in a circular topology is given. The Hamiltonian is found to be equal to the time-rate of change of the extrinsic curvature multiplied by the proper circumference of the circle. Exact solutions for pure gravity and for gravity coupled to a single particle are obtained. The presence of a single particle significantly modifies the spacetime evolution by either slowing down or reversing the cosmological expansion of the circle, depending upon the choice of parameters.
Emergent noncommutative gravity from a consistent deformation of gauge theory
Cortese, Ignacio; Garcia, J Antonio [Departamento de Fisica de Altas Energias, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico D. F. 04510 (Mexico)
2010-05-15T23:59:59.000Z
Starting from a standard noncommutative gauge theory and using the Seiberg-Witten map, we propose a new version of a noncommutative gravity. We use consistent deformation theory starting from a free gauge action and gauging a killing symmetry of the background metric to construct a deformation of the gauge theory that we can relate with gravity. The result of this consistent deformation of the gauge theory is nonpolynomial in A{sub {mu}.} From here we can construct a version of noncommutative gravity that is simpler than previous attempts. Our proposal is consistent and is not plagued with the problems of other approaches like twist symmetries or gauging other groups.
Fitton, I. [European Georges Pompidou Hospital, Department of Radiology, 20 rue Leblanc, 75015, Paris (France); Cornelissen, S. A. P. [Image Sciences Institute, UMC, Department of Radiology, P.O. Box 85500, 3508 GA Utrecht (Netherlands); Duppen, J. C.; Rasch, C. R. N.; Herk, M. van [The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Department of Radiotherapy, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands); Steenbakkers, R. J. H. M. [University Medical Center Groningen, Department of Radiation Oncology, Hanzeplein 1, 9713 GZ Groningen (Netherlands); Peeters, S. T. H. [UZ Gasthuisberg, Herestraat 49, 3000 Leuven, Belgique (Belgium); Hoebers, F. J. P. [Maastricht University Medical Center, Department of Radiation Oncology (MAASTRO clinic), GROW School for Oncology and Development Biology Maastricht, 6229 ET Maastricht (Netherlands); Kaanders, J. H. A. M. [UMC St-Radboud, Department of Radiotherapy, Geert Grooteplein 32, 6525 GA Nijmegen (Netherlands); Nowak, P. J. C. M. [ERASMUS University Medical Center, Department of Radiation Oncology,Groene Hilledijk 301, 3075 EA Rotterdam (Netherlands)
2011-08-15T23:59:59.000Z
Purpose: To develop a delineation tool that refines physician-drawn contours of the gross tumor volume (GTV) in nasopharynx cancer, using combined pixel value information from x-ray computed tomography (CT) and magnetic resonance imaging (MRI) during delineation. Methods: Operator-guided delineation assisted by a so-called ''snake'' algorithm was applied on weighted CT-MRI registered images. The physician delineates a rough tumor contour that is continuously adjusted by the snake algorithm using the underlying image characteristics. The algorithm was evaluated on five nasopharyngeal cancer patients. Different linear weightings CT and MRI were tested as input for the snake algorithm and compared according to contrast and tumor to noise ratio (TNR). The semi-automatic delineation was compared with manual contouring by seven experienced radiation oncologists. Results: A good compromise for TNR and contrast was obtained by weighing CT twice as strong as MRI. The new algorithm did not notably reduce interobserver variability, it did however, reduce the average delineation time by 6 min per case. Conclusions: The authors developed a user-driven tool for delineation and correction based a snake algorithm and registered weighted CT image and MRI. The algorithm adds morphological information from CT during the delineation on MRI and accelerates the delineation task.
Weighted power counting and chiral dimensional regularization
Damiano Anselmi
2014-06-27T23:59:59.000Z
We define a modified dimensional-regularization technique that overcomes several difficulties of the ordinary technique, and is specially designed to work efficiently in chiral and parity violating quantum field theories, in arbitrary dimensions greater than 2. When the dimension of spacetime is continued to complex values, spinors, vectors and tensors keep the components they have in the physical dimension, therefore the $\\gamma $ matrices are the standard ones. Propagators are regularized with the help of evanescent higher-derivative kinetic terms, which are of the Majorana type in the case of chiral fermions. If the new terms are organized in a clever way, weighted power counting provides an efficient control on the renormalization of the theory, and allows us to show that the resulting chiral dimensional regularization is consistent to all orders. The new technique considerably simplifies the proofs of properties that hold to all orders, and makes them suitable to be generalized to wider classes of models. Typical examples are the renormalizability of chiral gauge theories and the Adler-Bardeen theorem. The difficulty of explicit computations, on the other hand, may increase.
Weight Distribution of a Class of Binary Linear Block Codes Formed from RCPC Codes
Shen, Yushi Dr.; Cosman, Pamela C; Milstein, Laurence B
2006-01-01T23:59:59.000Z
On the weight distribution of terminated convolutionalViterbi, “On the weight distribution of linear block codes9, SEPTEMBER 2005 Weight Distribution of a Class of Binary
Weight and volume relationships in fluid dairy products
Wilson, Robert Ray
1962-01-01T23:59:59.000Z
regxession equations xelating pounds per gallon at given temperatures to the fat percentage and the specific gravity at 102o/'102oP determined with the Watson lactometer in 50 samples of xaw hexd milk . . . . . . . 50 vi LIST 0F TABLES (Cont. ) Table... relating specific gravity by the Babcock bottle method and pounds per gallon to the fat percentage, solids-not-fat percentage, and temperature (op) in 35 samples of fortified and non-fortified skim- milk ~ o ~ e a ~ ~ ~ a ~ o ~ o ~ ~ ~ ~ ~ ~ ~ 70...
