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Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

On the no-gravity limit of gravity  

E-Print Network (OSTI)

We argue that Relative Locality may arise in the no gravity $G\\rightarrow0$ limit of gravity. In this limit gravity becomes a topological field theory of the BF type that, after coupling to particles, may effectively deform its dynamics. We briefly discuss another no gravity limit with a self dual ground state as well as the topological ultra strong $G\\rightarrow\\infty$ one.

Kowalski-Glikman, J

2012-01-01T23:59:59.000Z

2

PPN-limit of Fourth Order Gravity inspired by Scalar-Tensor Gravity  

E-Print Network (OSTI)

Based on the {\\it dynamical} equivalence between higher order gravity and scalar-tensor gravity the PPN-limit of fourth order gravity is discussed. We exploit this analogy developing a fourth order gravity version of the Eddington PPN-parameters. As a result, Solar System experiments can be reconciled with higher order gravity, if physical constraints descending from experiments are fulfilled.

S. Capozziello; A. Troisi

2005-07-22T23:59:59.000Z

3

Interactions between Upper and Lower Tropospheric Gravity Waves on Squall Line Structure and Maintenance  

Science Conference Proceedings (OSTI)

Using a simplified thermodynamic sounding, and variable vertical wind shear, we investigate the role of gravity waves on the structure and propagation of a simulated two-dimensional squall line. Based on an observed squall line environment, the ...

Jerome M. Schmidt; William R. Cotton

1990-05-01T23:59:59.000Z

4

Limits from Weak Gravity Conjecture on Dark Energy Models  

E-Print Network (OSTI)

The weak gravity conjecture has been proposed as a criterion to distinguish the landscape from the swampland in string theory. As an application in cosmology of this conjecture, we use it to impose theoretical constraint on parameters of two types of dark energy models. Our analysis indicates that the Chaplygin-gas-type models realized in quintessence field are in the swampland, whereas the $a$ power-low decay model of the variable cosmological constant can be viable but the parameters are tightly constrained by the conjecture.

Xing Wu; Zong-Hong Zhu

2007-10-07T23:59:59.000Z

5

Performance limits of gravity-assist heat pipes with simple wick structures  

SciTech Connect

Experiments using gravity-assist heat pipes with simple wick structures were used to establish performance limits due to entrainment of the liquid by the counterflowing vapor. A physical model is postulated which leads to a single correlation predicting entrainment limits for all data investigated. The characteristic length in the entrainment parameter is the depth of the wick structure and the model infers an upper bound on this parameter.

Prenger, F.C. Jr.; Kemme, J.E.

1981-01-01T23:59:59.000Z

6

Modeling the Interaction between Cumulus Convection and Linear Gravity Waves Using a Limited-Domain Cloud System–Resolving Model  

Science Conference Proceedings (OSTI)

A limited-domain cloud system–resolving model (CSRM) is used to simulate the interaction between cumulus convection and two-dimensional linear gravity waves, a single horizontal wavenumber at a time. With a single horizontal wavenumber, soundings ...

Zhiming Kuang

2008-02-01T23:59:59.000Z

7

The Parameterised Post-Newtonian Limit of Bimetric Theories of Gravity  

E-Print Network (OSTI)

We consider the post-Newtonian limit of a general class of bimetric theories of gravity, in which both metrics are dynamical. The established parameterised post-Newtonian approach is followed as closely as possible, although new potentials are found that do not exist within the standard frame-work. It is found that these theories can evade solar system tests of post-Newtonian gravity remarkably well. We show that perturbations about Minkowski space in these theories contain both massless and massive degrees of freedom, and that in general there are two different types of massive mode, each with a different mass parameter. If both of these masses are sufficiently large then the predictions of the most general class of theories we consider are indistinguishable from those of general relativity, up to post-Newtonian order in a weak field, low velocity expansion. In the limit that the massive modes become massless, we find that these general theories do not exhibit a van Dam-Veltman-Zakharov-like discontinuity in their gamma parameter, although there are discontinuities in other post-Newtonian parameters as the massless limit is approached. This smooth behaviour in gamma is due to the discontinuities from each of the two different massive modes cancelling each other out. Such cancellations cannot occur in special cases with only one massive mode, such as the Isham-Salam-Strathdee theory.

Timothy Clifton; Máximo Bañados; Constantinos Skordis

2010-06-29T23:59:59.000Z

8

An Einstein-like theory of gravity with a non-newtonian weak-field limit  

E-Print Network (OSTI)

We propose a model describing Einstein gravity coupled to a scalar field with an exponential potential. We show that the weak-field limit of the model has static solutions given by a gravitational potential behaving for large distances as \\ln r . The Newtonian term GM/r appears only as subleading. Our model can be used to give a phenomenological explanation of the rotation curves of the galaxies without postulating the presence of dark matter. This can be achieved only by giving up at galactic scales Einstein equivalence principle.

Mariano Cadoni

2003-12-09T23:59:59.000Z

9

A Numerical Study of Stratospheric Gravity Waves Triggered by Squall Lines Observed during the TOGA COARE and COPT-81 Experiments  

Science Conference Proceedings (OSTI)

A 3D mesoscale model is used to study the structure and intensity of stratospheric gravity waves generated by tropical convection. Two prototypical cases are examined: a squall line observed during the Tropical Ocean Global Atmosphere Coupled ...

C. Piani; D. R. Durran

2001-12-01T23:59:59.000Z

10

Liouville gravity from Einstein gravity  

E-Print Network (OSTI)

We show that Liouville gravity arises as the limit of pure Einstein gravity in 2+epsilon dimensions as epsilon goes to zero, provided Newton's constant scales with epsilon. Our procedure - spherical reduction, dualization, limit, dualizing back - passes several consistency tests: geometric properties, interactions with matter and the Bekenstein-Hawking entropy are as expected from Einstein gravity.

D. Grumiller; R. Jackiw

2007-12-21T23:59:59.000Z

11

Massive gravity from bimetric gravity  

E-Print Network (OSTI)

We discuss the subtle relationship between so-called massive gravity (that is, gravity incorporating a non-zero graviton mass) and bimetric gravity, focussing particularly on the manner in which massive gravity may be viewed as a suitable limit of bimetric gravity. The limiting procedure is more delicate than currently appreciated, and in particular, in a cosmological context can lead to an interesting interplay between the "background" and "foreground" metrics. The fact that in bimetric theories one always has two sets of metric equations of motion, one for each metric, continues to have an effect even in the massive gravity limit. Thus, solutions of bimetric gravity in the limit of vanishing kinetic term are also solutions of massive gravity, but the contrary statement is not necessarily true.

Baccetti, Valentina; Visser, Matt

2012-01-01T23:59:59.000Z

12

The Stability of Dilute Plasmas with Thermal and Composition Gradients. I. The Slow Conduction Limit: Overstable Gravity Modes  

E-Print Network (OSTI)

We analyze the stability of a dilute plasma with thermal and composition gradients in the limit where conduction is slow compared to the dynamical timescale. We find necessary and sufficient conditions for stability when the background magnetic field is either parallel or perpendicular to the thermal and composition gradients that are parallel to the gravitational field. We provide approximate solutions for all the relevant modes involved, which are driven by gravity, conduction, and diffusion. We discuss the astrophysical implications of our findings for a representative galaxy cluster where helium has sedimented.

Pessah, Martin E

2011-01-01T23:59:59.000Z

13

The Gravity Wave Response above Deep Convection in a Squall Line Simulation  

Science Conference Proceedings (OSTI)

High-frequency gravity waves generated by convective storms likely play an important role in the general circulation of the middle atmosphere. Yet little is known about waves from this source. This work utilizes a fully compressible, nonlinear, ...

M. J. Alexander; J. R. Holton; D. R. Durran

1995-06-01T23:59:59.000Z

14

Is nonrelativistic gravity possible?  

SciTech Connect

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.

Kocharyan, A. A. [School of Mathematical Sciences, Monash University, Clayton 3800 (Australia)

2009-07-15T23:59:59.000Z

15

Spherically symmetric solutions, Newton's Law, and the infrared limit {lambda}{yields}1 in covariant Horava-Lifshitz gravity  

SciTech Connect

In this note we examine whether spherically symmetric solutions in covariant Horava-Lifshitz gravity can reproduce Newton's Law in the IR limit {lambda}{yields}1. We adopt the position that the auxiliary field A is independent of the space-time metric [J. Alexandre and P. Pasipoularides, Phys. Rev. D 83, 084030 (2011).][J. Greenwald, V. H. Satheeshkumar, and A. Wang, J. Cosmol. Astropart. Phys. 12 (2010) 007.], and we assume, as in [A. M. da Silva, Classical Quantum Gravity 28, 055011 (2011).], that {lambda} is a running coupling constant. We show that under these assumptions, spherically symmetric solutions fail to restore the standard Newtonian physics in the IR limit {lambda}{yields}1, unless {lambda} does not run, and has the fixed value {lambda}=1. Finally, we comment on the Horava and Melby-Thompson approach [P. Horava and C. M. Melby-Thompson, Phys. Rev. D 82, 064027 (2010).] in which A is assumed as a part of the space-time metric in the IR.

Alexandre, Jean [King's College London, Department of Physics, London WC2R 2LS (United Kingdom); Pasipoularides, Pavlos [Department of Physics, National Technical University of Athens, Zografou Campus GR 157 73, Athens (Greece)

2011-10-15T23:59:59.000Z

16

Newtonian gravity in loop quantum gravity  

E-Print Network (OSTI)

We apply a recent argument of Verlinde to loop quantum gravity, to conclude that Newton's law of gravity emerges in an appropriate limit and setting. This is possible because the relationship between area and entropy is realized in loop quantum gravity when boundaries are imposed on a quantum spacetime.

Smolin, Lee

2010-01-01T23:59:59.000Z

17

RESULTS OF CAUSTIC DISSOLUTION OF ALUMINOSILICATE SCALE AND CHARACTERIZATION DATA FOR SAMPLES FROM THE EVAPORATOR POT AND GRAVITY DRAIN LINE  

Science Conference Proceedings (OSTI)

The build-up of sodium aluminosilicate scale in the 2H Evaporator system continues to cause operational difficulties. The use of a nitric acid cleaning operation proved successful in 2001. However, the operation required additional facilities to support spent cleaning solution neutralization and was quite costly. A proposed caustic cleaning flowsheet has many advantages over the acid flowsheet. Therefore, samples were retrieved from the evaporator system (gravity drain line and pot) for both chemical and radiological characterization and dissolution testing. The characterization of these scale samples showed the presence of nitrated cancrinite along with a dehydrated zeolite. Small amounts of depleted uranium were also found in these samples as expected and the amount of uranium ranged from 0.5 wt% to 2 wt%. Dissolution in sodium hydroxide solutions of various caustic concentrations showed that the scale slowly dissolves at elevated temperature (90 C). Data from similar testing indicate that the scale removed from the GDL in 2005 dissolves slower than that removed in 1997. Differences in the particle size of these samples of scale may well explain the measured dissolution rate differences.

Wilmarth, B; Rita Sullivan, R; Chris Martino, C

2006-08-21T23:59:59.000Z

18

A lossy transmission line as a quantum open system in the standard quantum limit  

E-Print Network (OSTI)

We systematically investigate how to quantize a transmission line resonator (TLR) in a mesoscopic electrical circuits in the presence of the resistance and the conductance of the dielectric media. Developed from the quantum bath based effective Hamiltonian method for single mode harmonic oscillator, the approach we presented in this article is a microscopic theory integrating quantum fluctuation-dissipation relation. To qualitatively check the condition under which the TLR can behave as a quantum object we study the classical-quantum boundary characterized by the standard quantum limit.

Y. D. Wang; C. P. Sun

2004-06-30T23:59:59.000Z

19

Limiter  

DOE Patents (OSTI)

A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

1984-10-19T23:59:59.000Z

20

Beating the confusion limit: The necessity of high angular resolution for probing the physics of Sagittarius A* and its environment: Opportunities for LINC-NIRVANA (LBT), GRAVITY (VLTI) and and METIS (E-ELT)  

E-Print Network (OSTI)

The super-massive 4 million solar mass black hole (SMBH) SgrA* shows variable emission from the millimeter to the X-ray domain. A detailed analysis of the infrared light curves allows us to address the accretion phenomenon in a statistical way. The analysis shows that the near-infrared flux density excursions are dominated by a single state power law, with the low states of SgrA* limited by confusion through the unresolved stellar background. We show that for 8-10m class telescopes blending effects along the line of sight will result in artificial compact star-like objects of 0.5-1 mJy that last for about 3-4 years. We discuss how the imaging capabilities of GRAVITY at the VLTI, LINC-NIRVANA at the LBT and METIS at the E-ELT will contribute to the investigation of the low variability states of SgrA*.

Eckart, A; Witzel, G; Straubmeier, C; Shahzamanian, B; Valencia-S., M; Garcia-Marin, M; Horrobin, M; Moser, L; Zuther, J; Fischer, S; Rauch, C; Rost, S; Iserlohe, C; Yazici, S; Smajic, S; Wiest, M; Araujo-Hauck, C; Wank, I

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Low surface brightness galaxies rotation curves in the low energy limit of $R^n$ gravity : no need for dark matter?  

E-Print Network (OSTI)

We investigate the possibility that the observed flatness of the rotation curves of spiral galaxies is not an evidence for the existence of dark matter haloes, but rather a signal of the breakdown of General Relativity. To this aim, we consider power - law fourth order theories of gravity obtained by replacing the scalar curvature $R$ with $f(R) = f_0 R^n$ in the gravity Lagrangian. We show that, in the low energy limit, the gravitational potential generated by a pointlike source may be written as $\\Phi(r) \\propto r^{-1} \\left [ 1 + (r/r_c)^{\\beta} \\right ]$ with $\\beta$ a function of the slope $n$ of the gravity Lagrangian and $r_c$ a scalelength depending on the gravitating system properties. In order to apply the model to realistic systems, we compute the modified potential and the rotation curve for spherically symmetric and for thin disk mass distributions. It turns out that the potential is still asymptotically decreasing, but the corrected rotation curve, although not flat, is higher than the Newtonian one thus offering the possibility to fit rotation curves without dark matter. To test the viability of the model, we consider a sample of 15 low surface brightness (LSB) galaxies with combined HI and H$\\alpha$ measurements of the rotation curve extending in the putative dark matter dominated region. We find a very good agreement between the theoretical rotation curve and the data using only stellar disk and interstellar gas.

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

2006-03-20T23:59:59.000Z

22

Squall Lines and Convectively Coupled Gravity Waves in the Tropics: Why Do Most Cloud Systems Propagate Westward?  

Science Conference Proceedings (OSTI)

The coupling between tropical convection and zonally propagating gravity waves is assessed through Fourier analysis of high-resolution (3-hourly, 0.5°) satellite rainfall data. Results show the familiar enhancement in power along the dispersion ...

Stefan N. Tulich; George N. Kiladis

2012-10-01T23:59:59.000Z

23

Limiter  

SciTech Connect

A limiter with a specially contoured front face accommodates the various power scrape-off distances .lambda..sub.p, which depend on the parallel velocity, V.sub..parallel., of the impacting particles. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution.

Cohen, Samuel A. (Hopewell, NJ); Hosea, Joel C. (Princeton, NJ); Timberlake, John R. (Allentown, NJ)

1986-01-01T23:59:59.000Z

24

A line-imaging velocity interferometer technique for shock diagnostics without x-ray preheat limitation  

Science Conference Proceedings (OSTI)

A study was conducted with a line-imaging velocity interferometer on sandwich targets at the Shen Guang-III prototype laser facility in China, with the goal of eliminating the preheat effect. A sandwich target structure was used to reduce the x-ray preheat limitation (radiation temperature {approx}170 eV) in a radiative drive shock experiment. With a thick ablator, the preheat effect appeared before the shock arrived at the window. After adding a shield layer of high-Z material on the ablator, x-rays which penetrated the ablator were so weak that the blank-out effect could not be measured. This experiment indicates that the sandwich target may provide a valuable technique in experiments such as equation of state and shock timing for inertial confinement fusion studies.

Wang Feng; Peng Xiaoshi; Liu Shenye; Xu Tao; Mei Lusheng; Jiang Xiaohua; Ding Yongkun [Research Center of Laser Fusion, CAEP, P.O. Box 919-986, Mianyang 621900 (China)

2011-10-15T23:59:59.000Z

25

Near-horizon limit of the charged BTZ black hole and AdS_2 quantum gravity  

E-Print Network (OSTI)

We show that the 3D charged Banados-Teitelboim-Zanelli (BTZ) black hole solution interpolates between two different 2D AdS spacetimes: a near-extremal, near-horizon AdS_2 geometry with constant dilaton and U(1) field and an asymptotic AdS_2 geometry with a linear dilaton. Thus, the charged BTZ black hole can be considered as interpolating between the two different formulations proposed until now for AdS_2 quantum gravity. In both cases the theory is the chiral half of a 2D CFT and describes, respectively, Brown-Hennaux-like boundary deformations and near-horizon excitations. The central charge c_as of the asymptotic CFT is determined by 3D Newton constant G and the AdS length l, c_as=3l/G, whereas that of the near-horizon CFT also depends on the U(1) charge Q, c_nh \\propto l Q/\\sqrt G.

Mariano Cadoni; Mohammad R. Setare

2008-06-17T23:59:59.000Z

26

Numerical Simulation and Analysis of a Prefrontal Squall Line. Part II: Propagation of the Squall Line as an Internal Gravity Wave  

Science Conference Proceedings (OSTI)

A numerical study of the squall line that occurred on 17–18 June 1978 was described in Part I of this paper. The squall line was collocated with a surface front during its initial development (at 0000 UTC 18 June 1978), but then propagated faster ...

Jennifer M. Cram; Roger A. Pielke; William R. Cotton

1992-02-01T23:59:59.000Z

27

Massive Gravity  

E-Print Network (OSTI)

We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali-Gabadadze-Porrati model, cascading gravity and ghost-free massive gravity. We then explore their theoretical and phenomenological consistency, proving the absence of Boulware-Deser ghosts and reviewing the Vainshtein mechanism and the cosmological solutions in these models. Finally we present alternative and related models of massive gravity such as new massive gravity, Lorentz-violating massive gravity and non-local massive gravity.

de Rham, Claudia

2014-01-01T23:59:59.000Z

28

Massive Gravity  

E-Print Network (OSTI)

We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali-Gabadadze-Porrati model, cascading gravity and ghost-free massive gravity. We then explore their theoretical and phenomenological consistency, proving the absence of Boulware-Deser ghosts and reviewing the Vainshtein mechanism and the cosmological solutions in these models. Finally we present alternative and related models of massive gravity such as new massive gravity, Lorentz-violating massive gravity and non-local massive gravity.

Claudia de Rham

2014-01-16T23:59:59.000Z

29

Gravity Waves in a Horizontal Shear Flow. Part II: Interaction between Gravity Waves and Potential Vorticity Perturbations  

E-Print Network (OSTI)

Interaction among potential vorticity perturbations and propagating internal gravity waves in a horizontally sheared zonal flow is investigated. In the strong stratification limit, an initial vorticity perturbation weakly excites two propagating gravity waves while the density component of the potential vorticity perturbation is significantly amplified, potentially leading to convective collapse. If stratification is sufficiently weak, a strong coupling between vorticity perturbations and gravity waves is found and spontaneous gravity wave generation occurs. This coupling can be traced to the nonnormal interaction between the potential vorticity and gravity wave manifolds in the weak stratification limit. Vorticity perturbations amplify in energy due to downgradient Reynolds stress when their phase lines tilt against the shear and the large growth attained is transferred to propagating gravity waves. When the flow geometry is such that the excited gravity waves are confined in the vicinity of the vorticity perturbation by their trapping levels, an overall convective collapse of this region can be anticipated. On the other hand, when the flow geometry permits wave propagation, significant gravity wave emission occurs. 1.

Nikolaos A. Bakas; Brian; F. Farrell

2007-01-01T23:59:59.000Z

30

Limit theorem for a time-dependent coined quantum walk on the line  

E-Print Network (OSTI)

We study time-dependent discrete-time quantum walks on the one-dimensional lattice. We compute the limit distribution of a two-period quantum walk defined by two orthogonal matrices. For the symmetric case, the distribution is determined by one of two matrices. Moreover, limit theorems for two special cases are presented.

Takuya Machida; Norio Konno

2010-04-03T23:59:59.000Z

31

Limitations on the obligation to provide access to electric transmission and distribution lines  

Science Conference Proceedings (OSTI)

The authors examine the limited availability of wheeling under the Federal Power Act, as amended by the Public Utility Regulatory Policies Act. They demonstrate that the adoption of the essential facilities doctrine to determine possession of monopoly power may be a positive step toward more realistic analysis of refusals to deal by regulated companies. Without objective cost standards, however, to determine whether a facility is essential, this step may be counterproductive or even meaningless. In the context of requests to wheel, they identify the specific competition to be protected and the proper standards for determining whether a facility is essential. The obligation to wheel remains an uncertainty which the courts will resolve on a case-by-case basis. The scope of legitimate business conduct, however, can be clarified by the courts and, potentially, could be resolved to limit further a utility's obligation to wheel. 146 references.

Norton, F.L. IV; Early, M.B.

1984-01-01T23:59:59.000Z

32

Experimental Verification of the Kruskal-Shafranov Stability Limit in Line-Tied Partial Toroidal Plasmas  

SciTech Connect

The stability properties of partial toroidal flux ropes are studied in detail in the laboratory, motivated by ubiquitous arched magnetic structures found on the solar surface. The flux ropes studied here are magnetized arc discharges formed between two electrodes in the Magnetic Reconnection Experiment (MRX) [Yamada et al., Phys. Plasmas, 4, 1936 (1997)]. The three dimensional evolution of these flux ropes is monitored by a fast visible light framing camera, while their magnetic structure is measured by a variety of internal magnetic probes. The flux ropes are consistently observed to undergo large-scale oscillations as a result of an external kink instability. Using detailed scans of the plasma current, the guide field strength, and the length of the flux rope, we show that the threshold for kink stability is governed by the Kruskal-Shafranov limit for a flux rope that is held fixed at both ends (i.e., qa = 1).

E. Oz, C.E. Myers, M. Yamada, H. Ji, R.M.. Kulsrud and J. Xie

2011-07-19T23:59:59.000Z

33

Gravity in Gauge Mediation  

E-Print Network (OSTI)

We investigate O'Raifeartaigh-type models for F-term supersymmetry breaking in gauge mediation scenarios in the presence of gravity. It is pointed out that the vacuum structure of those models is such that in metastable vacua gravity mediation contribution to scalar masses is always suppressed to the level below 1 percent, almost sufficient for avoiding FCNC problem. Close to that limit, gravitino mass can be in the range 10-100 GeV, opening several interesting possibilities for gauge mediation models, including Giudice-Masiero mechanism for mu and Bmu generation. Gravity sector can include stabilized moduli.

Zygmunt Lalak; Stefan Pokorski; Krzysztof Turzynski

2008-08-04T23:59:59.000Z

34

Entropic Gravity in Rindler Space  

E-Print Network (OSTI)

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.

Halyo, Edi

2011-01-01T23:59:59.000Z

35

Entropic Gravity in Rindler Space  

E-Print Network (OSTI)

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.

Edi Halyo

2011-04-13T23:59:59.000Z

36

Cascading gravity is ghost free  

SciTech Connect

We perform a full perturbative stability analysis of the 6D cascading gravity model in the presence of 3-brane tension. We demonstrate that for sufficiently large tension on the (flat) 3-brane, there are no ghosts at the perturbative level, consistent with results that had previously only been obtained in a specific 5D decoupling limit. These results establish the cascading gravity framework as a consistent infrared modification of gravity.

Rham, Claudia de [Departement de Physique Theorique, Universite de Geneve, 24 Quai E. Ansermet, CH-1211 Geneve (Switzerland); Khoury, Justin [Center for Particle Cosmology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6395 (United States); Tolley, Andrew J. [Perimeter Institute for Theoretical Physics, 31 Caroline St. N., Waterloo, ON, N2L 2Y5 (Canada)

2010-06-15T23:59:59.000Z

37

Einstein Gravity from Conformal Gravity  

E-Print Network (OSTI)

We show that that four dimensional conformal gravity plus a simple Neumann boundary condition can be used to get the semiclassical (or tree level) wavefunction of the universe of four dimensional asymptotically de-Sitter or Euclidean anti-de Sitter spacetimes. This simple Neumann boundary condition selects the Einstein solution out of the more numerous solutions of conformal gravity. It thus removes the ghosts of conformal gravity from this computation. In the case of a five dimensional pure gravity theory with a positive cosmological constant we show that the late time superhorizon tree level probability measure, $|\\Psi [ g ]|^2$, for its four dimensional spatial slices is given by the action of Euclidean four dimensional conformal gravity.

Juan Maldacena

2011-05-27T23:59:59.000Z

38

Gravity brake  

DOE Patents (OSTI)

A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.

Lujan, Richard E. (Santa Fe, NM)

2001-01-01T23:59:59.000Z

39

Gravity Waves in a Horizontal Shear Flow. Part II: Interaction between Gravity Waves and Potential Vorticity Perturbations  

E-Print Network (OSTI)

Gravity Waves in a Horizontal Shear Flow. Part II: Interaction between Gravity Waves and Potential perturbations and propagating internal gravity waves in a horizon- tally sheared zonal flow is investigated. In the strong stratification limit, an initial vorticity perturbation weakly excites two propagating gravity

Farrell, Brian F.

40

Lovelock gravity from entropic force  

E-Print Network (OSTI)

In this paper, we first generalize the formulation of entropic gravity to (n+1)-dimensional spacetime. Then, we propose an entropic origin for Gauss-Bonnet gravity and more general Lovelock gravity in arbitrary dimensions. As a result, we are able to derive Newton's law of gravitation as well as the corresponding Friedmann equations in these gravity theories. This procedure naturally leads to a derivation of the higher dimensional gravitational coupling constant of Friedmann/Einstein equation which is in complete agreement with the results obtained by comparing the weak field limit of Einstein equation with Poisson equation in higher dimensions. Our study shows that the approach presented here is powerful enough to derive the gravitational field equations in any gravity theory. PACS: 04.20.Cv, 04.50.-h, 04.70.Dy.

A. Sheykhi; H. Moradpour; N. Riazi

2011-09-11T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Gravity settling  

DOE Patents (OSTI)

Solids are separated from a liquid in a gravity settler provided with inclined solid intercepting surfaces to intercept the solid settling path to coalesce the solids and increase the settling rate. The intercepting surfaces are inverted V-shaped plates, each formed from first and second downwardly inclined upwardly curved intersecting conical sections having their apices at the vessel wall.

Davis, Hyman R. (Glenridge, NJ); Long, R. H. (Morristown, NJ); Simone, A. A. (Dover, NJ)

1979-01-01T23:59:59.000Z

42

Understanding gravity  

E-Print Network (OSTI)

AdS/CFT correspondence provides a holographic duality between gravitational physics and gauge dynamics. What field theory configurations lend themselves to a good semi-classical description? Relevance: Making precise the nature of the holographic map Understanding the emergence of geometry. What are “legal ” singularities in gravity (cosmic censorship)? Insight into new solutions. Motivation Conformal fluids Bulk geometry Horizons & entropy Conclusion

Mukund Rangamani

2008-01-01T23:59:59.000Z

43

Applications of operation research to the analysis for the impacts of the transmission line capacity limitation on  

E-Print Network (OSTI)

of the wind power generated from wind turbines or released from its storage system out of the total power and the transmission line capacity. If the power supply from wind turbines cannot be transmitted online in real and the total wind power that can be captured by wind turbines at hour t. It is also impacted

44

Born-Infeld gravity in three dimensions  

Science Conference Proceedings (OSTI)

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.

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

45

Intrusive gravity currents  

E-Print Network (OSTI)

The front speed of intrusive gravity currents. J. FluidP.F. Linden. Intrusive gravity currents. J. Fluid Mechanics,of mesoscale variability of gravity waves. Part II: Frontal,

Hang, Alice Thanh

2009-01-01T23:59:59.000Z

46

TORSION AND QUANTUM GRAVITY  

E-Print Network (OSTI)

more restrictive context of Einstein's theory of gravity.6782 TORSION AND QUANTUM GRAVITY Andrevr J, Him son Lawrencetorsion in conventional gravity cou~d in fact be dynamicaL A

Hanson, Andrew J.

2011-01-01T23:59:59.000Z

47

Deformed Einstein Gravity  

Science Conference Proceedings (OSTI)

We introduce the necessary concepts for an algebraic construction of a gravity theory on noncommutative spaces. The ??deformed diffeomorphisms are studied and a tensor calculus is defined. This leads to a deformed Einstein?Hilbert action which is invariant with respect to deformed diffeomorphisms. The dynamical variable is the vierbein field. The deformed action is a deformation of the usual Einstein?Hilbert action and reduces to it in the limit where the noncommutativity vanishes. This contribution is based on joint work with P. Aschieri

Frank Meyer

2006-01-01T23:59:59.000Z

48

Overlap Fermion in External Gravity  

E-Print Network (OSTI)

On a lattice, we construct an overlap Dirac operator which describes the propagation of a Dirac fermion in external gravity. The local Lorentz symmetry is manifestly realized as a lattice gauge symmetry, while the general coordinate invariance is expected to be restored only in the continuum limit. The lattice index density in the presence of a gravitational field is calculated.

Hiroto So; Masashi Hayakawa; Hiroshi Suzuki

2006-10-04T23:59:59.000Z

49

Generation of Turbulence by Atmospheric Gravity Waves  

Science Conference Proceedings (OSTI)

The standard current criterion for the generation of turbulence by atmospheric gravity waves and for the associated limitation on wave growth is based upon the standard criterion for static instability of the unperturbed atmosphere, namely, that ...

Colin O. Hines

1988-04-01T23:59:59.000Z

50

Effect of Nonlinearity on Atmospheric Gravity Waves  

Science Conference Proceedings (OSTI)

The weakly nonlinear limit of two-dimensional gravity waves in an incompressible, inviscid and stably stratified atmosphere is studied. The three-wave resonant interaction theory indicates an energy cascade from a vertically propagating wave (...

Mostafa M. Ibrahim

1987-02-01T23:59:59.000Z

51

Ground Gravity Survey At Lake City Hot Springs Area (Warpinski, Et Al.,  

Open Energy Info (EERE)

Lake City Hot Springs Area (Warpinski, Et Al., Lake City Hot Springs Area (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Lake City Hot Springs Area (Warpinski, Et Al., 2004) Exploration Activity Details Location Lake City Hot Springs Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes The Lake City site, which is located in far northeastern California, consists of a previously identified geothermal site that has been explored with both geophysics and drilling (Hedel, 1981), but has not been characterized adequately to allow accurate siting or drilling of production wells. Some deep wells, several seismic lines, limited gravity surveys, and geochemical and geological studies have suggested that the geothermal

52

Chiral gravity, log gravity, and extremal CFT  

Science Conference Proceedings (OSTI)

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.

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

53

Chiral Gravity, Log Gravity and Extremal CFT  

E-Print Network (OSTI)

We show that the linearization of all exact solutions of classical chiral gravity around the AdS3 vacuum have positive energy. Non-chiral 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 CFT. Moreover we show that log gravity contains chiral gravity within it as a decoupled charge superselection sector. We normally 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.

Alexander Maloney; Wei Song; Andrew Strominger

2009-03-26T23:59:59.000Z

54

A new approach to quantum gravity  

E-Print Network (OSTI)

A new idea of quantum gravity is developed based on Gravitational Complementary Principle. This principle states that gravity has dual complement features: The quantum and classical aspects of gravity are complement and absolutely separated by the planck length into planckian and over-planckian domains, respectively. The classical Einstein equations are correct at the fundamental level at over-planckian domain and general relativity is not a low energy limit of a more fundamental theory. The quantum gravity is totally confined to the planckian domain with a new kind of ultra-short range interaction, mediated by massive (Planck mass) particles, through the virtual microscopic wormholes of the Planck scale with action ¯h. There is no room for gravitons or extra dimensions in ?e-mail:f.darabi@azaruniv.edu 1this scenario. It is shown that the hierarchy problem can solve the cosmological constant problem via this new quantum gravity. 2 1

F. Darabi

2008-01-01T23:59:59.000Z

55

Scattering in Topologically Massive Gravity, Chiral Gravity and the corresponding Anyon-Anyon Potential Energy  

E-Print Network (OSTI)

We compute the tree-level scattering amplitude between two covariantly conserved sources in generic Cosmological Topologically Massive Gravity augmented with a Fierz-Pauli term that has three massive degrees of freedom. We consider the Chiral Gravity limit in the anti-de Sitter space as well as the limit of Flat-Space Chiral Gravity. We show that Chiral Gravity cannot be unitarily deformed with a Fierz-Pauli mass. We calculate the non-relativistic potential energy between two point-like spinning sources. In addition to the expected mass-mass and spin-spin interactions, there are mass-spin interactions due to the presence of the gravitational Chern-Simons term which induces spin for any massive object and turns it to an anyon. We also show that the tree-level scattering is trivial for the Flat-Space Chiral Gravity.

Dengiz, Suat; Tekin, Bayram

2013-01-01T23:59:59.000Z

56

Towards noncommutative gravity  

E-Print Network (OSTI)

In this short article accessible for non-experts I discuss possible ways of constructing a non-commutative gravity paying special attention to possibilities of realizing the full diffeomorphism symmetry and to relations with 2D gravities.

D. V. Vassilevich

2009-02-04T23:59:59.000Z

57

Heigth and Gravity  

NLE Websites -- All DOE Office Websites (Extended Search)

Heigth and Gravity Name: Evan Location: NA Country: NA Date: NA Question: Does gravity effect a person's height? How does it? Would people with back problems benefit from time...

58

Motion in Quantum Gravity  

E-Print Network (OSTI)

We tackle the question of motion in Quantum Gravity: what does motion mean at the Planck scale? Although we are still far from a complete answer we consider here a toy model in which the problem can be formulated and resolved precisely. The setting of the toy model is three dimensional Euclidean gravity. Before studying the model in detail, we argue that Loop Quantum Gravity may provide a very useful approach when discussing the question of motion in Quantum Gravity.

Karim Noui

2010-03-31T23:59:59.000Z

59

Stephen Hawking Quantum Gravity  

E-Print Network (OSTI)

Stephen Hawking and Quantum Gravity Matt Visser Physics Department Washington University Saint Louis USA Science Saturdays 4 Nov 2000 #12; Stephen Hawking and Quantum Gravity Abstract: Through research, Stephen Hawking has captured a place in the popular imagina- tion. Quantum gravity in its various

Visser, Matt

60

Quantum Physics Einstein's Gravity  

E-Print Network (OSTI)

Quantum Physics confronts Einstein's Gravity Matt Visser Physics Department Washington University Saint Louis USA Science Saturdays 13 October 2001 #12; Quantum Physics confronts Einstein's Gravity and with Einstein's theory of gravity (the general relativity) is still the single biggest theoretical problem

Visser, Matt

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Ultraviolet Complete Quantum Gravity  

E-Print Network (OSTI)

An ultraviolet complete (UV) quantum gravity theory is formulated in which vertex functions in Feynman graphs are entire functions and the propagating gravitons are described by local, causal propagators. A scalar-tensor action describes classical gravity theory. The cosmological constant problem is investigated in the context of the UV complete quantum gravity.

Moffat, J W

2010-01-01T23:59:59.000Z

62

Quantum Gravity at the LHC  

E-Print Network (OSTI)

It has recently been shown that if there is a large hidden sector in Nature, the scale of quantum gravity could be much lower than traditionally expected. We study the production of massless gravitons at the LHC and compare our results to those obtained in extra dimensional models. The signature in both cases is missing energy plus jets. In case of non observation, the LHC could be used to put the tightest limit to date on the value of the Planck mass.

