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1606.03005
Roberto Pierini
Roberto Pierini, Shahpoor Moradi and Stefano Mancini
Spacetime anisotropy affects cosmological entanglement
14 pages
Nuclear Physics B 924 (2017) 684
10.1016/j.nuclphysb.2017.09.025
null
gr-qc quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most existing cosmological entanglement studies are focused on the isotropic Robertson-Walker (RW) spacetime. Here we go beyond this limitation and study the influence of anisotropy on entanglement generated by dynamical spacetime. Since the isotropic spacetime is viewed as a background medium and the anisotropy is i...
[ { "created": "Thu, 9 Jun 2016 15:47:12 GMT", "version": "v1" } ]
2017-11-16
[ [ "Pierini", "Roberto", "" ], [ "Moradi", "Shahpoor", "" ], [ "Mancini", "Stefano", "" ] ]
Most existing cosmological entanglement studies are focused on the isotropic Robertson-Walker (RW) spacetime. Here we go beyond this limitation and study the influence of anisotropy on entanglement generated by dynamical spacetime. Since the isotropic spacetime is viewed as a background medium and the anisotropy is inc...
gr-qc/9803052
Janna Levin
Janna Levin
Curing singularities: From the big bang to black holes
To appear as a brief report in Phys. Rev. D
Phys.Rev. D57 (1998) 7611-7614
10.1103/PhysRevD.57.7611
CfPA-97-TH-08
gr-qc
null
Singular spacetimes are a natural prediction of Einstein's theory. Most memorable are the singular centers of black holes and the big bang. However, dilatonic extensions of Einstein's theory can support nonsingular spacetimes. The cosmological singularities can be avoided by dilaton driven inflation. Furthermore, a n...
[ { "created": "Fri, 13 Mar 1998 19:56:51 GMT", "version": "v1" } ]
2009-10-31
[ [ "Levin", "Janna", "" ] ]
Singular spacetimes are a natural prediction of Einstein's theory. Most memorable are the singular centers of black holes and the big bang. However, dilatonic extensions of Einstein's theory can support nonsingular spacetimes. The cosmological singularities can be avoided by dilaton driven inflation. Furthermore, a non...
1208.5442
Sharmanthie Fernando
Sharmanthie Fernando and Juan Correa
Quasinormal Modes of Bardeen Black Hole: Scalar Perturbations
25 figures, Published in Physical Review D. Reference numbers corrected
Physical Review D 86 (2012) 064039
10.1103/PhysRevD.86.064039
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The purpose of this paper is to study quasinormal modes (QNM) of the Bardeen black hole due to scalar perturbations. We have done a thorough analysis of the QNM frequencies by varying the charge $q$, mass $M$ and the spherical harmonic index $l$. The unstable null geodesics are used to compute the QNM's in the eikona...
[ { "created": "Mon, 27 Aug 2012 16:50:08 GMT", "version": "v1" }, { "created": "Thu, 25 Oct 2012 18:12:51 GMT", "version": "v2" }, { "created": "Thu, 22 Aug 2013 13:38:20 GMT", "version": "v3" }, { "created": "Wed, 8 Jan 2014 17:27:45 GMT", "version": "v4" } ]
2015-06-11
[ [ "Fernando", "Sharmanthie", "" ], [ "Correa", "Juan", "" ] ]
The purpose of this paper is to study quasinormal modes (QNM) of the Bardeen black hole due to scalar perturbations. We have done a thorough analysis of the QNM frequencies by varying the charge $q$, mass $M$ and the spherical harmonic index $l$. The unstable null geodesics are used to compute the QNM's in the eikonal ...
2201.09908
Ivan Kolar
Ivan Kol\'a\v{r}
Non-local scalar fields in static spacetimes via heat kernels
19 pages, 6 figures, comments welcome!
Phys. Rev. D 105, 084026 (2022)
10.1103/PhysRevD.105.084026
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We solve the non-local equation ${-e^{-\ell^2\square}\square{\phi}=J}$ for i) static scalar fields in static spacetimes and ii) time-dependent scalar fields in ultrastatic spacetimes. Corresponding equations are rewritten as non-local Poisson/inhomogeneous Helmholtz equations in compact and non-compact weighted/Riema...
[ { "created": "Mon, 24 Jan 2022 19:05:46 GMT", "version": "v1" } ]
2022-04-19
[ [ "Kolář", "Ivan", "" ] ]
We solve the non-local equation ${-e^{-\ell^2\square}\square{\phi}=J}$ for i) static scalar fields in static spacetimes and ii) time-dependent scalar fields in ultrastatic spacetimes. Corresponding equations are rewritten as non-local Poisson/inhomogeneous Helmholtz equations in compact and non-compact weighted/Riemann...