Plan averaging for multicriteria navigation of sliding window IMRT and VMAT
Craft, David, E-mail: dcraft@partners.org; Papp, Dávid; Unkelbach, Jan [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States)] [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States)
2014-02-15T23:59:59.000Z
Purpose: To describe a method for combining sliding window plans [intensity modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT)] for use in treatment plan averaging, which is needed for Pareto surface navigation based multicriteria treatment planning. Methods: The authors show that by taking an appropriately defined average of leaf trajectories of sliding window plans, the authors obtain a sliding window plan whose fluence map is the exact average of the fluence maps corresponding to the initial plans. In the case of static-beam IMRT, this also implies that the dose distribution of the averaged plan is the exact dosimetric average of the initial plans. In VMAT delivery, the dose distribution of the averaged plan is a close approximation of the dosimetric average of the initial plans. Results: The authors demonstrate the method on three Pareto optimal VMAT plans created for a demanding paraspinal case, where the tumor surrounds the spinal cord. The results show that the leaf averaged plans yield dose distributions that approximate the dosimetric averages of the precomputed Pareto optimal plans well. Conclusions: The proposed method enables the navigation of deliverable Pareto optimal plans directly, i.e., interactive multicriteria exploration of deliverable sliding window IMRT and VMAT plans, eliminating the need for a sequencing step after navigation and hence the dose degradation that is caused by such a sequencing step.
High-average-power, diode-pumped solid state lasers for energy and industrial applications
Krupke, W.F.
1994-03-02T23:59:59.000Z
Progress at LLNL in the development high-average-power diode-pumped solid state lasers is summarized, including the development of enabling technologies.
E-Print Network 3.0 - area average temperature Sample Search...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
and Fisheries Sciences Collection: Environmental Sciences and Ecology 24 The Greenhouse Effect Temperature Equilibrium Summary: - it is neither heating nor cooling on average....
Hendi, Seyed Hossein; Panah, Behzad Eslam
2015-01-01T23:59:59.000Z
In this paper, we are considering two first order corrections to both gravity and gauge sides of the Einstein-Maxwell gravity: Gauss-Bonnet gravity and quadratic Maxwell invariant as corrections. We obtain horizonless magnetic solutions by implying a metric which representing a topological defect. We analyze the geometric properties of the solutions and investigate the effects of both corrections, and find that these solutions may be interpreted as the magnetic branes. We study the singularity condition and find a nonsingular spacetime with a conical geometry. We also investigate the effects of different parameters on deficit angle of spacetime near the origin.
2-D weighted least-squares phase unwrapping
Ghiglia, Dennis C. (Placitas, NM); Romero, Louis A. (Albuquerque, NM)
1995-01-01T23:59:59.000Z
Weighted values of interferometric signals are unwrapped by determining the least squares solution of phase unwrapping for unweighted values of the interferometric signals; and then determining the least squares solution of phase unwrapping for weighted values of the interferometric signals by preconditioned conjugate gradient methods using the unweighted solutions as preconditioning values. An output is provided that is representative of the least squares solution of phase unwrapping for weighted values of the interferometric signals.
affects body weight: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
weight perceptions may be influ- enced by food habits and food environments, nutritional knowledge, cultural norms and expectations and mass media Mikolajczyk, Rafael T; Maxwell,...
FORCE RECONSTRUCTION USING THE SUM OF WEIGHTED ACCELERATIONS
Office of Scientific and Technical Information (OSTI)
coordinates. This methodof determiningthe SWAT weights would Now recall the definition of the SWAT dof, equation be equivalentto inverting the mode-shape matrix to...
The evolution of miscible gravity currents in horizontal porous layers
Szulczewski, Michael Lawrence
Gravity currents of miscible fluids in porous media are important to understand because they occur in important engineering projects, such as enhanced oil recovery and geologic CO[subscript 2] sequestration. These flows ...
Dust-shell Universe in the modified gravity scenario
Michael Maziashvili
2005-04-15T23:59:59.000Z
The dynamics of the dust-shell model of universe is exactly solved for the modified Schwarzschild solution. This solution is used to derive the cosmology corresponding to the modified gravity.
Ground Gravity Survey At Neal Hot Springs Geothermal Area (U...
Hot Springs. Data from these surveys will be integrated with older data from Chevron Minerals 1979 drill hole. Notes The gravity survey covered an area of approximately 34 km2...
Horava-Lifshitz Gravity From Dynamical Newton-Cartan Geometry
Hartong, Jelle
2015-01-01T23:59:59.000Z
Recently it has been established that torsional Newton-Cartan (TNC) geometry is the appropriate geometrical framework to which non-relativistic field theories couple. We show that when these geometries are made dynamical they give rise to Horava-Lifshitz (HL) gravity. Projectable HL gravity corresponds to dynamical Newton-Cartan (NC) geometry without torsion and non-projectable HL gravity corresponds to dynamical NC geometry with twistless torsion (hypersurface orthogonal foliation). We build a precise dictionary relating all fields (including the scalar khronon), their transformations and other properties in both HL gravity and dynamical TNC geometry. We use TNC invariance to construct the effective action for dynamical twistless torsional Newton-Cartan geometries in 2+1 dimensions for dynamical exponent 1
Ground Gravity Survey At Mt Princeton Hot Springs Geothermal...
Notes Gravity low associated with Mt. Princeton Batholith; density contrast of -0.5 gcm3 of valley-fill sediments relative to batholith References J.E. Case, R.F. Sikora...
Ground Gravity Survey At Dixie Valley Geothermal Area (Iovenitti...
project area. These data were used in conjunction with past gravity data reported in by Smith et al (2001) and Blackwell et al (2005). The analysis of these data had not been...
Mixed convection and heat management in the Mars gravity biosatellite
Marsh, Jesse B. (Jesse Benjamin)
2007-01-01T23:59:59.000Z
The Mars Gravity Biosatellite will house fifteen mice in a low Earth orbit satellite spinning about its longitudinal axis. The satellite's payload thermal control system will reject heat through the base of the payload ...