Xavier Calmet; Priscila de Aquino

2009-06-02T23:59:59.000Z

63

The Universe Adventure - Gravity  

NLE Websites -- All DOE Office Websites (Extended Search)

Gravity: The Main Attraction Gravity: The Main Attraction Gravity Acts on All Matter Gravity's effect is apparent even at the largest scales: just as gravity keeps the Earth orbiting the sun, it holds these two irregular galaxies M32 and M110 in orbit around the larger Andromeda galaxy. In the late 1600s, the English mathematician Sir Isaac Newton gave the first scientific description of gravitation. Gravity is an attractive force existing between any two objects that have mass, causing them to accelerate towards each other. It is the weakest of the four fundamental forces but can act over great distances and is responsible for the formation of planets, stars, galaxies, and even larger scale structures such as groups and superclusters. Gravity is also the force that governs the motion of

64

Quantization of Emergent Gravity  

E-Print Network (OSTI)

Emergent gravity is based on a novel form of the equivalence principle known as the Darboux theorem or the Moser lemma in symplectic geometry stating that the electromagnetic force can always be eliminated by a local coordinate transformation as far as spacetime admits a symplectic structure, in other words, a microscopic spacetime becomes noncommutative (NC). If gravity emerges from U(1) gauge theory on NC spacetime, this picture of emergent gravity suggests a completely new quantization scheme where quantum gravity is defined by quantizing spacetime itself, leading to a dynamical NC spacetime. Therefore the quantization of emergent gravity is radically different from the conventional approach trying to quantize a phase space of metric fields. This approach for quantum gravity allows a background independent formulation where spacetime as well as matter fields is equally emergent from a universal vacuum of quantum gravity.

Hyun Seok Yang

2013-12-02T23:59:59.000Z

65

Comment on "A limit on the variation of the speed of light arising from quantum gravity effects" aka "Testing Einstein's special relativity with Fermi's short hard gamma-ray burst GRB090510"  

E-Print Network (OSTI)

Recently the Fermi GBM and LAT Collaborations reported their new observational data disfavoring quite a number of the quantum gravity theories, including the one suggesting the nonlinear (logarithmic) modification of a quantum wave equation. We show that the latter is still far from being ruled out: it is not only able to explain the new data but also its phenomenological implications turn out to be more vast (and more interesting) than one expected before.

Konstantin G. Zloshchastiev

2009-11-30T23:59:59.000Z

66

Category:Gravity Techniques | Open Energy Information  

Open Energy Info (EERE)

Techniques page? For detailed information on Gravity Techniques, click here. Category:Gravity Techniques Add.png Add a new Gravity Techniques Technique Pages in category "Gravity...

67

Solar System experiments do not yet veto modified gravity models  

E-Print Network (OSTI)

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.

Valerio Faraoni

2006-07-05T23:59:59.000Z

68

Lectures on loop gravity  

E-Print Network (OSTI)

This is the first version of the introductory lectures on loop quantum gravity that I will give at the quantum gravity school in Zakopane. The theory is presented in self-contained form, without emphasis on its derivation from classical general relativity. Dynamics is given in the covariant form. The approximations needed to compute physical quantities are discussed. Some applications are described, including the recent derivation of de Sitter cosmology from full quantum gravity.

Rovelli, Carlo

2011-01-01T23:59:59.000Z

69

Dark gravity and cosmology  

E-Print Network (OSTI)

The previous version of this article was a first attempt to confront the Dark Gravity theory to cosmological data. However, more recent developments lead to the conclusion that the cosmological principle is probably not valid in Dark Gravity so that this kind of analysis is at best very premature. A more recent and living review of the Dark Gravity theory can be found in gr-qc/0610079

F. Henry-Couannier; A. Tilquin; C. Tao; A. Ealet

2005-09-05T23:59:59.000Z

70

Is Gravity an Interaction?  

E-Print Network (OSTI)

We consider a possibility that gravity is not an interaction but a manifestation of a symmetry based on a Galois field.

Felix M. Lev

2009-05-06T23:59:59.000Z

71

Gold Standard Gravity ?†  

E-Print Network (OSTI)

This paper provides striking confirmation of the restrictions of the structural gravity model of trade. Structural forces predicted by theory explain 95 % of the variation of the fixed effects used to control for them in the recent gravity literature, fixed effects that in principle could reflect other forces. This validation opens avenues to inferring unobserved sectoral activity and multilateral resistance variables by equating fixed effects with structural gravity counterparts. Our findings also provide important validation of a host of general equilibrium comparative static exercises based on the structural gravity model.

James E. Anderson; Yoto V. Yotov; Dave Donaldson; Keith Head; Michael Waugh; We Arthur Lewbel

2012-01-01T23:59:59.000Z

72

Quantum gravity on the lattice  

E-Print Network (OSTI)

the Conference Quantum Gravity: Challenges and Perspectives.divergences in quantum gravity. In: Hawking, S.W. , Israel,f ) V n?1 ( f ) = Quantum gravity on the lattice Similarly,

Hamber, Herbert W.

2009-01-01T23:59:59.000Z

73

Gauge/Gravity Duality (Gauge Gravity Duality)  

SciTech Connect

Gauge theories, which describe the particle interactions, are well understood, while quantum gravity leads to many puzzles. Remarkably, in recent years we have learned that these are actually dual, the same system written in different variables. On the one hand, this provides our most precise description of quantum gravity, resolves some long-standing paradoxes, and points to new principles. On the other, it gives a new perspective on strong interactions, with surprising connections to other areas of physics. I describe these ideas, and discuss current and future directions.

Polchinski, Joseph (Kavli Institute for Theoretical Physics)

2010-02-24T23:59:59.000Z

74

Particle Dynamics And Emergent Gravity  

E-Print Network (OSTI)

The emergent gravity proposal is examined within the framework of noncommutative QED/gravity correspondence from particle dynamics point of view.

Amir H. Fatollahi

2008-05-08T23:59:59.000Z

75

GRAVITY DARKENING AND BRIGHTENING IN BINARIES  

SciTech Connect

We apply a von Zeipel gravity darkening model to corotating binaries to obtain a simple, analytical expression for the emergent radiative flux from a tidally distorted primary orbiting a point-mass secondary. We adopt a simple Roche model to determine the envelope structure of the primary, assumed massive and centrally condensed, and use the results to calculate the flux. As for single rotating stars, gravity darkening reduces the flux along the stellar equator of the primary, but, unlike for rotating stars, we find that gravity brightening enhances the flux in a region around the stellar poles. We identify a critical limiting separation beyond which hydrostatic equilibrium no longer is possible, whereby the flux vanishes at the point on the stellar equator of the primary facing the companion. For equal-mass binaries, the total luminosity is reduced by about 13% when this limiting separation is reached.

White, Helen E.; Baumgarte, Thomas W. [Department of Physics and Astronomy, Bowdoin College, Brunswick, ME 04011 (United States); Shapiro, Stuart L. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

2012-06-20T23:59:59.000Z

76

Parametic Study of the current limit within a single driver-scale transport beam line of an induction Linac for Heavy Ion Fusion  

E-Print Network (OSTI)

of the RIA or SNS beam lines. ..the Spallation Neutron Source (SNS) Front End [38,39,40] anddistributions. For example the SNS linac [38,166] or Rare

Prost, Lionel Robert

2007-01-01T23:59:59.000Z

77

A quantized frequency reference in the short-ranged gravity potential and its application for dark matter and dark energy searches  

E-Print Network (OSTI)

The evidence for the observation of the Higgs spin-0-boson as a manifestation of a scalar field provides the missing corner stone for the standard model of particles (SM). However, the SM fails to explain the non-visible but gravitationally active part of the universe. Its nature is unknown but the confirmation of a scalar Higgs is giving a boost to scalar-field-theories. So far gravity experiments and observations performed at different distances find no deviation from Newton's gravity law. Therefore dark energy must possess a screening mechanism which suppresses the scalar-mediated fifth force. Our line of attack is a novel gravity experiment with neutrons based on a quantum interference technique. The spectroscopic measurement of quantum states on resonances with an external coupling makes this a powerful search for dark matter and dark energy contributions in the universe. Quantum states in the gravity potential are intimately related to other scalar field or spin-0-bosons if they exist. If the reason is that some undiscovered particle interact with a neutron, this results in a measurable energy shift of quantum states in the gravity potential, because for neutrons the screening effect is absent. We use Gravity Resonance Spectroscopy to measure the energy splitting at the highest level of precision, providing a constraint on any possible new interaction. We obtain a sensitivity of 10^-14 eV. We set an experimental limit on any fifth force, in particular on parameter \\betagravity is understood at this improved level of precision.

T. Jenke; G. Cronenberg; P. Geltenbort; A. N. Ivanov; T. Lauer; T. Lins; U. Schmidt; H. Saul; H. Abele

2012-08-19T23:59:59.000Z

78

Energy extraction and particle acceleration around a rotating black hole in Horava-Lifshitz gravity  

E-Print Network (OSTI)

Energy extraction and particle acceleration around a rotating black hole in Horava-Lifshitz gravity-Lifshitz gravity is studied. The strong dependence of the extracted energy from the special range of parameters that the fundamental parameter of the Horava-Lifshitz gravity can impose a limitation on the energy of the accelerating

79

Probability around the Quantum Gravity. Part 1: Planar Pure Gravity  

E-Print Network (OSTI)

Probability around the Quantum Gravity. Part 1: Planar Pure Gravity V.A.Malyshev \\Lambda September 17, 1998 Abstract In this paper we study stochastic dynamics which leaves quantum gravity equilibrium science and biology. At the same time the paper can serve an intro­ duction to quantum gravity

80

Status of Matter-Gravity Couplings in the SME  

E-Print Network (OSTI)

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.

Tasson, Jay D

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Quantum Gravity An introductory survey  

E-Print Network (OSTI)

Quantum Gravity An introductory survey Hermann Nicolai Max-Planck-Institut f¨ur Gravitationsphysik (Albert­Einstein­Institut, Potsdam) . ­ p.1/25 #12;Why Quantum Gravity? . ­ p.2/25 #12;Why Quantum Gravity theories: . ­ p.2/25 #12;Why Quantum Gravity? General Relativity and Quantum Theory: not only very

Rossak, Wilhelm R.

82

Toroidal solutions in Horava Gravity  

E-Print Network (OSTI)

Recently a new four-dimensional non relativistic renormalizable theory of gravity was proposed by Horava. This gravity reduces to Einstein gravity at large distances. In this paper by using the new action for gravity we present different toroidal solutions to the equations of motion. Our solutions describe the near horizon geometry with slow rotating parameter.

Ahmad Ghodsi

2009-05-06T23:59:59.000Z

83

Equivalence between therm and gravity  

E-Print Network (OSTI)

We introduce the notion of thermal entropy density, and first demonstrated that there exists an equivalence between therm and gravity without depending on the definition of temperature or horizon. This equivalence indicates that gravity possesses thermal features, or, therm possesses effects of gravity. This may shed light on the nature of gravity.

Yang, Rong-Jia

2011-01-01T23:59:59.000Z

84

Gravity and the quantum potential  

E-Print Network (OSTI)

We review some material connecting gravity and the quantum potential and provide a few new observations.

Robert Carroll

2004-06-02T23:59:59.000Z

85

Solar system constraints on R$^n$ gravity  

E-Print Network (OSTI)

Recently, gravitational microlensing has been investigated in the framework of the weak field limit of fourth order gravity theory. However, solar system data (i.e. planetary periods and light bending) can be used to put strong constraints on the parameters of this class of gravity theories. We find that these parameters must be very close to those corresponding to the Newtonian limit of the theory.

A. F. Zakharov; A. A. Nucita; F. De Paolis; G. Ingrosso

2006-11-02T23:59:59.000Z

86

Gravity Waves in a Horizontal Shear Flow. Part II: Interaction between Gravity Waves and Potential Vorticity Perturbations  

Science Conference Proceedings (OSTI)

Interaction among potential vorticity perturbations and propagating internal gravity waves in a horizontally sheared zonal flow is investigated. In the strong stratification limit, an initial vorticity perturbation weakly excites two propagating ...

Nikolaos A. Bakas; Brian F. Farrell

2009-03-01T23:59:59.000Z

87

Gravity Waves from Thunderstorms  

Science Conference Proceedings (OSTI)

Gravity waves generated by severe thunderstorms in the eastern Ohio-Pennsylvania area were recorded by an array of microbarovariographs at Palisades, New York and by standard microbarographs across northeastern United States. The waves were ...

Nambath K. Balachandran

1980-06-01T23:59:59.000Z

88

Why gravity is fundamental  

E-Print Network (OSTI)

It is argued that the existence of a minimum size of spacetime may imply the fundamental existence of gravity as a geometric property of spacetime described by general relativity.

Shan Gao

2010-01-18T23:59:59.000Z

89

Causal Newton Gravity Law  

E-Print Network (OSTI)

The equations of the relativistic causal Newton gravity law for the planets of the solar system are studied in the approximation when the Sun rests at the coordinates origin and the planets do not iteract between each other.

Yury M. Zinoviev

2012-01-17T23:59:59.000Z

90

Exercise in artificial gravity  

E-Print Network (OSTI)

Artificial gravity provided by short radius centrifugation is considered a promising countermeasure to the deleterious physiological effects of microgravity during long-duration space flight. We investigated the feasibility ...

Edmonds, Jessica Leigh

2005-01-01T23:59:59.000Z

91

Dog Center of Gravity  

NLE Websites -- All DOE Office Websites (Extended Search)

Dog Center of Gravity Name: Dania Status: Student Grade: 9-12 Location: AZ Country: USA Date: NA Question: Currently in physics we are working with projectile motion. I am...

92

Why gravity is fundamental  

E-Print Network (OSTI)

It is argued that the existence of a minimum size of spacetime may imply the fundamental existence of gravity as a geometric property of spacetime described by general relativity.

Gao, Sheldon

2010-01-01T23:59:59.000Z

93

Quantum gravity effects in the Kerr spacetime  

Science Conference Proceedings (OSTI)

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.

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

94

Gravity-driven intrusions in stratified fluids  

E-Print Network (OSTI)

5.5.1 Five interleaving interfacial gravity currents 5.5.2Ten interleaving interfacial gravity currents . 5.6partial- depth intrusive gravity currents,” Atmosphere -

Maurer, Benjamin Dudley

2011-01-01T23:59:59.000Z

95

Non-trivial 2+1-Dimensional Gravity  

E-Print Network (OSTI)

We analyze 2+1-dimensional gravity in the framework of quantum gauge theory. We find that Einstein gravity has a trivial physical subspace which reflects the fact that the classical solution in empty space is flat. Therefore we study massive gravity which is not trivial. In the limit of vanishing graviton mass we obtain a non-trivial massless theory different from Einstein gravity. We derive the interaction from descent equations and obtain the cosmological topologically massive gravity. However, in addition to Einstein and Chern-Simons coupling we need coupling to fermionic ghost and anti-ghost fields and to a vector-graviton field with the same mass as the graviton.

D. R. Grigore; G. Scharf

2010-08-07T23:59:59.000Z

96

Exploring Gravity and Gravitational Wave Dynamics Part II: Gravity Models  

Science Conference Proceedings (OSTI)

The need for a new gravity model may explain anomalous behavior exhibited by several recent experiments described in Part I. Although Newtonian gravity is adequate for predicting the motion of celestial bodies

P. A. Murad

2007-01-01T23:59:59.000Z

97

Glossary API Gravity: An  

Gasoline and Diesel Fuel Update (EIA)

5 60 60 131 5 . . The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below. Intermediate crudes fall in the range of 22 degrees to 38 degrees API gravity. ASTM: American Society for Testing and Materials. Aviation Gasoline (Finished): A complex mixture of relatively volatile hydrocarbons with or without small quantities of additives, blended to form a fuel suitable for use in aviation reciprocating engines. Fuel specifi- cations are provided in ASTM Specification D 910 and Military Specification MIL-G-5572. Note: Data on blending components are not counted in data on fin- ished aviation gasoline. Barrel: A volumetric unit of measure for crude oil and petroleum products equivalent to 42 U.S. gallons. Bulk Sales: Wholesale sales of gasoline in individual

98

Glossary API Gravity: An  

Gasoline and Diesel Fuel Update (EIA)

60 60 1315 . . The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below. Intermediate crudes fall in the range of 22 degrees to 38 degrees API gravity. ASTM: American Society for Testing and Materials. Aviation Gasoline (Finished): A complex mixture of relatively volatile hydrocarbons with or without small quantities of additives, blended to form a fuel suitable for use in aviation reciprocating engines. Fuel specifi- cations are provided in ASTM Specification D 910 and Military Specification MIL-G-5572. Note: Data on blending components are not counted in data on fin- ished aviation gasoline. Barrel: A volumetric unit of measure for crude oil and petroleum products equivalent to 42 U.S. gallons. Bulk Sales: Wholesale sales of gasoline in individual

99

Macroscopic quantization of gravity  

E-Print Network (OSTI)

The moon is receding from earth at an average rate of 3.8 cm/yr [6][7][9][12].This anomaly cannot be attributed to the well-known tidal exchange of angular momentum between earth and moon [8]. A secular change in the astronomical unit AU is definitely a concern, it is reportedly increasing by about 15 cm/yr [9][10], in this letter; the concept of macroscopic quantization of gravity is introduced to account for these anomalies on theoretical basis. Interestingly, it was found useful in measuring the speed of gravity! What is more interesting is the fact that this concept is based on solid well known classical physics with no modifications to any standard model. It was found that the speed of gravity cg is in the range 10^4 c < cg < 10^5 c.

M. Y. Amin

2009-12-12T23:59:59.000Z

100

Euler Chern Simons Gravity from Lovelock Born Infeld Gravity  

E-Print Network (OSTI)

In the context of a gauge theoretical formulation, higher dimensional gravity invariant under the AdS group is dimensionally reduced to Euler-Chern-Simons gravity. The dimensional reduction procedure of Grignani-Nardelli [Phys. Lett. B 300, 38 (1993)] is generalized so as to permit reducing D-dimensional Lanczos Lovelock gravity to d=D-1 dimensions.

Fernando Izaurieta; Eduardo Rodriguez; Patricio Salgado

2004-02-25T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Gravity wraps Higgs boson  

E-Print Network (OSTI)

It is shown that, by rescaling the matter fields and metric tensor with appropriate powers of the Higgs field, the Higgs boson can be wholly transferred from material sector to the gravity sector in which it possesses only gravitational interactions and escapes detection in collider experiments. The Higgs boson gets buried in a scalar-tensor theory of gravity wherein it might be of relevance for Dark Energy. It is absent from the electroweak spectrum yet leptons, quarks and vector bosons possess their already known properties. The Higgs boson can contact with the matter sector via only the higher-dimensional operators suppressed by a cutoff scale.

Demir, Durmus A

2011-01-01T23:59:59.000Z

102

Sodium Nightglow and Gravity Waves  

Science Conference Proceedings (OSTI)

Oscillations in intensity of NaD nightglow attributed to mesospheric gravity waves have bean studied. Fractional atmospheric density perturbations have been obtained by means of the linear gravity waves theory of Hines. Values of other parameters ...

A. Molina

1983-10-01T23:59:59.000Z

103

Quantum gravity on the lattice  

E-Print Network (OSTI)

C. : Fields on a random lattice. In: Progress in Gauge Field= Quantum gravity on the lattice Similarly, one can considerQuantum gravity on the lattice Herbert W. Hamber Received:

Hamber, Herbert W.

2009-01-01T23:59:59.000Z

104

Introduction to Loop Quantum Gravity  

E-Print Network (OSTI)

The questions I have been asked during the 5th International School on Field Theory and Gravitation, have compelled me to give an account of the premises that I consider important for a beginner's approach to Loop Quantum Gravity. After a description of some general arguments and an introduction to the canonical theory of gravity, I review the background independent approach to quantum gravity, giving only a brief survey of Loop Quantum Gravity.

Mercuri, Simone

2010-01-01T23:59:59.000Z

105

Gravity's weight on worldline fuzziness  

E-Print Network (OSTI)

We investigate a connection between recent results in 3D quantum gravity, providing an effective noncommutative-spacetime description, and some earlier heuristic descriptions of a quantum-gravity contribution to the fuzziness of the worldlines of particles. We show that 3D-gravity-inspired spacetime noncommutativity reflects some of the features suggested by previous heuristic arguments. Most notably, gravity-induced worldline fuzziness, while irrelevantly small on terrestrial scales, could be observably large for propagation of particles over cosmological distances.

Amelino-Camelia, Giovanni; Rosati, Giacomo

2012-01-01T23:59:59.000Z

106

Introduction to Loop Quantum Gravity  

E-Print Network (OSTI)

The questions I have been asked during the 5th International School on Field Theory and Gravitation, have compelled me to give an account of the premises that I consider important for a beginner's approach to Loop Quantum Gravity. After a description of some general arguments and an introduction to the canonical theory of gravity, I review the background independent approach to quantum gravity, giving only a brief survey of Loop Quantum Gravity.

Simone Mercuri

2010-01-08T23:59:59.000Z

107

Massive gravity on a brane  

E-Print Network (OSTI)

Dam, Veltman and Zakharov [13], implies that the tensor structure of the gravitational interaction deviates from that of Einstein gravity.

Chacko, Z.; Graesser, M.L.; Grojean, C.; Pilo, L.

2003-01-01T23:59:59.000Z

108

New probe of modified gravity  

E-Print Network (OSTI)

We suggest a new efficient way to constrain a certain class of large scale modifications of gravity. We show that the scale-free relation between density and size of Dark Matter halos, predicted within the LambdaCDM model with Newtonian gravity, gets modified in a wide class of theories of modified gravity.

Boyarsky, Alexey

2010-01-01T23:59:59.000Z

109

D-Dimensional Log Gravity  

E-Print Network (OSTI)

We study Einstein gravity in dimensions $D\\geq 4$ modified by curvature squared at critical point where the theory contains only massless gravitons. We show that at the critical point a new mode appears leading to a logarithmic gravity in the theory. The corresponding logarithmic solution may provide a gravity description of logarithmic CFT in higher dimensions.

Alishahiha, Mohsen

2011-01-01T23:59:59.000Z

110

5, 1102911054, 2005 Convective gravity  

E-Print Network (OSTI)

ACPD 5, 11029­11054, 2005 Convective gravity waves at mid-latitudes Y. G. Choi et al. Title Page Discussions Wind-profiler observations of gravity waves produced by convection at mid-latitudes Y. G. Choi1­11054, 2005 Convective gravity waves at mid-latitudes Y. G. Choi et al. Title Page Abstract Introduction

Paris-Sud XI, Université de

111

CFT, Integrable Models Liouville Gravity  

E-Print Network (OSTI)

CFT, Integrable Models And Liouville Gravity Chernogolovka 2009 Sunday June 28, 2009. Conference as one of components of their L, A pairs. #12;CFT, Integrable Models And Liouville Gravity Chernogolovka Gravity Chernogolovka, 2009 Tuesday June 30, 2009. CONFERENCE HALL 09:30­10:10 Herman Boos (Wuppertal

Fominov, Yakov

112

From Classical To Quantum Gravity: Introduction to Loop Quantum Gravity  

E-Print Network (OSTI)

We present an introduction to the canonical quantization of gravity performed in loop quantum gravity, based on lectures held at the 3rd quantum geometry and quantum gravity school in Zakopane in 2011. A special feature of this introduction is the inclusion of new proposals for coupling matter to gravity that can be used to deparametrize the theory, thus making its dynamics more tractable. The classical and quantum aspects of these new proposals are explained alongside the standard quantization of vacuum general relativity in loop quantum gravity.

Giesel, Kristina

2012-01-01T23:59:59.000Z

113

Even-dimensional topological gravity from Chern-Simons gravity  

E-Print Network (OSTI)

It is shown that the topological action for gravity in 2n-dimensions can be obtained from the 2n+1-dimensional Chern-Simons gravity genuinely invariant under the Poincare group. The 2n-dimensional topological gravity is described by the dynamics of the boundary of a 2n+1-dimensional Chern-Simons gravity theory with suitable boundary conditions. The field $\\phi^{a}$, which is necessary to construct this type of topological gravity in even dimensions, is identified with the coset field associated with the non-linear realizations of the Poincare group ISO(d-1,1).

Nelson Merino; Alfredo Perez; Patricio Salgado

2009-10-08T23:59:59.000Z

114

Bigravity and Massive Gravity  

Science Conference Proceedings (OSTI)

We discuss some issues concerning the global structure of spherically symmetric solutions of bigravity. We propose maximal extensions of manifolds where two causal structure coexist. Besides we make some comments about the perturbations of these solutions and their relation to massive gravity and the cosmological constant problem.

D. Blas

2006-01-01T23:59:59.000Z

115

Isometrodynamics and Gravity  

E-Print Network (OSTI)

Isometrodynamics (ID), the gauge theory of the group of volume-preserving diffeomorphisms of an "inner" D-dimensional flat space, is tentatively interpreted as a fundamental theory of gravity. Dimensional analysis shows that the Planck length l_P - and through it \\hbar and \\Gamma - enters the gauge field action linking ID and gravity in a natural way. Noting that the ID gauge field couples solely through derivatives acting on "inner" space variables all ID fields are Taylor-expanded in "inner" space. Integrating out the "inner" space variables yields an effective field theory for the coefficient fields with l_P^2 emerging as the expansion parameter. For \\hbar goint to zero only the leading order field does not vanish. This classical field couples to the matter Noether currents and charges related to the translation invariance in "inner" space. A model coupling this leading order field to a matter point source is established and solved. Interpreting the matter Noether charge in terms of gravitational mass Newton's inverse square law is finally derived for a static gauge field source and a slowly moving test particle. Gravity emerges as potentially related to field variations over "inner" space and might microscopically be described by the ID gauge field or equivalently by an infinite string of coefficient fields only the leading term of which is related to the macroscopical effects of gravity.

Christian Wiesendanger

2009-06-23T23:59:59.000Z

116

Quantum Gravity and Turbulence  

E-Print Network (OSTI)

We apply recent advances in quantum gravity to the problem of turbulence. Adopting the AdS/CFT approach we propose a string theory of turbulence that explains the Kolmogorov scaling in 3+1 dimensions and the Kraichnan and Kolmogorov scalings in 2+1 dimensions. In the gravitational context, turbulence is intimately related to the properties of spacetime, or quantum, foam.

Vishnu Jejjala; Djordje Minic; Y. Jack Ng; Chia-Hsiung Tze

2010-05-18T23:59:59.000Z

117

The gravity of light  

E-Print Network (OSTI)

A solution of the old problem raised by Tolman, Ehrenfest, Podolsky and Wheeler, concerning the lack of attraction of two light pencils "moving parallel", is proposed, considering that the light can be source of nonlinear gravitational waves corresponding (in the would be quantum theory of gravity) to spin-1 massless particles.

G. Sparano; G. Vilasi; S. Vilasi

2010-09-12T23:59:59.000Z

118

High energy scattering in gravity and supergravity  

E-Print Network (OSTI)

We investigate features of perturbative gravity and supergravity by studying scattering in the ultraplanckian limit, and sharpen arguments that the dynamics is governed by long-distance physics. A simple example capturing aspects of the eikonal resummation suggests why short distance phenomena and in particular divergences or nonrenormalizability do not necessarily play a central role in this regime. A more profound problem is apparently unitarity. These considerations can be illustrated by showing that known gravity and supergravity amplitudes have the same long-distance behavior, despite the extra light states of supergravity, and this serves as an important check on long-range dynamics in a context where perturbative amplitudes are finite. We also argue that these considerations have other important implications: they obstruct probing the conjectured phenomenon of asymptotic safety through a physical scattering process, and ultraplanckian scattering exhibiting Regge behavior. These arguments sharpen the need to find a nonperturbative completion of gravity with mechanisms which restore unitarity in the strong gravity regime.

Steven B. Giddings; Maximilian Schmidt-Sommerfeld; Jeppe R. Andersen

2010-05-28T23:59:59.000Z

119

Flavorful hybrid anomaly-gravity mediation  

SciTech Connect

We consider supersymmetric models where anomaly and gravity mediation give comparable contributions to the soft terms and discuss how this can be realized in a five-dimensional brane world. The gaugino mass pattern of anomaly mediation is preserved in such a hybrid setup. The flavorful gravity-mediated contribution cures the tachyonic slepton problem of anomaly mediation. The supersymmetric flavor puzzle is solved by alignment. We explicitly show how a working flavor-tachyon link can be realized with Abelian flavor symmetries and give the characteristic signatures of the framework, including O(1) slepton mass splittings between different generations and between doublets and singlets. This provides opportunities for same flavor dilepton edge measurements with missing energy at the Large Hadron Collider (LHC). Rare lepton decay rates could be close to their current experimental limit. Compared to pure gravity mediation, the hybrid model is advantageous because it features a heavy gravitino which can avoid the cosmological gravitino problem of gravity-mediated models combined with leptogenesis.

Gross, Christian; Hiller, Gudrun [Institut fuer Physik, Technische Universitaet Dortmund, D-44221 Dortmund (Germany)

2011-05-01T23:59:59.000Z

120

Tolerance Limits  

Science Conference Proceedings (OSTI)

... LIMITS Y ** *** 2-SIDED NORMAL TOLERANCE LIMITS: XBAR +- K*S REFERENCE--CRC HANDBOOK, PAGES 32-35 ...

2010-12-06T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Ghost dark energy in $f(R)$ model of gravity  

E-Print Network (OSTI)

We study a correspondence between $f(R)$ model of gravity and a phenomenological kind of dark energy (DE), which is known as QCD ghost dark energy. Since this kind of dark energy is not stable in the context of Einsteinian theory of gravity and Brans-Dicke model of gravity, we consider two kinds of correspondence between modified gravity and DE. By studding the dynamical evolution of model and finding relevant quantities such as, equation of state parameter, deceleration parameter, dimensionless density parameter, we show that the model can describe the present Universe and also the EoS parameter can cross the phantom divide line without needs to any kinetic energy with negative sign. Furthermore, by obtaining the adiabatic squared sound speed of the model for different cases of interaction, we show that this model is stable.

Saaidi, Kh; Sabet, B

2012-01-01T23:59:59.000Z

122

A perspective on Quantum Gravity Phenomenology  

E-Print Network (OSTI)

I give a brief overview of some Quantum-Gravity-Phenomenology research lines, focusing on studies of cosmic rays and gamma-ray bursts that concern the fate of Lorentz symmetry in quantum spacetime. I also stress that the most valuable phenomenological analyses should not mix too many conjectured new features of quantum spacetime, and from this perspective it appears that it should be difficult to obtain reliable guidance on the quantum-gravity problem from the analysis of synchrotron radiation from the Crab nebula and from the analysis of phase coherence of light from extragalactic sources. Forthcoming observatories of ultra-high-energy neutrinos should provide several opportunities for clean tests of some simple hypothesis for the short-distance structure of spacetime. In particular, these neutrino studies, and some related cosmic-ray studies, should provide access to the regime $E>\\sqrt{m E_p}$.

Giovanni Amelino-Camelia

2004-02-02T23:59:59.000Z

123

Photon and graviton mass limits  

Science Conference Proceedings (OSTI)

We review past and current studies of possible long-distance, low-frequency deviations from Maxwell electrodynamics and Einstein gravity. Both have passed through three phases: (1) Testing the inverse-square laws of Newton and Coulomb, (2) Seeking a nonzero value for the rest mass of photon or graviton, and (3) Considering more degrees of freedom, allowing mass while preserving gauge or general-coordinate invariance. For electrodynamics there continues to be no sign of any deviation. Since our previous review the lower limit on the photon Compton wavelength (associated with weakening of electromagnetic fields in vacuum over large distance scale) has improved by four orders of magnitude, to about one astronomical unit. Rapid current progress in astronomical observations makes it likely that there will be further advances. These ultimately could yield a bound exceeding galactic dimensions, as has long been contemplated. Meanwhile, for gravity there have been strong arguments about even the concept of a graviton rest mass. At the same time there are striking observations, commonly labeled 'dark matter' and 'dark energy' that some argue imply modified gravity. This makes the questions for gravity much more interesting. For dark matter, which involves increased attraction at large distances, any explanation by modified gravity would be qualitatively different from graviton mass. Because dark energy is associated with reduced attraction at large distances, it might be explained by a graviton-mass-like effect.

Nieto, Michael [Los Alamos National Laboratory; Goldhaber Scharff, Alfred [SUNY

2008-01-01T23:59:59.000Z

124

Quantum gravity and "singularities"  

E-Print Network (OSTI)

The paper concerns the fictitious entanglement of the so-called ``singularities'' in problems, pertaining to quantum gravity, due, in point of fact, to the way we try to employ, in that context, differential geometry, the latter being associated, in effect, by far, classically (:smooth manifolds), on the basis of an erroneous correspondence between what we may call/understand, as ``physical space'' and the ``cartesian-newtonian'' one.

Anastasios Mallios

2004-05-20T23:59:59.000Z

125

Lorentz Breaking and Gravity  

E-Print Network (OSTI)

Gravitational theories with Lorentz violation must account for a number of possible features in order to be consistent theoretically and phenomenologically. A brief summary of these features is given here. They include evasion of a no-go theorem, connections between spontaneous Lorentz breaking and diffeomorphism breaking, the appearance of massless Nambu-Goldstone modes and massive Higgs modes, and the possibility of a Higgs mechanism in gravity.

R. Bluhm

2013-07-22T23:59:59.000Z

126

Gravity, Dimension, Equilibrium, & Thermodynamics  

E-Print Network (OSTI)

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.

Jerome Perez

2006-03-30T23:59:59.000Z

127

The Particle Adventure | What holds it together? | Gravity  

NLE Websites -- All DOE Office Websites (Extended Search)

holds it together? > Gravity Gravity What about gravity? Gravity is weird. It is clearly one of the fundamental interactions, but the Standard Model cannot satisfactorily explain...

128

Einstein gravity as a 3D conformally invariant theory  

E-Print Network (OSTI)

We give an alternative description of the physical content of general relativity that does not require a Lorentz invariant spacetime. Instead, we find that gravity admits a dual description in terms of a theory where local size is irrelevant. The dual theory is invariant under foliation preserving 3-diffeomorphisms and 3D conformal transformations that preserve the 3-volume (for the spatially compact case). Locally, this symmetry is identical to that of Horava-Lifshitz gravity in the high energy limit but our theory is equivalent to Einstein gravity. Specifically, we find that the solutions of general relativity, in a gauge where the spatial hypersurfaces have constant mean extrinsic curvature, can be mapped to solutions of a particular gauge fixing of the dual theory. Moreover, this duality is not accidental. We provide a general geometric picture for our procedure that allows us to trade foliation invariance for conformal invariance. The dual theory provides a new proposal for the theory space of quantum gravity.

Henrique Gomes; Sean Gryb; Tim Koslowski

2010-10-12T23:59:59.000Z

129

Quantum gravity and inventory accumulation  

E-Print Network (OSTI)

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.

Scott Sheffield

2011-08-10T23:59:59.000Z

130

Gravity Methods | Open Energy Information  

Open Energy Info (EERE)

Gravity Methods Gravity Methods Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Gravity Methods Details Activities (0) Areas (0) Regions (0) NEPA(3) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Gravity Techniques Parent Exploration Technique: Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Gravity Methods: No definition has been provided for this term. Add a Definition References No exploration activities found. Document # Analysis Type Applicant Geothermal Area Lead Agency District Office Field Office Mineral Manager Surface Manager Development Phase(s) Techniques NVN-084630 CU Vulcan Energy Patua Geothermal Area BLM Nevada State Office BLM Winnemucca District Office BLM Humboldt River Field Office BLM BLM Geothermal/Exploration Gravity Methods

131

Non-Newtonian gravity in finite nuclei  

E-Print Network (OSTI)

In this talk, we report our recent study of constraining the non-Newtonian gravity at femtometer scale. We incorporate the Yukawa-type non-Newtonian gravitational potential consistently to the Skyrme functional form using the exact treatment for the direct contribution and density-matrix expansion method for the exchange contribution. The effects from the non-Newtonian potential on finite nuclei properties are then studied together with a well-tested Skyrme force. Assuming that the framework without non-Newtonian gravity can explain the binding energies and charge radii of medium to heavy nuclei within 2% error, we set an upper limit for the strength of the non-Newtonian gravitational potential at femtometer scale.