0704.3986
Sergiu Vacaru I.
Sergiu I. Vacaru
Parametric Nonholonomic Frame Transforms and Exact Solutions in Gravity
a latex 2e [11pt] variant corresponding to proofs for IJMMP, 54 pages
Int.J.Geom.Meth.Mod.Phys.04:1285-1334,2008
10.1142/S0219887807002570
null
gr-qc hep-th math-ph math.DG math.MP
null
A generalized geometric method is developed for constructing exact solutions of gravitational field equations in Einstein theory and generalizations. First, we apply the formalism of nonholonomic frame deformations (formally considered for nonholonomic manifolds and Finsler spaces) when the gravitational field equati...
[ { "created": "Mon, 30 Apr 2007 17:49:57 GMT", "version": "v1" }, { "created": "Tue, 1 May 2007 21:29:55 GMT", "version": "v2" }, { "created": "Mon, 24 Sep 2007 20:32:45 GMT", "version": "v3" }, { "created": "Mon, 19 Nov 2007 18:07:55 GMT", "version": "v4" } ]
2008-11-26
[ [ "Vacaru", "Sergiu I.", "" ] ]
A generalized geometric method is developed for constructing exact solutions of gravitational field equations in Einstein theory and generalizations. First, we apply the formalism of nonholonomic frame deformations (formally considered for nonholonomic manifolds and Finsler spaces) when the gravitational field equation...
gr-qc/0506005
Sergey Kozyrev
S.M.Kozyrev
Some aspects of the three dimensional gravity theories with temporal scalar field
null
null
null
null
gr-qc
null
The present paper proposes a new explanation for the 3-dimensional Einstein general theory of relativity which is free of contradictions and consistent with usual 4-dimensional physics. We discuss the property of the new gravity theory with temporal scalar field arise in lower-dimensional theories as the reduction of...
[ { "created": "Wed, 1 Jun 2005 05:06:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kozyrev", "S. M.", "" ] ]
The present paper proposes a new explanation for the 3-dimensional Einstein general theory of relativity which is free of contradictions and consistent with usual 4-dimensional physics. We discuss the property of the new gravity theory with temporal scalar field arise in lower-dimensional theories as the reduction of t...
gr-qc/9607067
Martin Rainer
M. Rainer
The moduli space of local homogeneous 3-geometries
lecture presented at Pac. Conf. Grav. Cosm. (Feb. 1996, Seoul), 5 pages, latex (+3 figures available as hardcopy)
null
10.1007/978-94-011-5812-1_37
IPM-96-Seoul
gr-qc
null
For a canonical formulation of quantum gravity, the superspace of all possible 3-geometries on a Cauchy hypersurface of a 3+1-dimensional Lorentzian manifold plays a key role. While in the analogous 2+1-dimensional case the superspace of all Riemannian 2-geometries is well known, the structure of the superspace of al...
[ { "created": "Fri, 26 Jul 1996 13:07:40 GMT", "version": "v1" } ]
2016-01-27
[ [ "Rainer", "M.", "" ] ]
For a canonical formulation of quantum gravity, the superspace of all possible 3-geometries on a Cauchy hypersurface of a 3+1-dimensional Lorentzian manifold plays a key role. While in the analogous 2+1-dimensional case the superspace of all Riemannian 2-geometries is well known, the structure of the superspace of all ...
1710.03272
Lydia Bieri
Lydia Bieri, David Garfinkle, Nicolas Yunes
Gravitational Waves and Their Mathematics
null
AMS Notices, Vol. 64, Issue 07, 2017, (August issue 2017). http://www.ams.org/publications/journals/notices/201707/rnoti-p693.pdf
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is an overview article of the mathematics of gravitational waves. We explain the mathematics and physics of these waves in general relativity theory, discuss the gravitational wave experiment aLIGO and their detection of gravitational waves as well as its implications for astrophysics. A version of this article ...
[ { "created": "Mon, 9 Oct 2017 19:29:00 GMT", "version": "v1" } ]
2017-10-11
[ [ "Bieri", "Lydia", "" ], [ "Garfinkle", "David", "" ], [ "Yunes", "Nicolas", "" ] ]
This is an overview article of the mathematics of gravitational waves. We explain the mathematics and physics of these waves in general relativity theory, discuss the gravitational wave experiment aLIGO and their detection of gravitational waves as well as its implications for astrophysics. A version of this article wa...