Hyperbolic Equations for Vacuum Gravity Using Special Orthonormal Frames
Frank B. Estabrook; R. Steve Robinson; Hugo D. Wahlquist
2004-09-29T23:59:59.000Z
By adopting Nester's higher dimensional special orthonormal frames (HSOF) the tetrad equations for vacuum gravity are put into first order symmetric hyperbolic (FOSH) form with constant coefficients, independent of any time slicing or coordinate specialization.
Regional Gravity Survey of the Northern Great Salt Lake Desert...
Northern Great Salt Lake Desert and Adjacent Areas in Utah, Nevada, and Idaho Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Regional Gravity...
Quantized gauge-affine gravity in the superfiber bundle approach
Meziane, A.; Tahiri, M. [Laboratoire de Physique Theorique, Universite d'Oran Es-senia, 31100 Oran (Algeria)
2005-05-15T23:59:59.000Z
The quantization of gauge-affine gravity within the superfiber bundle formalism is proposed. By introducing an even pseudotensorial 1-superform over a principal superfiber bundle with superconnection, we obtain the geometrical Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST transformations of the fields occurring in such a theory. Reducing the four-dimensional general affine group double-covering GA(4,R) to the Poincare group double-covering ISO(1,3) we also find the BRST and anti-BRST transformations of the fields present in Einstein's gravity. Furthermore, we give a prescription leading to the construction of both BRST-invariant gauge-fixing action for gauge-affine gravity and Einstein's gravity.
Status of Matter-Gravity Couplings in the SME
Tasson, Jay D
2013-01-01T23:59:59.000Z
Constraints on Lorentz violation in matter-gravity couplings are summarized along with existing proposals to obtain sensitivities that exceed current limits by up to 11 orders of magnitude.
Status of Matter-Gravity Couplings in the SME
Jay D. Tasson
2013-08-06T23:59:59.000Z
Constraints on Lorentz violation in matter-gravity couplings are summarized along with existing proposals to obtain sensitivities that exceed current limits by up to 11 orders of magnitude.
axisymmetric viscous gravity: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
largely by the coefficient Wesley N. Colley; Linda S. Sparke 1995-12-19 4 Viscous Dark Energy in f(T) Gravity General Relativity & Quantum Cosmology (arXiv) Summary: We...
Constraining gravity using entanglement in AdS/CFT
Shamik Banerjee; Arpan Bhattacharyya; Apratim Kaviraj; Kallol Sen; Aninda Sinha
2014-07-09T23:59:59.000Z
We investigate constraints imposed by entanglement on gravity in the context of holography. First, by demanding that relative entropy is positive and using the Ryu-Takayanagi entropy functional, we find certain constraints at a nonlinear level for the dual gravity. Second, by considering Gauss-Bonnet gravity, we show that for a class of small perturbations around the vacuum state, the positivity of the two point function of the field theory stress tensor guarantees the positivity of the relative entropy. Further, if we impose that the entangling surface closes off smoothly in the bulk interior, we find restrictions on the coupling constant in Gauss-Bonnet gravity. We also give an example of an anisotropic excited state in an unstable phase with broken conformal invariance which leads to a negative relative entropy.
Application Of Gravity And Deep Dipole Geoelectrics In The Volcanic...
Of Mt Etna (Sicily) Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Application Of Gravity And Deep Dipole Geoelectrics In The Volcanic Area Of...
assisted gravity drainage: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Enhanced Oil Recovery through Steam Assisted Gravity Drainage January 22, 2014 Geosciences Websites Summary: are water,...
Absence of scalar hair in scalar-tensor gravity
Valerio Faraoni; Thomas P. Sotiriou
2013-03-04T23:59:59.000Z
Stationary, asymptotically flat black holes in scalar-tensor theories of gravity are studied. It is shown that such black holes have no scalar hair and are the same as in General Relativity.
Gravity Control Propulsion: Towards a General Relativistic Approach
O. Bertolami; F. G. Pedro
2006-10-16T23:59:59.000Z
Evaluation of gravity control concepts should be examined with respect to currently known physical theories. In this work we study the hypothetical conversion of gravitational potential energy into kinetic energy using the formalism of general relativity. We show that the energy involved in the process greatly exceeds the Newtonian estimate, given the nature of general relativity. We conclude that the impact of any gravity manipulation for propulsion greatly depends fundamentally on its exact definition.
A bird's eye view of f(R)-gravity
S. Capozziello; M. De Laurentis; V. Faraoni
2009-10-02T23:59:59.000Z
We survey the landscape of $f(R)$ theories of gravity in their various formulations, which have been used to model the cosmic acceleration as alternatives to dark energy and dark matter. Besides, we take into account the problem of gravitational waves in such theories. We discuss some successes of $f(R)$-gravity (where $f(R)$ is a generic function of Ricci scalar $R$), theoretical and experimental challenges that they face in order to satisfy minimal criteria for viability.
Einstein's other gravity and the acceleration of the Universe
Linder, Eric V. [Berkeley Lab and University of California, Berkeley, California 94720 (United States); Institute for the Early Universe, Ewha Womans University, Seoul 120-750 (Korea, Republic of)
2010-06-15T23:59:59.000Z
Spacetime curvature plays the primary role in general relativity but Einstein later considered a theory where torsion was the central quantity. Just as the Einstein-Hilbert action in the Ricci curvature scalar R can be generalized to f(R) gravity, we consider extensions of teleparallel, or torsion scalar T, gravity to f(T) theories. The field equations are naturally second order, avoiding pathologies, and can give rise to cosmic acceleration with unique features.
Gravity-free hydraulic jumps and metal femtocups
Rama Govindarajan; Manikandan Mathur; Ratul DasGupta; N. R. Selvi; Neena Susan John; G. U. Kulkarni
2006-10-03T23:59:59.000Z
Hydraulic jumps created by gravity are seen every day in the kitchen sink. We show that at small scales a circular hydraulic jump can be created in the absence of gravity, by surface tension. The theory is motivated by our experimental finding of a height discontinuity in spreading submicron molten metal droplets created by pulsed-laser ablation. By careful control of initial conditions, we show that this leads to solid femtolitre cups of gold, silver, copper, niobium and tin.