Xu, Jun; Chen, Lie-Wen; Zheng, Hao

2012-01-01T23:59:59.000Z

132

The Interactions of Gravity Waves with Mesocyclones: Preliminary Observations and Theory  

Science Conference Proceedings (OSTI)

Apparent interactions between ducted gravity waves and preexisting mesocyclones are investigated. Preliminary analyses of Weather Surveillance Radar-1988 Doppler (WSR-88D) observations from several cases reveal that the intersection of fine lines,...

Timothy A. Coleman; Kevin R. Knupp

2008-11-01T23:59:59.000Z

133

Effects of Tropospheric Wind Shear on the Spectrum of Convectively Generated Gravity Waves  

Science Conference Proceedings (OSTI)

The authors examine the effects of tropospheric wind shear on the phase speed spectrum of gravity waves generated by tropical convection. A two-dimensional cloud-resolving model is used to perform numerous squall line simulations with the ...

Jadwiga H. Beres; M. Joan Alexander; James R. Holton

2002-06-01T23:59:59.000Z

134

D-dimensional log gravity  

SciTech Connect

We study Einstein gravity in dimensions D{>=}4 modified by curvature squared at critical point where the theory contains only massless gravitons. We show that at the critical point a new mode appears leading to a logarithmic gravity in the theory. The corresponding logarithmic solution may provide a gravity description of logarithmic conformal field theories (CFT) in higher dimensions. We note also that for special values of the parameters of the theory, the model admits solutions with nonrelativistic isometries.

Alishahiha, Mohsen; Fareghbal, Reza [School of physics, Institute for Research in Fundamental Sciences (IPM), P. O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

2011-04-15T23:59:59.000Z

135

Bulalo field, Philippines: Reservoir modeling for prediction of limits to sustainable generation  

DOE Green Energy (OSTI)

The Bulalo geothermal field, located in Laguna province, Philippines, supplies 12% of the electricity on the island of Luzon. The first 110 MWe power plant was on line May 1979; current 330 MWe (gross) installed capacity was reached in 1984. Since then, the field has operated at an average plant factor of 76%. The National Power Corporation plans to add 40 MWe base load and 40 MWe standby in 1995. A numerical simulation model for the Bulalo field has been created that matches historic pressure changes, enthalpy and steam flash trends and cumulative steam production. Gravity modeling provided independent verification of mass balances and time rate of change of liquid desaturation in the rock matrix. Gravity modeling, in conjunction with reservoir simulation provides a means of predicting matrix dry out and the time to limiting conditions for sustainable levelized steam deliverability and power generation.

Strobel, Calvin J.

1993-01-28T23:59:59.000Z

136

Dark Matter and Dark Energy as Effects of Quantum Gravity  

E-Print Network (OSTI)

I present a theory of quantum gravity based on the principle of gravitational energy fluctuations. Gravitational energy fluctuations -- gravitons -- are responsible for elastic scattering of subatomic particles. Such scattering corresponds to complimentary force -- graviton scattering force -- arising in gravitational interaction in addition to Newtonian gravity. The strength of the graviton scattering force is proportional to the graviton scattering probability. Unlike Newtonian gravity the graviton scattering force follows the 1/r law and dominates the former on cosmological scale in the limit of low orbital accelerations. Similarly to Modified Newtonian Dynamics the quantum gravity accounts for variations in observed M/L ratios of diverse stellar systems ranging from dwarf spheroid galaxies to X-ray galaxy clusters without requiring an invisible matter (which is still required by MOND in X-Ray cluster cores). Unlike MOND the presented theory neither violates cornerstone Newton Laws nor suffers from the ambiguity of acceleration frames while enjoying vast experimental evidence usually cited in favor of MOND. To ascertain the validity of the presented theory I have examined the predictions of quantum gravity for dwarf spheroid, ordinary and giant elliptic galaxies, and X-ray clusters. In all cases quantum gravity yields M/L ratios and scaling relations consistent with observations. Quantum gravity accounts for the tilt of the Fundamental Plane of elliptical galaxies erasing the differences in M/L vs. luminosity relations for faint and bright ellipticals, which cannot be easily explained by CDM model. Lastly, by analyzing the behavior of the gravitational energy fluctuations in the limit of high matter density expected in the early Universe I show that primordial inflation and dark energy (i.e. non-zero cosmological constant) arise as natural effects of quantum gravity in the expanding Universe.

Max I. Fomitchev

2010-09-07T23:59:59.000Z

137

Is Gravity an Entropic Force?  

E-Print Network (OSTI)

The remarkable connections between gravity and thermodynamics seem to imply that gravity is not fundamental but emergent, and in particular, as Verlinde suggested, gravity is probably an entropic force. In this paper, we will argue that the idea of gravity as an entropic force is debatable. It is shown that there is no convincing analogy between gravity and entropic force in Verlinde's example. Neither holographic screen nor test particle satisfies all requirements for the existence of entropic force in a thermodynamics system. Furthermore, we show that the entropy increase of the screen is not caused by its statistical tendency to increase entropy as required by the existence of entropic force, but in fact caused by gravity. Therefore, Verlinde's argument for the entropic origin of gravity is problematic. In addition, we argue that the existence of a minimum size of spacetime, together with the Heisenberg uncertainty principle in quantum theory, may imply the fundamental existence of gravity as a geometric property of spacetime. This may provide a further support for the conclusion that gravity is not an entropic force.

Shan Gao

2010-02-13T23:59:59.000Z

138

Topological methods in quantum gravity.  

E-Print Network (OSTI)

??The main technical problem with background independent approaches to quantum gravity is inapplicability of standard quantum field theory methods. New methods are needed which would… (more)

Starodubtsev, Artem

2005-01-01T23:59:59.000Z

139

Lorentz Invariance Violation in Modified Gravity  

E-Print Network (OSTI)

We consider an environmentally dependent violation of Lorentz invariance in scalar-tensor models of modified gravity where General Relativity is retrieved locally thanks to a screening mechanism. We find that fermions have a modified dispersion relation and would go faster than light in an anisotropic and space-dependent way along the scalar field lines of force. We analyse briefly the OPERA results and show that they could be reproduced with chameleon models. We suggest that neutrinos emitted radially, at different energies, and observed on the other side of the earth would provide a test of these models.

Brax, Philippe

2012-01-01T23:59:59.000Z

140

Gravity wraps Higgs boson  

E-Print Network (OSTI)

It is shown that, under a conformal transformation with reference to the Higgs field, the Higgs boson can be completely decoupled from electroweak interactions with no apparent change in known properties of leptons, quarks and vector bosons. Higgs boson becomes part of a scalar-tensor gravity which can be relevant for Dark Energy. It interacts with matter sector via higher-dimensional terms (e.g. neutrino Majorana mass), and via the fields (of new physics) whose masses are not generated by the Higgs mechanism. Dark Matter and two-Higgs-doublet model are the simplest examples.

Durmus A. Demir

2011-10-17T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Discrete gravity models and Loop Quantum Gravity: a short review  

E-Print Network (OSTI)

We review the relation between loop quantum gravity on a fixed graph and discrete models of gravity. We compare Regge and twisted geometries, and discuss discrete actions based on twisted geometries and on the discretization of the Plebanski action. We discuss the role of discrete geometries in the spin foam formalism, with particular attention to the definition of the simplicity constraints.

Dupuis, Maite; Speziale, Simone

2012-01-01T23:59:59.000Z

142

Gravity-Driven Intrusions in Stratified Fluids  

E-Print Network (OSTI)

5.5.1 Five interleaving interfacial gravity currents 5.5.2Ten interleaving interfacial gravity currents . 5.6in Iceland showing multiple gravity-driven intrusions c ´

Maurer, Benjamin D.

2011-01-01T23:59:59.000Z

143

The role of information in gravity  

E-Print Network (OSTI)

It is argued that particle-specific information on energy-momentum adjusts the strength of gravity. This form of gravity has no free parameters, preserves Einstein gravity locally and predicts 6 times stronger accelerations on galaxy scales.

M. Spaans

2009-03-25T23:59:59.000Z

144

Definition: Airborne Gravity Survey | Open Energy Information  

Open Energy Info (EERE)

Survey Jump to: navigation, search Dictionary.png Airborne Gravity Survey Airborne gravity gradiometry (AGG) surveys provide information regarding the mass distribution of the...

145

Gravity Waves in the Sun  

E-Print Network (OSTI)

We present numerical simulations of penetrative convection and gravity wave excitation in the Sun. Gravity waves are self-consistently generated by a convective zone overlying a radiative interior. We produce power spectra for gravity waves in the radiative region as well as estimates for the energy flux of gravity waves below the convection zone. We calculate a peak energy flux in waves below the convection zone to be three orders of magnitude smaller than previous estimates for m=1. The simulations show that the linear dispersion relation is a good approximation only deep below the convective-radiative boundary. Both low frequency propagating gravity waves as well as higher frequency standing modes are generated; although we find that convection does not continually drive the standing g-mode frequencies.

Tamara M. Rogers; Gary A. Glatzmaier

2005-08-25T23:59:59.000Z

146

Geometry and symmetries in lattice spinor gravity  

SciTech Connect

Lattice spinor gravity is a proposal for regularized quantum gravity based on fermionic degrees of freedom. In our lattice model the local Lorentz symmetry is generalized to complex transformation parameters. The difference between space and time is not put in a priori, and the euclidean and the Minkowski quantum field theory are unified in one functional integral. The metric and its signature arise as a result of the dynamics, corresponding to a given ground state or cosmological solution. Geometrical objects as the vierbein, spin connection or the metric are expectation values of collective fields built from an even number of fermions. The quantum effective action for the metric is invariant under general coordinate transformations in the continuum limit. The action of our model is found to be also invariant under gauge transformations. We observe a 'geometrical entanglement' of gauge- and Lorentz-transformations due to geometrical objects transforming non-trivially under both types of symmetry transformations. - Highlights: Black-Right-Pointing-Pointer We formulate the geometrical aspects of a proposal for a lattice regularized model of quantum gravity. Black-Right-Pointing-Pointer The vierbein shows an entanglement between Lorentz symmetry and gauge symmetry. Black-Right-Pointing-Pointer Euclidean and Minkowski signatures of the collective metric and the vierbein are described within the same functional integral.

Wetterich, C., E-mail: c.wetterich@thphys.uni-heidelberg.de

2012-09-15T23:59:59.000Z

147

Gravity quantized: Loop quantum gravity with a scalar field  

Science Conference Proceedings (OSTI)

...''but we do not have quantum gravity.'' This phrase is often used when analysis of a physical problem enters the regime in which quantum gravity effects should be taken into account. In fact, there are several models of the gravitational field coupled to (scalar) fields for which the quantization procedure can be completed using loop quantum gravity techniques. The model we present in this paper consists of the gravitational field coupled to a scalar field. The result has similar structure to the loop quantum cosmology models, except that it involves all the local degrees of freedom of the gravitational field because no symmetry reduction has been performed at the classical level.

Domagala, Marcin; Kaminski, Wojciech [Instytut Fizyki Teoretycznej, Uniwersytet Warszawski, ul. Hoza 69, 00-681 Warszawa (Warsaw), Polska (Poland) (Poland); Giesel, Kristina [Excellence Cluster Universe, Technische Universitaet Muenchen, Boltzmannstrasse 2, 85748 Garching (Germany); Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Lewandowski, Jerzy [Instytut Fizyki Teoretycznej, Uniwersytet Warszawski, ul. Hoza 69, 00-681 Warszawa (Warsaw), Polska (Poland) (Poland); Institute for Gravitation and the Cosmos, Physics Department, Penn State, University Park, Pennsylvania 16802 (United States)

2010-11-15T23:59:59.000Z

148

Geophysics IV. Gravity, Magnetic, and Magnetotelluric Methods  

SciTech Connect

During the past two decades, the technology of geophysics has exploded. At the same time, the petroleum industry has been forced to look for more and more subtle traps in more and more difficult terrain. The choice of papers in this geophysics reprint volume reflects this evolution. The papers were chosen to help geologists, not geophysicists, enhance their knowledge of geophysics. Math-intensive papers were excluded because those papers are relatively esoteric and have limited applicability for most geologists. This volume concentrates on gravity, magnetic, and magnetotelluric methods. Each of the 10 papers were abstracted and indexed for the U.S. Department of Energy's Energy Data Base.

Beaumont, E.A.; Foster, N.H. (comps.)

1989-01-01T23:59:59.000Z

149

Collapse of charged scalar field in dilaton gravity  

Science Conference Proceedings (OSTI)

We elaborated the gravitational collapse of a self-gravitating complex charged scalar field in the context of the low-energy limit of the string theory, the so-called dilaton gravity. We begin with the regular spacetime and follow the evolution through the formation of an apparent horizon and the final central singularity.

Borkowska, Anna; Rogatko, Marek; Moderski, Rafal [Institute of Physics, Maria Curie-Sklodowska University, 20-031 Lublin, pl. Marii Curie-Sklodowskiej 1 (Poland); Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, 00-716 Warsaw, Bartycka 18 (Poland)

2011-04-15T23:59:59.000Z

150

Test of relativistic gravity for propulsion at the Large Hadron Collider  

E-Print Network (OSTI)

A design is presented of a laboratory experiment that could test the suitability of relativistic gravity for propulsion of spacecraft to relativistic speeds. An exact time-dependent solution of Einstein's gravitational field equation confirms that even the weak field of a mass moving at relativistic speeds could serve as a driver to accelerate a much lighter payload from rest to a good fraction of the speed of light. The time-dependent field of ultrarelativistic particles in a collider ring is calculated. An experiment is proposed as the first test of the predictions of general relativity in the ultrarelativistic limit by measuring the repulsive gravitational field of bunches of protons in the Large Hadron Collider (LHC). The estimated 'antigravity beam' signal strength at a resonant detector of each proton bunch is 3 nm/s^2 for 2 ns during each revolution of the LHC. This experiment can be performed off-line, without interfering with the normal operations of the LHC.

Franklin Felber

2009-10-06T23:59:59.000Z

151

Quantum Histories and Quantum Gravity  

E-Print Network (OSTI)

This paper reviews the histories approach to quantum mechanics. This discussion is then applied to theories of quantum gravity. It is argued that some of the quantum histories must approximate (in a suitable sense) to classical histories, if the correct classical regime is to be recovered. This observation has significance for the formulation of new theories (such as quantum gravity theories) as it puts a constraint on the kinematics, if the quantum/classical correspondence principle is to be preserved. Consequences for quantum gravity, particularly for Lorentz symmetry and the idea of "emergent geometry", are discussed.

Joe Henson

2009-01-26T23:59:59.000Z

152

Spin-gravity coupling and gravity-induced quantum phases  

E-Print Network (OSTI)

External gravitational fields induce phase factors in the wave functions of particles. The phases are exact to first order in the background gravitational field, are manifestly covariant and gauge invariant and provide a useful tool for the study of spin-gravity coupling and of the optics of particles in gravitational or inertial fields. We discuss the role that spin-gravity coupling plays in particular problems.

Giorgio Papini

2007-09-06T23:59:59.000Z

153

Nonlinear Evolution of an Upward Propagating Gravity Wave: Overturning, Convection, Transience and Turbulence  

Science Conference Proceedings (OSTI)

A numerical simulation of the nonlinear evolution of an upward propagating gravity wave shows that over-turning (the turning over of isopotential temperature surfaces) is the mechanism responsible for limiting the growth of the wave. Wave ...

R. L. Walterscheid; G. Schubert

1990-01-01T23:59:59.000Z

154

Comments on "Solar System constraints to general f(R) gravity"  

E-Print Network (OSTI)

We comment on, and complete, the analysis of the weak field limit of metric f(R) gravity in T. Chiba, T.L. Smith, and A.L. Erickcek, Phys. Rev. D 75, 124014 (2007).

Valerio Faraoni; Nicolas Lanahan-Tremblay

2007-12-19T23:59:59.000Z

155

Normal Mode Initialization and the Generation of Gravity Waves by Quasi-Geostrophic Forcing  

Science Conference Proceedings (OSTI)

Several numerical weather prediction models now use nonlinear normal-mode initialization schemes. These schemes describe balanced states which act to limit the initial presence of high-frequency gravity waves and their subsequent growth by ...

Ronald M. Errico

1982-03-01T23:59:59.000Z

156

Oklahoma, Kansas, Missouri Refinery District API Gravity ...  

U.S. Energy Information Administration (EIA)

Oklahoma, Kansas, Missouri Refinery District API Gravity (Weighted Average) of Crude Oil Input to Refineries (Degree)

157

Intrusive gravity currents in two-layer  

E-Print Network (OSTI)

Intrusive gravity currents in two-layer stratified media Morris R. Flynn & Paul F. Linden Dept to as a gravity current · In contrast to waves, gravity currents transport significant mass (e.g. fluid parcels, sediment, insects, etc.) Introduction Gravity currents in the environment www

Flynn, Morris R.

158

Gravity's Cosmic ShadowsGravity's Cosmic Shadows A Mathematical UnveilingA Mathematical Unveiling  

E-Print Network (OSTI)

Gravity's Cosmic ShadowsGravity's Cosmic Shadows A Mathematical UnveilingA Mathematical Unveiling of gravity on light SUNSUN #12;Gravitational Lensing - action of gravity on light SUNSUN #12;Gravitational Lensing - action of gravity on light SUNSUN nn 1801: Johann von1801: Johann von SoldnerSoldner (Newtonian

Weinberger, Hans

159

Waste Isolation Pilot Plant (WIPP) site gravity survey and interpretation  

Science Conference Proceedings (OSTI)

A portion of the WIPP site has been extensively surveyed with high-precision gravity. The main survey (in T22S, R31E) covered a rectangular area 2 by 4-1/3 mi encompassing all of WIPP site Zone II and part of the disturbed zone to the north of the site. Stations were at 293-ft intervals along 13 north-south lines 880 ft apart. The data are considered accurate to within a few hundredths of a milligal. Long-wavelength gravity anomalies correlate well with seismic time structures on horizons below the Castile Formation. Both the gravity anomalies and the seismic time structures are interpreted as resulting from related density and velocity variations within the Ochoan Series. Shorter wavelength negative gravity anomalies are interpreted as resulting from bulk density alteration in the vicinity of karst conduits. The WIPP gravity survey was unable to resolve low-amplitude, long-wavelength anomalies that should result from the geologic structures within the disturbed zone. It did indicate the degree and character of karst development within the surveyed area.

Barrows, L.J.; Fett, J.D.

1983-04-01T23:59:59.000Z

160

Gravity Techniques | Open Energy Information  

Open Energy Info (EERE)

Gravity Techniques Gravity Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Gravity Techniques Details Activities (0) Areas (0) Regions (0) NEPA(1) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Gravity Techniques Parent Exploration Technique: Geophysical Techniques Information Provided by Technique Lithology: Distribution of density in the subsurface enables inference of rock type. Stratigraphic/Structural: Delineation of steeply dipping formations, geological discontinuities and faults, intrusions and the deposition of silicates due to hydrothermal activity. Hydrological: Density of sedimentary rocks are strongly influenced by fluid contained within pore space. Dry bulk density refers to the rock with no moisture, while the wet bulk density accounts for water saturation; fluid content may alter density by up to 30%.(Sharma, 1997)

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Numerical Dispersion of Gravity Waves  

Science Conference Proceedings (OSTI)

When atmospheric gravity waves are simulated in numerical models, they are not only dispersive for physical but also for numerical reasons. Their wave properties (e.g., damping or propagation speed and direction) can depend on grid spacing as ...

Guido Schroeder; K. Heinke Schlünzen

2009-12-01T23:59:59.000Z

162

Critical Gravity in Four Dimensions  

SciTech Connect

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.

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

163

Structure formation in modified gravity  

Science Conference Proceedings (OSTI)

We pursue a (1+3) ?covariant analysis of cosmological peculiar velocity of pressure?free matter induced by the matter density perturbations in modified f(R) gravity theories. Instead of working in a quasi?Newtonian Eulerian frame

D. M. Solomons; P. K. S. Dunsby; S. Carloni

2009-01-01T23:59:59.000Z

164

Identifying Student Concepts of Gravity.  

E-Print Network (OSTI)

??This paper discusses a survey developed to investigate student concepts of "gravity" among AST 109 astronomy students and pre-service K-12 teachers. Survey questions were developed… (more)

Feeley, Roger Eastman

2007-01-01T23:59:59.000Z

165

Gravity Currents in Aquatic Canopies  

E-Print Network (OSTI)

A lock exchange experiment is used to investigate the propagation of gravity currents through a random array of rigid, emergent cylinders which represents a canopy of aquatic plants. As canopy drag increases, the propagating ...

Tanino, Yukie

166

Momentum Balance of Gravity Flows  

Science Conference Proceedings (OSTI)

A unified scale analysis of the momentum balance of downslope gravity flows is developed to organize previous theories for the case of negligible ambient flow and fixed temperature deficit scale. The values of several nondimensional parameters ...

L. Mahrt

1982-12-01T23:59:59.000Z

167

Quench cooling under reduced gravity  

E-Print Network (OSTI)

We report the quench cooling experiments performed with liquid O2 under different levels of gravity simulated with the magnetic gravity compensation. A copper disk is quenched from 270K to 90K. It is found that the cooling time in microgravity is very long in comparison with any other gravity level. This phenomenon is explained by the isolation effect of the gas surrounding the disk. The liquid subcooling is shown to drastically improuve the heat exchange thus reducing the cooling time (about 20 times). The effect of subcooling on the heat transfer is analyzed at different gravity levels. It is shown that such type of experiments cannot be used for the analysis of the critical heat flux (CHF) of the boiling crisis. The minimum heat flux (MHF) of boiling is analyzed instead.

Chatain, D; Nikolayev, V S; Beysens, D

2013-01-01T23:59:59.000Z

168

Performance characteristics of gravity-assisted, potassium heat pipes  

SciTech Connect

Experiments with potassium-stainless steel gravity-assisted heat pipes were performed. Performance limitations due to entrainment or flooding of the liquid return flow are compared with analytical model predictions. The effect of heated pool height was investigated and problems with surface wetting are discussed. A comparison between entrainment limits for smooth-walled and textured-walled heat pipes was made and a minimum internal surface texturing depth is suggested.

Prenger, F.C.; Keddy, E.S.; Sena, J.T.

1985-01-01T23:59:59.000Z

169

Attractions of Affine Quantum Gravity  

E-Print Network (OSTI)

All attempts to quantize gravity face several difficult problems. Among these problems are: (i) metric positivity (positivity of the spatial distance between distinct points), (ii) the presence of anomalies (partial second-class nature of the quantum constraints), and (iii) perturbative nonrenormalizability (the need for infinitely many distinct counterterms). In this report, a relatively nontechnical discussion is presented about how the program of affine quantum gravity proposes to deal with these problems.

John R. Klauder

2004-11-10T23:59:59.000Z

170

Lectures on Screened Modified Gravity  

E-Print Network (OSTI)

The acceleration of the expansion of the Universe has led to the construction of Dark Energy models where a light scalar field may have a range reaching up to cosmological scales. Screening mechanisms allow these models to evade the tight gravitational tests in the solar system and the laboratory. I will briefly review some of the salient features of screened modified gravity models of the chameleon, dilaton or symmetron types using $f(R)$ gravity as a template.

Philippe Brax

2012-11-22T23:59:59.000Z

171

Ghost dark energy in $f(R)$ model of gravity  

E-Print Network (OSTI)

We study a correspondence between $f(R)$ model of gravity and a phenomenological kind of dark energy (DE), which is known as QCD ghost dark energy. Since this kind of dark energy is not stable in the context of Einsteinian theory of gravity and Brans-Dicke model of gravity, we consider two kinds of correspondence between modified gravity and DE. By studding the dynamical evolution of model and finding relevant quantities such as, equation of state parameter, deceleration parameter, dimensionless density parameter, we show that the model can describe the present Universe and also the EoS parameter can cross the phantom divide line without needs to any kinetic energy with negative sign. Furthermore, by obtaining the adiabatic squared sound speed of the model for different cases of interaction, we show that this model is stable. Finally, we fit this model with supernova observational data in a non interaction case and we find the best values of parameter at $1\\sigma$ confidence interval as; $f_0=0.958^{+0.07}_{-0.25}$, $\\beta=-0,256^{+0.2}_{-0.1}$, and $\\Om_{m_0} = 0.23^{+0.3}_{-0.15}$. These best-fit values show that dark energy equation of state parameter, $\\om_{d_0}$, can cross the phantom divide line at the present time.

Kh. Saaidi; Ali. Aghamohammadi; B. Sabet; O. Farooq

2012-03-17T23:59:59.000Z

172

Observational Tests of Modified Gravity  

E-Print Network (OSTI)

Modified gravity theories have richer observational consequences for large-scale structure than conventional dark energy models, in that different observables are not described by a single growth factor even in the linear regime. We examine the relationships between perturbations in the metric potentials, density and velocity fields, and discuss strategies for measuring them using gravitational lensing, galaxy cluster abundances, galaxy clustering/dynamics and the ISW effect. We show how a broad class of gravity theories can be tested by combining these probes. A robust way to interpret observations is by constraining two key functions: the ratio of the two metric potentials, and the ratio of the Gravitational ``constant'' in the Poisson equation to Newton's constant. We also discuss quasilinear effects that carry signatures of gravity, such as through induced three-point correlations. Clustering of dark energy can mimic features of modified gravity theories and thus confuse the search for distinct signatures of such theories. It can produce pressure perturbations and anisotropic stresses, which breaks the equality between the two metric potentials even in general relativity. With these two extra degrees of freedom, can a clustered dark energy model mimic modified gravity models in all observational tests? We show with specific examples that observational constraints on both the metric potentials and density perturbations can in principle distinguish modifications of gravity from dark energy models. We compare our result with other recent studies that have slightly different assumptions (and apparently contradictory conclusions).

Bhuvnesh Jain; Pengjie Zhang

2007-09-17T23:59:59.000Z

173

Higgs-induced spectroscopic shifts near strong gravity sources  

SciTech Connect

We explore the consequences of the mass generation due to the Higgs field in strong gravity astrophysical environments. The vacuum expectation value of the Higgs field is predicted to depend on the curvature of spacetime, potentially giving rise to peculiar spectroscopic shifts, named hereafter 'Higgs shifts'. Higgs shifts could be searched through dedicated multiwavelength and multispecies surveys with high spatial and spectral resolution near strong gravity sources such as Sagittarius A* or broad searches for signals due to primordial black holes. The possible absence of Higgs shifts in these surveys should provide limits to the coupling between the Higgs particle and the curvature of spacetime, a topic of interest for a recently proposed Higgs-driven inflationary model. We discuss some conceptual issues regarding the coexistence between the Higgs mechanism and gravity, especially for their different handling of fundamental and composite particles.

Onofrio, Roberto [Dipartimento di Fisica 'Galileo Galilei', Universita di Padova, Via Marzolo 8, Padova 35131 (Italy) and ITAMP, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States)

2010-09-15T23:59:59.000Z

174

Spectral dimension in graph models of causal quantum gravity  

E-Print Network (OSTI)

The phenomenon of scale dependent spectral dimension has attracted special interest in the quantum gravity community over the last eight years. It was first observed in computer simulations of the causal dynamical triangulation (CDT) approach to quantum gravity and refers to the reduction of the spectral dimension from 4 at classical scales to 2 at short distances. Thereafter several authors confirmed a similar result from different approaches to quantum gravity. Despite the contribution from different approaches, no analytical model was proposed to explain the numerical results as the continuum limit of CDT. In this thesis we introduce graph ensembles as toy models of CDT and show that both the continuum limit and a scale dependent spectral dimension can be defined rigorously. First we focus on a simple graph ensemble, the random comb. It does not have any dynamics from the gravity point of view, but serves as an instructive toy model to introduce the characteristic scale of the graph, study the continuum limit and define the scale dependent spectral dimension. Having defined the continuum limit, we study the reduction of the spectral dimension on more realistic toy models, the multigraph ensembles, which serve as a radial approximation of CDT. We focus on the (recurrent) multigraph approximation of the two-dimensional CDT whose ensemble measure is analytically controlled. The latter comes from the critical Galton-Watson process conditioned on non-extinction. Next we turn our attention to transient multigraph ensembles, corresponding to higher-dimensional CDT. Firstly we study their fractal properties and secondly calculate the scale dependent spectral dimension and compare it to computer simulations. We comment further on the relation between Horava-Lifshitz gravity, asymptotic safety, multifractional spacetimes and CDT-like models.

Georgios Giasemidis

2013-10-30T23:59:59.000Z

175

Reconstructing f(T)-gravity from the polytropic and different Chaplygin gas dark energy models  

E-Print Network (OSTI)

Motivated by a recent work of us [1], we reconstruct the different f(T)-gravity models corresponding to a set of dark energy scenarios containing the polytropic, the standard Chaplygin, the generalized Chaplygin and the modified Chaplygin gas models. We also derive the equation of state parameter of the selected f(T)-gravity models and obtain the necessary conditions for crossing the phantom-divide line.

Karami, K

2010-01-01T23:59:59.000Z

176

Principal facts for a gravity survey of Baltazor Known Geothermal Resource Area, Nevada  

DOE Green Energy (OSTI)

The data presented are referenced to a gravity base station in Denio, Nevada at the Post Office, 50 meters south of the Oregon-Nevada State line, 1.6 meters south of the door in the southeast corner of the concrete porch, near the mailbox. Site is monumented with a ''USAF Gravity Station'' disc (A.C.I.C. reference number 2352-1). Base value is 979945.94.

Peterson, D.L.; Hoover, D.B.

1977-01-01T23:59:59.000Z

177

Dilaton Gravity, Poisson Sigma Models and Loop Quantum Gravity  

E-Print Network (OSTI)

Spherically symmetric gravity in Ashtekar variables coupled to Yang-Mills theory in two dimensions and its relation to dilaton gravity and Poisson sigma models are discussed. After introducing its loop quantization, quantum corrections for inverse triad components are shown to provide a consistent deformation without anomalies. The relation to Poisson sigma models provides a covariant action principle of the quantum corrected theory with effective couplings. Results are also used to provide loop quantizations of spherically symmetric models in arbitrary D space-time dimensions.

Martin Bojowald; Juan D. Reyes

2008-10-28T23:59:59.000Z

178

WILSON-BAPPU EFFECT: EXTENDED TO SURFACE GRAVITY  

SciTech Connect

In 1957, Wilson and Bappu found a tight correlation between the stellar absolute visual magnitude (M{sub V} ) and the width of the Ca II K emission line for late-type stars. Here, we revisit the Wilson-Bappu relationship (WBR) to claim that the WBR can be an excellent indicator of stellar surface gravity of late-type stars as well as a distance indicator. We have measured the width (W) of the Ca II K emission line in high-resolution spectra of 125 late-type stars obtained with the Bohyunsan Optical Echelle Spectrograph and adopted from the Ultraviolet and Visual Echelle Spectrograph archive. Based on our measurement of the emission line width (W), we have obtained a WBR of M{sub V} = 33.76 - 18.08 log W. In order to extend the WBR to being a surface gravity indicator, stellar atmospheric parameters such as effective temperature (T{sub eff}), surface gravity (log g), metallicity ([Fe/H]), and micro-turbulence ({xi}{sub tur}) have been derived from self-consistent detailed analysis using the Kurucz stellar atmospheric model and the abundance analysis code, MOOG. Using these stellar parameters and log W, we found that log g = -5.85 log W+9.97 log T{sub eff} - 23.48 for late-type stars.

Park, Sunkyung; Kang, Wonseok; Lee, Jeong-Eun [School of Space Research, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701 (Korea, Republic of); Lee, Sang-Gak, E-mail: sunkyung@khu.ac.kr, E-mail: wskang@khu.ac.kr, E-mail: jeongeun.lee@khu.ac.kr, E-mail: sanggak@snu.ac.kr [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)

2013-10-01T23:59:59.000Z

179

Modified gravity from the quantum part of the metric  

E-Print Network (OSTI)

It is shown that if a metric in quantum gravity can be decomposed as a sum of classical and quantum parts then Einstein quantum gravity looks approximately like modified gravity with a nonminimal interaction between gravity and matter.

Vladimir Dzhunushaliev; Vladimir Folomeev; Burkhard Kleihaus; Jutta Kunz

2013-12-01T23:59:59.000Z

180

Enhanced and Inhibited Gravity Wave Spectra  

Science Conference Proceedings (OSTI)

Balloon measurements were used to investigate gravity waves in the upper troposphere and lower stratosphere above the Canadian high Arctic. The amount of gravity wave activity in the stratosphere was found to be related to particular ...

James A. Whiteway

1999-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Questions and Answers - Does gravity affect atoms?  

NLE Websites -- All DOE Office Websites (Extended Search)

and Answers Main Index Next Question (Can you crush atoms?) Can you crush atoms? Does gravity affect atoms? Gravity affects atoms the same way it affects all other matter. Every...

182

A Coherent Strategy for Qauntum Gravity  

E-Print Network (OSTI)

Affine quantum gravity, which differs notably from either string theory or loop quantum gravity, is briefly reviewed. Emphasis in this article is placed on the use of affine coherent states in this program.

John R. Klauder

2004-11-10T23:59:59.000Z

183

New models of f(R) theories of gravity  

SciTech Connect

We introduce new models of f(R) theories of gravity that are a generalization of Horava-Lifshitz gravity.

Kluson, J. [Department of Theoretical Physics and Astrophysics, Faculty of Science, Masaryk University, Kotlarska 2, 611 37, Brno (Czech Republic)

2010-03-15T23:59:59.000Z

184

New Models of f(R) Theories of Gravity  

E-Print Network (OSTI)

We introduce new models of f(R) theories of gravity that are generalization of Horava-Lifshitz gravity.

J. Kluson

2009-10-30T23:59:59.000Z

185

New Models of f(R) Theories of Gravity  

E-Print Network (OSTI)

We introduce new models of f(R) theories of gravity that are generalization of Horava-Lifshitz gravity.

Kluson, J

2009-01-01T23:59:59.000Z

186

Rapid gravity and gravity gradiometry terrain corrections via an adaptive quadtree mesh discretization  

E-Print Network (OSTI)

Rapid gravity and gravity gradiometry terrain corrections via an adaptive quadtree mesh discretization Kristofer Davis1,2 M. Andy Kass1 Yaoguo Li1 1 Center for Gravity, Electrical, and Magnetic Studies of gravity gradiometry surveys utilising an adaptive quadtree mesh discretization. The data- and terrain

187

Unification of Gravity and Electromagnetism Revisited  

E-Print Network (OSTI)

Unification of gravity and electromagnetism based on a theory with an affine non-symmetric connection $\\Gamma^\\lambda_{\\mu\

Partha Ghose

2013-02-14T23:59:59.000Z

188

Help Line  

NLE Websites -- All DOE Office Websites (Extended Search)

Help Line Help Line Ombuds Help Line Committed to the fair and equitable treatment of all employees, contractors, and persons doing business with the Laboratory. Contact Ombuds Office (505)665-2837 Email Help Line (505) 667-9370 Fax (505) 667-3119 Map & Hours Help Line: (505) 667-9370 As an option to visiting the Ombuds office, we provide service through a telephone Help Line and email. The telephone Help Line is useful for individuals who have concerns and want advice or referral while preserving confidentiality and anonymity. Callers may remain anonymous and the Help Line does not have caller ID or other methods of identifying callers. The Help Line maintains the same level of confidentiality and neutrality as the other Ombuds services. The Ombuds Help Line is not for reporting emergencies or officially

189

A gravity term from spontaneous symmetry breaking  

E-Print Network (OSTI)

In this model, the gravity term in the Lagrangean comes from spontaneous symmetry breaking of an additional scalar quadruplet field $\\Upsilon$. The resulting gravitational field is approximate to one of the models of coframe gravity with parameters $\\rho_1 + 4 \\rho_2 = 0$, $\\rho_3 = 0$. This article includes an exact solution of coframe gravity with model parameters $\\rho_1 \

Mihai Moise

2014-01-02T23:59:59.000Z

190

Gravity Transform for Input Conditioning in  

E-Print Network (OSTI)

Gravity Transform for Input Conditioning in Brain Machine Interfaces António R. C. Paiva, José C. Motivation 2. Methods i. Gravity Transform ii. Modeling and output sensitivity analysis 3. Data Analysis #12;3 Outline 1. Motivation 2. Methods i. Gravity Transform ii. Modeling and output sensitivity analysis 3. Data

Paiva, António R. C.

191

The detection of low-energy Quantum Gravity fluctuations with entangled states  

E-Print Network (OSTI)

We propose a thought experiment to detect low-energy Quantum Gravity phenomena using Quantum Optical Information Technologies. Gravitational field perturbations, such as gravitational waves and quantum gravity fluctuations, decohere the entangled photon pairs, revealing the presence of gravitational field fluctuations including those more speculative sources such as compact extra dimensions and the sub-millimetric hypothetical low-energy quantum gravity phenomena and then set a limit for the decoherence of photon bunches and entangled pairs in space detectable with the current astronomical space technology.

Tamburini, Fabrizio

2009-01-01T23:59:59.000Z

192

The detection of low-energy Quantum Gravity fluctuations with entangled states  

E-Print Network (OSTI)

We propose a thought experiment to detect low-energy Quantum Gravity phenomena using Quantum Optical Information Technologies. Gravitational field perturbations, such as gravitational waves and quantum gravity fluctuations, decohere the entangled photon pairs, revealing the presence of gravitational field fluctuations including those more speculative sources such as compact extra dimensions and the sub-millimetric hypothetical low-energy quantum gravity phenomena and then set a limit for the decoherence of photon bunches and entangled pairs in space detectable with the current astronomical space technology.

Fabrizio Tamburini

2009-10-13T23:59:59.000Z

193

GRAVITY: The adaptive optics assisted, two object beam combiner for the VLTI  

E-Print Network (OSTI)

We present the adaptive optics assisted, near-infrared VLTI instrument - GRAVITY - for precision narrow-angle astrometry and interferometric phase referenced imaging of faint objects. Precision astrometry and phase-referenced interferometric imaging will realize the most advanced vision of optical/infrared interferometry with the VLT. Our most ambitious science goal is to study motions within a few times the event horizon size of the Galactic Center massive black hole and to test General Relativity in its strong field limit. We define the science reference cases for GRAVITY and derive the top level requirements for GRAVITY. The installation of the instrument at the VLTI is planned for 2012.

S. Gillessen; G. Perrin; W. Brandner; C. Straubmeier; F. Eisenhauer; S. Rabien; A. Eckart; P. Lena; R. Genzel; T. Paumard; S. Hippler

2006-07-17T23:59:59.000Z

194

Massless Limit of Gravitational Higgs Mechanism  

E-Print Network (OSTI)

In gravitational Higgs mechanism graviton components acquire mass via spontaneous diffeomorphism breaking by scalar vacuum expectation values. We point out that in the massless limit the resulting theory is not Einstein-Hilbert gravity (EHG) but constrained gravity (CG). Consequently, massive solutions in the massless limit must be compared to those in CG (as opposed to EHG). We discuss spherically symmetric solutions in this context. The Schwarzschild solution in EHG can be coordinate-transformed such that it is also a solution in CG. The resulting solutions are non-perturbative in the asymptotic regime, and are reproduced in the massless limit of asymptotic massive solutions, hence no van Dam-Veltman-Zakharov discontinuity. We point out that higher curvature terms must be included to obtain non-singular spherically symmetric massive solutions and discuss a suitable framework.

Zurab Kakushadze

2007-11-02T23:59:59.000Z

195

Momentum Transport by Gravity Waves  

Science Conference Proceedings (OSTI)

The momentum flux by orographic gravity waves and the turbulent heat flux in wave-breaking regions are estimated from aircraft data from ALPEX. The fluxes on 6 March 1982 are controlled by low-level directional shear of the mean flow and ...

Jinwon Kim; L. Mahrt

1992-05-01T23:59:59.000Z

196

High-gravity central stars  

E-Print Network (OSTI)

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.

Thomas Rauch

2006-07-11T23:59:59.000Z

197

Rheological measurements in reduced gravity  

Science Conference Proceedings (OSTI)

Rheology of fluidized beds and settling suspensions were studied experimentally in a series of reduced gravity parabolic flights aboard NASA’s KC?135 aircraft. Silica sands of two different size distributions were fluidized by air. The slurries were made using silica sand and Glycerol solution. The experimental set up incorporated instrumentation to measure the air flow rate

Sayavur I. Bakhtiyarov; Ruel A. Overfelt

1999-01-01T23:59:59.000Z

198

Gravity and the Fermion Mass  

E-Print Network (OSTI)

It is shown that gravity generates mass for the fermion. It does so by coupling directly with the spinor field. The coupling term is invariant with respect to the electroweak gauge group $ U(1) \\otimes SU(2)_L. $ It replaces the fermion mass term $ m\\bar{\\psi} \\psi $.

Kenneth Dalton

2004-09-08T23:59:59.000Z

199

Fundamental decoherence in quantum gravity  

E-Print Network (OSTI)

A recently introduced discrete formalism allows to solve the problem of time in quantum gravity in a relational manner. Quantum mechanics formulated with a relational time is not exactly unitary and implies a fundamental mechanism for decoherence of quantum states. The mechanism is strong enough to render the black hole information puzzle unobservable.

Rodolfo Gambini; Rafael Porto; Jorge Pullin

2005-01-09T23:59:59.000Z

200

Spin-Gauge Theory of Gravity with Higgs-field Mechanism  

E-Print Network (OSTI)

We propose a Lorentz-covariant Yang-Mills spin-gauge theory, where the function valued Dirac matrices play the role of a non-scalar Higgs-field. As symmetry group we choose $SU(2) \\times U(1)$. After symmetry breaking a non-scalar Lorentz-covariant Higgs-field gravity appears, which can be interpreted within a classical limit as Einstein's metrical theory of gravity, where we restrict ourselves in a first step to its linearized version.

H. Dehnen; E. Hitzer

2013-06-10T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Spacetime Structure of an Evaporating Black Hole in Quantum Gravity  

E-Print Network (OSTI)

The impact of the leading quantum gravity effects on the dynamics of the Hawking evaporation process of a black hole is investigated. Its spacetime structure is described by a renormalization group improved Vaidya metric. Its event horizon, apparent horizon, and timelike limit surface are obtained taking the scale dependence of Newton's constant into account. The emergence of a quantum ergosphere is discussed. The final state of the evaporation process is a cold, Planck size remnant.

Bonanno, A

2006-01-01T23:59:59.000Z

202

Schrodinger-like (Dilaton-)Gravity  

E-Print Network (OSTI)

We investigate possibilities for the Schrodinger-like gravity with the dynamical critical exponent z=2, where the action only contains the first-order time derivative. The Horava gravity always admits such a relevant deformation because the full (d+1) dimensional diffeomorphism of the Einstein gravity is replaced by the foliation preserving diffeomorphism. The dynamics is locally trivial or topological for the pure gravity case, but we can construct a dynamical field theory with z=2 dispersion relation by introducing a dilaton degree of freedom. Our model gives birth to a new model for quantum (dilaton-)gravity which may be applied to a membrane quantization.

Nakayama, Yu

2010-01-01T23:59:59.000Z

203

ON EFFICIENTLY COMBINING LIMITED MEMORY AND TRUST ...  

E-Print Network (OSTI)

... Euclidean norm with an insignificant computational overhead compared with the cost of computing the quasi-Newton direction in line-search limited memory ...

204

Observational signatures of Jordan-Brans-Dicke theories of gravity  

E-Print Network (OSTI)

We analyze the Jordan-Brans-Dicke model (JBD) of gravity, where deviations from General Relativity (GR) are described by a scalar field non-minimally coupled to gravity. The theory is characterized by a constant coupling parameter, $\\omega_{\\rm JBD}$; GR is recovered in the limit $\\omega_{\\rm JBD} \\to \\infty$. In such theories, gravity modifications manifest at early times, so that one cannot rely on the usual approach of looking for inconsistencies in the expansion history and perturbations growth in order to discriminate between JBD and GR. However, we show that a similar technique can be successfully applied to early and late times observables instead. Cosmological parameters inferred extrapolating early-time observations to the present will match those recovered from direct late-time observations only if the correct gravity theory is used. We use the primary CMB, as will be seen by the Planck satellite, as the early-time observable; and forthcoming and planned Supernov{\\ae}, Baryonic Acoustic Oscillations and Weak Lensing experiments as late-time observables. We find that detection of values of $\\omega_{\\rm JBD}$ as large as 500 and 1000 is within reach of the upcoming (2010) and next-generation (2020) experiments, respectively.

Viviana Acquaviva; Licia Verde

2007-09-01T23:59:59.000Z

205

A Regional Strategy For Geothermal Exploration With Emphasis On Gravity And  

Open Energy Info (EERE)

Strategy For Geothermal Exploration With Emphasis On Gravity And Strategy For Geothermal Exploration With Emphasis On Gravity And Magnetotellurics Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Regional Strategy For Geothermal Exploration With Emphasis On Gravity And Magnetotellurics Details Activities (4) Areas (2) Regions (0) Abstract: As part of the resource evaluation and exploration program conducted by Los Alamos Scientific Laboratory for the national Hot Dry Rock (HDR) Geothermal Program, a regional magnetotelluric (MT) survey of New Mexico and Arizona is being performed. The MT lines are being located in areas where the results of analysis of residual gravity anomaly maps of Arizona and New Mexico, integrated with other geologic and geophysical studies indicate the greatest potential for HDR resources. The residual

206

THE OUTSKIRTS OF GLOBULAR CLUSTERS AS MODIFIED GRAVITY PROBES  

SciTech Connect

In the context of theories of gravity modified to account for the observed dynamics of galactic systems without the need to invoke the existence of dark matter, a prediction often appears regarding low-acceleration systems: wherever a falls below a{sub 0}, one should expect a transition from the classical to the modified gravity regime. This modified gravity regime will be characterized by equilibrium velocities that become independent of distance and that scale with the fourth root of the total baryonic mass, V{sup 4}{proportional_to}M. The two conditions above are the well-known flat rotation curves and Tully-Fisher relations of the galactic regime. Recently, however, a similar phenomenology has been hinted at, at the outskirts of Galactic globular clusters, precisely in the region where a < a{sub 0}. Radial profiles of the projected velocity dispersion have been observed to stop decreasing along Keplerian expectations and to level off at constant values beyond the radii where a < a{sub 0}. We have constructed gravitational equilibrium dynamical models for a number of globular clusters for which the above gravitational anomaly has been reported, using a modified Newtonian force law that yields equilibrium velocities equivalent to modified Newtonian dynamics. We find models having an inner Newtonian region and an outer modified gravity regime, which reproduce all observational constraints, surface brightness profiles, total masses, and line-of-sight velocity dispersion profiles, can be easily constructed. Through the use of detailed single stellar population models tuned individually to each of the globular clusters in question, we derive estimates of the total masses for these systems. Interestingly, we find that the asymptotic values of the velocity dispersion profiles are consistent with scaling with the fourth root of the total masses, as expected under modified gravity scenarios.

Hernandez, X.; Jimenez, M. A., E-mail: xavier@astroscu.unam.mx [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-264, C.P. 04510 Mexico D.F. (Mexico)

2012-05-01T23:59:59.000Z

207

Studies of strong-field gravity : testing the black hole hypothesis and investigating spin-curvature coupling  

E-Print Network (OSTI)

Observations of gravitational systems agree well with the predictions of general relativity (GR); however, to date we have only tested gravity in the weak-field limit. In the next few years, observational advances may make ...

Vigeland, Sarah Jane

2012-01-01T23:59:59.000Z

208

The Dark Gravity model predictions for Gravity Probe B  

E-Print Network (OSTI)

The previous version of this article gave erroneous predictions. The correct uptodate predictions can be found in the section devoted to gravitomagnetism in the living review of the Dark Gravity theory: gr-qc/0610079 The most natural prediction is zero frame dragging and the same geodetic effect as predicted by GR. However, a straightforward extension of the theory could lead to the same frame-dragging as in GR.

Frederic Henry-Couannier

2005-09-05T23:59:59.000Z

209

Fault Current Limiters  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Fault Fault Current Limiters Superconducting & Solid-state Power Equipment Office of Electricity Delivery and Energy Reliability www.oe.energy.gov Office of Electricity Delivery and Energy Reliability, OE-1 U.S. Department of Energy - 1000 Independence Avenue, SW - Washington, DC 20585 Plugging America Into the Future of Power What are FCLs? A fault is an unintentional short circuit, or partial short-circuit, in an electric circuit. A variety of factors such as lightning, downed power lines, or crossed power lines cause faults. During a fault, excessive current-called fault current- flows through the electrical system often resulting in a failure of one section of that system by causing a

210

Dark Energy and Dark Gravity  

E-Print Network (OSTI)

Observations provide increasingly strong evidence that the universe is accelerating. This revolutionary advance in cosmological observations confronts theoretical cosmology with a tremendous challenge, which it has so far failed to meet. Explanations of cosmic acceleration within the framework of general relativity are plagued by difficulties. General relativistic models are nearly all based on a dark energy field with fine-tuned, unnatural properties. There is a great variety of models, but all share one feature in common -- an inability to account for the gravitational properties of the vacuum energy. Speculative ideas from string theory may hold some promise, but it is fair to say that no convincing model has yet been proposed. An alternative to dark energy is that gravity itself may behave differently from general relativity on the largest scales, in such a way as to produce acceleration. The alternative approach of modified gravity (or dark gravity) provides a new angle on the problem, but also faces serious difficulties, including in all known cases severe fine-tuning and the problem of explaining why the vacuum energy does not gravitate. The lack of an adequate theoretical framework for the late-time acceleration of the universe represents a deep crisis for theory -- but also an exciting challenge for theorists. It seems likely that an entirely new paradigm is required to resolve this crisis.

Ruth Durrer; Roy Maartens

2007-11-01T23:59:59.000Z

211

Dynamical 3-Space: Emergent Gravity  

E-Print Network (OSTI)

The laws of gravitation devised by Newton, and by Hilbert and Einstein, have failed many experimental and observational tests, namely the bore hole g anomaly, flat rotation curves for spiral galaxies, supermassive black hole mass spectrum, uniformly expanding universe, cosmic filaments, laboratory G measurements, galactic EM bending, precocious galaxy formation,.. The response has been the introduction of the new epicycles: ``dark matter", ``dark energy", and others. To understand gravity we must restart with the experimental discoveries by Galileo, and following a heuristic argument we are led to a uniquely determined theory of a dynamical 3-space. That 3-space exists has been missed from the beginning of physics, although it was 1st directly detected by Michelson and Morley in 1887. Uniquely generalising the quantum theory to include this dynamical 3-space we deduce the response of quantum matter and show that it results in a new account of gravity, and explains the above anomalies and others. The dynamical theory for this 3-space involves G, which determines the dissipation rate of space by matter, and alpha, which experiments and observation reveal to be the fine structure constant. For the 1st time we have a comprehensive account of space and matter and their interaction - gravity.

Reginald T Cahill

2011-02-16T23:59:59.000Z

212

Energy-momentum complexes in f(R) theories of gravity  

E-Print Network (OSTI)

Despite the fact that modified theories of gravity, in particular the f(R) gravity models have attracted much attention in the last years, the problem of the energy localization in the framework of these models has not been addressed. In the present work the concept of energy-momentum complexes is presented in this context. For the case of the Schwarzschild-de Sitter black hole solution of f(R) gravity the Landau-Lifshitz prescription is employed. In the limiting case where f(R) equals the Ricci scalar, the energy-momentum complex of the Schwarzschild-de Sitter black hole is equal to that derived in the framework of General Relativity. Furthermore, the energy-momentum complexes of widely used models of f(R) gravity for which the Schwarzschild-de Sitter black hole metric is a special case are computed in the Landau-Lifshitz prescription.

Multamaki, Tuomas; Vagenas, Elias C; Vilja, Iiro

2007-01-01T23:59:59.000Z

213

Spectral Estimates of Gravity Wave Energy and Momentum Fluxes. Part III: Gravity Wave-Tidal Interactions  

Science Conference Proceedings (OSTI)

An application of the gravity wave parameterization scheme developed in the companion papers by Fritts and VanZandt and Fritts and Lu to the mutual interaction of gravity waves and tidal motions is presented. The results suggest that interaction ...

Wentong Lu; David C. Fritts

1993-11-01T23:59:59.000Z

214

Static solutions for fourth order gravity  

SciTech Connect

The Lichnerowicz and Israel theorems are extended to higher order theories of gravity. In particular it is shown that Schwarzschild is the unique spherically symmetric, static, asymptotically flat, black-hole solution, provided the spatial curvature is less than the quantum gravity scale outside the horizon. It is then shown that in the presence of matter (satisfying certain positivity requirements), the only static and asymptotically flat solutions of general relativity that are also solutions of higher order gravity are the vacuum solutions.

Nelson, William [Institute of Gravitation and the Cosmos, Penn State University, State College, Pennsylvania 16801 (United States)

2010-11-15T23:59:59.000Z

215

Quantum Gravity: Has Spacetime Quantum Properties?  

E-Print Network (OSTI)

The incompatibility between GR and QM is generally seen as a sufficient motivation for the development of a theory of Quantum Gravity. If - so a typical argumentation - QM gives a universally valid basis for the description of all natural systems, then the gravitational field should have quantum properties. Together with the arguments against semi-classical theories of gravity, this leads to a strategy which takes a quantization of GR as the natural avenue to Quantum Gravity. And a quantization of the gravitational field would in some sense correspond to a quantization of geometry. Spacetime would have quantum properties. But, this strategy will only be successful, if gravity is a fundamental interaction. - What, if gravity is instead an intrinsically classical phenomenon? Then, if QM is nevertheless fundamentally valid, gravity can not be a fundamental interaction. An intrinsically classical gravity in a quantum world would have to be an emergent, induced or residual, macroscopic effect, caused by other interactions. The gravitational field (as well as spacetime) would not have any quantum properties. A quantization of GR would lead to artifacts without any relation to nature. The serious problems of all approaches to Quantum Gravity that start from a direct quantization of GR or try to capture the quantum properties of gravity in form of a 'graviton' dynamics - together with the, meanwhile, rich spectrum of approaches to an emergent gravity and/or spacetime - make this latter option more and more interesting for the development of a theory of Quantum Gravity. The most advanced emergent gravity (and spacetime) scenarios are of an information-theoretical, quantum-computational type.

Reiner Hedrich

2009-02-02T23:59:59.000Z

216

Simultaneous measurement of gravity acceleration and gravity gradient with an atom interferometer  

SciTech Connect

We demonstrate a method to measure the gravitational acceleration with a dual cloud atom interferometer; the use of simultaneous atom interferometers reduces the effect of seismic noise on the gravity measurement. At the same time, the apparatus is capable of accurate measurements of the vertical gravity gradient. The ability to determine the gravity acceleration and gravity gradient simultaneously and with the same instrument opens interesting perspectives in geophysical applications.

Sorrentino, F.; Lien, Y.-H.; Rosi, G.; Tino, G. M. [Dipartimento di Fisica e Astronomia and LENS, Universita di Firenze, INFN Sezione di Firenze, via Sansone 1, I-50019 Sesto Fiorentino (Italy); Bertoldi, A. [Laboratoire Charles Fabry de l'Institut d'Optique, CNRS and Universite Paris-Sud Campus Polytechnique, RD 128, F-91127 Palaiseau cedex (France); Bodart, Q. [Dipartimento di Fisica e Astronomia and LENS, Universita di Firenze, INFN Sezione di Firenze, via Sansone 1, I-50019 Sesto Fiorentino (Italy); European Space Agency, Research and Scientific Support Department, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Cacciapuoti, L. [European Space Agency, Research and Scientific Support Department, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Angelis, M. de [Istituto di Fisica Applicata 'Nello Carrara' CNR, via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy); Prevedelli, M. [Dipartimento di Fisica dell'Universita di Bologna, Via Irnerio 46, I-40126, Bologna (Italy)

2012-09-10T23:59:59.000Z

217

Lovelock gravity is equivalent to Einstein gravity coupled to form fields  

E-Print Network (OSTI)

Lovelock gravity is a class of higher-derivative gravitational theories whose linearized equations of motion have no more than two time derivatives. Here, it is shown that any Lovelock theory can be effectively described as Einstein gravity coupled to a p-form gauge field. This extends the known example of an f(R) theory of gravity, which can be described as Einstein gravity coupled to a scalar field.

Brustein, Ram

2012-01-01T23:59:59.000Z

218

Gravity Waves and GOES IR Data Study of an Isolated Tornadic Storm on 29 May 1977  

Science Conference Proceedings (OSTI)

Enhanced convection-initiated gravity waves associated with an isolated tornado in the absence of a squall line are investigated. Ray-tracing computations based on data observed on 29 May 1977 indicated that the wave sources were located in north-...

R. J. Hung; T. Phan; D. C. Lin; R. E. Smith; R. R. Jayroe; S. West

1980-04-01T23:59:59.000Z

219

A Model Study of Zonal Forcing in the Equatorial Stratosphere by Convectively Induced Gravity Waves  

Science Conference Proceedings (OSTI)

A two-dimensional cloud-resolving model is used to examine the possible role of gravity waves generated by a simulated tropical squall line in forcing the quasi-biennial oscillation (QBO) of the zonal winds in the equatorial stratosphere. A ...

M. J. Alexander; J. R. Holton

1997-02-01T23:59:59.000Z

220

Cosmological Acceleration: Dark Energy or Modified Gravity?  

E-Print Network (OSTI)

We review the evidence for recently accelerating cosmological expansion or "dark energy", either a negative pressure constituent in General Relativity (Dark Energy) or modified gravity (Dark Gravity), without any Dark Energy constituent. If constituent Dark Energy does not exist, so that our universe is now dominated by pressure-free matter, Einstein gravity must be modified at low curvature. The vacuum symmetry of any Robertson-Walker universe then characterizes Dark Gravity as low- or high-curvature modifications of Einstein gravity. The dynamics of either kind of "dark energy" cannot be derived from the homogeneous expansion alone, but requires also observing the growth of inhomogeneities. Present and projected observations are all consistent with a small fine tuned cosmological constant, with nearly static Dark Energy, or with gravity modified at cosmological scales. The growth of cosmological fluctuations will potentially distinguish static "dark energy" from dynamic "dark energy" with equation of state $w(z)$ either changing rapidly or tracking the background matter. But to cosmologically distinguish $\\Lambda$CDM from modified gravity will require a weak lensing shear survey more ambitious than any now projected. Dvali-Gabadadze-Porrati modifications of Einstein gravity may also be detected in refined bservations in the solar system or at the intermediate Vainstein scale. Dark Energy's epicyclic character, failure to explain the original Cosmic Coincidence ("Why now?") without fine tuning, inaccessibility to laboratory or solar system tests, along with braneworld theories, now motivate future precision solar system, Vainstein-scale and cosmological-scale studies of Dark Gravity.

Sidney Bludman

2006-05-08T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Gravity Gold Concentration at Newmont Mining  

Science Conference Proceedings (OSTI)

Abstract Scope, The process of gold recovery by gravity concentration is incorporated ... Energy Management Planning, Following the ISO 50001 Draft Standard.

222

Optimising Circuit Design for Gravity Gold Recovery  

Science Conference Proceedings (OSTI)

Abstract Scope, To determine the optimal circuit configuration for gravity gold recovery ... Energy Management Planning, Following the ISO 50001 Draft Standard.

223

Thermophysical Property Measurements Under Reduced Gravity ...  

Science Conference Proceedings (OSTI)

Presentation Title, Thermophysical Property Measurements Under Reduced Gravity Conditions: Evolution and Status of theThermoLab Project. Author(s), H-J

224

Gravity from the extension of spatial diffeomorphisms  

E-Print Network (OSTI)

The possibility of the extension of spatial diffeomorphisms to a larger family of symmetries in a class of classical field theories is studied. The generator of the additional local symmetry contains a quadratic kinetic term and a potential term which can be a general (not necessarily local) functional of the metric. From the perspective of the foundation of Einstein's gravity our results are positive: The extended constraint algebra is either that of Einstein's gravity, or ultralocal gravity. If our goal is a simple modification of Einstein's gravity that for example makes it perturbatively renormalizable, as has recently been suggested, then our results show that there is no such theory within this class.

Szilard Farkas; Emil J. Martinec

2010-02-24T23:59:59.000Z

225

Palatini formulation of L(R) gravity  

E-Print Network (OSTI)

We review the Palatini formulation of the higher-derivative gravity of the $L(R)$ form and its applications in cosmology.

Peng Wang; Xin-He Meng

2004-06-21T23:59:59.000Z

226

Photoemission with Chemical Potential from QCD Gravity Dual  

E-Print Network (OSTI)

We consider a $D4-D8-\\bar D8$ brane construction which gives rise to a large N QCD at sufficiently small energies. Using the gravity dual of this system, we study chiral phase transition at finite chemical potential and temperature and find a line of first order phase transitions in the phase plane. We compute the spectral function and the photon emission rate. The trace of the spectral function is monotonic at vanishing chemical potential, but develops some interesting features as the value of the chemical potential is increased.

Andrei Parnachev; David A. Sahakyan

2006-10-23T23:59:59.000Z

227

Introduction to Quantum-Gravity Phenomenology  

E-Print Network (OSTI)

After a brief review of the first phase of development of Quantum-Gravity Phenomenology, I argue that this research line is now ready to enter a more advanced phase: while at first it was legitimate to resort to heuristic order-of-magnitude estimates, which were sufficient to establish that sensitivity to Planck-scale effects can be achieved, we should now rely on detailed analyses of some reference test theories. I illustrate this point in the specific example of studies of Planck-scale modifications of the energy/momentum dispersion relation, for which I consider two test theories. Both the photon-stability analyses and the Crab-nebula synchrotron-radiation analyses, which had raised high hopes of ``beyond-Plankian'' experimental bounds, turn out to be rather ineffective in constraining the two test theories. Examples of analyses which can provide constraints of rather wide applicability are the so-called ``time-of-flight analyses'', in the context of observations of gamma-ray bursts, and the analyses of the cosmic-ray spectrum near the GZK scale.

Giovanni Amelino-Camelia

2004-12-30T23:59:59.000Z

228

Universality in Pure Gravity Mediation  

E-Print Network (OSTI)

If low energy supersymmetry is realized in nature, the apparent discovery of a Higgs boson with mass around 125 GeV points to a supersymmetric mass spectrum in the TeV or multi-TeV range. Multi-TeV scalar masses are a necessary component of supersymmetric models with pure gravity mediation or in any model with strong moduli stabilization. Here, we show that full scalar mass universality remains viable as long as the ratio of Higgs vevs, tan beta is relatively small (\\lesssim 2.5). We discuss in detail the low energy (observable) consequences of these models.

Jason L. Evans; Masahiro Ibe; Keith A. Olive; Tsutomu T. Yanagida

2013-02-21T23:59:59.000Z

229

Quantum Geometry and Quantum Gravity  

E-Print Network (OSTI)

The purpose of this contribution is to give an introduction to quantum geometry and loop quantum gravity for a wide audience of both physicists and mathematicians. From a physical point of view the emphasis will be on conceptual issues concerning the relationship of the formalism with other more traditional approaches inspired in the treatment of the fundamental interactions in the standard model. Mathematically I will pay special attention to functional analytic issues, the construction of the relevant Hilbert spaces and the definition and properties of geometric operators: areas and volumes.

J. Fernando Barbero G.

2008-04-23T23:59:59.000Z

230

Gravity monitoring of CO2 movement during sequestration: Model studies  

E-Print Network (OSTI)

right. Figure 14: Surface gravity response (?Gal) for theAbsolute and relative gravity integration for high precision2003, Seafloor Micro-gravity Survey of the Sleipner CO 2

Gasperikova, E.

2008-01-01T23:59:59.000Z

231

The Opening of the Tasman Sea: A Gravity Anomaly Animation  

Science Conference Proceedings (OSTI)

The first plate tectonic gravity anomaly grid animation using data from the Tasman Sea is presented. In this animation the tectonic elements are represented by their respective gravity fields, based on recent marine-satellite-derived gravity ...

C. Gaina; R. D. Müller; W. R. Roest; P. Symonds

1998-01-01T23:59:59.000Z

232

Gravity  

NLE Websites -- All DOE Office Websites (Extended Search)

das Farb-Kraftfeld, das entsteht, wenn sich das b Quark vom b Antiquark trennt, ignoriert. Diese Energie wandelt sich in ein weiteres Quark-Antiquark Paar um; was zur Emission...

233

Gravity  

NLE Websites -- All DOE Office Websites (Extended Search)

wissen zwar, wie man Gravitationskrfte berechnet, aber wir wissen nicht, wie man Gravitation in das mathematische Gebude der Quantentheorie des Standardmodells einbauen kann....

234

Gravity  

NLE Websites -- All DOE Office Websites (Extended Search)

Gravedad Avanzar Volver Principal ESTOY PERDIDO La fuerza gravitacional es quizs la fuerza ms familiar para nosotros, pero no est includa en el Modelo Standard, porque...

235

Gravity in Complex Hermitian Space-Time  

E-Print Network (OSTI)

A generalized theory unifying gravity with electromagnetism was proposed by Einstein in 1945. He considered a Hermitian metric on a real space-time. In this work we review Einstein's idea and generalize it further to consider gravity in a complex Hermitian space-time.

Ali H. Chamseddine

2006-10-09T23:59:59.000Z

236

Scale-Free Growing Networks and Gravity  

E-Print Network (OSTI)

We propose a possible relation between complex networks and gravity. Our guide in our proposal is the power-law distribution of the node degree in network theory and the information approach to gravity. The established bridge may allow us to carry geometric mathematical structures, which are considered in gravitational theories, to probabilistic aspects studied in the framework of complex networks and vice versa.

J. A. Nieto

2011-12-08T23:59:59.000Z

237

Ground Gravity Survey At Dixie Valley Geothermal Field Area ...  

Open Energy Info (EERE)

Details Location Dixie Valley Geothermal Field Area Exploration Technique Ground Gravity Survey Activity Date Usefulness useful DOE-funding Unknown Notes The gravity data are...

238

Ground Gravity Survey At Marysville Mt Area (Blackwell) | Open...  

Open Energy Info (EERE)

Ground Gravity Survey At Marysville Mt Area (Blackwell) Exploration Activity Details Location Marysville Mt Area Exploration Technique Ground Gravity Survey Activity Date...

239

Ground Gravity Survey At Valles Caldera - Sulphur Springs Area...  

Open Energy Info (EERE)

Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes A computer program capable of two-dimensional modeling of gravity data was used in interpreting...

240

Ground Gravity Survey At Valles Caldera - Redondo Area (Wilt...  

Open Energy Info (EERE)

Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes A computer program capable of two-dimensional modeling of gravity data was used in interpreting...

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Mechanical Properties of Counter-gravity Cast IN718  

Science Conference Proceedings (OSTI)

Key Words: Counter-gravity, investment casting, superalloys, IN718, inert ... using the Counter-gravity Low-pressure Inert-atmosphere (CLI) investment casting ...

242

Ground Gravity Survey At Mcgee Mountain Area (DOE GTP) | Open...  

Open Energy Info (EERE)

Ground Gravity Survey At Mcgee Mountain Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Mcgee Mountain...

243

Airborne Gravity Survey | Open Energy Information  

Open Energy Info (EERE)

Airborne Gravity Survey Airborne Gravity Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Airborne Gravity Survey Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Gravity Techniques Parent Exploration Technique: Gravity Techniques Information Provided by Technique Lithology: Distribution of density in the subsurface enables inference of rock type. Stratigraphic/Structural: Delineation of steeply dipping formations, geological discontinuities and faults, intrusions and the deposition of silicates due to hydrothermal activity. Hydrological: Density of sedimentary rocks are strongly influenced by fluid contained within pore space. Dry bulk density refers to the rock with no moisture, while the wet bulk density accounts for water saturation; fluid content may alter density by up to 30%.(Sharma, 1997)

244

Definition: Ground Gravity Survey | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Ground Gravity Survey Jump to: navigation, search Dictionary.png Ground Gravity Survey The ground gravitational method is the study of the distribution of mass in the subsurface with the observation point at the earth's surface.[1] View on Wikipedia Wikipedia Definition A gravity anomaly is the difference between the observed acceleration of a planet's gravity and a value predicted from a model. A location with a positive anomaly exhibits more gravity than predicted, while a negative anomaly exhibits a lower value than predicted. References ↑ http://www.amazon.com/Geophysical-Field-Theory-Three-Volume-Gravitational/dp/0124020410 Ret Like Like You like this.Sign Up to see what your friends like.

245

Ground Gravity Survey | Open Energy Information  

Open Energy Info (EERE)

Ground Gravity Survey Ground Gravity Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Ground Gravity Survey Details Activities (48) Areas (34) Regions (2) NEPA(2) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Gravity Techniques Parent Exploration Technique: Gravity Techniques Information Provided by Technique Lithology: Distribution of density in the subsurface enables inference of rock type. Stratigraphic/Structural: Delineation of steeply dipping formations, geological discontinuities and faults, intrusions and large-scale deposition of silicates due to hydrothermal activity. Hydrological: Density of sedimentary rocks are strongly influenced by fluid contained within pore space. Dry bulk density refers to the rock with no moisture, while the wet bulk density accounts for water saturation; fluid content may alter density by up to 30%.(Sharma, 1997)

246

Rainbow gravity and scale-invariant fluctuations  

E-Print Network (OSTI)

We re-examine a recently proposed scenario where the deformed dispersion relations associated with a flow of the spectral dimension to a UV value of 2 leads to a scale-invariant spectrum of cosmological fluctuations, without the need for inflation. In that scenario Einstein gravity was assumed. The theory displays a wavelength-dependent speed of light but by transforming to a suitable "rainbow frame" this feature can be removed, at the expense of modifying gravity. We find that the ensuing rainbow gravity theory is such that gravity switches off at high energy (or at least leads to a universal conformal coupling). This explains why the fluctuations are scale-invariant on all scales: there is no horizon scale as such. For dispersion relations that do not lead to exact scale invariance we find instead esoteric inflation in the rainbow frame. We argue that these results shed light on the behaviour of gravity under the phenomenon of dimensional reduction.

Giovanni Amelino-Camelia; Michele Arzano; Giulia Gubitosi; Joao Magueijo

2013-07-02T23:59:59.000Z

247

Solar System constraints to nonminimally coupled gravity  

E-Print Network (OSTI)

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.

Orfeu Bertolami; Riccardo March; Jorge Páramos

2013-06-05T23:59:59.000Z

248

OBSERVING GRAVITATIONAL LENSING EFFECTS BY Sgr A* WITH GRAVITY  

SciTech Connect

The massive black hole Sgr A* at the Galactic center is surrounded by a cluster of stars orbiting around it. Light from these stars is bent by the gravitational field of the black hole, giving rise to several phenomena: astrometric displacement of the primary image, the creation of a secondary image that may shift the centroid of Sgr A*, and magnification effects on both images. The soon-to-be second-generation Very Large Telescope Interferometer instrument GRAVITY will perform observations in the near-infrared of the Galactic center at unprecedented resolution, opening the possibility of observing such effects. Here we investigate the observability limits for GRAVITY of gravitational lensing effects on the S-stars in the parameter space 1[D{sub LS}, {gamma}, K], where D{sub LS} is the distance between the lens and the source, {gamma} is the alignment angle of the source, and K is the source's apparent magnitude in the K band. The easiest effect to observe in future years is the astrometric displacement of primary images. In particular, the shift of the star S17 from its Keplerian orbit will be detected as soon as GRAVITY becomes operative. For exceptional configurations, it will be possible to detect effects related to the spin of the black hole or post-Newtonian orders in the deflection.

Bozza, V. [Department of Physics 'E.R. Caianiello', University of Salerno, Via Ponte Don Melillo, Fisciano I-84084 (Italy); Mancini, L., E-mail: valboz@physics.unisa.it, E-mail: mancini@mpia-hd.mpg.de [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany)

2012-07-01T23:59:59.000Z

249

HVDC Overhead Line Performance Study  

Science Conference Proceedings (OSTI)

The Electric Power Research Institute (EPRI) is documenting the various factors that should be considered when designing and building new high-voltage direct current (HVDC) lines or when converting AC lines to HVDC. Given the limited number of HVDC lines that have been designed and built around the world, even some basic factors (for example, insulator flashover in severely contaminated regions) are not completely understood. This report concerns a crucial first step in better understanding and improving...