Gravity Effects on Antimatter in the Standard-Model Extension
Jay D. Tasson
2015-01-30T23:59:59.000Z
The gravitational Standard-Model Extension (SME) is the general field-theory based framework for the analysis of CPT and Lorentz violation. In this work we summarize the implications of Lorentz and CPT violation for antimatter gravity in the context of the SME. Implications of various attempts to place indirect limits on anomalous antimatter gravity are considered in the context of SME-based models.
Gravity Effects on Antimatter in the Standard-Model Extension
Tasson, Jay D
2015-01-01T23:59:59.000Z
The gravitational Standard-Model Extension (SME) is the general field-theory based framework for the analysis of CPT and Lorentz violation. In this work we summarize the implications of Lorentz and CPT violation for antimatter gravity in the context of the SME. Implications of various attempts to place indirect limits on anomalous antimatter gravity are considered in the context of SME-based models.
Entropy and Area of Black Holes in Loop Quantum Gravity
I. B. Khriplovich
2002-03-31T23:59:59.000Z
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.
Finite field-dependent symmetries in perturbative quantum gravity
Upadhyay, Sudhaker, E-mail: sudhaker@boson.bose.res.in
2014-01-15T23:59:59.000Z
In this paper we discuss the absolutely anticommuting nilpotent symmetries for perturbative quantum gravity in general curved spacetime in linear and non-linear gauges. Further, we analyze the finite field-dependent BRST (FFBRST) transformation for perturbative quantum gravity in general curved spacetime. The FFBRST transformation changes the gauge-fixing and ghost parts of the perturbative quantum gravity within functional integration. However, the operation of such symmetry transformation on the generating functional of perturbative quantum gravity does not affect the theory on physical ground. The FFBRST transformation with appropriate choices of finite BRST parameter connects non-linear Curci–Ferrari and Landau gauges of perturbative quantum gravity. The validity of the results is also established at quantum level using Batalin–Vilkovisky (BV) formulation. -- Highlights: •The perturbative quantum gravity is treated as gauge theory. •BRST and anti-BRST transformations are developed in linear and non-linear gauges. •BRST transformation is generalized by making it finite and field dependent. •Connection between linear and non-linear gauges is established. •Using BV formulation the results are established at quantum level also.
Testing Horava-Lifshitz gravity using thin accretion disk properties
Harko, Tiberiu; Kovacs, Zoltan; Lobo, Francisco S. N. [Department of Physics and Center for Theoretical and Computational Physics, University of Hong Kong, Pok Fu Lam Road (Hong Kong); Centro de Fisica Teorica e Computacional, Faculdade de Ciencias da Universidade de Lisboa, Avenida Professor Gama Pinto 2, P-1649-003 Lisboa (Portugal)
2009-08-15T23:59:59.000Z
Recently, a renormalizable gravity theory with higher spatial derivatives in four dimensions was proposed by Horava. The theory reduces to Einstein gravity with a nonvanishing cosmological constant in IR, but it has improved UV behaviors. The spherically symmetric black hole solutions for an arbitrary cosmological constant, which represent the generalization of the standard Schwarzschild-(anti) de Sitter solution, have also been obtained for the Horava-Lifshitz theory. The exact asymptotically flat Schwarzschild-type solution of the gravitational field equations in Horava gravity contains a quadratic increasing term, as well as the square root of a fourth order polynomial in the radial coordinate, and it depends on one arbitrary integration constant. The IR-modified Horava gravity seems to be consistent with the current observational data, but in order to test its viability more observational constraints are necessary. In the present paper we consider the possibility of observationally testing Horava gravity by using the accretion disk properties around black holes. The energy flux, the temperature distribution, the emission spectrum, as well as the energy conversion efficiency are obtained, and compared to the standard general relativistic case. Particular signatures can appear in the electromagnetic spectrum, thus leading to the possibility of directly testing Horava gravity models by using astrophysical observations of the emission spectra from accretion disks.
Table 8. Retail sales, revenue, and average retail price by sector, 1990 through 2013
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012, 2011,
Table 8. Retail sales, revenue, and average retail price by sector, 1990 through 2013
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012, 2011,Colorado"
Table 8. Retail sales, revenue, and average retail price by sector, 1990 through 2013
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012, 2011,Colorado"Kentucky"
Table 8. Retail sales, revenue, and average retail price by sector, 1990 through 2013
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012,
Table 8. Retail sales, revenue, and average retail price by sector, 1990 through 2013
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are nowTotal" (Percent) Type: Sulfur Content API GravityDakota" "Fuel, quality", 2013, 2012,Montana"
GRADE NUMBER OF CREDITS FACTOR QUALITY POINTS HOW TO COMPUTE A GRADE POINT AVERAGE
Massachusetts at Amherst, University of
.00 = __________ TOTALS: _________ __________ CREDITS QUALITY PTS. Divide total credits into total quality pointsGRADE NUMBER OF CREDITS FACTOR QUALITY POINTS HOW TO COMPUTE A GRADE POINT AVERAGE A _________ x 4 and the result is the grade point average (GPA). QUALITY PTS. = GPA ____________ = CREDITS
Boyer, Edmond
trajectory of the averaged system. Key words: Optimal control, Singular perturbations, occupational measures is to study singularly perturbed control systems. Firstly, we provide linearized formulation version and sufficient conditions in order to identify the optimal trajectory of the averaged system. Linear programming
Tradeoffs and Average-Case Equilibria in Selfish Routing Martin Hoefer
Reiterer, Harald
the expected price of anarchy of the game for various social cost functions. For total latency social cost cost in polyno- mial time. Furthermore, our analyses of the expected prices are average-case analyses, 2007 Abstract We consider the price of selfish routing in terms of tradeoffs and from an average
A spatiotemporal auto-regressive moving average model for solar radiation
Stone, J. V.
A spatiotemporal auto-regressive moving average model for solar radiation C.A. Glasbey and D 1). Solar radiation, averaged over ten minute intervals, was recorded at each site for two years otherwise there are too many parameters to be estimated. As we wish to simulate solar radiation on a network
Variances of the Average Numbers of Nucleotide Substitutions Within and Between Populations'
Nei, Masatoshi
Variances of the Average Numbers of Nucleotide Substitutions Within and Between Populations the variances of nucleotide diversity within pop- ulations and of nucleotide divergence between populations of the extent of DNA polymorphism is nucleotide diversity (z), which is defined as the average number of either
Practical 1P9 Polymers -Molecular weight effects
Paxton, Anthony T.
this entire set of guidelines · Familiarisation with equipment · Prepare jellies as required for Experiment 1 a spherical object on the surface of the set jelly, and measuring the depth of the indentation: [ ] 2 1 2 3 2 to gravity = 9.8 m.s-2 h = depth of indentation = Poisson's ratio of jelly (you should be able to estimate
J. W. Maluf
2003-04-01T23:59:59.000Z
We show that the coupling of a Dirac spinor field with the gravitational field in the teleparallel equivalent of general relativity is consistent. For an arbitrary SO(3,1) connection there are two possibilities for the coupling of the spinor field with the gravitational field. The problems of consistency raised by Y. N. Obukhov and J. G. Pereira in the paper {\\it Metric-affine approach to teleparallel gravity} [gr-qc/0212080] take place only in the framework of one particular coupling. By adopting an alternative coupling the consistency problem disappears.
Anti-gravity and/or dark matter contributions from massive gravity
Bebronne, Michael V
2009-01-01T23:59:59.000Z
Recently, the static spherically symmetric solution of the gravitational field equations have been found in theories describing massive graviton with spontaneous breaking of the Lorentz invariance. These solutions, which show off two integration constants instead of one in General Relativity, are discussed. They are candidates for modified black holes provided they are stable against small perturbations. These solutions may have both attractive or repulsive behavior at large distances. Therefore, these modified black holes may mimics the presence of dark matter or be a source of anti-gravity.
Volume-averaged macroscopic equation for fluid flow in moving porous media
Wang, Liang; Guo, Zhaoli; Mi, Jianchun
2014-01-01T23:59:59.000Z
Darcy's law and the Brinkman equation are two main models used for creeping fluid flows inside moving permeable particles. For these two models, the time derivative and the nonlinear convective terms of fluid velocity are neglected in the momentum equation. In this paper, a new momentum equation including these two terms are rigorously derived from the pore-scale microscopic equations by the volume-averaging method, which can reduces to Darcy's law and the Brinkman equation under creeping flow conditions. Using the lattice Boltzmann equation method, the macroscopic equations are solved for the problem of a porous circular cylinder moving along the centerline of a channel. Galilean invariance of the equations are investigated both with the intrinsic phase averaged velocity and the phase averaged velocity. The results demonstrate that the commonly used phase averaged velocity cannot serve as the superficial velocity, while the intrinsic phase averaged velocity should be chosen for porous particulate systems.
A Nonempirical Test on the Weight of Pseudorandom Number Generators
Matsumoto, Makoto
A Nonempirical Test on the Weight of Pseudorandom Number Generators Makoto Matsumoto1 and Takuji introduce a theoretical test, named weight discrepancy test, on pseu- dorandom number generators. This test selected. This test can be performed for most generators based on a linear recursion over the two
Implementing Weighted Abduction in Markov Logic James Blythe
Anderson, Richard
Implementing Weighted Abduction in Markov Logic James Blythe USC ISI blythe@isi.edu Jerry R. Hobbs@cs.utexas.edu Abstract Abduction is a method for finding the best explanation for observations. Arguably the most advanced approach to abduction, especially for natural language processing, is weighted abduction, which
Weighted Hypothesis Testing Larry Wasserman and Kathryn Roeder1
loss remains nearly constant. specified weights, but minute power loss for poorly specified weights; and (ii) in the non-sparse case, under weak conditions, the worst case power loss for poorly specified the potential power loss. Figure 2 shows the non-sparse case. The plots on the left show the power as a function
Weighted Parametric Operational Hydrology Forecasting Thomas E. Croley II1
1 Weighted Parametric Operational Hydrology Forecasting Thomas E. Croley II1 1 Great Lakes forecasts in operational hydrology builds a sample of possibilities for the future, of climate series from-parametric method can be extended into a new weighted parametric hydrological forecasting technique to allow
Weighted Graph Cuts without Eigenvectors: A Multilevel Approach
to handle data that is not linearly separable; spectral clustering and kernel k-means are two of the main different methods--in particular, a general weighted kernel k-means objective is mathematically equivalent multilevel algorithm removes this restriction by using kernel k-means to optimize weighted graph cuts
A component GARCH model with time varying weights
Nesterov, Yurii
2007/19 A component GARCH model with time varying weights Luc Bauwens and Giuseppe Storti #12;CORE DISCUSSION PAPER 2007/19 A component GARCH model with time varying weights Luc BAUWENS1 and Giuseppe STORTI2 March2007 Abstract We present a novel GARCH model that accounts for time varying, state dependent
Computing Symmetrized Weight Enumerators for Lifted Quadratic Residue Codes
Duursma, Iwan M.