2011-08-02T23:59:59.000Z

250

Spontaneously Induced Gravity: From Rippled Dark Matter to Einstein Corpuscles  

E-Print Network (OSTI)

Suppose General Relativity, provocatively governed by a dimensional coupling constant, is a spontaneously induced theory of Gravity. Invoking Zee's mechanism, we represent the reciprocal Newton constant by a Brans Dicke scalar field, and let it damped oscillating towards its General Relativistic VEV. The corresponding cosmological evolution, in the Jordan frame, averagely resembles the familiar dark radiation -> dark matter -> dark energy domination sequence. The fingerprints of the theory are fine ripples, hopefully testable, in the FRW scale factor; they die away at the strict General Relativity limit. Also derived is the spherically symmetric static configuration associated with spontaneously induced General Relativity. At the stiff scalar potential limit, the exterior Schwarzschild solution is recovered. However, due to level crossing at the would have been horizon, it now connects with a novel dark core characterized by a locally varying Newton constant. The theory further predicts light Einstein-style gravitational corpuscles (elementary particles?) which become point-like at the GR-limit.

Aharon Davidson; Ilya Gurwich

2006-06-13T23:59:59.000Z

251

The Lightest Higgs Boson Mass in Pure Gravity Mediation Model  

E-Print Network (OSTI)

We discuss the lightest Higgs boson mass in the minimal supersymmetric Standard Model with "pure gravity mediation". By requiring that the model provides the observed dark matter density, we find that the lightest Higgs boson is predicted to be below 132GeV. We also find that the upper limit on the lightest Higgs boson mass becomes 128GeV, if we further assume thermal leptogenesis mechanism as the origin of baryon asymmetry of universe. The interrelations between the Higgs boson mass and the gaugino masses are also discussed.

Ibe, Masahiro

2011-01-01T23:59:59.000Z

252

Thermodynamics in Modified Gravity Theories  

E-Print Network (OSTI)

We demonstrate that there does exist an equilibrium description of thermodynamics on the apparent horizon in the expanding cosmological background for a wide class of modified gravity theories with the Lagrangian density $f(R, \\phi, X)$, where $R$ is the Ricci scalar and $X$ is the kinetic energy of a scalar field $\\phi$. This comes from a suitable definition of an energy momentum tensor of the "dark" component obeying the local energy conservation law in the Jordan frame. It is shown that the equilibrium description in terms of the horizon entropy $S$ is convenient because it takes into account the contribution of the horizon entropy $\\hat{S}$ in non-equilibrium thermodynamics as well as an entropy production term.

Kazuharu Bamba; Chao-Qiang Geng; Shinji Tsujikawa

2011-01-19T23:59:59.000Z

253

Non-Gaussian Stochastic Gravity  

E-Print Network (OSTI)

This paper presents a new, non-Gaussian formulation of stochastic gravity by incorporating the higher moments of the fluctuations of the quantum stress energy tensor for a free quantum scalar field in a consistent way. A scheme is developed for obtaining realizations of these fluctuations in terms of the Wightman function, and the behavior of the fluctuations is investigated. The resulting probability distribution for fluctuations of the energy density in Minkowski spacetime is found to be similar to a shifted Gamma distribution. This distribution features a minimum energy density cutoff at a small negative value, but a sharp peak in the vicinity of this cutoff such that the total probability of observing a negative value is approximately 62%, balanced by correspondingly larger but rarer positive values.

Jason D. Bates

2013-05-16T23:59:59.000Z

254

Nonlinear Fluid Dynamics from Gravity  

E-Print Network (OSTI)

Black branes in AdS5 appear in a four parameter family labeled by their velocity and temperature. Promoting these parameters to Goldstone modes or collective coordinate fields -- arbitrary functions of the coordinates on the boundary of AdS5 -- we use Einstein's equations together with regularity requirements and boundary conditions to determine their dynamics. The resultant equations turn out to be those of boundary fluid dynamics, with specific values for fluid parameters. Our analysis is perturbative in the boundary derivative expansion but is valid for arbitrary amplitudes. Our work may be regarded as a derivation of the nonlinear equations of boundary fluid dynamics from gravity. As a concrete application we find an explicit expression for the expansion of this fluid stress tensor including terms up to second order in the derivative expansion.

Sayantani Bhattacharyya; Veronika E Hubeny; Shiraz Minwalla; Mukund Rangamani

2007-12-14T23:59:59.000Z

255

Exact Solutions in Massive Gravity  

E-Print Network (OSTI)

Massive gravity is a good theoretical laboratory to study modifications of General Relativity. The theory offers a concrete set-up to study models of dark energy, since it admits cosmological self-accelerating solutions in the vacuum, in which the size of the acceleration depends on the graviton mass. Moreover, non-linear gravitational self-interactions, in the proximity of a matter source, manage to mimic the predictions of linearised General Relativity, hence agreeing with solar-system precision measurements. In this article, we review our work in the subject, classifying, on one hand, static solutions, and on the other hand, self-accelerating backgrounds. For what respects static solutions we exhibit black hole configurations, together with other solutions that recover General Relativity near a source via the Vainshtein mechanism. For the self-accelerating solutions we describe a wide class of cosmological backgrounds, including an analysis of their stability.

Gianmassimo Tasinato; Kazuya Koyama; Gustavo Niz

2013-04-02T23:59:59.000Z

256

Emergent Horava gravity in graphene  

E-Print Network (OSTI)

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.

G. E. Volovik; M. A. Zubkov

2013-05-20T23:59:59.000Z

257

Dark Energy and Modified Gravity  

E-Print Network (OSTI)

Explanations of the late-time cosmic acceleration within the framework of general relativity are plagued by difficulties. General relativistic models are mostly based on a dark energy field with fine-tuned, unnatural properties. There is a great variety of models, but all share one feature in common -- an inability to account for the gravitational properties of the vacuum energy, and a failure to solve the so-called coincidence problem. Two broad alternatives to dark energy have emerged as candidate models: these typically address only the coincidence problem and not the vacuum energy problem. The first is based on general relativity and attempts to describe the acceleration as an effect of inhomogeneity in the universe. If this alternative could be shown to work, then it would provide a dramatic resolution of the coincidence problem; however, a convincing demonstration of viability has not yet emerged. The second alternative is based on infra-red modifications to general relativity, leading to a weakening of gravity on the largest scales and thus to acceleration. Most examples investigated so far are scalar-tensor or brane-world models, and we focus on the simplest candidates of each type: $f(R)$ models and DGP models respectively. Both of these provide a new angle on the problem, but they also face serious difficulties. However, investigation of these models does lead to valuable insights into the properties of gravity and structure formation, and it also leads to new strategies for testing the validity of General Relativity itself on cosmological scales.

Ruth Durrer; Roy Maartens

2008-11-25T23:59:59.000Z

258

Scattering of internal gravity waves  

E-Print Network (OSTI)

dots within a black background and (b) black dots against a transparent background. Blue lines show ideal pixel intensities across a dot; red lines are representative of actual dot intensities due to optical blurring and electronic effects; green lines... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 3.33 RMST images showing development of horizontal intrusions near sawtooth topogra- phy after cylinder oscillation at frequency ? = 0.79, i.e. ?/N = 0.59, for durations of (a) tˆ+ 0, (b) tˆ+ 40 and (c) tˆ+ 80 minutes, where tˆ = 4 minutes...

Leaman Nye, Abigail

2011-04-19T23:59:59.000Z

259

On the extension of Jackiw's scalar theory to (2+1)- dimensional gravity  

E-Print Network (OSTI)

We study some aspects of three-dimensional gravity by extending Jackiw's scalar theory to (2+1)-dimensions and find a black hole solution. We show that in in general this teory does not possess a Newtonian limit except for special metric configurations.

V. B. Bezerra; J. Spinelly; C. Romero

2001-04-28T23:59:59.000Z

260

Generalised Wick Transform in Dimensionally Reduced Gravity  

E-Print Network (OSTI)

In the context of canonical quantum gravity, we study an alternative real quantisation scheme, which is arising by relating simpler Riemannian quantum theory to the more complicated physical Lorentzian theory - the generalised Wick transform. On the symmetry reduced models, homogenous Bianchi cosmology and 2+1 gravity, we investigate its generalised construction principle, demonstrate that the emerging quantum theory is equivalent to the one obtained from standard quantisation and how to obtain physical states in Lorentzian gravity from Wick transforming solutions of Riemannian quantum theory.

B. Hartmann; J. Wisniewski

2003-09-17T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Dark Energy from Brane-world Gravity  

E-Print Network (OSTI)

Summary. Recent observations provide strong evidence that the universe is accelerating. This confronts theory with a severe challenge. Explanations of the acceleration within the framework of general relativity are plagued by difficulties. General relativistic models require a “dark energy ” field with effectively negative pressure. An alternative to dark energy is that gravity itself may behave differently from general relativity on the largest scales, in such a way as to produce acceleration. The alternative approach of modified gravity also faces severe difficulties, but does provide a new angle on the problem. This review considers an example of modified gravity, provided by brane-world models that self-accelerate at late times. 1 1

Roy Maartens

2006-01-01T23:59:59.000Z

262

Consistent matter couplings for Plebanski gravity  

SciTech Connect

We develop a scheme for the minimal coupling of all standard types of tensor and spinor field matter to Plebanski gravity. This theory is a geometric reformulation of vacuum general relativity in terms of two-form frames and connection one-forms, and provides a covariant basis for various quantization approaches. Using the spinor formalism we prove the consistency of the newly proposed matter coupling by demonstrating the full equivalence of Plebanski gravity plus matter to Einstein-Cartan gravity. As a by-product we also show the consistency of some previous suggestions for matter actions.

Tennie, Felix; Wohlfarth, Mattias N. R. [Zentrum fuer Mathematische Physik und II. Institut fuer Theoretische Physik, Universitaet Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany)

2010-11-15T23:59:59.000Z

263

Gravity as BF theory plus potential  

E-Print Network (OSTI)

Spin foam models of quantum gravity are based on Plebanski's formulation of general relativity as a constrained BF theory. We give an alternative formulation of gravity as BF theory plus a certain potential term for the B-field. When the potential is taken to be infinitely steep one recovers general relativity. For a generic potential the theory still describes gravity in that it propagates just two graviton polarizations. The arising class of theories is of the type amenable to spin foam quantization methods, and, we argue, may allow one to come to terms with renormalization in the spin foam context.

Kirill Krasnov

2009-07-23T23:59:59.000Z

264

Texas Gulf Coast Refinery District API Gravity (Weighted Average ...  

U.S. Energy Information Administration (EIA)

Texas Gulf Coast Refinery District API Gravity (Weighted Average) of Crude Oil Input to Refineries (Degree)

265

Ph.D.Thesis Binary inversion of gravity  

E-Print Network (OSTI)

Ph.D.Thesis Binary inversion of gravity data for salt imaging Richard A. Krahenbuhl Center for Gravity, Electrical & Magnetic Studies Colorado School of Mines Department of Geophysics Colorado School of gravity data for salt imaging Richard A. Krahenbuhl Center for Gravity, Electrical & Magnetic Studies

266

Texas Gulf Coast Refinery District API Gravity (Weighted ...  

U.S. Energy Information Administration (EIA)

Texas Gulf Coast Refinery District API Gravity (Weighted Average) of Crude Oil Input to Refineries (Degree)

267

Minimum Experimental Standards in the Laboratory Search for Gravity Effects  

Science Conference Proceedings (OSTI)

Peer?reviewed reports of experimental modifications of gravity over rotating superconductors (Podkletnov

H. Reiss; G. Hathaway

2006-01-01T23:59:59.000Z

268

Gravity and General Relativity at KCL D C Robinson  

E-Print Network (OSTI)

Gravity and General Relativity at KCL D C Robinson Mathematics Department King's College London Strand, London WC2R 2LS, UK. February 22, 2011 1 The study of gravity at KCL Research on gravity has been, an approach to New- tonian gravity similar to his field theory formulation of electromagnetism published

Bushnell, Colin J.

269

Gravity Recovery And Climate Experiment Hydrology, Earth Science and Climate  

E-Print Network (OSTI)

GRACE Gravity Recovery And Climate Experiment Hydrology, Earth Science and Climate Ole Baltazar of blood cell Delivers 10-Day / Monthly gravity field From 2002 Onwards Study gravity field changes | side 6 Range responds to Gravity #12;GRACE science results | 28. November 2007 | OA | side 7 Variations

Mosegaard, Klaus

270

Process Limits on Euclid  

NLE Websites -- All DOE Office Websites (Extended Search)

Process Limits Process Limits Limit Hard Soft core file size (blocks) 0 unlimited data seg size (kbytes) unlimited unlimited scheduling priority 0 0 file size (blocks) unlimited...

271

Reduced Gravity Education Flight Opportunity for Students at Minority  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Reduced Gravity Education Flight Opportunity for Students at Reduced Gravity Education Flight Opportunity for Students at Minority Serving Institutions Reduced Gravity Education Flight Opportunity for Students at Minority Serving Institutions March 21, 2013 - 5:21pm Addthis Reduced Gravity Education Flight Opportunity for Students at Minority Serving Institutions NASA is offering undergraduate students from Minority Serving Institutions an opportunity to test experiments in microgravity aboard NASA's reduced gravity aircraft. This opportunity is a partnership between the Minority University Research and Education Program and NASA's Reduced Gravity Education Flight Program, which gives aspiring explorers a chance to propose, design and fabricate a reduced-gravity experiment. Selected teams will test and evaluate their

272

Reduced Gravity Education Flight Opportunity for Students at Minority  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Reduced Gravity Education Flight Opportunity for Students at Reduced Gravity Education Flight Opportunity for Students at Minority Serving Institutions Reduced Gravity Education Flight Opportunity for Students at Minority Serving Institutions March 21, 2013 - 5:21pm Addthis Reduced Gravity Education Flight Opportunity for Students at Minority Serving Institutions NASA is offering undergraduate students from Minority Serving Institutions an opportunity to test experiments in microgravity aboard NASA's reduced gravity aircraft. This opportunity is a partnership between the Minority University Research and Education Program and NASA's Reduced Gravity Education Flight Program, which gives aspiring explorers a chance to propose, design and fabricate a reduced-gravity experiment. Selected teams will test and evaluate their

273

Plasmon-graviton conversion in a magnetic field in TeV-scale gravity  

E-Print Network (OSTI)

Kaluza-Klein (KK) gravitons emission rates due to plasmon-graviton conversion in magnetic field are computed within the ADD model of TeV-scale gravity. Plasma is described in the kinetic approach as the system of charged particles and Maxwell field both confined on the brane. Interaction with multidimensional gravity living in the bulk with $n$ compact extra dimensions is introduced within the linearized theory. Plasma collective effects enter through the two-point correlation function of the fluctuations of the energy-momentum tensor. The estimate for magnetic stars is presented leading to the lower limit of the D-dimensional Plank mass.

Melkumova, E Yu

2011-01-01T23:59:59.000Z

274

Observations of a Mesoscale Ducted Gravity Wave  

Science Conference Proceedings (OSTI)

This paper reports coordinated observations of a mesoscale gravity wave made during the FRONTS 84 field experiment conducted in southwestern France in the summer of 1984. The observations were unique in the sense that all relevant wave ...

F. M. Ralph; V. Venkateswaran; M. Crochet

1993-10-01T23:59:59.000Z

275

Filtering of Gravity Modes in Atmospheric Models  

Science Conference Proceedings (OSTI)

The impact of gravity modes in atmospheric model predictions is assessed quantitatively by comparing integrations with a normal mode initialized primitive equation model and its corresponding pseudogeostrophic form to document some generally ...

F. Baer; J. J. Tribbia

1984-05-01T23:59:59.000Z

276

Stochastic Parameterization of Gravity Wave Stresses  

Science Conference Proceedings (OSTI)

Selective transmission of gravity waves into the upper mesosphere and lower thermosphere leads to the generation of mean flows opposite to those below. This interaction is addressed in the context of a simplified transient, stochastic, ...

Timothy J. Dunkerton

1982-08-01T23:59:59.000Z

277

Inertia–Gravity Waves in the Stratosphere  

Science Conference Proceedings (OSTI)

The propagation and refraction of stationary inertia–gravity waves in the winter stratosphere is examined with ray tracing. Due to their smaller vertical group velocity these waves experience more lateral ray movement and horizontal refraction ...

Timothy J. Dunkerton

1984-12-01T23:59:59.000Z

278

Definition: Gravity Techniques | Open Energy Information  

Open Energy Info (EERE)

0521576326 Ret LikeLike UnlikeLike You like this.Sign Up to see what your friends like. rieved from "http:en.openei.orgwindex.php?titleDefinition:GravityTechniques&oldid598...

279

Quantum gravity and renormalization: The tensor track  

SciTech Connect

We propose a new program to quantize and renormalize gravity based on recent progress on the analysis of large random tensors. We compare it briefly with other existing approaches.

Rivasseau, Vincent [Laboratoire de Physique Theorique, CNRS UMR 8627 Universite Paris-Sud, 91405 Orsay (France)

2012-06-27T23:59:59.000Z

280

Energy conditions in f(R)-gravity  

E-Print Network (OSTI)

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.

Santos, J; Rebouças, M J; Carvalho, F C

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Energy and Hamiltonian in first order gravity  

E-Print Network (OSTI)

In this work the definition of a quasilocal energy for four dimensional first order gravity is developed. Using this an action principle which is adequate for the canonical ensemble is obtained. The microcanonical action principle is obtained as well.

Rodrigo Aros

2005-04-29T23:59:59.000Z

282

Probes of strong-field gravity  

E-Print Network (OSTI)

In this thesis, I investigate several ways to probe gravity in the strong-field regime. These investigations focus on observables from the gravitational dynamics, i.e. when time derivatives are large: thus I focus on sources ...

Stein, Leo Chaim

2012-01-01T23:59:59.000Z

283

Observationally Verifiable Predictions of Modified Gravity  

Science Conference Proceedings (OSTI)

MOG is a fully relativistic modified theory of gravity based on an action principle. The MOG field equations are exactly solvable numerically in two important cases. In the spherically symmetric

J. W. Moffat; V. T. Toth

2010-01-01T23:59:59.000Z

284

SUSY QM meets 5d Gravity  

E-Print Network (OSTI)

We report hidden quantum mechanical supersymmetry structure in five-dimensional gravity with the Randall-Sundrum background. We show that two N=2 supersymmetries are hidden in the spectrum.

Ohya, Satoshi

2010-01-01T23:59:59.000Z

285

Dynamical Foundations of the Brane Induced Gravity  

E-Print Network (OSTI)

We present a comprehensive formalism to derive precise expressions for the induced gravity of the braneworld, assuming the dynamics of the Dirac-Nambu-Goto type. The quantum fluctuations of the brane at short distances give rise to divergences, which should be cutoff at the scale of the inverse thickness of the brane. It turns out that the induced-metric formula is converted into an Einstein-like equation via the quantum effects. We determine the coefficients of the induced cosmological and gravity terms, as well as those of the terms including the extrinsic curvature and the normal connection gauge field. The latter is the characteristic of the brane induced gravity theory, distinguished from ordinary none-brane induced gravity.

Keiichi Akama; Takashi Hattori

2013-09-12T23:59:59.000Z

286

Shear Excitation of Atmospheric Gravity Waves  

Science Conference Proceedings (OSTI)

Unstable Velocity shears are a Common source of vertically propagating gravity waves in the atmosphere. However, the growth rates of unstable modes predicted by linear theory cannot always amount for their observed importance.

David C. Fritts

1982-09-01T23:59:59.000Z

287

Earthlings : humanity's essential relationship with gravity  

E-Print Network (OSTI)

A realm of serious scientific questions about gravity's role in biology is being researched in labs around the world, from NASA's Dryden Research Laboratories in the Mohave Desert, to Japan's Radioisotope Center at the ...

Vargas Medina, Iris Mónica

2009-01-01T23:59:59.000Z

288

Energy conditions in f(R)-gravity  

E-Print Network (OSTI)

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.

J. Santos; J. S. Alcaniz; M. J. Reboucas; F. C. Carvalho

2007-08-02T23:59:59.000Z

289

Internal Gravity Wave Generation and Hydrodynamic Instability  

Science Conference Proceedings (OSTI)

Two mechanisms are proposed whereby internal gravity waves (IGW) may radiate from a linearly unstable region of Boussinesq parallel flow that is characterized in the far field by constant horizontal velocity and Brunt-Väisälä frequency. Through ...

B. R. Sutherland; C. P. Caulfield; W. R. Peltier

1994-11-01T23:59:59.000Z

290

Finite temperature R-squared quantum gravity  

E-Print Network (OSTI)

The quantum gravity path integral's measure can be written as the product of classical backgrounds and quantum fluctuations about each background. After proving that fluctuations about the background do not diffuse in Hilbert space and obey the laws of many-body statistics, their probability distributions, entropy, and expected background are determined. This background obeys expectation-valued Einstein equations and features an entropy-based positive cosmological constant. From the fluctuation probability distributions, a finite temperature, R-squared, quantum gravity path integral is constructed whose action presents an interaction picture of quantum gravity that `moves with' the expected background in Hilbert space. Within this interaction picture of quantum fluctuations about an expected background, the fields required to describe quantum gravity have been transformed into `ordinary' quantum fields propagating on this `rigid' or `fixed' expected background. Back-reaction has been fully accounted for, and the quantum formulation is manifestly background independent.

C. D. Burton

2013-02-07T23:59:59.000Z

291

BEAM LINE  

NLE Websites -- All DOE Office Websites (Extended Search)

BEAM LINE BEAM LINE 45 W ILHELM ROENTGEN'S INITIAL DISCOVERY of X-radiation in 1895 led immediately to practical applications in medicine. Over the next few decades X rays proved to be an invaluable tool for the investigation of the micro-world of the atom and the development of the quantum theory of matter. Almost a century later, telescopes designed to detect X-radiation are indispensable for understanding the structure and evolution of the macro-world of stars, galaxies, and the Universe as a whole. The X-Ray Universe by WALLACE H. TUCKER X-ray images of the Universe are strikingly different from the usual visible-light images. 46 SUMMER 1995 did not think: I investigated." Undeterred by NASA's rejection of a proposal to search for cosmic X-radiation, Giacconi persuaded the

292

Towards Gravity-Gauge-Higgs Unification  

E-Print Network (OSTI)

We discuss a possibility to solve the gauge hierarchy problem in the framework of Gravity-Gauge-Higgs Unification scenario. We have calculated 1-loop correction to the mass of the scalar field, which is originated from 55-component of the metric, in five dimensional gravity theory with the bulk scalar field compactified on S^1. It is shown that the quadratic divergences are canceled and the finite mass is generated by explicit diagrammatic calculations and the effective potential calculations.

K. Hasegawa; C. S. Lim; Nobuhito Maru

2004-08-24T23:59:59.000Z

293

Localizing gravity on exotic thick 3-branes  

Science Conference Proceedings (OSTI)

We consider localization of gravity on thick branes with a nontrivial structure. Double walls that generalize the thick Randall-Sundrum solution, and asymmetric walls that arise from a Z{sub 2} symmetric scalar potential, are considered. We present a new asymmetric solution: a thick brane interpolating between two AdS{sub 5} spacetimes with different cosmological constants, which can be derived from a 'fake supergravity' superpotential, and show that it is possible to confine gravity on such branes.

Castillo-Felisola, Oscar [Centro de Fisica Fundamental, Universidad de Los Andes, Merida (Venezuela); International Centre for Theoretical Physics, 34100 Trieste (Italy); Melfo, Alejandra; Pantoja, Nelson; Ramirez, Alba [Centro de Fisica Fundamental, Universidad de Los Andes, Merida (Venezuela)

2004-11-15T23:59:59.000Z

294

Thermodynamics of space quanta models quantum gravity  

E-Print Network (OSTI)

Canonically quantized 3+1 general relativity with the global one dimensionality (1D) conjecture defines the model, which dimensionally reduced and secondary quantized yields the 1D quantum field theory wherein generic one-point correlations create physical scales. This simple quantum gravity model, however, can be developed in a wider sense. In this paper we propose to consider ab initio thermodynamics of space quanta as the quantum gravity phenomenology. The thermodynamics is constructed in the entropic formalism.

L. A. Glinka

2009-06-20T23:59:59.000Z

295

Anti-gravity: The key to 21st century physics  

Science Conference Proceedings (OSTI)

The masses coupling constants and cosmological parameters obtained using our discrete and combinatorial physics based on discrimination between bit-strings indicate that we can achieve the unification of quantum mechanics with relativity which had become the goal of twentieth century physics. To broaden our case we show that limitations on measurement of the position and velocity of an individual massive particle observed in a colliding beam scattering experiment imply real, rational commutation relations between position and velocity. Prior to this limit being pushed down to quantum effects, the lower bound is set by the available technology, but is otherwise scale invariant. Replacing force by force per unit mass and force per unit charge allows us to take over the Feynman-Dyson proof of the Maxwell Equations and extend it to weak gravity. The crossing symmetry of the individual scattering processes when one or more particles are replaced by anti-particles predicts both Coulomb attraction (for charged particles) and a Newtonian repulsion between any particle and its anti-particle. Previous quantum results remain intact, and predict the expected relativistic fine structure and spin dependencies. Experimental confirmation of this anti-gravity prediction would inaugurate the physics of the twenty-first century.

Noyes, H.P.

1993-01-01T23:59:59.000Z

296

Assessing Hypothetical Gravity Control Propulsion  

E-Print Network (OSTI)

Gauging the benefits of hypothetical gravity control propulsion is difficult, but addressable. The major challenge is that such breakthroughs are still only notional concepts rather than being specific methods from which performance can be rigorously quantified. A recent assessment by Tajmar and Bertolami used the rocket equation to correct naive misconceptions, but a more fundamental analysis requires the use of energy as the basis for comparison. The energy of a rocket is compared to an idealized space drive for the following cases: Earth-to-orbit, interstellar transit, and levitation. The space drive uses 3.6 times less energy for Earth to orbit. For deep space travel, space drive energy scales as the square of delta-v, while rocket energy scales exponentially. This has the effect of rendering a space drive 150-orders-of-magnitude better than a 17,000-sec Specific Impulse rocket for sending a modest 5000 kg probe to traverse 5 light-years in 50 years. Indefinite levitation, which is impossible for a rocket, could conceivably require 62 MJ/kg for a space drive. Assumption sensitivities and further analysis options are listed to guide further inquires.

Marc G. Millis

2006-03-14T23:59:59.000Z

297

Transmission line capital costs  

Science Conference Proceedings (OSTI)

The displacement or deferral of conventional AC transmission line installation is a key benefit associated with several technologies being developed with the support of the U.S. Department of Energy`s Office of Energy Management (OEM). Previous benefits assessments conducted within OEM have been based on significantly different assumptions for the average cost per mile of AC transmission line. In response to this uncertainty, an investigation of transmission line capital cost data was initiated. The objective of this study was to develop a database for preparing preliminary estimates of transmission line costs. An extensive search of potential data sources identified databases maintained by the Bonneville Power Administration (BPA) and the Western Area Power Administration (WAPA) as superior sources of transmission line cost data. The BPA and WAPA data were adjusted to a common basis and combined together. The composite database covers voltage levels from 13.8 to 765 W, with cost estimates for a given voltage level varying depending on conductor size, tower material type, tower frame type, and number of circuits. Reported transmission line costs vary significantly, even for a given voltage level. This can usually be explained by variation in the design factors noted above and variation in environmental and land (right-of-way) costs, which are extremely site-specific. Cost estimates prepared from the composite database were compared to cost data collected by the Federal Energy Regulatory Commission (FERC) for investor-owned utilities from across the United States. The comparison was hampered because the only design specifications included with the FERC data were voltage level and line length. Working within this limitation, the FERC data were not found to differ significantly from the composite database. Therefore, the composite database was judged to be a reasonable proxy for estimating national average costs.

Hughes, K.R.; Brown, D.R.

1995-05-01T23:59:59.000Z

298

Mass spectrum and thermodynamics of quasiconformal gauge theories from gauge/gravity duality  

SciTech Connect

We use gauge/gravity duality to study simultaneously the mass spectrum and the thermodynamics of a generic quasiconformal gauge theory, specified by its beta function. The beta function of a quasiconformal theory almost vanishes, and the coupling is almost constant between two widely separated energy scales. Depending on whether the gravity dual has a black hole or not, the mass spectrum is either a spectrum of quasinormal oscillations or a normal T=0 mass spectrum. The mass spectrum is quantitatively correlated with the thermal properties of the system. As the theory approaches conformality, the masses have to vanish. We show that in this limit, the masses calculated via gauge/gravity duality satisfy expected scaling properties.

Alanen, J.; Kajantie, K. [Department of Physics, P.O. Box 64, FI-00014 University of Helsinki (Finland); Helsinki Institute of Physics, P.O. Box 64, FI-00014 University of Helsinki (Finland); Alho, T.; Tuominen, K. [Helsinki Institute of Physics, P.O. Box 64, FI-00014 University of Helsinki (Finland); Department of Physics, University of Jyvaeskylae (Finland)

2011-10-15T23:59:59.000Z

299

Black Holes or Frozen Stars? A Viable Theory of Gravity without Black Holes  

E-Print Network (OSTI)

Do observations of black hole candidates rule out alternative theories of gravity without horizon formation? This depends on the existence, viability and reasonableness of alternative theories of gravity without black holes. Here a theory of gravity without black hole horizon formation is presented. The gravitational collapse stops shortly before horizon formation and leaves a stable frozen star. In the limit $\\Xi, \\Upsilon\\to 0$ the Einstein equations of GR are recovered, and the frozen stars become observationally indistinguishable from GR black holes. The theory therefore provides a counterexample to recent claims that observational evidence from black hole candidates "all but requires the existence of a horizon". The theory presented here shares its equations with RTG. Nonetheless, as is shown, there remain important conceptual and physical differences. In particular, some serious problems of RTG are not present in the theory proposed here. So it can be argued that the theory is a physically viable and conceptually sound alternative to GR.

I. Schmelzer

2010-03-07T23:59:59.000Z

300

Deeply virtual Compton scattering from gauge/gravity duality  

Science Conference Proceedings (OSTI)

We use gauge/gravity duality to study deeply virtual Compton scattering (DVCS) in the limit of high center of mass energy at fixed momentum transfer, corresponding to the limit of low Bjorken x, where the process is dominated by the exchange of the pomeron. At strong coupling, the pomeron is described as the graviton Regge trajectory in AdS space, with a hard wall to mimic confinement effects. This model agrees with HERA data in a large kinematical range. The behavior of the DVCS cross section for very high energies, inside saturation, can be explained by a simple AdS black disk model. In a restricted kinematical window, this model agrees with HERA data as well.

Costa, Miguel S.; Djuric, Marko [University of Porto (Portugal)

2013-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Bioethanol Limited | Open Energy Information  

Open Energy Info (EERE)

Bioethanol Limited Bioethanol Limited Jump to: navigation, search Name Bioethanol Limited Place London, United Kingdom Zip SE1 7TJ Sector Renewable Energy Product Aims to develop a global renewable transport fuel business supplying primarily bioethanol but also biodiesel. Coordinates 51.506325°, -0.127144° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":51.506325,"lon":-0.127144,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

302

Ablamp Limited | Open Energy Information  

Open Energy Info (EERE)

Ablamp Limited Ablamp Limited Jump to: navigation, search Name Ablamp Limited Place Nanhai, Guangdong Province, China Sector Solar Product Manufacturer of energy-saving Compact Fluorescent Light Bulbs, solar-powered lights, LED bulbs, auto lamps and other speciality lamps. Coordinates 23.049681°, 113.173737° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":23.049681,"lon":113.173737,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

303

Solfex Limited | Open Energy Information  

Open Energy Info (EERE)

Solfex Limited Solfex Limited Jump to: navigation, search Name Solfex Limited Address Energy Arena Bannister Hall Works Off Shop Lane, Higher Walton Preston, Lancashire PR5 4DZ Place Preston, United Kingdom Sector Solar Product Solar thermal collectors Phone number 01772 312847 Website http://www.solfex.co.uk/home.h Coordinates 53.743452°, -2.64416° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":53.743452,"lon":-2.64416,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

304

Renpro Limited | Open Energy Information  

Open Energy Info (EERE)

Renpro Limited Renpro Limited Jump to: navigation, search Name Renpro Limited Place London, England, United Kingdom Zip WC2N 4JF Sector Renewable Energy Product String representation "Founded in 2005 ... newable energy." is too long. Coordinates 51.506325°, -0.127144° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":51.506325,"lon":-0.127144,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

305

Gravity model studies of Newberry Volcano, Oregon  

SciTech Connect

Newberry, Volcano, a large Quaternary volcano located about 60 km east of the axis of the High Cascades volcanoes in central Oregon, has a coincident positive residual gravity anomaly of about 12 mGals. Model calculations of the gravity anomaly field suggest that the volcano is underlain by an intrusive complex of mafic composition of about 20-km diameter and 2-km thickness, at depths above 4 km below sea level. However, uplifted basement in a northwest trending ridge may form part of the underlying excess mass, thus reducing the volume of the subvolcanic intrusive. A ring dike of mafic composition is inferred to intrude to near-surface levels along the caldera ring fractures, and low-density fill of the caldera floor probably has a thickness of 0.7--0.9 km. The gravity anomaly attributable to the volcano is reduced to the east across a north-northwest trending gravity anomaly gradient through Newberry caldera and suggests that normal, perhaps extensional, faulting has occurred subsequent to caldera formation and may have controlled the location of some late-stage basaltic and rhyolitic eruptions. Significant amounts of felsic intrusive material may exist above the mafic intrusive zone but cannot be resolved by the gravity data.

Gettings, M.E.; Griscom, A.

1988-09-10T23:59:59.000Z

306

Optimization Online - On Efficiently Combining Limited Memory and ...  

E-Print Network (OSTI)

Nov 25, 2013... the limited memory methods are usually combined with a line search. ... by the Euclidean norm with an insignificant computational overhead ...

307

Gravitational Shock Waves and Their Scattering in Brane-Induced Gravity  

E-Print Network (OSTI)

In this paper, following hep-th/0501028, we present a detailed derivation and discussion of the exact gravitational field solutions for a relativistic particle localized on a tensional brane in brane-induced gravity. Our derivation yields the metrics for both the normal branch and the self-inflating branch DGP braneworlds. They generalize the 4D gravitational shock waves in de Sitter space, and so we compare them to the corresponding 4D General Relativity solution and to the case when gravity resides only in the 5D bulk, and there are no brane-localized graviton kinetic terms. We write down the solutions in terms of two-variable hypergeometric functions and find that at short distances the shock wave profiles look exactly the same as in 4D Minkowski space, thus recovering the limit one expects if gravity is to be mediated by a metastable, but long-lived, bulk resonance. The corrections far from the source differ from the long distance corrections in 4D de Sitter space, coming in with odd powers of the distance. We discuss in detail the limiting case on the self-inflating branch when gravity is modified exactly at de Sitter radius, and energy can be lost into the bulk by resonance-like processes. Finally, we consider Planckian scattering on the brane, and find that for a sufficiently small impact parameter it is approximated very closely by the usual 4D description.

Nemanja Kaloper

2005-02-03T23:59:59.000Z

308

Nonlinear magnetoinductive transmission lines  

E-Print Network (OSTI)

Power transmission in one-dimensional nonlinear magnetic metamaterials driven at one end is investigated numerically and analytically in a wide frequency range. The nonlinear magnetic metamaterials are composed of varactor-loaded split-ring resonators which are coupled magnetically through their mutual inductances, forming thus a magnetoiductive transmission line. In the linear limit, significant power transmission along the array only appears for frequencies inside the linear magnetoinductive wave band. We present analytical, closed form solutions for the magnetoinductive waves transmitting the power in this regime, and their discrete frequency dispersion. When nonlinearity is important, more frequency bands with significant power transmission along the array may appear. In the equivalent circuit picture, the nonlinear magnetoiductive transmission line driven at one end by a relatively weak electromotive force, can be modeled by coupled resistive-inductive-capacitive (RLC) circuits with voltage-dependent cap...