Computing Symmetrized Weight Enumerators for Lifted Quadratic Residue Codes I. M. Duursma Dept for the computation of structural parameters for ring-linear codes. This article therefore presents a method to eĂ?ciently compute weight enumerators of linear codes over primary integer residue rings. For the lifted QR-codes
The Complexity of Weighted Boolean #CSP with Mixed Signs
Bulatov, Andrei
The Complexity of Weighted Boolean #CSP with Mixed Signs Andrei Bulatova , Martin Dyerb , Leslie constraint satisfaction problem (CSP), which corresponds to the case where all functions in have range {0, 1}. The problem we consider here is to compute the partition function of a given instance of weighted CSP; that is
Characterizing Ideal Weighted Threshold Secret Amos Beimel1
Beimel, Amos
Characterizing Ideal Weighted Threshold Secret Sharing Amos Beimel1 , Tamir Tassa1,2 , and Enav Science, The Open University, Ra'anana, Israel. Abstract. Weighted threshold secret sharing was introduced by Shamir in his seminal work on secret sharing. In such settings, there is a set of users where each user
Weighted modulated secret image sharing method Chien-Chang Chen
Chen, Chaur-Chin
Weighted modulated secret image sharing method Chien-Chang Chen Hsuan Chuang University Department-layered structure for grouping participants with different weights in a secret image sharing problem. Conventional secret im- age sharing methods suffer from truncation distortion, which is the difference between a pixel
Scalar-tensor gravity and conformal continuations
Kirill A. Bronnikov
2002-03-30T23:59:59.000Z
Global properties of vacuum static, spherically symmetric configurations are studied in a general class of scalar-tensor theories (STT) of gravity in various dimensions. The conformal mapping between the Jordan and Einstein frames is used as a tool. Necessary and sufficient conditions are found for the existence of solutions admitting a conformal continuation (CC). The latter means that a singularity in the Einstein-frame manifold maps to a regular surface S_(trans) in the Jordan frame, and the solution is then continued beyond this surface. S_(trans) can be an ordinary regular sphere or a horizon. In the second case, S_(trans) proves to connect two epochs of a Kantowski-Sachs type cosmology. It is shown that, in an arbitrary STT, with arbitrary potential functions $U(\\phi)$, the list of possible types of causal structures of vacuum space-times is the same as in general relativity with a cosmological constant. This is true even for conformally continued solutions. It is found that when S_(trans) is an ordinary sphere, one of the generic structures appearing as a result of CC is a traversable wormhole. Two explicit examples are presented: a known solution illustrating the emergence of singularities and wormholes, and a nonsingular 3-dimensional model with an infinite sequence of CCs.
Gravity stabilized thermal miscible displacement process
Vogel, J.V.
1987-10-06T23:59:59.000Z
A method is described of recovering viscous hydrocarbons from a subterranean reservoir. The reservoir is penetrated by at least one injection well and one production well. The injection well is in fluid communication with the upper portion of the reservoir and the production well is in fluid communication with the lower portion of the reservoir. The injection well and the production well defines a fluid flow path therebetween. The method comprises the steps of: (a) injecting a steam-solvent vapor mixture into the upper portion of the reservoir through the injection well. The steam-solvent vapor mixture is undersaturated in solvent and saturated with steam; (b) reducing the viscosity of the hydrocarbons by heat released upon condensation of the steam-solvent vapor mixture and reducing the viscosity of the hydrocarbons further upon condensation of solvent vapors. The condensed solvent vapors goes into solution with the hydrocarbons; and (c) collecting a mixture of hydrocarbons and solvent accumulated at the bottom of the production well substantially entirely under the force of gravity.
Testing Gravity with Cold-Atom Interferometers
G. W. Biedermann; X. Wu; L. Deslauriers; S. Roy; C. Mahadeswaraswamy; M. A. Kasevich
2014-12-10T23:59:59.000Z
We present a horizontal gravity gradiometer atom interferometer for precision gravitational tests. The horizontal configuration is superior for maximizing the inertial signal in the atom interferometer from a nearby proof mass. In our device, we have suppressed spurious noise associated with the horizonal configuration to achieve a differential acceleration sensitivity of 4.2$\\times10^{-9}g/\\sqrt{Hz}$ over a 70 cm baseline or 3.0$\\times10^{-9}g/\\sqrt{Hz}$ inferred per accelerometer. Using the performance of this instrument, we characterize the results of possible future gravitational tests. We complete a proof-of-concept measurement of the gravitational constant with a precision of 3$\\times10^{-4}$ that is competitive with the present limit of 1.2$\\times10^{-4}$ using other techniques. From this measurement, we provide a statistical constraint on a Yukawa-type fifth force at 8$\\times$10$^{-3}$ near the poorly known length scale of 10 cm. Limits approaching 10$^{-5}$ appear feasible. We discuss improvements that can enable uncertainties falling well below 10$^{-5}$ for both experiments.
Non-Singular Cosmology in Modified Gravity
J. W. Moffat
2007-10-24T23:59:59.000Z
A non-singular cosmology is derived in modified gravity (MOG) with a varying gravitational coupling strength $G(t)=G_N\\xi(t)$. Assuming that the curvature $k$, the cosmological constant $\\Lambda$ and $\\rho$ vanish at $t=0$, we obtain a non-singular universe with a negative pressure, $p_G < 0$. Quantum fluctuations at $t\\sim 0$ produce creation of pairs of particles from the vacuum explaining the origin of matter. The universe expands for $t\\to \\infty$ according to the standard radiation and matter dominated solutions. The arrow of time reverses at $t=0$ always pointing in the direction of increasing entropy ${\\cal S}$ and the entropy is at a minimum value at $t=0$, solving the conundrum of the Second Law of Thermodynamics. The Hubble radius $H^{-1}(t)$ is infinite at $t=0$ removing the curvature and particle horizons. The negative pressure $p_G$ generated by the scalar field $\\xi$ at $t\\sim 0$ can produce quantum spontaneous creation of particles explaining the origin of matter and radiation.
Infrared modified gravity with dynamical torsion
Nikiforova, V. [Physics Department, Moscow State University, Moscow, 119899 (Russian Federation); Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, Moscow, 117312 (Russian Federation); Randjbar-Daemi, S. [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, I-34014, Trieste (Italy); Rubakov, V. [Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, Moscow, 117312 (Russian Federation)
2009-12-15T23:59:59.000Z
We continue the recent study of the possibility of constructing a consistent infrared modification of gravity by treating the vierbein and connection as independent dynamical fields. We present the generalized Fierz-Pauli equation that governs the propagation of a massive spin-2 mode in a model of this sort in the backgrounds of arbitrary torsionless Einstein manifolds. We show explicitly that the number of propagating degrees of freedom in these backgrounds remains the same as in flat space-time. This generalizes the recent result that the Boulware-Deser phenomenon does not occur in de Sitter and anti-de Sitter backgrounds. We find that, at least for weakly curved backgrounds, there are no ghosts in the model. We also discuss the interaction of sources in flat background. It is generally believed that the spinning matter is the only source of torsion. Our flat space study shows that this is not the case. We demonstrate that an ordinary conserved symmetric energy-momentum tensor can also generate torsion fields and thus excite massive spin-2 degrees of freedom.
Quantization of neutron in Earth's gravity
Pulak Ranjan Giri
2007-08-22T23:59:59.000Z
Gravity is the weakest of all four known forces in the universe. Quantum states of an elementary particle due to such a weak field is certainly very shallow and would therefore be an experimental challenge to detect. Recently an experimental attempt was made by V. V. Nesvizhevsky et al., Nature 415, 297 (2002), to measure the quantum states of a neutron, which shows that ground state and few excited states are \\sim 10^{-12}eV. We show that the energy of the ground state of a neutron confined above Earth's surface should be \\sim 10^{-37}eV. The experimentally observed energy levels are 10^{25} times deeper than the actual energy levels it should be and thus certainly not due to gravitational effect of Earth. Therefore the correct interpretation for the painstaking experimental results of Ref. \\cite{nes1} is due to the confinement potential of a one dimensional box of length L \\sim 50\\mu m, generated from the experimental setup as commented before \\cite{hansoon}. Our results thus creates a new challenge to the experimentalist to resolve the shallow energy levels of the neutron in Earth's gravitational field in future.
Scale-invariant gravity: Spacetime recovered
Bryan Kelleher
2004-07-28T23:59:59.000Z
The configuration space of general relativity is superspace - the space of all Riemannian 3-metrics modulo diffeomorphisms. However, it has been argued that the configuration space for gravity should be conformal superspace - the space of all Riemannian 3-metrics modulo diffeomorphisms and conformal transformations. Recently a manifestly 3-dimensional theory was constructed with conformal superspace as the configuration space. Here a fully 4-dimensional action is constructed so as to be invariant under conformal transformations of the 4-metric using general relativity as a guide. This action is then decomposed to a (3+1)-dimensional form and from this to its Jacobi form. The surprising thing is that the new theory turns out to be precisely the original 3-dimensional theory. The physical data is identified and used to find the physical representation of the theory. In this representation the theory is extremely similar to general relativity. The clarity of the 4-dimensional picture should prove very useful for comparing the theory with those aspects of general relativity which are usually treated in the 4-dimensional framework.
Beach, R.; Emanuel, M.; Benett, W.; Freitas, B.; Ciarlo, D.; Carlson, N.; Sutton, S.; Skidmore, J.; Solarz, R.
1994-01-01T23:59:59.000Z
The average power performance capability of semiconductor diode laser arrays has improved dramatically over the past several years. These performance improvements, combined with cost reductions pursued by LLNL and others in the fabrication and packaging of diode lasers, have continued to reduce the price per average watt of laser diode radiation. Presently, we are at the point where the manufacturers of commercial high average power solid state laser systems used in material processing applications can now seriously consider the replacement of their flashlamp pumps with laser diode pump sources. Additionally, a low cost technique developed and demonstrated at LLNL for optically conditioning the output radiation of diode laser arrays has enabled a new and scalable average power diode-end-pumping architecture that can be simply implemented in diode pumped solid state laser systems (DPSSL`s). This development allows the high average power DPSSL designer to look beyond the Nd ion for the first time. Along with high average power DPSSL`s which are appropriate for material processing applications, low and intermediate average power DPSSL`s are now realizable at low enough costs to be attractive for use in many medical, electronic, and lithographic applications.
Averaged Energy Inequalities for Non-Minimally Coupled Classical Scalar Fields
Lutz W. Osterbrink
2006-12-11T23:59:59.000Z
The stress-energy tensor for the non-minimally coupled scalar field is known not to satisfy the pointwise energy conditions, even on the classical level. We show, however, that local averages of the classical stress-energy tensor satisfy certain inequalities and give bounds for averages along causal geodesics. It is shown that in vacuum background spacetimes, ANEC and AWEC are satisfied. Furthermore we use our result to show that in the classical situation we have an analogue to the so called quantum interest conjecture. These results lay the foundations for averaged energy inequalities for the quantised non-minimally coupled fields.
Matter Bounce Loop Quantum Cosmology from $F(R)$ Gravity
S. D. Odintsov; V. K. Oikonomou
2014-12-04T23:59:59.000Z
Using the reconstruction method, we investigate which $F(R)$ theories, with or without the presence of matter fluids, can produce the matter bounce scenario of holonomy corrected Loop Quantum Cosmology. We focus our study in two limits of the cosmic time, the large cosmic time limit and the small cosmic time limit. For the former, we found that, in the presence of non-interacting and non-relativistic matter, the $F(R)$ gravity that reproduces the late time limit of the matter bounce solution is actually the Einstein-Hilbert gravity plus a power law term. In the early time limit, since it corresponds to large spacetime curvatures, assuming that the Jordan frame is described by a general metric that when it is conformally transformed to the Einstein frame, produces an accelerating Friedmann-Robertson-Walker metric, we found explicitly the scalar field dependence on time. After demonstrating that the solution in the Einstein frame is indeed accelerating, we calculate the spectral index derived from the Einstein frame scalar-tensor counterpart theory of the $F(R)$ theory and compare it with the Planck experiment data. In order to implement the resulting picture, we embed the $F(R)$ gravity explicitly in a Loop Quantum Cosmology framework by introducing holonomy corrections to the $F(R)$ gravity. In this way, the resulting inflation picture corresponding to the $F(R)$ gravity can be corrected in order it coincides to some extent with the current experimental data.