Lazarides, Nikos; Tsironis, G P

2011-01-01T23:59:59.000Z

309

Problems with Mannheim's conformal gravity program  

E-Print Network (OSTI)

We show that Mannheim's conformal gravity program, whose potential has a term proportional to $1/r$ and another term proportional to $r$, does not reduce to Newtonian gravity at short distances, unless one assumes undesirable singularities of the mass density of the proton. Therefore, despite the claim that it successfully explains galaxy rotation curves, unless one assumes the singularities, it seems to be falsified by numerous Cavendish-type experiments performed at laboratories on Earth whose work have not found any deviations from Newton's theory. Moreover, it can be shown that as long as the total mass of the proton is positive, Mannheim's conformal gravity program leads to negative linear potential, which is problematic from the point of view of fitting galaxy rotation curves, which necessarily requires positive linear potential.

Youngsub Yoon

2013-05-01T23:59:59.000Z

310

Energy Distribution in f(R) Gravity  

E-Print Network (OSTI)

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.

Sharif, M

2009-01-01T23:59:59.000Z

311

Energy Distribution in f(R) Gravity  

E-Print Network (OSTI)

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.

M. Sharif; M. Farasat Shamir

2009-12-18T23:59:59.000Z

312

Gravity waves from vortex dipoles and jets  

E-Print Network (OSTI)

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. Within these dipoles, inertia-gravity waves with intrinsic frequencies 1-2 times the Coriolis parameter are simulated in the jet exit region. The ray tracing analysis reveals strong variation of wave characteristics along ray paths. The dependence of wave amplitude on the Rossby number is examined through experiments in which the two vortices are initially separated by a large distance but subsequently approach each other and form a vortex dipole with an associated amplifying localized jet. The amplitude of stationary gravity waves in the simulations with a 90-km grid spacing increases nearly linearly with the square of the Rossby number but significantly more rapidly when smaller grid spacing is used. To further address the source mechanism of the gravity waves within the vortex dipole, a linear numerical framework is developed based on the framework proposed by Plougonven and Zhang (2007). Using the nonlinearly balanced fields as the basic state and driven by three types of large scale forcing, the vorticity, divergence and thermodynamic forcing, this linear model is utilized to obtain linear wave responses. The wave packets in the linear responses compare reasonably well with the MM5 simulated gravity waves. It is suggested that the vorticity forcing is the leading contribution to both gravity waves in the jet exit region and the ascent/descent feature in the jet core. This linear model is also adopted to study inertia-gravity waves in the vicinity of a baroclinic jet during the life cycle of an idealized baroclinic wave. It is found that the thermodynamic forcing and the vorticity forcing are equally important to the gravity waves in the low stratosphere, but the divergence forcing is again playing a lesser role. Two groups of wave packets are present in the linear responses; their sources appear to locate either near the surface front or near the middle/upper tropospheric jet.

Wang, Shuguang

2008-08-01T23:59:59.000Z

313

Proper Time Flow Equation for Gravity  

E-Print Network (OSTI)

We analyze a proper time renormalization group equation for Quantum Einstein Gravity in the Einstein-Hilbert truncation and compare its predictions to those of the conceptually different exact renormalization group equation of the effective average action. We employ a smooth infrared regulator of a special type which is known to give rise to extremely precise critical exponents in scalar theories. We find perfect consistency between the proper time and the average action renormalization group equations. In particular the proper time equation, too, predicts the existence of a non-Gaussian fixed point as it is necessary for the conjectured nonperturbative renormalizability of Quantum Einstein Gravity.

Bonanno, A

2005-01-01T23:59:59.000Z

314

Linear Stratospheric Gravity Waves above Convective Thermal Forcing  

Science Conference Proceedings (OSTI)

The spectra of linear gravity waves generated by a time-varying tropospheric thermal forcing representing organized convection are compared to the spectra of stratospheric gravity waves generated by organized convection in a fully nonlinear two-...

Rajul E. Pandya; M. Joan Alexander

1999-07-01T23:59:59.000Z

315

Coupling between Gravity Waves and Tropical Convection at Mesoscales  

Science Conference Proceedings (OSTI)

An idealized cloud-system-resolving model simulation is used to examine the coupling between a tropical cloud population and the mesoscale gravity waves that it generates. Spectral analyses of the cloud and gravity wave fields identify a clear ...

Todd P. Lane; Fuqing Zhang

2011-11-01T23:59:59.000Z

316

New Gravity Wave Treatments for GISS Climate Models  

Science Conference Proceedings (OSTI)

Previous versions of GISS climate models have either used formulations of Rayleigh drag to represent unresolved gravity wave interactions with the model-resolved flow or have included a rather complicated treatment of unresolved gravity waves that,...

Marvin A. Geller; Tiehan Zhou; Reto Ruedy; Igor Aleinov; Larissa Nazarenko; Nikolai L. Tausnev; Shan Sun; Maxwell Kelley; Ye Cheng

2011-08-01T23:59:59.000Z

317

Influence of Gravity Waves in the Tropical Upwelling: WACCM Simulations  

Science Conference Proceedings (OSTI)

The annual cycle of tropical upwelling and contributions by planetary and gravity waves are investigated from climatological simulations using the Whole Atmosphere Community Climate Model (WACCM) including three gravity wave drag (GWD) ...

Hye-Yeong Chun; Young-Ha Kim; Hyun-Joo Choi; Jung-Yoon Kim

2011-11-01T23:59:59.000Z

318

Mobility Characterization of Planetary Rover in Reduced Gravity Environment  

Science Conference Proceedings (OSTI)

This paper describes effects of gravity on mobility performance of wheeled rovers for future lunar/planetary exploration missions. A series of model tests of a wheel?terrain system were performed on an aircraft during variable gravity maneuvers

Taizo Kobayashi; Hidetoshi Ochiai; Junya Yamakawa; Shigeru Aoki; Kai Matsui; Akira Miyahara

2008-01-01T23:59:59.000Z

319

Correlation Between Precision Gravity and Subsidence Measurements at Cerro Prieto  

E-Print Network (OSTI)

PRECISION GRAVITY AND SUBSIDENCE MEASUREMENTS AT CERROPRECISION GRAVITY AND SUBSIDENCE MEASUREMENTS AT CERROn d i c a t e s t h a t subsidence took place. Uost of t h e

Zelwer, R.

2010-01-01T23:59:59.000Z

320

An Ultrasimple Spectral Parameterization for Nonorographic Gravity Waves  

Science Conference Proceedings (OSTI)

This paper describes a new computationally efficient, ultrasimple nonorographic spectral gravity wave parameterization model. Its predictions compare favorably, though not perfectly, with a model of gravity wave propagation and breaking that ...

C. D. Warner; M. E. McIntyre

2001-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Numerical Study of Gravity Currents in a Channel  

Science Conference Proceedings (OSTI)

A three-dimensional primitive-equation model was used to study gravity currents produced by instantaneous releases of a buoyant fluid in a rectangular channel. Without rotation, the gravity current passes through two distinct phases: an initial ...

Dong-Ping Wang

1985-03-01T23:59:59.000Z

322

Quantum gravity as a group field theory: a sketch  

E-Print Network (OSTI)

We give a very brief introduction to the group field theory approach to quantum gravity, a generalisation of matrix models for 2-dimensional quantum gravity to higher dimension, that has emerged recently from research in spin foam models.

Daniele Oriti

2005-12-07T23:59:59.000Z

323

Linear Spectral Numerical Model for Internal Gravity Wave Propagation  

Science Conference Proceedings (OSTI)

A three-dimensional linear spectral numerical model is proposed to simulate the propagation of internal gravity wave fluctuations in a stably stratified atmosphere. The model is developed to get first-order estimations of gravity wave ...

J. Marty; F. Dalaudier

2010-05-01T23:59:59.000Z

324

An Unusually Strong Gravity Wave over Western Washington  

Science Conference Proceedings (OSTI)

A mesoscale wave disturbance, observed over western Washington State, is studied through local observations and recognized by comparisons with theory as a large-amplitude gravity wave. It is shown that this gravity wave propagated over 200 km in ...

Bruce H. Bauck

1992-06-01T23:59:59.000Z

325

U.S. Percent Total Imported by API Gravity of Crude ...  

U.S. Energy Information Administration (EIA)

Referring Pages: Percentages of Total Imported Crude Oil by API Gravity; Percentages of Total Imported Crude Oil by API Gravity

326

Rapid gravity and gravity gradiometry terrain correction via adaptive quadtree mesh discretization Kristofer Davis, M. Andy Kass, and Yaoguo Li, Center for Gravity, Electrical and Magnetic Studies, Colorado School  

E-Print Network (OSTI)

Rapid gravity and gravity gradiometry terrain correction via adaptive quadtree mesh discretization Kristofer Davis, M. Andy Kass, and Yaoguo Li, Center for Gravity, Electrical and Magnetic Studies, Colorado School of Mines SUMMARY We present a method for modeling the terrain response in gravity and gravity

327

The behavior of $f(R)$ gravity in the solar system, galaxies and clusters  

E-Print Network (OSTI)

For cosmologically interesting $f(R)$ gravity models, we derive the complete set of the linearized field equations in the Newtonian gauge, under environments of the solar system, galaxies and clusters respectively. Based on these equations, we confirmed previous $\\gamma=1/2$ solution in the solar system. However, $f(R)$ gravity models can be strongly environment-dependent and the high density (comparing to the cosmological mean) solar system environment can excite a viable $\\gamma=1$ solution for some $f(R)$ gravity models. Although for $f(R)\\propto -1/R$, it is not the case; for $f(R)\\propto -\\exp(-R/\\lambda_2H_0^2)$, such $\\gamma=1$ solution does exist. This solution is virtually indistinguishable from that in general relativity (GR) and the value of the associated curvature approaches the GR limit, which is much higher than value in the $\\gamma=1/2$ solution. We show that for some forms of $f(R)$ gravity, this solution is physically stable in the solar system and can smoothly connect to the surface of the Sun. The derived field equations can be applied directly to gravitational lensing of galaxies and clusters. We find that, despite significant difference in the environments of galaxies and clusters comparing to that of the solar system, gravitational lensing of galaxies and clusters can be virtually identical to that in GR, for some forms of $f(R)$ gravity. Fortunately, galaxy rotation curve and intra-cluster gas pressure profile may contain valuable information to distinguish these $f(R)$ gravity models from GR.

Pengjie Zhang

2007-01-23T23:59:59.000Z

328

Gravity monitoring of CO{sub 2} movement during sequestration: Model studies  

SciTech Connect

Sequestration/enhanced oil recovery (EOR) petroleum reservoirs have relatively thin injection intervals with multiple fluid components (oil, hydrocarbon gas, brine, and carbon dioxide, or CO{sub 2}), whereas brine formations usually have much thicker injection intervals and only two components (brine and CO{sub 2}). Coal formations undergoing methane extraction tend to be thin (3-10 m) but shallow compared to either EOR or brine formations. Injecting CO{sub 2} into an oil reservoir decreases the bulk density in the reservoir. The spatial pattern of the change in the vertical component of gravity (G{sub z}) is correlated directly with the net change in reservoir density. Furthermore, time-lapse changes in the borehole G{sub z} clearly identify the vertical section of the reservoir where fluid saturations are changing. The CO{sub 2}-brine front, on the order of 1 km within a 20-m-thick brine formation at 1900-m depth with 30% CO{sub 2} and 70% brine saturations, respectively, produced a -10-{mu} Gal surface gravity anomaly. Such an anomaly would be detectable in the field. The amount of CO{sub 2} in a coal-bed methane scenario did not produce a large enough surface gravity response; however, we would expect that for an industrial-size injection, the surface gravity response would be measurable. Gravity inversions in all three scenarios illustrate that the general position of density changes caused by CO{sub 2} can be recovered but not the absolute value of the change. Analysis of the spatial resolution and detectability limits shows that gravity measurements could, under certain circumstances, be used as a lower-cost alternative to seismic measurements.

Gasperikova, E.; Hoversten, G.M. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

2008-11-15T23:59:59.000Z

329

Hypothetical Gravity Control and Implications for Spacecraft Propulsion  

E-Print Network (OSTI)

A scientific analysis of the conditions under which gravity could be controlled and the implications that an hypothetical manipulation of gravity would have for known schemes of space propulsion have been the scope of a recent study carried out for the European Space Agency. The underlying fundamental physical principles of known theories of gravity were analysed and shown that even if gravity could be modified it would bring somewhat modest gains in terms of launching of spacecraft and no breakthrough for space propulsion.

O. Bertolami; M. Tajmar

2002-07-31T23:59:59.000Z

330

Ground Gravity Survey At Blue Mountain Area (Fairbank Engineering...  

Open Energy Info (EERE)

to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Blue Mountain Area (Fairbank Engineering, 2006) Exploration Activity...

331

Exact solutions with noncommutative symmetries in Einstein and gauge gravity  

Science Conference Proceedings (OSTI)

We present new classes of exact solutions with noncommutative symmetries constructed in vacuum Einstein gravity (in general

Sergiu I. Vacaru

2005-01-01T23:59:59.000Z

332

Materials Science in Reduced Gravity - Programmaster.org  

Science Conference Proceedings (OSTI)

Jul 31, 2012 ... About this Symposium. Meeting, 2013 TMS Annual Meeting & Exhibition. Symposium, Materials Science in Reduced Gravity. Sponsorship ...

333

Gravity and Yang?Mills Fields: Geometrical Approaches  

Science Conference Proceedings (OSTI)

A new geometrical framework for a tetrad?affine formulation of gravity coupled with Yang?Mills fields is proposed.

Roberto Cianci; Stefano Vignolo

2005-01-01T23:59:59.000Z

334

Gravity Waves in Shear and Implications for Organized Convection  

E-Print Network (OSTI)

Gravity Waves in Shear and Implications for Organized Convection Samuel N. Stechmann Department, Los Angeles, CA 90095­1555. E-mail: stechmann@math.ucla.edu #12;ABSTRACT It is known that gravity, the gravity waves can create a more favorable environment on one side of preexisting convection than the other

Stechmann, Samuel N.

335

Tomo-gravity How to ComputeHow to Compute  

E-Print Network (OSTI)

Tomo-gravity How to ComputeHow to Compute Accurate Traffic Matrices forAccurate Traffic MatricesStanford Shannon LabShannon Lab #12;Tomo-gravity Want to know demands from source to destination ProblemProblem Have link traffic measurements (from SNMP) A B C #12;Tomo-gravity Example App: reliability analysis

Roughan, Matthew

336

Gravity Load Collapse of Building Frames during Earthquakes  

E-Print Network (OSTI)

Gravity Load Collapse of Building Frames during Earthquakes J. P. Moehle, K. J. Elwood, H. Sezen to frames designed primarily for gravity loads. Columns generally were not designed to have strengths capacity of the column. As the axial capacity diminishes, the gravity loads carried by the column must

Sezen, Halil

337

Gravity currents in two-layer stratified media  

E-Print Network (OSTI)

Gravity currents in two-layer stratified media Morris R. Flynn & Alan W.Tan Dept. of Mechanical Engineering, U.Alberta Funding: NSERC #12;· Gravity currents appear over a broad range of time/length scales. (1999), Flynn & Linden (2006),White & Helfrich (2008), Ungarish (2009) Introduction current gravity

Flynn, Morris R.

338

Gravity Surface Wave Bifurcation in a Highly Turbulent Swirling Flow  

E-Print Network (OSTI)

Gravity Surface Wave Bifurcation in a Highly Turbulent Swirling Flow Michael Baumer University Gravity Wave 2 3 Measurements 3 4 Mechanical Hardware: Problems and Solutions 5 5 Results 7 6 Conclusions investigated a free-surface gravity wave bifurcation in the large-separation regime, that is, where

Witten, Thomas A.

339

Gravity waves excited by jets: Propagation versus generation R. Plougonven  

E-Print Network (OSTI)

Gravity waves excited by jets: Propagation versus generation R. Plougonven School of Mathematics September 2005. [1] Atmospheric jets are known to be an important source of inertia-gravity waves, yet mechanisms for the gravity waves, with the underlying assumption that the characteristics of the waves were

Plougonven, Riwal

340

Effects of Nonlinearity on Convectively Forced Internal Gravity Waves: Application to a Gravity Wave Drag Parameterization  

Science Conference Proceedings (OSTI)

In the present study, the authors propose a way to include a nonlinear forcing effect on the momentum flux spectrum of convectively forced internal gravity waves using a nondimensional numerical model (NDM) in a two-dimensional framework. In NDM, ...

Hye-Yeong Chun; Hyun-Joo Choi; In-Sun Song

2008-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Convective Generation of Gravity Waves in Venus's Atmosphere: Gravity Wave Spectrum and Momentum Transport  

Science Conference Proceedings (OSTI)

The emission of internal gravity waves from a layer of dry convection embedded within a stable atmosphere with static stability and zonal winds varying in height is calculated. This theory is applied to Venus to investigate whether these waves ...

Stephen S. Leroy; Andrew P. Ingersoll

1995-11-01T23:59:59.000Z

342

The Mars Gravity Biosatellite as an innovative partial gravity research platform  

E-Print Network (OSTI)

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 ...

Fulford-Jones, Thaddeus R. F

2008-01-01T23:59:59.000Z

343

Improvement of Orographic Gravity Wave Parameterization Using a Mesoscale Gravity Wave Model  

Science Conference Proceedings (OSTI)

Parameterization of gravity waves due to subgrid-scale orography is now included in most existing large-scale models of the atmosphere. Parameterization schemes, however, have so far been evaluated mainly in view of the overall performance of the ...

Young-Joon Kim; Akio Arakawa

1995-06-01T23:59:59.000Z

344

Sound damping constant for generalized theories of gravity  

Science Conference Proceedings (OSTI)

The near-horizon metric for a black brane in anti-de Sitter space and the metric near the AdS boundary both exhibit hydrodynamic behavior. We demonstrate the equivalence of this pair of hydrodynamic systems for the sound mode of a conformal theory. This is first established for Einstein's gravity, but we then show how the sound damping constant will be modified from its Einstein form for a generalized theory. The modified damping constant is expressible as the ratio of a pair of gravitational couplings that are indicative of the sound-channel class of gravitons. This ratio of couplings differs from both that of the shear diffusion coefficient and the shear viscosity to entropy ratio. Our analysis is mostly limited to conformal theories, but suggestions are made as to how this restriction might eventually be lifted.

Brustein, Ram [Department of Physics, Ben-Gurion University, Beer-Sheva, 84105 (Israel); Medved, A. J. M. [Physics Department, University of Seoul, Seoul 130-743 (Korea, Republic of)

2009-06-15T23:59:59.000Z

345

Mass gap for gravity localized on thick branes  

Science Conference Proceedings (OSTI)

We present a scalar thick brane configuration arising in a theory of 5D gravity coupled to a self—interacting scalar field. We start from a classical solution of the field equations and study the physics of linear fluctuations around this background which obey a Schrödinger—like equation. We further focus our attention on a special case in which it is possible to solve this equation analytically for any massive mode. This fact allows us to make a closed analysis of the massive spectrum of Kaluza–Klein (KK) excitations and to compute the corrections to Newton’s law in the thin brane limit. There exist two bound states: the massless 4D graviton

N. Barbosa–Cendejas; A. Herrera–Aguilar; U. Nucamendi; I. Quiros; M. A. Reyes Santos; C. Schubert

2008-01-01T23:59:59.000Z

346

Modulated Ground State of Gravity Theories with Stabilized Conformal Factor  

E-Print Network (OSTI)

We discuss the stabilization of the conformal factor by higher derivative terms in a conformally reduced $R+R^2$ Euclidean gravity theory. The flat spacetime is unstable towards the condensation of modes with nonzero momentum, and they "condense" in a modulated phase above a critical value of the coupling $\\beta$ of the $R^2$ term. By employing a combination of variational, numerical and lattice methods we show that in the semiclassical limit the corresponding functional integral is dominated by a single nonlinear plane wave of frequency $\\approx 1/\\sqrt{\\beta} \\lp$. We argue that the ground state of the theory is characterized by a spontaneous breaking of translational invariance at Planckian scales.

Bonanno, Alfio

2013-01-01T23:59:59.000Z

347

Universality and Symmetry Breaking in Conformally Reduced Quantum Gravity  

E-Print Network (OSTI)

The scaling properties of quantum gravity are discussed by employing a class of proper-time regulators in the functional flow equation for the conformal factor within the formalism of the background field method. Renormalization group trajectories obtained by projecting the flow on a flat topology are more stable than those obtained from a projection on a spherical topology. In the latter case the ultraviolet flow can be characterized by a Hopf bifurcation with an ultraviolet attractive limiting cycle. Although the possibility of determining the infrared flow for an extended theory space can be severely hampered due to the conformal factor instability, we present a robust numerical approach to study the flow structure around the non-gaussian fixed point as an inverse-problem strategy. In particular it is shown the possibility of having a spontaneous breaking of the diffeomorphism invariance can be realized with non-local functionals of the volume operator.

Bonanno, Alfio

2012-01-01T23:59:59.000Z

348

Atmospheric Gravity Waves and Aircraft Turbulence Encounters  

Science Conference Proceedings (OSTI)

We describe aircraft turbulence-atmospheric gravity wave events which occurred during a 2-day period over the Continental Divide. The waves are observed by two microbarograph networks an each side of the divide and last for several hours at a ...

A. J. Bedard Jr.; F. Canavero; F. Einaudi

1986-12-01T23:59:59.000Z

349

MODIFIED GRAVITY SPINS UP GALACTIC HALOS  

SciTech Connect

We investigate the effect of modified gravity on the specific angular momentum of galactic halos by analyzing the halo catalogs at z = 0 from high-resolution N-body simulations for a f(R) gravity model that meets the solar-system constraint. It is shown that the galactic halos in the f(R) gravity model tend to acquire significantly higher specific angular momentum than those in the standard {Lambda}CDM model. The largest difference in the specific angular momentum distribution between these two models occurs for the case of isolated galactic halos with mass less than 10{sup 11} h {sup -1} M {sub Sun }, which are likely least shielded by the chameleon screening mechanism. As the specific angular momentum of galactic halos is rather insensitive to other cosmological parameters, it can in principle be an independent discriminator of modified gravity. We speculate a possibility of using the relative abundance of low surface brightness galaxies (LSBGs) as a test of general relativity given that the formation of the LSBGs occurs in fast spinning dark halos.

Lee, Jounghun [Astronomy Program, Department of Physics and Astronomy, FPRD, Seoul National University, Seoul 151-747 (Korea, Republic of)] [Astronomy Program, Department of Physics and Astronomy, FPRD, Seoul National University, Seoul 151-747 (Korea, Republic of); Zhao, Gong-Bo [National Astronomy Observatories, Chinese Academy of Science, Beijing 100012 (China)] [National Astronomy Observatories, Chinese Academy of Science, Beijing 100012 (China); Li, Baojiu [Institute of Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom)] [Institute of Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Koyama, Kazuya, E-mail: jounghun@astro.snu.ac.kr [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom)] [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom)

2013-01-20T23:59:59.000Z

350

Gravity Currents in a Deep Anelastic Atmosphere  

Science Conference Proceedings (OSTI)

This study presents analytic results for steady gravity currents in a channel using the deep anelastic equations. Results are cast in terms of a nondimensional parameter H/H0 that relates the channel depth H to a scale depth H0 (the depth at ...

George H. Bryan; Richard Rotunno

2008-02-01T23:59:59.000Z

351

Gravity Waves, Dynamical Resistance, and Forcing Efficiency  

Science Conference Proceedings (OSTI)

The effect of the dynamical response associated with high-frequency gravity waves on the total energy generated by imposed heating is examined in a 2D linear compressible model. The work performed by waves against a sustained forcing is defined ...

Jeffrey M. Chagnon

2010-06-01T23:59:59.000Z

352

Energy definition for quadratic curvature gravities  

E-Print Network (OSTI)

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.

Ahmet Baykal

2012-12-03T23:59:59.000Z

353

Ultrasonic hydrometer. [Specific gravity of electrolyte  

DOE Patents (OSTI)

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.

Swoboda, C.A.

1982-03-09T23:59:59.000Z

354

Multiple Gravity-Wave Breaking Levels  

Science Conference Proceedings (OSTI)

It is noted that gravity waves for which |u¯?c| (u¯=mean flow speed, c=wave phase speed) has a sharp minimum in the upper troposphere or lower stratosphere will have decaying amplitudes above this level despite exponentially decreasing mean ...

Richard S. Lindzen

1985-02-01T23:59:59.000Z

355

Cosmological singularities and modified theories of gravity  

Science Conference Proceedings (OSTI)

We consider perturbative modifications of the Friedmann equations in terms of energy density corresponding to modified theories of gravity proposed as an alternative route to comply with the observed accelerated expansion of the universe. Assuming that the present matter content of the universe is a pressureless fluid

Leonardo Fernández?Jambrina; Ruth Lazkoz

2009-01-01T23:59:59.000Z

356

Superadiabatic Excess and Gravity Wave Saturation  

Science Conference Proceedings (OSTI)

Attention is called to a recent calculation of the superadiabatic excess—the ratio of wave amplitude at saturation to wave amplitude at convective instability threshold—caused by a saturated gravity wave. (This excess is also referred to as the ...

J. Weinstock

1988-11-01T23:59:59.000Z

357

Heat Transfer in Superfluids: Effect of Gravity  

E-Print Network (OSTI)

We discuss the influence of an external field on energy transport in superfluid. He-II is not isothermal in presence of Earth gravity; instead, it supports finite temperature gradient given by a Fourier-like equation. We calculate asymptotic behavior of the effective heat resistance in the vicinity of the $\\lambda$-transition.

L. A. Melnikovsky

2004-05-19T23:59:59.000Z

358

Charged Black Holes in New Massive Gravity  

E-Print Network (OSTI)

We construct charged black hole solutions to three-dimensional New Massive Gravity (NMG), by adding electromagnetic Maxwell and Chern-Simons actions. We find charged black holes in the form of warped AdS_3 and "log" solutions in specific critical point. The entropy, mass and angular momentum of these black holes are computed.

Ghodsi, Ahmad

2010-01-01T23:59:59.000Z

359

Free Gravity Waves and Balanced Dynamics  

Science Conference Proceedings (OSTI)

It is shown how a renormalization technique, which is a variant of classical Krylov–Bogolyubov–Mitropol'skii averaging, can be used to obtain slow evolution equations for the vortical and inertia–gravity wave components of the dynamics in a ...

D. Wirosoetisno; T. G. Shepherd; R. M. Temam

2002-12-01T23:59:59.000Z

360

On white dwarfs and neutron stars in Palatini f(R) gravity  

E-Print Network (OSTI)

In Palatini $f(R)$ gravity, the parameters of the Schwarzschild - de Sitter solution as well as the whole interior solutions of compact objects are expected to change when compared to general relativity. We solve the Palatini field equations numerically in the case of the models $f(R) = R + \\alpha R^2$ and $f(R) = R - \\mu^4/R$, and using the equation of state of Fermi gas. We show how the density profiles and the prediction for the maximum masses of white dwarfs (the Chandrasekhar limit) and neutron stars (the Tolman-Oppenheimer-Volkoff limit) are altered, and thereby conclude that observations on compact stars may be used to exclude alternative gravity models.

Vappu Reijonen

2009-12-04T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Nonlinearities in modified gravity cosmology: Signatures of modified gravity in the nonlinear matter power spectrum  

SciTech Connect

A large fraction of cosmological information on dark energy and gravity is encoded in the nonlinear regime. Precision cosmology thus requires precision modeling of nonlinearities in general dark energy and modified gravity models. We modify the Gadget-2 code and run a series of N-body simulations on modified gravity cosmology to study the nonlinearities. The modified gravity model that we investigate in the present paper is characterized by a single parameter {zeta}, which determines the enhancement of particle acceleration with respect to general relativity (GR), given the identical mass distribution ({zeta}=1 in GR). The first nonlinear statistics we investigate is the nonlinear matter power spectrum at k < or approx. 3h/Mpc, which is the relevant range for robust weak lensing power spectrum modeling at l < or approx. 2000. In this study, we focus on the relative difference in the nonlinear power spectra at corresponding redshifts where different gravity models have the same linear power spectra. This particular statistics highlights the imprint of modified gravity in the nonlinear regime and the importance of including the nonlinear regime in testing GR. By design, it is less susceptible to the sample variance and numerical artifacts. We adopt a mass assignment method based on wavelet to improve the power spectrum measurement. We run a series of tests to determine the suitable simulation specifications (particle number, box size, and initial redshift). We find that, the nonlinear power spectra can differ by {approx}30% for 10% deviation from GR (|{zeta}-1|=0.1) where the rms density fluctuations reach 10. This large difference, on one hand, shows the richness of information on gravity in the corresponding scales, and on the other hand, invalidates simple extrapolations of some existing fitting formulae to modified gravity cosmology.

Cui Weiguang; Zhang Pengjie; Yang Xiaohu [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Partner Group of MPA, Nandan Road 80, Shanghai, 200030 (China)

2010-05-15T23:59:59.000Z

362

Inelastic collapse in one-dimensional driven systems under gravity  

E-Print Network (OSTI)

We study the inelastic collapse in the one-dimensional $N$-particle systems in the situation where the system is driven from below under the gravity. We investigate the hard-sphere limit of the inelastic soft-sphere systems by numerical simulations to find how the collision rate per particle $n_{coll}$ increases as a function of the elastic constant of the sphere $k$ when the restitution coefficient $e$ is kept constant. For the systems with large enough $N \\agt 20$, we find three regimes in $e$ depending on the behavior of $n_{coll}$ in the hard-sphere limit: (i) uncollapsing regime for $1 \\ge e > e_{c1}$, where $n_{coll}$ converges to a finite value, (ii) logarithmically collapsing regime for $e_{c1} > e > e_{c2}$, where $n_{coll}$ diverges as $n_{coll} \\sim \\log k$, and (iii) power-law collapsing regime for $e_{c2} > e > 0$, where $n_{coll}$ diverges as $n_{coll} \\sim k^\\alpha$ with an exponent $\\alpha$ that depends on $N$. The power-law collapsing regime shrinks as $N$ decreases and seems not to exist for the system with N=3 while, for large $N$, the size of the uncollapsing and the logarithmically collapsing regime decreases as $e_{c1} \\simeq 1-2.6/N$ and $e_{c2} \\simeq 1-3.0/N$. We demonstrate that this difference between large and small systems exists already in the inelastic collapse without the external drive and the gravity.

Jun'ichi Wakou; Hiroyuki Kitagishi; Takahiro Sakaue; Hiizu Nakanishi

2013-03-19T23:59:59.000Z

363

Static spherically symmetric perfect fluid solutions in $f(R)$ theories of gravity  

E-Print Network (OSTI)

Static spherically symmetric perfect fluid solutions are studied in metric $f(R)$ theories of gravity. We show that pressure and density do not uniquely determine $f(R)$ ie. given a matter distribution and an equation state, one cannot determine the functional form of $f(R)$. However, we also show that matching the outside Schwarzschild-de Sitter-metric to the metric inside the mass distribution leads to additional constraints that severely limit the allowed fluid configurations.

T. Multamaki; I. Vilja

2006-12-29T23:59:59.000Z

364

Holographic Entanglement Entropy for 4D Conformal Gravity  

E-Print Network (OSTI)

Using the proposal for holographic entanglement entropy in higher derivative gravities, we compute holographic entanglement entropy for the conformal gravity in four dimensions which turns out to be finite. However, if one subtracts the contribution of the four dimensional Gauss-Bonnet term, the corresponding entanglement entropy has a divergent term and indeed restricted to an Einstein solution of the conformal gravity, the resultant entanglement entropy is exactly the same as that in the Einstein gravity. We will also make a comment on the first law of the entanglement thermodynamics for the conformal gravity in four dimensions.

Mohsen Alishahiha; Amin Faraji Astaneh; M. Reza Mohammadi Mozaffar

2013-11-18T23:59:59.000Z

365

On the z=4 Horava-Lifshitz Gravity  

E-Print Network (OSTI)

We consider z=4 Horava-Lifshitz gravity in both 3+1 and 4+1 dimensions. We find black hole solutions in the IR region for a kind of z=4 Horava-Lifshitz gravity which is inherited from the new massive gravity in three dimensions and an analog of the new massive gravity in four dimensions through the quantum inheritance principle. We analyze thermodynamic properties for the black hole solutions for z=4 Horava-Lifshitz gravity. We also write out the Friedmann equation in 3+1 dimensions for cosmological solutions.

Rong-Gen Cai; Yan Liu; Ya-Wen Sun

2009-04-27T23:59:59.000Z

366

Granular convection and the Brazil nut effect in reduced gravity  

E-Print Network (OSTI)

We present laboratory experiments of a vertically vibrated granular medium consisting of 1 mm diameter glass beads with embedded 8 mm diameter intruder glass beads. The experiments were performed in the laboratory as well as in a parabolic flight under reduced-gravity conditions (on Martian and Lunar gravity levels). We measured the mean rise velocity of the large glass beads and present its dependence on the fill height of the sample containers, the excitation acceleration, and the ambient gravity level. We find that the rise velocity scales in the same manner for all three gravity regimes and roughly linearly with gravity.

Carsten Güttler; Ingo von Borstel; Rainer Schräpler; Jürgen Blum

2013-04-02T23:59:59.000Z

367

Ground Gravity Survey At Coso Geothermal Area (1990) | Open Energy  

Open Energy Info (EERE)

Coso Geothermal Area (1990) Coso Geothermal Area (1990) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Coso Geothermal Area (1990) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Ground Gravity Survey Activity Date 1990 Usefulness not indicated DOE-funding Unknown Exploration Basis To identify features related to the heat source and to seek possible evidence for an underlying magma chamber Notes 2D and 3D gravity modeling was done using gridded Bouguer gravity data covering a 45 by 45 km region over the Coso geothermal area. Isostatic and terrain corrected Bouguer gravity data for about 1300 gravity stations were obtained from the US Geological Survey. After the data were checked, the gravity values were gridded at 1 km centers for the area of interest

368

Microsoft Word - CX-HotSpringsGravityDrainsFY12_WEB.doc  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

REPLY TO ATTN OF: KEPR-Bell-1 SUBJECT: Environmental Clearance Memorandum Todd Nicholson Project Manager - TELF-TPP-3 Proposed Action: Install gravity drain system and oil stop valves, reshape west side perimeter ditch and flush out yard drains at the Hot Springs Substation. PP&A Project No.: 2383 Categorical Exclusion Applied (from Subpart D, 10 C.F.R. Part 1021): B4.6, Additions and modifications to transmission facilities Location: T21N, R24W, S14, PM, Sanders County, Montana Proposed by: Bonneville Power Administration (BPA) Description of the Proposed Action: Using directional drilling equipment, approximately 3,644 linear feet of gravity drain line will be installed under the existing electrical manhole system located in the Hot Springs Substation 230 and 500 Kilovolt (kV) yards. Each manhole

369

Black Holes in Three Dimensional Topological Gravity  

E-Print Network (OSTI)

We investigate the black hole solution to (2+1)-dimensional gravity coupled to topological matter, with a vanishing cosmological constant. We calculate the total energy, angular momentum and entropy of the black hole in this model and compare with results obtained in Einstein gravity. We find that the theory with topological matter reverses the identification of energy and angular momentum with the parameters in the metric, compared with general relativity, and that the entropy is determined by the circumference of the inner rather than the outer horizon. We speculate that this results from the contribution of the topological matter fields to the conserved currents. We also briefly discuss two new possible (2+1)-dimensional black holes.

S. Carlip; J. Gegenberg; R. B. Mann

1994-10-17T23:59:59.000Z

370

Hydrogen atom in Palatini theories of gravity  

E-Print Network (OSTI)

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.