Unscreening modified gravity in the matter power spectrum
Lucas Lombriser; Fergus Simpson; Alexander Mead
2015-01-20T23:59:59.000Z
Viable modifications of gravity that may produce cosmic acceleration need to be screened in high-density regions such as the Solar System, where general relativity is well tested. Screening mechanisms also prevent strong anomalies in the large-scale structure and limit the constraints that can be inferred on these gravity models from cosmology. We find that by suppressing the contribution of the screened high-density regions in the matter power spectrum, allowing a greater contribution of unscreened low densities, modified gravity models can be more readily discriminated from the concordance cosmology. Moreover, by variation of density thresholds, degeneracies with other effects may be dealt with more adequately. Specializing to chameleon gravity as a worked example for screening in modified gravity, employing N-body simulations of f(R) models and the halo model of chameleon theories, we demonstrate the effectiveness of this method. We find that a percent-level measurement of the clipped power at k Solar System tests or distance indicators in unscreened dwarf galaxies.
Unscreening modified gravity in the matter power spectrum
Lombriser, Lucas; Mead, Alexander
2015-01-01T23:59:59.000Z
Viable modifications of gravity that may produce cosmic acceleration need to be screened in high-density regions such as the Solar System, where general relativity is well tested. Screening mechanisms also prevent strong anomalies in the large-scale structure and limit the constraints that can be inferred on these gravity models from cosmology. We find that by suppressing the contribution of the screened high-density regions in the matter power spectrum, allowing a greater contribution of unscreened low densities, modified gravity models can be more readily discriminated from the concordance cosmology. Moreover, by variation of density thresholds, degeneracies with other effects may be dealt with more adequately. Specializing to chameleon gravity as a worked example for screening in modified gravity, employing N-body simulations of f(R) models and the halo model of chameleon theories, we demonstrate the effectiveness of this method. We find that a percent-level measurement of the clipped power at k < 0.3 h...
Horava-Lifshitz Gravity From Dynamical Newton-Cartan Geometry
Jelle Hartong; Niels A. Obers
2015-04-28T23:59:59.000Z
Recently it has been established that torsional Newton-Cartan (TNC) geometry is the appropriate geometrical framework to which non-relativistic field theories couple. We show that when these geometries are made dynamical they give rise to Horava-Lifshitz (HL) gravity. Projectable HL gravity corresponds to dynamical Newton-Cartan (NC) geometry without torsion and non-projectable HL gravity corresponds to dynamical NC geometry with twistless torsion (hypersurface orthogonal foliation). We build a precise dictionary relating all fields (including the scalar khronon), their transformations and other properties in both HL gravity and dynamical TNC geometry. We use TNC invariance to construct the effective action for dynamical twistless torsional Newton-Cartan geometries in 2+1 dimensions for dynamical exponent 1Thompson as coming from the Bargmann extension of the local Galilean algebra that acts on the tangent space to TNC geometries. We argue that TNC geometry, which is manifestly diffeomorphism covariant, is a natural geometrical framework underlying HL gravity and discuss some of its implications.
average power diode-pumped: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
are required for numerous applications such as UV generation for lithography and pumping by a fiber- coupled diode bar1 generated 7-ps pulses with 4.5-W average power and...
Reconstruction of ionization probabilities from spatially averaged data in N dimensions
Stroahaber, James; Kolomenskii, A; Schuessler, Hans
2010-07-06T23:59:59.000Z
We present an analytical inversion technique, which can be used to recover ionization probabilities from spatially averaged data in an N-dimensional detection scheme. The solution is given as a power series in intensity. For this reason, we call...
Tamez, Jeannine Paola
2009-05-15T23:59:59.000Z
The current study examined the subjective and physiological reactivity to body image stimuli among females engaging in a social comparison task. Study I was conducted to select images of thin and average size models and neutral objects for Study...
System average rates of U.S. investor-owned electric utilities : a statistical benchmark study
Berndt, Ernst R.
1995-01-01T23:59:59.000Z
Using multiple regression methods, we have undertaken a statistical "benchmark" study comparing system average electricity rates charged by three California utilities with 96 other US utilities over the 1984-93 time period. ...
Experiments with a time-dependent, zonally averaged, seasonal, enery balance climatic model
Thompson, Starley Lee
1977-01-01T23:59:59.000Z
EXPERIMENTS WITH A TI&E-DEPENDENT, ZONALLY AVERAGED, SEASONAL, ENERGY BALANCE CLIMATIC MODEL A Thesis by STARLEY LEE THOMPSON Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the decree... of MASTER OF SCIENCE December 1977 Major Subject: Meteorology EXPERIMENTS WITH A TIME DEPENDENT~ ZONALLY AVERAGED~ SEASONAL, ENERGY BALANCE CLIMATIC MODEL A Thesis by STARLEY LEE THOMPSON Approved as to style and content by: (Chairman of Committee...
Variation in the annual average radon concentration measured in homes in Mesa County, Colorado
Rood, A.S.; George, J.L.; Langner, G.H. Jr.
1990-04-01T23:59:59.000Z
The purpose of this study is to examine the variability in the annual average indoor radon concentration. The TMC has been collecting annual average radon data for the past 5 years in 33 residential structures in Mesa County, Colorado. This report is an interim report that presents the data collected up to the present. Currently, the plans are to continue this study in the future. 62 refs., 3 figs., 12 tabs.
Experiments with a time-dependent, zonally averaged, seasonal, enery balance climatic model
Thompson, Starley Lee
1977-01-01T23:59:59.000Z
EXPERIMENTS WITH A TI&E-DEPENDENT, ZONALLY AVERAGED, SEASONAL, ENERGY BALANCE CLIMATIC MODEL A Thesis by STARLEY LEE THOMPSON Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the decree... of MASTER OF SCIENCE December 1977 Major Subject: Meteorology EXPERIMENTS WITH A TIME DEPENDENT~ ZONALLY AVERAGED~ SEASONAL, ENERGY BALANCE CLIMATIC MODEL A Thesis by STARLEY LEE THOMPSON Approved as to style and content by: (Chairman of Committee...