Gonzalo J. Olmo

2008-02-27T23:59:59.000Z

371

Modified Gravity via Spontaneous Symmetry Breaking  

E-Print Network (OSTI)

We construct effective field theories in which gravity is modified via spontaneous breaking of local Lorentz invariance. This is a gravitational analogue of the Higgs mechanism. These theories possess additional graviton modes and modified dispersion relations. They are manifestly well-behaved in the UV and free of discontinuities of the van Dam-Veltman-Zakharov type, ensuring compatibility with standard tests of gravity. They may have important phenomenological effects on large distance scales, offering an alternative to dark energy. For the case in which the symmetry is broken by a vector field with the wrong sign mass term, we identify four massless graviton modes (all with positive-definite norm for a suitable choice of a parameter) and show the absence of the discontinuity.

B. M. Gripaios

2004-08-17T23:59:59.000Z

372

Holographic Superconductivity with Gauss-Bonnet gravity  

E-Print Network (OSTI)

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.

Ruth Gregory

2010-12-07T23:59:59.000Z

373

Gravity controlled anti-reverse rotation device  

DOE Patents (OSTI)

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.

Dickinson, Robert J. (Shaler Township, Allegheny County, PA); Wetherill, Todd M. (Lower Burrell, PA)

1983-01-01T23:59:59.000Z

374

1 Quantum Gravity and Regge Calculus  

E-Print Network (OSTI)

This is an informal review of the formulation of canonical general relativity and of its implications for quantum gravity; the various versions are compared, both in the continuum and in a discretized approximation suggested by Regge calculus. I also show that the weakness of the link with the geometric content of the theory gives rise to what I think is a serious flaw in the claimed derivation of a discrete structure for space at the quantum level. 1.

Giorgio Immirzi A

1997-01-01T23:59:59.000Z

375

Twisted covariant noncommutative self-dual gravity  

Science Conference Proceedings (OSTI)

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.

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

376

Hydrocarbon prospect mapping using balanced cross sections and gravity modeling, Onin and Kumawa Peninsulas, Irian Jaya, Indonesia  

Science Conference Proceedings (OSTI)

Exploration field geology mapping and acquisition of gravity data has been conducted on 26 surveyed traverse lines totaling approximately 650 line km across the Onin and Kumawa peninsulas of western Irian Jaya. The predominant surface outcrop is karstified New Guinea Limestone with a maximum thickness of 2150 m, which precludes the use of seismic data. The integrated use of field geology data, balanced cross sections, and gravity modeling has, however, enabled identification of two giant hydrocarbon prospects. The Onin and Kumawa peninsulas lie at the margin of Jurassic age rift faulting associated with the Australian northwest shelf. Jurassic rift sands of the Lower Kembelangan Formation are the primary reservoir target. During the Pliocene-Pleistocene collision of the Australian plate and the Banda are inverted sections of the rift system including the Onin and Kumawa peninsulas. A better understanding of the regional structure was gained by integrating the Mobil Oil gravity data (1992) and that collected by Shell Oil in the 1950s in the structurally less-deformed Bomberai region east of Onin and Kumawa. Bouguer reduction was carried out using a density of 2.4 gm/cc and GRS67 and IGSN71 formulas. Spectral analyses indicate that basement is at a depth of about 3 km in the Onin area and at about 6 km in the Bomberai area. The Bomberai and Onin-Kumawa regions are separated from one another by a steep southeast-southwest-striking gravity gradient, which may mark a change of lithology.

Untung, M.; Budiman, S.I.; Nasution, J.; Mirnanda, E. (Geological Research and Development Centre, Bandung (Indonesia)); Sirodj, E.G.; Henage, L.F. (Mobil Oil Indonesia, Jakarta (Indonesia))

1994-07-01T23:59:59.000Z

377

Flipped spinfoam vertex and loop gravity  

E-Print Network (OSTI)

We introduce a vertex amplitude for 4d loop quantum gravity. We derive it from a conventional quantization of a Regge discretization of euclidean general relativity. This yields a spinfoam sum that corrects some difficulties of the Barrett-Crane theory. The second class simplicity constraints are imposed weakly, and not strongly as in Barrett-Crane theory. Thanks to a flip in the quantum algebra, the boundary states turn out to match those of SO(3) loop quantum gravity -- the two can be identified as eigenstates of the same physical quantities -- providing a solution to the problem of connecting the covariant SO(4) spinfoam formalism with the canonical SO(3) spin-network one. The vertex amplitude is SO(3) and SO(4)-covariant. It rectifies the triviality of the intertwiner dependence of the Barrett-Crane vertex, which is responsible for its failure to yield the correct propagator tensorial structure. The construction provides also an independent derivation of the kinematics of loop quantum gravity and of the result that geometry is quantized.

Jonathan Engle; Roberto Pereira; Carlo Rovelli

2007-08-09T23:59:59.000Z

378

Distinguishing Modified Gravity from Dark Energy  

E-Print Network (OSTI)

The acceleration of the universe can be explained either through dark energy or through the modification of gravity on large scales. In this paper we investigate modified gravity models and compare their observable predictions with dark energy models. Modifications of general relativity are expected to be scale-independent on super-horizon scales and scale-dependent on sub-horizon scales. For scale-independent modifications, utilizing the conservation of the curvature scalar and a parameterized post-Newtonian formulation of cosmological perturbations, we derive results for large scale structure growth, weak gravitational lensing, and cosmic microwave background anisotropy. For scale-dependent modifications, inspired by recent $f(R)$ theories we introduce a parameterization for the gravitational coupling $G$ and the post-Newtonian parameter $\\gamma$. These parameterizations provide a convenient formalism for testing general relativity. However, we find that if dark energy is generalized to include both entropy and shear stress perturbations, and the dynamics of dark energy is unknown a priori, then modified gravity cannot in general be distinguished from dark energy using cosmological linear perturbations.

Edmund Bertschinger; Phillip Zukin

2008-01-16T23:59:59.000Z

379

Supermassive galactic centre with repulsive gravity  

E-Print Network (OSTI)

Repulsive gravity has its origin in the 1939 article of Oppenheimer and Snyder which describes a collapsar, that is an idealized star of non-interacting material (dust) collapsing under its own gravity. The stellar material has a final state resembling a football, that is a significant part of it is concentrated in a thin surface shell. An interior pressure is exerted by the strong gravitational field, equivalent to a negative mass. However, the OS solution has been misunderstood, the shell's position being incorrectly identified with the "event horizon" in black-hole theory. While half the material is concentrated in a shell occupying a small fraction of the radius, some material is spread throughout the interior, unlike the concentration in a black hole's singularity. We deal with the singularity in density at the shell surface, by including Fermi pressure of degenerate electrons for a shell density comparable to a solar mass-sized white dwarf. Because the high-density region is concentrated in a shell, instead of at the centre as in a black hole, our conclusion is that repulsive gravity enables the existence of supermassive white dwarfs.

Trevor W. Marshall; Max K. Wallis

2013-03-18T23:59:59.000Z

380

Primordial nucleosynthesis in conformal Weyl gravity  

DOE Green Energy (OSTI)

Recently conformal Weyl gravity has been considered as a candidate alternative gravity theory. This fourth-order theory is attractive because it is the only metric theory of gravity which is invariant under local conformal transformations of the metric. The authors calculate the primordial light element abundances in this theory. The major difference from the standard cosmology is that the universe expands far more slowly throughout the nucleosynthesis epoch. The production of {sup 4}He depends strongly on {eta}, the ratio of baryons to photons. For {eta} = 10{sup {minus}8} the mass fraction of {sup 4}He is X{sub 4} {approx_equal} 0.25 and the number densities relative to hydrogen for {sup 2}H, {sup 3}He and {sup 7}Li are n({sup 2}H)/n(H) {approx_equal} 9 {times} 10{sup {minus}20}, n({sup 3}He)/n(H) {approx_equal}4 {times} 10{sup {minus}18} and n({sup 7}Li)/n(H) {approx_equal} 10{sup {minus}13}. This value of {eta} corresponds to a baryon mass density close to the standard model critical density. However, adjusting {eta} to give a reasonable helium yield forces the deuterium and lithium yields to be small enough that the theory cannot be reconciled with observations.

Knox, L.; Kosowsky, A. [Univ. of Chicago, IL (United States). Enrico Fermi Inst.]|[Fermi National Accelerator Lab., Batavia, IL (United States)

1993-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Lorentz covariance of loop quantum gravity  

SciTech Connect

The kinematics of loop gravity can be given a manifestly Lorentz-covariant formulation: the conventional SU(2)-spin-network Hilbert space can be mapped to a space K of SL(2,C) functions, where Lorentz covariance is manifest. K can be described in terms of a certain subset of the projected spin networks studied by Livine, Alexandrov and Dupuis. It is formed by SL(2,C) functions completely determined by their restriction on SU(2). These are square-integrable in the SU(2) scalar product, but not in the SL(2,C) one. Thus, SU(2)-spin-network states can be represented by Lorentz-covariant SL(2,C) functions, as two-component photons can be described in the Lorentz-covariant Gupta-Bleuler formalism. As shown by Wolfgang Wieland in a related paper, this manifestly Lorentz-covariant formulation can also be directly obtained from canonical quantization. We show that the spinfoam dynamics of loop quantum gravity is locally SL(2,C)-invariant in the bulk, and yields states that are precisely in K on the boundary. This clarifies how the SL(2,C) spinfoam formalism yields an SU(2) theory on the boundary. These structures define a tidy Lorentz-covariant formalism for loop gravity.

Rovelli, Carlo; Speziale, Simone [Centre de Physique Theorique de Luminy, Case 907, F-13288 Marseille (France)

2011-05-15T23:59:59.000Z

382

The Gravity Dual of the Ising Model  

E-Print Network (OSTI)

We evaluate the partition function of three dimensional theories of gravity in the quantum regime, where the AdS radius is Planck scale and the central charge is of order one. The contribution from the AdS vacuum sector can - with certain assumptions - be computed and equals the vacuum character of a minimal model CFT. The torus partition function is given by a sum over geometries which is finite and computable. For generic values of Newton's constant G and the AdS radius L the result has no Hilbert space interpretation, but in certain cases it agrees with the partition function of a known CFT. For example, the partition function of pure Einstein gravity with G=3L equals that of the Ising model, providing evidence that these theories are dual. We also present somewhat weaker evidence that the 3-state and tricritical Potts models are dual to pure higher spin theories of gravity based on SL(3) and E_6, respectively.

Alejandra Castro; Matthias R. Gaberdiel; Thomas Hartman; Alexander Maloney; Roberto Volpato

2011-11-08T23:59:59.000Z

383

The Gravity Dual of the Ising Model  

E-Print Network (OSTI)

We evaluate the partition function of three dimensional theories of gravity in the quantum regime, where the AdS radius is Planck scale and the central charge is of order one. The contribution from the AdS vacuum sector can - with certain assumptions - be computed and equals the vacuum character of a minimal model CFT. The torus partition function is given by a sum over geometries which is finite and computable. For generic values of Newton's constant G and the AdS radius L the result has no Hilbert space interpretation, but in certain cases it agrees with the partition function of a known CFT. For example, the partition function of pure Einstein gravity with G=3L equals that of the Ising model, providing evidence that these theories are dual. We also present somewhat weaker evidence that the 3-state and tricritical Potts models are dual to pure higher spin theories of gravity based on SL(3) and E_6, respectively.

Castro, Alejandra; Hartman, Thomas; Maloney, Alexander; Volpato, Roberto

2011-01-01T23:59:59.000Z

384

Quantum Theory at Planck Scale, Limiting Values, Deformed Gravity and Dark Energy Problem  

E-Print Network (OSTI)

Within a theory of the existing fundamental length on the order of Planck's a high-energy deformation of the General Relativity for the space with horizon has been constructed. On this basis, Markov's work of the early eighties of the last century has been given a new interpretation to show that the heuristic model considered by him may be placed on a fundamental footing. The obtained results have been applied to solving of the dark energy problem, making it possible to frame the following hypothesis: a dynamic cosmological term is a measure of deviation from a thermodynamic identity (the first law of thermodynamics) of the high-energy (Planck's) deformation of Einstein equations for horizon spaces in their thermodynamic interpretation.

A. E. Shalyt-Margolin

2011-02-24T23:59:59.000Z

385

Detector limitations, STAR  

Science Conference Proceedings (OSTI)

Every detector has limitations in terms of solid angle, particular technologies chosen, cracks due to mechanical structure, etc. If all of the presently planned parts of STAR [Solenoidal Tracker At RHIC] were in place, these factors would not seriously limit our ability to exploit the spin physics possible in RHIC. What is of greater concern at the moment is the construction schedule for components such as the Electromagnetic Calorimeters, and the limited funding for various levels of triggers.

Underwood, D. G.

1998-07-13T23:59:59.000Z

386

A model of accelerating dark energy in decelerating gravity  

E-Print Network (OSTI)

The expansion of the Universe is accelerated as testified by observations of SNeIa at varying redshifts. Explanations of this acceleration are of two kinds: modifications of Einstein gravity or new forms of energy. An example of modified gravity is the braneworld Dvali-Gabadadze-Porrati (DGP) model, an example of dark energy is Chaplygin gas. Both are characterized by a cross-over length scale $r_c$ which marks the transition between physics occurring on our four-dimensional brane, and in a five-dimensional bulk space. Assuming that the scales $r_c$ in the two models are the same, we study Chaplygin gas dark energy in flat DGP geometries. The self-accelerating branch does not give a viable model, it causes too much acceleration. We derive the Hubble function and the luminosity distance for the self-decelerating branch, and then fit a compilation of 192 SNeIa magnitudes and redshifts in the space of the three parameters of the model. Our model with the self-decelerating branch fits the supernova data as successfully as does the $\\Lambda CDM$ model, and with only one additional parameter. In contrast to the $\\Lambda CDM$ model, this model needs no fine-tuning, and it can explain the coincidence problem. It is unique in the sense that it cannot be reduced to a cosmological constant model in any other limit of the parameter space than in the distant future. If later tests with other cosmological data are successful, we have here a first indication that we live in a five-dimensional braneworld.

M. Roos

2007-07-07T23:59:59.000Z

387

Two terminal line voltage thermostat  

Science Conference Proceedings (OSTI)

A two terminal line voltage thermostat includes a switch which effectively connects line voltage to a heater load. The entire process is controlled by an integrated circuit microcontroller which is powered by a rectified voltage from a transformer secondary connected to a primary which is in series with the heater load. Backup battery power is provided to maintain limited functions of the microcontroller in the event of overall power loss. The microcontroller is programmed to meet the temperature sensing and control requirements specific to a two terminal electric baseboard heating installation. 7 figs.

Stalsberg, K.J.; Ingalls, J.E.; Hoglund, S.R.

1995-10-10T23:59:59.000Z

388

A Proposed Alternative Low Energy Quantum Field Theory of Gravity Based on a Bose-Einstein Condensate Effect  

E-Print Network (OSTI)

An alternative quantum field theory for gravity is proposed for low energies based on an attractive effect between contaminants in a Bose-Einstein Condensate rather than on particle exchange. In the ``contaminant in condensate effect," contaminants cause a potential in an otherwise uniform condensate, forcing the condensate between two contaminants to a higher energy state. The energy of the system decreases as the contaminants come closer together, causing an attractive force between contaminants. It is proposed that mass-energy may have a similar effect on Einstein's space-time field, and gravity is quantized by the same method by which the contaminant in condensate effect is quantized. The resulting theory is finite and, if a physical condensate is assumed to underly the system, predictive. However, the proposed theory has several flaws at high energies and is thus limited to low energies. Falsifiable predictions are given for the case that the Higgs condensate is assumed to be the condensate underlying gravity.

Alexander Oshmyansky

2007-03-08T23:59:59.000Z

389

Limited discrepancy search revisited  

Science Conference Proceedings (OSTI)

Harvey and Ginsberg's limited discrepancy search (LDS) is based on the assumption that costly heuristic mistakes are made early in the search process. Consequently, LDS repeatedly probes the state space, going against the heuristic (i.e., taking discrepancies) ... Keywords: Heuristic mistakes, limited discrepancy search, performance improvement

Patrick Prosser; Chris Unsworth

2011-05-01T23:59:59.000Z

390

Limited Warranty Research In Motion Limited (“RIM”), the ...  

Science Conference Proceedings (OSTI)

... Handheld Limited Warranty (Jordan) 072406 (English) (UK Version 082504) 1 Page 2. Handheld Limited Warranty (Jordan ...

2012-11-15T23:59:59.000Z

391

More about spontaneous Lorentz-violation and infrared modification of gravity  

E-Print Network (OSTI)

We consider a model with Lorentz-violating vector field condensates, in which dispersion laws of all perturbations, including tensor modes, undergo non-trivial modification in the infrared. The model is free of ghosts and tachyons at high 3-momenta. At low 3-momenta there are ghosts, and at even lower 3-momenta there exist tachyons. Still, with appropriate choice of parameters, the model is phenomenologically acceptable. Beyond a certain large distance scale and even larger time scale, the gravity of a static source changes from that of General Relativity to that of van Dam--Veltman--Zakharov limit of the Fierz--Pauli theory. Yet the late time cosmological evolution is always determined by the standard Friedmann equation, modulo small correction to the ``cosmological Planck mass'', so the modification of gravity cannot by itself explain the accelerated expansion of the Universe. We argue that the latter property is generic in a wide class of models with condensates.

M. V. Libanov; V. A. Rubakov

2005-05-25T23:59:59.000Z

392

New Agegraphic Dark Energy in $f(R)$ Gravity  

E-Print Network (OSTI)

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 $nenergy model in flat universe in the modified gravity cosmology framework. Also we develop a reconstruction scheme for the modified gravity with $f(R)$ action.

Setare, M R

2009-01-01T23:59:59.000Z

393

New Agegraphic Dark Energy in $f(R)$ Gravity  

E-Print Network (OSTI)

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 $nenergy model in flat universe in the modified gravity cosmology framework. Also we develop a reconstruction scheme for the modified gravity with $f(R)$ action.

M. R. Setare

2009-08-03T23:59:59.000Z

394

AdS waves as exact solutions to quadratic gravity  

SciTech Connect

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.

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

395

Gravity Couplings in the Standard-Model Extension  

E-Print Network (OSTI)

The Standard-Model Extension (SME) is an action-based expansion describing general Lorentz violation for known matter and fields, including gravity. In this talk, I will discuss the Lorentz-violating gravity couplings in the SME. Toy models that match the SME expansion, including vector and two-tensor models, are reviewed. Finally I discuss the status of experiments and observations probing gravity coefficients for Lorentz violation.

Bailey, Quentin G

2010-01-01T23:59:59.000Z

396

Static and dynamic response of a fluid-fluid interface to electric point and line charge  

SciTech Connect

We consider the behavior of a dielectric fluid-fluid interface in the presence of a strong electric field from a point charge and line charge, respectively, both statically and, in the latter case, dynamically. The fluid surface is elevated above its undisturbed level until balance is reached between the electromagnetic lifting force, gravity and surface tension. We derive ordinary differential equations for the shape of the fluid-fluid interface which are solved numerically with standard means, demonstrating how the elevation depends on field strength and surface tension coefficient. In the dynamic case of a moving line charge, the surface of an inviscid liquid-liquid interface is left to oscillate behind the moving charge after it has been lifted against the force of gravity. We show how the wavelength of the oscillations depends on the relative strength of the forces of gravity and inertia, whereas the amplitude of the oscillations is a nontrivial function of the velocity at which the line charge moves. - Highlights: Black-Right-Pointing-Pointer Fluid surface elevation analyzed near a static point and line charge. Black-Right-Pointing-Pointer Elevation determined by interaction of gravity, dielectric force and surface tension. Black-Right-Pointing-Pointer Dynamic equation of motion for the moving line charge is derived. Black-Right-Pointing-Pointer Surface waves behind moving charge calculated and analysed for different velocities.

Ellingsen, Simen A, E-mail: simen.a.ellingsen@ntnu.no; Brevik, Iver, E-mail: iver.h.brevik@ntnu.no

2012-12-15T23:59:59.000Z

397

Akhter Solar Limited | Open Energy Information  

Open Energy Info (EERE)

Akhter Solar Limited Akhter Solar Limited Jump to: navigation, search Name Akhter Solar Limited Place Islamabad, Pakistan Product Owns a 3MW module assembly line in Pakistan, which uses Q-Cells cells. Coordinates 33.709839°, 73.075912° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":33.709839,"lon":73.075912,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

398

CONTROL LIMITER DEVICE  

DOE Patents (OSTI)

A control-limiting device for monltoring a control system is described. The system comprises a conditionsensing device, a condition-varying device exerting a control over the condition, and a control means to actuate the condition-varying device. A control-limiting device integrates the total movement or other change of the condition-varying device over any interval of time during a continuum of overlapping periods of time, and if the tothl movement or change of the condition-varying device exceeds a preset value, the control- limiting device will switch the control of the operated apparatus from automatic to manual control.

DeShong, J.A.

1960-03-01T23:59:59.000Z

399

Exercise protocols during short-radius centrifugation for artificial gravity  

E-Print Network (OSTI)

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 ...

Edmonds, Jessica Leigh

2008-01-01T23:59:59.000Z

400

Ground Gravity Survey At Newberry Caldera Area (DOE GTP) | Open...  

Open Energy Info (EERE)

GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Newberry Caldera Area (DOE GTP) Exploration Activity Details Location Newberry Caldera Area...

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Ground Gravity Survey At Under Steamboat Springs Area (Warpinski...  

Open Energy Info (EERE)

to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Under Steamboat Springs Area (Warpinski, Et Al., 2002) Exploration Activity...

402

Ground Gravity Survey At San Francisco Volcanic Field Area (Warpinski...  

Open Energy Info (EERE)

Ground Gravity Survey At San Francisco Volcanic Field Area (Warpinski, Et Al., 2004) Exploration Activity Details Location San Francisco Volcanic Field Area Exploration Technique...

403

Ground Gravity Survey At Cove Fort Area - Vapor (Warpinski, Et...  

Open Energy Info (EERE)

to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Cove Fort Area (Warpinski, Et Al., 2004) Exploration Activity Details...

404

Ground Gravity Survey At Lake City Hot Springs Area (Warpinski...  

Open Energy Info (EERE)

to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Lake City Hot Springs Area (Warpinski, Et Al., 2004) Exploration Activity...

405

Ground Gravity Survey At Coso Geothermal Area (1980) | Open Energy...  

Open Energy Info (EERE)

Activity Details Location Coso Geothermal Area Exploration Technique Ground Gravity Survey Activity Date 1980 Usefulness not indicated DOE-funding Unknown Notes The...

406

Reconstruction of modified gravity with ghost dark energy models  

E-Print Network (OSTI)

In this work, we reconstruct the $f(R)$ modified gravity for different ghost and generalized ghost dark energy models in FRW flat universe, which describe the accelerated expansion of the universe. The equation of state of reconstructed $f(R)$ - gravity has been calculated. We show that the corresponding $f(R)$ gravity of ghost dark energy model can behave like phantom or quintessence. We also show that the equation of state of reconstructed $f(R)$ gravity for generalized ghost model can transit from quintessence regime to the phantom regime as indicated by recent observations.

Khodam-Mohammadi, A

2012-01-01T23:59:59.000Z

407

Effect of Centrifugal And Gravity Casting Technique over ...  

Science Conference Proceedings (OSTI)

In this work an attempt is made to study the effect of centrifugal and gravity casting ... A Minimum Pollution, Low Energy Process for the Recovery of Cobalt and ...

408

Ground Gravity Survey At Kilauea East Rift Area (Broyles, Et...  

Open Energy Info (EERE)

Activity Details Location Kilauea East Rift Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown References M. L....

409

Lorentz Invariant phenomenological model of quantum gravity: A minimalistic presentation  

SciTech Connect

The purpose of this paper is to give a minimalistic and self-contained presentation of a Lorentz Invariant phenomenological model of Quantum Gravity.

Bonder, Yuri [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico Apartado Postal 70-543, Distrito Federal 04510 (Mexico)

2012-08-24T23:59:59.000Z

410

Ground Gravity Survey At Dixie Valley Geothermal Field Area ...  

Open Energy Info (EERE)

In Dixie Valley, Nevada Retrieved from "http:en.openei.orgwindex.php?titleGroundGravitySurveyAtDixieValleyGeothermalFieldArea(Blackwell,EtAl.,2009)&oldid38834...

411

Ground Gravity Survey At Under Steamboat Springs Area (Warpinski...  

Open Energy Info (EERE)

to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Under Steamboat Springs Area (Warpinski, Et Al., 2004) Exploration Activity...

412

Ground Gravity Survey At Walker Lake Valley Area (Shoffner, Et...  

Open Energy Info (EERE)

to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Walker Lake Valley Area (Shoffner, Et Al., 2010) Exploration Activity...

413

Ground Gravity Survey At Baltazor Hot Springs Area (Isherwood...  

Open Energy Info (EERE)

to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Baltazor Hot Springs Area (Isherwood & Mabey, 1978) Exploration Activity...

414

Ground Gravity Survey At Raft River Geothermal Area (1978) |...  

Open Energy Info (EERE)

Activity Details Location Raft River Geothermal Area Exploration Technique Ground Gravity Survey Activity Date 1978 Usefulness not indicated DOE-funding Unknown Exploration...

415

Hidden Lorentz symmetry of the Horava - Lifshitz gravity  

E-Print Network (OSTI)

In this letter it is shown that the Horava-Lifshitz gravity theory admits Lorentz symmetry preserving preferred global time foliation of the spacetime.

Jakub Rembielinski

2013-09-03T23:59:59.000Z

416

Gravity wave coupling of the lower and middle atmosphere.  

E-Print Network (OSTI)

??A method of inferring tropospheric gravity wave source characteristics from middle atmosphere observations has been adapted from previous studies for use with MF radar observations… (more)

Love, Peter Thomas

2009-01-01T23:59:59.000Z

417

Jefferson Lab Science Series - Detecting Einstein's Gravity Waves  

NLE Websites -- All DOE Office Websites (Extended Search)

Science Series Video Archive Next Video (Symmetry) Symmetry Detecting Einstein's Gravity Waves Dr. David Shoemaker - Massachusetts Institute of Technology March 18, 1997 LIGO...

418

Effects of Gravity on the Columnar to Equiaxed Transition in ...  

Science Conference Proceedings (OSTI)

The effects of gravity, thermal natural convection and dendrite transport were integrated into the model. Simulations of vertical directional solidification of an ...

419

Gravity in Randall-Sundrum two D-brane model  

E-Print Network (OSTI)

We analyse Randall-Sundrum two D-brane model by linear perturbation and then consider the linearised gravity on the D-brane. The qualitative contribution from the Kaluza-Klein modes of gauge fields to the coupling to the gravity on the brane will be addressed. As a consequence, the gauge fields localised on the brane are shown not to contribute to the gravity on the brane at large distances. Although the coupling between gauge fields and gravity appears in the next order, the ordinary coupling cannot be realised.

Tetsuya Shiromizu; Keitaro Takahashi; Yoshiaki Himemoto; Shuto Yamamoto

2004-07-30T23:59:59.000Z

420

The Link Between Gravity Recovery and Hydrometallurgy - TMS  

Science Conference Proceedings (OSTI)

Aug 1, 2003 ... The Link Between Gravity Recovery and Hydrometallurgy: The Case of Gold by A.R. Laplante and W. Staunton ...

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Can gravity be added to Pilot Wave models?  

E-Print Network (OSTI)

The purpose of this paper is to come up with one of the many possible schemes of "adding" gravity to Pilot Wave models.

Sverdlov, Roman

2010-01-01T23:59:59.000Z

422

Polytropic and Chaplygin f(R)-gravity models  

E-Print Network (OSTI)

We reconstruct different f(R)-gravity models corresponding to the polytropic, standard Chaplygin, generalized Chaplygin, modified Chaplygin and modified variable Chaplygin gas dark energy models. We also obtain the equation of state parameters of the corresponding f(R)-gravity models which describe the accelerated expansion of the universe. We conclude that although the equation of state parameters of the obtained f(R)-gravities can behave like phantom or quintessence dark energy models, they cannot justify the transition from the quintessence state to the phantom regime. Furthermore, the polytropic and Chaplygin f(R)-gravity models in de Sitter space can satisfy the inflation condition.

K. Karami; M. S. Khaledian

2010-10-13T23:59:59.000Z

423

Regional Gravity Survey of the Northern Great Salt Lake Desert...  

Open Energy Info (EERE)

of the Northern Great Salt Lake Desert and Adjacent Areas in Utah, Nevada, and Idaho Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Regional Gravity...

424

Evolution of Gold Gravity Recovery in Grinding Circuits - A Critical ...  

Science Conference Proceedings (OSTI)

Presentation Title, Evolution of Gold Gravity Recovery in Grinding Circuits - A Critical .... Selective Separations of Gold and Contaminants from Various Gold and ...

425

Ground Gravity Survey At Snake River Plain Region (DOE GTP) ...  

Open Energy Info (EERE)

Snake River Plain Region (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Snake River Plain Region (DOE GTP)...

426

Definition: Stability Limit | Open Energy Information  

Open Energy Info (EERE)

Limit Limit Jump to: navigation, search Dictionary.png Stability Limit The maximum power flow possible through some particular point in the system while maintaining stability in the entire system or the part of the system to which the stability limit refers.[1] Related Terms power, system, stability References ↑ Glossary of Terms Used in Reliability Standards An in LikeLike UnlikeLike You like this.Sign Up to see what your friends like. line Glossary Definition Retrieved from "http://en.openei.org/w/index.php?title=Definition:Stability_Limit&oldid=480505" Categories: Definitions ISGAN Definitions What links here Related changes Special pages Printable version Permanent link Browse properties 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load)

427

Dynamics of gravity driven three-dimensional thin films on hydrophilic-hydrophobic patterned substrates  

E-Print Network (OSTI)

We investigate numerically the dynamics of unstable gravity driven three-dimensional thin liquid films on hydrophilic-hydrophobic patterned substrates of longitudinal stripes and checkerboard arrangements. The thin film can be guided preferentially on hydrophilic longitudinal stripes, while fingers develop on adjacent hydrophobic stripes if their width is large enough. On checkerboard patterns, the film fingering occurs on hydrophobic domains, while lateral spreading is favoured on hydrophilic domains, providing a mechanism to tune the growth rate of the film. By means of kinematical arguments, we quantitatively predict the growth rate of the contact line on checkerboard arrangements, providing a first step towards potential techniques that control thin film growth in experimental setups.

Rodrigo Ledesma-Aguilar; Aurora Hernandez-Machado; Ignacio Pagonabarraga

2010-01-20T23:59:59.000Z

428

Refurbishment of ballast water system of the gravity base structure - Beryl 'A'  

SciTech Connect

The Beryl Alpha Gravity Base Platform has operated satisfactorily for the past 11 years and is expected to stay in operation until the year 2017. The Ballast Water System is a vital part of the platform's oil storage and export equipment. In 1986, during routine pipe inspections in the lower part of the utility shaft, significant defects were discovered which resulted in major refurbishment work. Innovative designs and working procedures were employed for replacement and reinforced grout encasement of line pipe sections. This paper details the important aspects of this refurbishment work.

Seume, K.; Gilchrist, J.M.

1987-01-01T23:59:59.000Z

429

Powerful evidences for supporting the claim that gamma-ray burst redshifts are gravity-generated  

E-Print Network (OSTI)

At present, it is widely believed that the phenomenon of the gamma-ray burst redshift is cosmological origin. From a theoretical point of view, this redshift has either a cosmological or a cause that is related to gravity. However, the question of whether the gamma-ray burst redshift has a cosmological origin or not should be answerable in no uncertain terms because both the spectrum characteristics and the count distribution law arising from the two distinct settings are completely different. If the redshift of GRB is generated by gravity, then the afterglow spectrum will certainly contain both the gravitational redshits (containing emission and absorption feature) and Doppler absorption redshift, and hold a definite relation between the two redshifts. In this paper, we present nine direct and decisive evidences to show that the gamma-ray burst redshift is indeed generated by gravity of neutron stars in their merging process; in which, 114 GRBs' redshifts showed that the statistical count distribution law for the two kinds redshift is the same (with errors less than 1.5%), and 74 spectral line redshifts of two GRBs showed that the relation between the two kinds redshift is completely correct (with errors less than 0.0061%).

Fu-Gao Song

2008-05-22T23:59:59.000Z

430

Testing general scalar-tensor gravity and massive gravity with cluster lensing  

E-Print Network (OSTI)

We explore the possibility of testing modified gravity exhibiting the Vainshtein mechanism against observations of cluster lensing. We work in the most general scalar-tensor theory with second-order field equations (Horndeski's theory), and derive static and spherically symmetric solutions, for which the scalar field is screened below a certain radius. It is found that the essential structure of the problem in the most general case can be captured by the program of classifying Vainshtein solutions out of different solutions to a quintic equation, as has been performed in the context of massive gravity. The key effect on gravitational lensing is that the second derivative of the scalar field can substantially be large at the transition from screened to unscreened regions, leaving a dip in the convergence. This allows us to put observational constraints on parameters characterizing the general scalar-tensor modification of gravity. We demonstrate how this occurs in massive gravity as an example, and discuss its observational signatures in cluster lensing.

Tatsuya Narikawa; Tsutomu Kobayashi; Daisuke Yamauchi; Ryo Saito

2013-02-10T23:59:59.000Z

431

Can $f(T)$ gravity theories mimic $?$CDM cosmic history  

E-Print Network (OSTI)

Recently the teleparallel Lagrangian density described by the torsion scalar T has been extended to a function of T. The $f(T)$ modified teleparallel gravity has been proposed as the natural gravitational alternative for dark energy to explain the late time acceleration of the universe. In order to reconstruct the function $f(T)$ by demanding a background $\\Lambda$CDM cosmology we assume that, (i) the background cosmic history provided by the flat $\\Lambda$CDM (the radiation ere with $\\omega_{eff}=1/3$, matter and de Sitter eras with $\\omega_{eff}=0$ and $\\omega_{eff}=-1$, respectively) (ii) the radiation dominate in the radiation era with $\\Omega_{0r}=1$ and the matter dominate during the matter phases when $\\Omega_{0m}=1$. We find the cosmological dynamical system which can obey the $\\Lambda$CDM cosmic history. In each era, we find a critical lines that, the radiation dominated and the matter dominated are one points of them in the radiation and matter phases, respectively. Also, we drive the cosmologically viability condition for these models. We investigate the stability condition with respect to the homogeneous scalar perturbations in each era and we obtain the stability conditions for the fixed points in each eras. Finally, we reconstruct the function $f(T)$ which mimics cosmic expansion history.

M. R. Setare; N. Mohammadipour

2013-01-12T23:59:59.000Z

432

Conservation laws for vacuum tetrad gravity  

E-Print Network (OSTI)

Ten conservation laws in useful polynomial form are derived from a Cartan form and Exterior Differential System (EDS) for the tetrad equations of vacuum relativity. The Noether construction of conservation laws for well posed EDS is introduced first, and an illustration given, deriving 15 conservation laws of the free field Maxwell Equations from symmetries of its EDS. The Maxwell EDS and tetrad gravity EDS have parallel structures, with their numbers of dependent variables, numbers of generating 2-forms and generating 3-forms, and Cartan character tables all in the ratio of 1 to 4. They have 10 corresponding symmetries with the same Lorentz algebra, and 10 corresponding conservation laws.

Frank B. Estabrook

2005-08-20T23:59:59.000Z

433

Conservation of energy and Gauss Bonnet gravity  

E-Print Network (OSTI)

It is shown how can be made the classification of all tensors constructed from the Riemann tensor that verify the conservation of gravitational energy momentum. More precisely we explain that there exists a unique tensor of degree n in the Riemann tensor and its contractions that verifies the conservation of energy. We show that this tensor, only because it obeys this degree n structure as well as energy conservation, two facts which are true in all dimensions, verifies in dimension 2n this striking particularity of being Euler gravity. We stick here to the case n=2 but explain briefly why the general case is similar.

Christophe Real

2006-12-21T23:59:59.000Z

434

Bringing Together Gravity and the Quanta  

E-Print Network (OSTI)

Due to its underlying gauge structure, teleparallel gravity achieves a separation between inertial and gravitational effects. It can, in consequence, describe the isolated gravitational interaction without resorting to the equivalence principle, and is able to provide a tensorial definition for the energy-momentum density of the gravitational field. Considering the conceptual conflict between the local equivalence principle and the nonlocal uncertainty principle, the replacement of general relativity by its teleparallel equivalent can be considered an important step towards a prospective reconciliation between gravitation and quantum mechanics.

R. Aldrovandi; L. C. T. Guillen; J. G. Pereira; K. H. Vu

2006-03-30T23:59:59.000Z

435

The dualities of 3D dilaton gravity  

E-Print Network (OSTI)

We investigate Brans-Dicke dilaton gravity theories in 2+1 dimensions. We show that the reduced field equations for solutions with diagonal metric and depending only on one spacetime coordinate have a continuous O(2) symmetry. Using this symmetry we derive general static and cosmological solutions of the theory. The action of the discrete group O(2,Z) on the space of the solutions is discussed. Three-dimensional string effective theory and three-dimensional general relativity are discussed in detail. In particular, we find that the previously discovered black string solution is dual to a spacetime with a conical singularity.

Mariano Cadoni

1996-06-17T23:59:59.000Z

436

Gravity duals for non-relativistic CFTs  

E-Print Network (OSTI)

We attempt to generalize the AdS/CFT correspondence to non-relativistic conformal field theories which are invariant under Galilean transformations. Such systems govern ultracold atoms at unitarity, nucleon scattering in some channels, and more generally, a family of universality classes of quantum critical behavior. We construct a family of metrics which realize these symmetries as isometries. They are solutions of gravity with negative cosmological constant coupled to pressureless dust. We discuss realizations of the dust, which include a bulk superconductor. We develop the holographic dictionary and compute some two-point correlators. A strange aspect of the correspondence is that the bulk geometry has two extra noncompact dimensions.

Koushik Balasubramanian; John McGreevy

2008-04-25T23:59:59.000Z

437

Thermodynamics of 5D dilaton-gravity  

Science Conference Proceedings (OSTI)

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.

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

438

Maxwell's equations, linear gravity, and twistors  

SciTech Connect

A detailed outline is presented of several convergent points of view connecting the self-dual and anti-self-dual fields with their free data. This is doen for the Maxwell and for linearized gravity as exemplifying the approaches. The Sparling equation provides one tool of great power and characterizes one approach. The twistor theory of Penrose yields another equally powerful point of view. The links between these two basic approaches given in this paper provide a unification that allows workers and others with interest in this area to proceed more readily toward the goal of understanding the full nonlinear Einstein equations.

Kozameh, C.N.; Newman, E.T.; Porter, J.R.

1984-11-01T23:59:59.000Z

439

Seven-Dimensional Gravity with Topological Terms  

E-Print Network (OSTI)

We construct new seven-dimensional gravity by adding two topological terms to the Einstein-Hilbert action. For certain choice of the coupling constants, these terms may be related to the R^4 correction to the 3-form field equation of eleven-dimensional supergravity. 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_7, and also squashed seven spheres and Q^{111} spaces in Euclidean signature.

H. Lu; Yi Pang

2009-12-30T23:59:59.000Z

440

Gamma Ray Burst Neutrinos Probing Quantum Gravity  

E-Print Network (OSTI)

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.

M. C. Gonzalez-Garcia; F. Halzen

2006-11-28T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Hall viscosity from gauge/gravity duality  

E-Print Network (OSTI)

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.

Omid Saremi; Dam Thanh Son

2011-03-24T23:59:59.000Z

442

Robust approach to f(R) gravity  

Science Conference Proceedings (OSTI)

We consider metric f(R) theories of gravity without mapping them to their scalar-tensor counterpart, but using the Ricci scalar itself as an ''extra'' degree of freedom. This approach avoids then the introduction of a scalar-field potential that might be ill defined (not single valued). In order to explicitly show the usefulness of this method, we focus on static and spherically symmetric spacetimes and deal with the recent controversy about the existence of extended relativistic objects in certain class of f(R) models.

Jaime, Luisa G. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico Distrito Federal 04510 (Mexico); Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, Apartado Postal 50-542, Mexico Distrito Federal 04510 (Mexico); Patino, Leonardo [Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, Apartado Postal 50-542, Mexico Distrito Federal 04510 (Mexico); Salgado, Marcelo [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico Distrito Federal 04510 (Mexico)

2011-01-15T23:59:59.000Z

443

Application of Vertical-Mode Initialization to a Limited-Area Model in Flux Form  

Science Conference Proceedings (OSTI)

The vertical-mode initialization procedure of Bourke and MeGregor is applied to a limited-area weather prediction model that is formulated in flux form and is shown to be successful in reducing the undesirable gravity-wave oscillations in ...

Keith D. Sashegyi; Rangarao V. Madala

1993-01-01T23:59:59.000Z

444

Principal facts for gravity stations in the Darrough Known Geothermal Resource Area (KGRA), Nevada  

DOE Green Energy (OSTI)

The latitude, longitude, elevation, observed gravity, theoretical gravity, terrain correction, free-air correction, Bougner correction, and Bougner anomaly are tabulated for 71 gravity stations in the Darrough KGRA, Nevada area. (WHK)

Peterson, D.L.; Dansereau, D.A.

1976-01-01T23:59:59.000Z

445

Principal facts for a gravity survey of Summer Lake Known Geothermal Resource Area, Oregon  

DOE Green Energy (OSTI)

Gravity survey data are tabulated for 73 stations. Site latitude, longitude, elevation, observed gravity, theoretical gravity, free-air correction, Bouguer correction, and the simple Bouguer anomaly are included. (WHK)

Peterson, D.L.; Meyer, R.F.

1976-01-01T23:59:59.000Z

446

Cosmography of f(R) gravity  

E-Print Network (OSTI)

It is nowadays accepted that the universe is undergoing a phase of accelerated expansion as tested by the Hubble diagram of Type Ia Supernovae (SNeIa) and several LSS observations. Future SNeIa surveys and other probes will make it possible to better characterize the dynamical state of the universe renewing the interest in cosmography which allows a model independent analysis of the distance - redshift relation. On the other hand, fourth order theories of gravity, also referred to as $f(R)$ gravity, have attracted a lot of interest since they could be able to explain the accelerated expansion without any dark energy. We show here how it is possible to relate the cosmographic parameters (namely the deceleration $q_0$, the jerk $j_0$, the snap $s_0$ and the lerk $l_0$ parameters) to the present day values of $f(R)$ and its derivatives $f^{(n)}(R) = d^nf/dR^n$ (with $n = 1, 2, 3$) thus offering a new tool to constrain such higher order models. Our analysis thus offers the possibility to relate the model independ...

Capozziello, S; Salzano, V

2008-01-01T23:59:59.000Z

447

Cosmography of f(R) gravity  

E-Print Network (OSTI)

It is nowadays accepted that the universe is undergoing a phase of accelerated expansion as tested by the Hubble diagram of Type Ia Supernovae (SNeIa) and several LSS observations. Future SNeIa surveys and other probes will make it possible to better characterize the dynamical state of the universe renewing the interest in cosmography which allows a model independent analysis of the distance - redshift relation. On the other hand, fourth order theories of gravity, also referred to as $f(R)$ gravity, have attracted a lot of interest since they could be able to explain the accelerated expansion without any dark energy. We show here how it is possible to relate the cosmographic parameters (namely the deceleration $q_0$, the jerk $j_0$, the snap $s_0$ and the lerk $l_0$ parameters) to the present day values of $f(R)$ and its derivatives $f^{(n)}(R) = d^nf/dR^n$ (with $n = 1, 2, 3$) thus offering a new tool to constrain such higher order models. Our analysis thus offers the possibility to relate the model independent results coming from cosmography to the theoretically motivated assumptions of $f(R)$ cosmology.

S. Capozziello; V. F. Cardone; V. Salzano

2008-02-12T23:59:59.000Z

448

Vacuum energy: quantum hydrodynamics vs quantum gravity  

E-Print Network (OSTI)

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.

G. E. Volovik

2005-05-20T23:59:59.000Z

449

Security Clearances; Limitations  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

SEC. 1072. SECURITY CLEARANCES; LIMITATIONS. SEC. 1072. SECURITY CLEARANCES; LIMITATIONS. (a) In General.-Title III of the Intelligence Reform and Terrorism Prevention Act of 2004 (50 U.S.C. 435b) is amended by adding at the end the following new section: "SEC. 3002. SECURITY CLEARANCES; LIMITATIONS. "(a) Definitions.-In this section: "(1) Controlled substance.-The term `controlled substance' has the meaning given that term in section 102 of the Controlled Substances Act (21 U.S.C. 802). "(2) Covered person.-The term `covered person' means- "(A) an officer or employee of a Federal agency; "(B) a member of the Army, Navy, Air Force, or Marine Corps who is on active duty or is in an active status; and "(C) an officer or employee of a contractor of a Federal agency.

450

Constraint structure of the three dimensional massive gravity  

Science Conference Proceedings (OSTI)

Constraint analysis of the three-dimensional massive gravity, the so-called new massive gravity, is studied in the Palatini formalism. We show that amongst 6 components of the metric, 2 are dynamical, which is compatible with the existence of one vector massive graviton in the linearized theory (Fierz-Pauli theory).

Sadegh, M.; Shirzad, A. [Department of Physics, Isfahan University of Technology , P.O.Box 84156-83111, Isfahan (Iran, Islamic Republic of); School of Physics, Institute for Research in Fundamental Sciences (IPM), P.O.Box 19395-5531, Tehran (Iran, Islamic Republic of)

2011-04-15T23:59:59.000Z

451

Constraints on Dark Energy Models from Weak Gravity Conjecture  

E-Print Network (OSTI)

We study the constraints on the dark energy model with constant equation of state parameter $w=p/\\rho$ and the holographic dark energy model by using the weak gravity conjecture. The combination of weak gravity conjecture and the observational data gives $wenergy model realized by a scalar field is in swampland.

Chen, Ximing; Gong, Yungui

2008-01-01T23:59:59.000Z

452

Constraints on Dark Energy Models from Weak Gravity Conjecture  

E-Print Network (OSTI)

We study the constraints on the dark energy model with constant equation of state parameter $w=p/\\rho$ and the holographic dark energy model by using the weak gravity conjecture. The combination of weak gravity conjecture and the observational data gives $wenergy model realized by a scalar field is in swampland.

Ximing Chen; Jie Liu; Yungui Gong

2008-06-15T23:59:59.000Z

453

Walking in simulated reduced gravity: mechanical energy fluctuations and exchange  

E-Print Network (OSTI)

Walking in simulated reduced gravity: mechanical energy fluctuations and exchange TIMOTHY M reduced gravity: mechanical energy fluctuations and exchange. J. Appl. Physiol. 86(1): 383­390, 1999.--Walking humans conserve mechanical and, presum- ably, metabolic energy with an inverted pendulum-like ex

Kram, Rodger

454

A note on positive energy of topologically massive gravity  

E-Print Network (OSTI)

I review how "classical SUGRA" embeddability establishes positive energy E for D=3 topologically massive gravity (TMG), with or without a cosmological term, a procedure familiar from D=4 Einstein gravity (GR). It also provides explicit expressions for E. In contrast to GR, E is not manifestly positive, due to the peculiar two-term nature of TMG.

Deser, S

2009-01-01T23:59:59.000Z

455

Gravity Waves in Shear and Implications for Organized Convection  

Science Conference Proceedings (OSTI)

It is known that gravity waves in the troposphere, which are often excited by preexisting convection, can favor or suppress the formation of new convection. Here it is shown that in the presence of wind shear or barotropic wind, the gravity waves ...

Samuel N. Stechmann; Andrew J. Majda

2009-09-01T23:59:59.000Z

456

Gravity on a Dilatonic Gauss-Bonnet Brane World  

E-Print Network (OSTI)

The effective four-dimensional, linearised gravity of a Randall-Sundrum-like brane world model is analysed. The model includes higher order curvature terms (such as the Gauss-Bonnet term) and a scalar field. The resulting brane worlds can have better agreement with observations than the equivalent Einstein gravity models.

Stephen C. Davis

2004-08-18T23:59:59.000Z

457

Three?dimensional group manifold reductions of gravity  

Science Conference Proceedings (OSTI)

We review the three?dimensional group manifold reductions of pure Einstein gravity and we exhibit a new consistent group manifold reduction of gravity when the compactification group manifold is S 3. The new reduction leads to a lower dimensional theory whose gauge group is SU (2).

Román Linares

2005-01-01T23:59:59.000Z

458

Modeling the Hydrological Effect on Local Gravity at Moxa, Germany  

Science Conference Proceedings (OSTI)

A superconducting gravimeter has observed with high accuracy (to within a few nm s?2) and high frequency (1 Hz) the temporal variations in the earth’s gravity field near Moxa, Germany, since 1999. Hourly gravity residuals are obtained by time ...

Shaakeel Hasan; Peter A. Troch; J. Boll; C. Kroner

2006-06-01T23:59:59.000Z

459

Quantum Corrections to Newton's Law in Resummed Quantum Gravity  

E-Print Network (OSTI)

We present the elements of resummed quantum gravity, a new approach to quantum gravity based on the work of Feynman using the simplest example of a scalar field as the representative matter. We show that we get a UV finite quantum correction to Newton's law.

B. F. L. Ward

2004-11-03T23:59:59.000Z

460

COMPUTER SIMULATION OF SINGLE-WELL STEAM ASSISTED GRAVITY DRAINAGE  

E-Print Network (OSTI)

COMPUTER SIMULATION OF SINGLE-WELL STEAM ASSISTED GRAVITY DRAINAGE (SW-SAGD) TR 119 By Keith T of Sensitivity Analysis Cases 32 #12;v List of Figures Figure 1: Steam Assisted Gravity Drainage Concept: Recovery Factor vs. Time for All Cases (10 Years Production) 13 Figure 8: Cumulative Steam-Oil Ratio vs

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Gravity base, jack-up platform - method and apparatus  

SciTech Connect

The invention relates to an offshore, gravity base, jack-up platform comprising a deck, a gravity base and one or more legs interconnecting the deck and base. The gravity base comprises a generally polygonal shaped, monolithic hull structure with reaction members extending downwardly from the hull to penetrate the waterbed and react to vertical and lateral loads imposed upon the platform while maintaining the gravity hull in a posture elevated above the surface of the waterbed. A method aspect of the invention includes the steps of towing a gravity base, jack-up platform, as a unit, to a preselected offshore site floating upon the gravity hull. During the towing operation, the deck is mounted adjacent the gravity base with a leg or legs projecting through the deck. At a preselected offshore station ballast is added to the gravity base and the platform descends slightly to a posture where the platform is buoyantly supported by the deck. The base is then jacked down toward the seabed and the platform is laterally brought onto station. Ballast is then added to the deck and the reaction members are penetrated into the waterbed to operational soil refusal. Ballast is then ejected from the deck and the deck is jacked to an operational elevation above a predetermined statistical wave crest height.

Herrmann, R.P.; Pease, F.T.; Ray, D.R.

1981-05-05T23:59:59.000Z

462

Ground Gravity Survey At Maui Area (DOE GTP) | Open Energy Information  

Open Energy Info (EERE)

Ground Gravity Survey At Maui Area (DOE GTP) Exploration Activity Details Location Maui Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated...

463

Aeromagnetic and gravity surveys in the Coso Range, California | Open  

Open Energy Info (EERE)

and gravity surveys in the Coso Range, California and gravity surveys in the Coso Range, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Aeromagnetic and gravity surveys in the Coso Range, California Details Activities (2) Areas (1) Regions (0) Abstract: The effect of an underlying magma reservoir cannot be identified within the complex gravity pattern in the Coso Range, California. Rather, linear gravity contours, which suggest a regional tectonic origin, enclose the location of most of the volcanic activity of the Coso Range. Faults along the edges of northwest trending, magnetic blocks probably provided paths of minimum resistance to the ascending viscous magma that was extruded as rhyolite domes. Dense, magnetic rocks associated with a complex mafic pluton 9 km in diameter form a relatively impermeable north border of

464

Generalized Misner-Sharp Energy in f(R) Gravity  

E-Print Network (OSTI)

We study generalized Misner-Sharp energy in $f(R)$ gravity in a spherically symmetric spacetime. We find that unlike the cases of Einstein gravity and Gauss-Bonnet gravity, the existence of the generalized Misner-Sharp energy depends on a constraint condition in the $f(R)$ gravity. When the constraint condition is satisfied, one can define a generalized Misner-Sharp energy, but it cannot always be written in an explicit quasi-local form. However, such a form can be obtained in a FRW universe and for static spherically symmetric solutions with constant scalar curvature. In the FRW universe, the generalized Misner-Sharp energy is nothing but the total matter energy inside a sphere with radius $r$, which acts as the boundary of a finite region under consideration. The case of scalar-tensor gravity is also briefly discussed.

Cai, Rong-Gen; Hu, Ya-Peng; Ohta, Nobuyoshi

2009-01-01T23:59:59.000Z

465

The Fundamental Limitation of Atmospheric Remote Sensing by Dissection...  

NLE Websites -- All DOE Office Websites (Extended Search)

The Fundamental Limitation of Atmospheric Remote Sensing by Dissection of Single-Photon State Space, and the Paradigms that Lie Beyond Illustrated with WAIL, O2 A-BandLine...

466

Anisotropy and Forming Limit Diagram Comparison of DC and CC ...  

Science Conference Proceedings (OSTI)

Presentation Title, Anisotropy and Forming Limit Diagram Comparison of DC and CC ... Advanced Experimental Grid Pattern Techniques Coupled with FE-analysis ... Effect of Exploitation Overhead Power Lines on the Evolution of Mechanical ...

467

New gravity-capillary waves at low speeds. Part 1: Linear geometries  

E-Print Network (OSTI)

When traditional linearised theory is used to study gravity-capillary waves produced by flow past an obstruction, the geometry of the object is assumed to be small in one or several of its dimensions. In order to preserve the nonlinear nature of the obstruction, asymptotic expansions in the low-Froude or low-Bond number limits can be derived, but here, the solutions invariably predict a waveless surface at every order. This is because the waves are in fact, exponentially small, and thus beyond-all-orders of regular asymptotics; their formation is a consequence of the divergence of the asymptotic series and the associated Stokes Phenomenon. By applying techniques in exponential asymptotics to this problem, we have discovered the existence of new classes of gravity-capillary waves, from which the usual linear solutions form but a special case. In this paper, we present the initial theory for deriving these waves through a study of gravity-capillary flow over a linearised step; this will be done using two approaches: in the first, we derive the surface waves using the the standard method of Fourier transforms; in the second, we derive the same result using exponential asymptotics. Ultimately, these two methods give the same result, but conceptually, they offer different insights into the study of the low-Froude, low-Bond number problem.

Philippe H. Trinh; S. Jonathan Chapman

2013-04-23T23:59:59.000Z

468

Repetitive precision gravity studies at the Cerro Prieto and Heber geothermal fields  

DOE Green Energy (OSTI)

To study subsidence and mass removal, a precise gravity network was established on 60 permanent monuments in the Cerro Prieto geothermal field in early 1978, and repeated annually through early 1981; the survey was tied to two bedrock sites outside the limits of the current production zone. The looping technique of station occupation was utilized, in which occupation of the base was followed by occupation of several stations, followed by a return to the base. Use of two LaCoste and Romberg gravity meters, and replication of values within loops as well as entire loops, enhanced precision such that the median standard deviations of the base-to-station differences, reduced to observed gravity values, ranged from 7 to 15 microgals for individual surveys. The smaller values were obtained as field and data reduction techniques were improved and experience was gained. A similar survey was initiated in the Heber area just north of the Mexican border in early 1980. It too was established on permanent monuments, was tied to bedrock stations outside the geothermal area, and used multiple repetitions of values with two meters to achieve high precision.

Grannell, R.B.

1982-09-01T23:59:59.000Z

469

Wavenumber–Frequency Spectra of Inertia–Gravity and Mixed Rossby–Gravity Waves in the Equatorial Pacific Ocean  

Science Conference Proceedings (OSTI)

In the 1970s and 1980s, there was considerable interest in near-equatorial variability at periods of days to weeks associated with oceanic equatorial inertia–gravity waves and mixed Rossby–gravity waves. At that time, the measurements available ...

J. Thomas Farrar; Theodore S. Durland

2012-11-01T23:59:59.000Z

470

Nuclear reactor overflow line  

DOE Patents (OSTI)

The overflow line for the reactor vessel of a liquid-metal-cooled nuclear reactor includes means for establishing and maintaining a continuous bleed flow of coolant amounting to 5 to 10% of the total coolant flow through the overflow line to prevent thermal shock to the overflow line when the reactor is restarted following a trip. Preferably a tube is disposed concentrically just inside the overflow line extending from a point just inside the reactor vessel to an overflow tank and a suction line is provided opening into the body of liquid metal in the reactor vessel and into the annulus between the overflow line and the inner tube.

Severson, Wayne J. (Pittsburgh, PA)

1976-01-01T23:59:59.000Z

471

BlackLining Demo BlackLining Demo  

E-Print Network (OSTI)

BlackLining Demo BlackLining Demo BlackLining Demo YOUR PAYCHECKPAYROLL TAXES AND EMPLOYMENT LAW BY SPONSORED BY #12;BlackLining Demo e BlackLining Demo e BlackLining Demo e AMERICAN PAYROLL ASSOCIATION i Design by PRIWORKS.com. Images from Thinkstock.com. #12;BlackLining Demo BlackLining Demo Black

Harms, Kyle E.

472

Comment about constraints on nanometer-range modifications to gravity from low-energy neutron experiments  

E-Print Network (OSTI)

A topic of present interest is the application of experimentally observed quantum mechanical levels of ultra-cold neutrons in the earth's gravitational field for searching short-range modifications to gravity. A constraint on new forces in the nanometer-range published by Nesvizhevsky and Protasov follows from inadequate modelling of the interaction potential of a neutron with a mirror wall. Limits by many orders of magnitude better were already derived long ago from the consistency of experiments on the neutron-electron interaction.

O. Zimmer; N. Kaiser

2006-02-14T23:59:59.000Z

473

Low-energy quantum gravity: new challenges for an experiment and observation  

E-Print Network (OSTI)

Some new challenges for an experiment and observation, which are consequences of the model of low-energy quantum gravity by the author, are considered here. In particular, the property of asymptotic freedom of this model leads to the unexpected consequence: if a black hole arises due to a collapse of a matter with some characteristic mass of particles, its full mass should be restricted from the bottom. For usual baryonic matter, this limit of mass is of the order $10^{7}M_{\\odot}$.

Michael A. Ivanov

2009-01-05T23:59:59.000Z

474

North Australian Cloud Lines  

Science Conference Proceedings (OSTI)

A satellite classification and climatology of propagating mesoscale cloud fines in northern Australia is presented. These cloud fines range from long, narrow lines of shallow convection to extensive deep convective squall lines with mesoscale ...

W. Drosdowsky; G. J. Holland

1987-11-01T23:59:59.000Z

475

Semiclassical approximation to supersymmetric quantum gravity  

SciTech Connect

We develop a semiclassical approximation scheme for the constraint equations of supersymmetric canonical quantum gravity. This is achieved by a Born-Oppenheimer type of expansion, in analogy to the case of the usual Wheeler-DeWitt equation. The formalism is only consistent if the states at each order depend on the gravitino field. We recover at consecutive orders the Hamilton-Jacobi equation, the functional Schroedinger equation, and quantum gravitational correction terms to this Schroedinger equation. In particular, the following consequences are found: (i) the Hamilton-Jacobi equation and therefore the background spacetime must involve the gravitino, (ii) a (many-fingered) local time parameter has to be present on super Riem {sigma} (the space of all possible tetrad and gravitino fields) (iii) quantum supersymmetric gravitational corrections affect the evolution of the very early Universe. The physical meaning of these equations and results, in particular, the similarities to and differences from the pure bosonic case, are discussed.

Kiefer, Claus; Lueck, Tobias; Moniz, Paulo [Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Strasse 77, 50937 Cologne (Germany); Astronomy Unit, School of Mathematical Sciences, Queen Mary College, University of London, Mile End Road, London E1 4NS (United Kingdom)

2005-08-15T23:59:59.000Z

476

Hydrodynamic orienting of asymmetric microobjects under gravity  

E-Print Network (OSTI)

It is shown that nonsymmetric microobjects orient while settling under gravity in a viscous fluid. To analyze this process, a simple shape is chosen: a non-deformable `chain'. The chain consists of two straight arms, made of touching solid spheres. In the absence of external torques, the spheres are free to spin along the arms. The motion of the chain is evaluated by solving the Stokes equations with the use of the multipole method. It is demonstrated that the spinning beads speed up sedimentation by a small amount, and increase the orientation rate significantly in comparison to the corresponding rigid chain. It is shown that chains orient towards the V-shaped stable stationary configuration. In contrast, rods and star-shaped microobjects do not rotate. The hydrodynamic orienting is relevant for efficient swimming of non-symmetric microobjects, and for sedimenting suspensions.

Maria L. Ekiel-Jezewska; Eligiusz Wajnryb

2008-12-12T23:59:59.000Z

477

Yang-Mills Gravity in Biconformal Space  

E-Print Network (OSTI)

We propose a new conformal supergravity model with direct relevance to string/gauge theory dualities. This biconformal supergravity theory is formulated with a Yang-Mills type action. The resulting 8-dim symplectic geometries describe 4-dim scale-invariant general relativity. We then show an extension of N = 4 SUSY Yang-Mills to a curved biconformal geometry such that the extended form of the Yang-Mills fields provides the curvatures for the biconformal space. These curvatures solve the biconformal field equations whenever the original 4-dim fields satisfy the 4-dim YM theory. This gives a 1-1 mapping between the gravity and gauge theories. We also display systematic extension of any spacetime co-tangent bundle to a biconformal space, and extension of any 4-dim Yang-Mills theory to an equivalent theory on that space. 1

Lara B. Anderson; James T. Wheeler

2008-01-01T23:59:59.000Z

478

Characterization of Planar Transmission Lines  

Science Conference Proceedings (OSTI)

... References on: On-Wafer Measurement and Calibration, Planar Transmission Line Characterization and Multiconductor Transmission Lines. ...

2011-12-15T23:59:59.000Z

479

Solar system tests of Ho?ava-Lifshitz gravity  

E-Print Network (OSTI)

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.

Tiberiu Harko; Zoltan Kovács; Francisco S. N. Lobo

2009-08-20T23:59:59.000Z

480

Massive gravity with mass term in three dimensions  

Science Conference Proceedings (OSTI)

We analyze the effect of the Pauli-Fierz mass term on a recently established, new massive gravity theory in three space-time dimensions. We show that the Pauli-Fierz mass term makes the new massive gravity theory nonunitary. Moreover, although we add the gravitational Chern-Simons term to this model, the situation remains unchanged and the theory stays nonunitary despite that the structure of the graviton propagator is greatly changed. Thus, the Pauli-Fierz mass term is not allowed to coexist with mass-generating higher-derivative terms in the new massive gravity.

Nakasone, Masashi; Oda, Ichiro [Department of Physics, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213 (Japan)

2009-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "lines limited gravity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

How to Distinguish Dark Energy and Modified Gravity?  

E-Print Network (OSTI)

The current accelerated expansion of our universe could be due to an unknown energy component (dark energy) or a modification to general relativity (modified gravity). It is proposed in literature that combining the probes of cosmic expansion history and growth history can distinguish between dark energy and modified gravity. In the present work, we show that the possible interaction between dark energy and dark matter could make interacting dark energy model and modified gravity model indistinguishable. An explicit example is also given. Therefore, it is required to seek some complementary probes beyond the ones of cosmic expansion history and growth history.

Wei, Hao

2008-01-01T23:59:59.000Z

482

Energy conditions in $f(R,L_{m})$ gravity  

E-Print Network (OSTI)

In order to constrain $f(R,L_{m})$ gravity from theoretical aspects, its energy conditions are derived in this paper. These energy conditions given by us are quite general and can be degenerated to the well-known energy conditions in General Relativity and $f(R)$ theories of gravity with arbitrary coupling, non-minimal coupling and non-coupling between matter and geometry, respectively, as special cases. To exemplify how to use these energy conditions to restrict $f(R,L_{m})$ gravity, we consider a special model in the FRW cosmology and give some corresponding results by using astronomical observations.

Wang, Jun

2012-01-01T23:59:59.000Z

483

Strong Energy Condition in $R + R^2$ Gravity  

E-Print Network (OSTI)

In this paper, we study Raychaudhuri's equation in the background of $R + \\beta R^2$ gravity with a phenomenological matter ($\\rho \\propto a(t)^{-n}$). We conclude that even though the Strong Energy Condition (S.E.C.) for Einstein's gravity, which guarantees singularity, is $n\\geq 2$ for $\\rho \\propto a(t)^{-n}$, a perturbative analysis of Raychaudhuri's equation in the background of $R + \\beta R^2$ gravity reveals that the big bang singularity may not be guaranteed for $n > 4$. We derive the following Strong Energy Conditions for $R + \\beta R^2$ ($\\beta \

J. H. Kung

1995-10-04T23:59:59.000Z

484

Gravity Effects on Information Filtering and Network Evolving  

E-Print Network (OSTI)

In this Letter, based on the gravity principle of classical physics, we propose a tunable gravity-based model, which considers tag usage pattern to weigh both the mass and distance of network nodes. We then apply this model in solving the problems of information filtering and network evolving. Experimental results on two real-world data sets, Del.icio.us and MovieLens, show that it can not only enhance the algorithmic performance, but also can better characterize the properties of real networks. This work may shed some light on the in-depth understanding the gravity effect

Liu, Jin-Hu; Yang, Chengcheng; Chen, Lingjiao; Liu, Chuang; Wang, Xueqi

2013-01-01T23:59:59.000Z

485

Gravity inversion using a binary formulation Richard A. Krahenbuhl* and Yaoguo Li  

E-Print Network (OSTI)

Gravity inversion using a binary formulation Richard A. Krahenbuhl* and Yaoguo Li Gravity contrast that gives rise to zero gravity response on the surface. As a result, part of the salt structure structure using gravity data can be divided into two general categories. The first are interface inversions

486

Gravity observations and 3D structure of the Earth , F. Chambat  

E-Print Network (OSTI)

1 Gravity observations and 3D structure of the Earth Y. Ricard1 , F. Chambat Laboratoire des, Michigan-Ann Harbor University, USA. Short title: GRAVITY OBSERVATIONS AND 3D STRUCTURE OF THE EARTH 1. The determination of Earth's gravity field has benefited from various gravity missions that have been launched

487

Critical gravity as van Dam-Veltman-Zakharov discontinuity in anti de Sitter space  

E-Print Network (OSTI)

We consider critical gravity as van Dam-Vletman-Zakharov (vDVZ) discontinuity in anti de Sitter space. For this purpose, we introduce the higher curvature gravity. This discontinuity can be confirmed by calculating the residues of relevant poles explicitly. For the non-critical gravity of $0gravity.

Yun Soo Myung

2011-07-18T23:59:59.000Z

488

(Limiting the greenhouse effect)  

SciTech Connect

Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

Rayner, S.

1991-01-07T23:59:59.000Z

489

(Limiting the greenhouse effect)  

SciTech Connect

Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

Rayner, S.

1991-01-07T23:59:59.000Z

490

Similarity-based fuzzy limits  

Science Conference Proceedings (OSTI)

In this paper the concept of similarity-based fuzzy limits in metric spaces is introduced and it is shown that it is an application of limit maps of topologies on [0,1]-valued sets, introduced by Hohle and Sostak, furthermore it is observed that the ... Keywords: Fuzzy limit, Limit map, Similarity-based fuzzy limit, [0,1]-Valued topology

Gültekin Soylu

2008-12-01T23:59:59.000Z

491

Symphony Energy Resources Limited | Open Energy Information  

Open Energy Info (EERE)

Symphony Energy Resources Limited Symphony Energy Resources Limited Jump to: navigation, search Name Symphony Energy Resources Limited Place Borehamwood, United Kingdom Zip WD6 1LE Product String representation "Symphony Energy ... dable plastics." is too long. Coordinates 51.65582°, -0.275754° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":51.65582,"lon":-0.275754,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

492

Mistral Invest Limited | Open Energy Information  

Open Energy Info (EERE)

Mistral Invest Limited Mistral Invest Limited Jump to: navigation, search Name Mistral Invest Limited Place London, United Kingdom Zip W1U 7DW Sector Wind energy Product Private Equity Fund aiming to build a portfolio of wind farms in the UK and France, participating early in the project development phase. Coordinates 51.506325°, -0.127144° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":51.506325,"lon":-0.127144,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

493

Fortune New Energy Limited | Open Energy Information  

Open Energy Info (EERE)

Fortune New Energy Limited Fortune New Energy Limited Jump to: navigation, search Name Fortune New Energy Limited Place Tianjin, Tianjin Municipality, China Sector Wind energy Product Tianjin-based wind project developer Coordinates 39.231831°, 117.878502° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":39.231831,"lon":117.878502,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

494

EPR Ely Power Limited | Open Energy Information  

Open Energy Info (EERE)

EPR Ely Power Limited EPR Ely Power Limited Jump to: navigation, search Name EPR Ely Power Limited Place London, Greater London, United Kingdom Zip SW1Y 5AU Sector Biomass Product Owns and operates the Ely biomass power plant. Coordinates 51.506325°, -0.127144° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":51.506325,"lon":-0.127144,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

495

Central Electronics Limited CEL | Open Energy Information  

Open Energy Info (EERE)

Electronics Limited CEL Electronics Limited CEL Jump to: navigation, search Name Central Electronics Limited (CEL) Place Sahibabad, Uttar Pradesh, India Zip 201010 Sector Solar Product String representation "Sahibabad-based ... nment of India." is too long. Coordinates 28.67127°, 77.371002° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":28.67127,"lon":77.371002,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

496

Acquasol Infrastructure Limited | Open Energy Information  

Open Energy Info (EERE)

Acquasol Infrastructure Limited Acquasol Infrastructure Limited Jump to: navigation, search Name Acquasol Infrastructure Limited Place Adelaide, South Australia, Australia Zip 5000 Sector Solar Product Adelaide based solar thermal project and technology developer. Coordinates -34.926102°, 138.599884° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":-34.926102,"lon":138.599884,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

497

Biodiesel Energy Trading Limited | Open Energy Information  

Open Energy Info (EERE)

Limited Limited Jump to: navigation, search Name Biodiesel Energy Trading Limited Place London, United Kingdom Zip W1J 8DY Product London-based company focused on trading of biodiesel. Coordinates 51.506325°, -0.127144° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":51.506325,"lon":-0.127144,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

498

Vihaan Networks Limited VNL | Open Energy Information  

Open Energy Info (EERE)

Vihaan Networks Limited VNL Vihaan Networks Limited VNL Jump to: navigation, search Name Vihaan Networks Limited (VNL) Place Gurgaon, Haryana, India Zip 122015 Sector Solar Product Developer of solar-powered GSM system for rural areas in India. Coordinates 28.55114°, 78.89427° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":28.55114,"lon":78.89427,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

499

Amperex Technology Limited ATL | Open Energy Information  

Open Energy Info (EERE)

Amperex Technology Limited ATL Amperex Technology Limited ATL Jump to: navigation, search Name Amperex Technology Limited (ATL) Place N.T., Hong Kong Product Designer and manufacturer of Lithium Ion Polymer (LIP) battery cells and batteries for OEM customers making cell phones, PDA, notebook PC, earphone, and smart card applications. Coordinates 44.994023°, -72.407693° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":44.994023,"lon":-72.407693,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

500

Armaec Energy Limited | Open Energy Information  

Open Energy Info (EERE)

Armaec Energy Limited Armaec Energy Limited Jump to: navigation, search Name Armaec Energy Limited Place Uxbridge, Greater London, United Kingdom Zip UB10 9NA Sector Wind energy Product London based wind farm developer with a focus on emerging markets such as Armenia, South Africa and India. Coordinates 42.060711°, -71.622467° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.060711,"lon":-71.622467,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}