1904.10303
Binaya Bishi Dr
N. Hulke, G. P. Singh, Binaya K. Bishi, A. Singh
Variable Chaplygin gas cosmologies in f(R, T) gravity with particle creation
null
null
10.1016/j.newast.2020.101357
null
gr-qc hep-th
http://creativecommons.org/publicdomain/zero/1.0/
A flat FLRW cosmological model with perfect fluid comprising of variable Chaplygin gas has been studied in context of f(R; T) gravity with particle creation. The considered scale factors describe the accelerated expansion of universe due to the effective negative pressure produced during evolution of universe. The ro...
[ { "created": "Mon, 22 Apr 2019 08:53:21 GMT", "version": "v1" } ]
2020-02-12
[ [ "Hulke", "N.", "" ], [ "Singh", "G. P.", "" ], [ "Bishi", "Binaya K.", "" ], [ "Singh", "A.", "" ] ]
A flat FLRW cosmological model with perfect fluid comprising of variable Chaplygin gas has been studied in context of f(R; T) gravity with particle creation. The considered scale factors describe the accelerated expansion of universe due to the effective negative pressure produced during evolution of universe. The role...
2006.04336
Pardyumn Kumar Sahoo
Snehasish Bhattacharjee, J.R.L. Santos, P.H.R.S. Moraes, P.K. Sahoo
Inflation in $f(R,T)$ Gravity
EPJ Plus accepted version
Eur. Phys. J. Plus 135, 576 (2020)
10.1140/epjp/s13360-020-00583-6
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The article presents modeling of inflationary scenarios for the first time in the $f(R,T)$ theory of gravity. We assume the $f(R,T)$ functional from to be $R + \eta T$, where $R$ denotes the Ricci scalar, $T$ the trace of the energy-momentum tensor and $\eta$ the model parameter (constant). We first investigated an i...
[ { "created": "Mon, 8 Jun 2020 03:17:16 GMT", "version": "v1" }, { "created": "Tue, 30 Jun 2020 09:59:08 GMT", "version": "v2" } ]
2020-08-03
[ [ "Bhattacharjee", "Snehasish", "" ], [ "Santos", "J. R. L.", "" ], [ "Moraes", "P. H. R. S.", "" ], [ "Sahoo", "P. K.", "" ] ]
The article presents modeling of inflationary scenarios for the first time in the $f(R,T)$ theory of gravity. We assume the $f(R,T)$ functional from to be $R + \eta T$, where $R$ denotes the Ricci scalar, $T$ the trace of the energy-momentum tensor and $\eta$ the model parameter (constant). We first investigated an inf...
1506.08038
Christian R\"oken
Christian R\"oken
The Massive Dirac Equation in the Kerr Geometry: Separability in Eddington-Finkelstein-type Coordinates and Asymptotics
19 pages, 3 figures, details added, reference added, minor corrections and improvements (published version)
null
10.1007/s10714-017-2194-y
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The separability of the massive Dirac equation in the non-extreme Kerr geometry in horizon-penetrating advanced Eddington-Finkelstein-type coordinates is shown. To this end, the Kerr geometry is described in the Newman-Penrose formalism by a regular Carter tetrad and the Dirac spinors and matrices are defined in a ch...
[ { "created": "Fri, 26 Jun 2015 12:03:45 GMT", "version": "v1" }, { "created": "Sun, 6 Dec 2015 16:04:15 GMT", "version": "v2" }, { "created": "Tue, 26 Jan 2016 14:24:21 GMT", "version": "v3" }, { "created": "Tue, 1 Nov 2016 16:50:05 GMT", "version": "v4" }, { "cre...
2019-02-21
[ [ "Röken", "Christian", "" ] ]
The separability of the massive Dirac equation in the non-extreme Kerr geometry in horizon-penetrating advanced Eddington-Finkelstein-type coordinates is shown. To this end, the Kerr geometry is described in the Newman-Penrose formalism by a regular Carter tetrad and the Dirac spinors and matrices are defined in a chir...
gr-qc/0311062
Igor I. Smolyaninov
Igor I. Smolyaninov
Linear and nonlinear optics of surface plasmon toy-models of black holes and wormholes
10 pages, 9 figures
Phys.Rev.B69:205417,2004
10.1103/PhysRevB.69.205417
null
gr-qc
null
Experimental and theoretical studies of linear and nonlinear optics of surface plasmon toy wormholes and black holes have been performed. These models are based on dielectric microdroplets on the metal surfaces and on nanoholes drilled in thin metal films. Toy surface plasmon black holes and wormholes are shown to ex...
[ { "created": "Wed, 19 Nov 2003 21:23:12 GMT", "version": "v1" } ]
2014-11-17
[ [ "Smolyaninov", "Igor I.", "" ] ]
Experimental and theoretical studies of linear and nonlinear optics of surface plasmon toy wormholes and black holes have been performed. These models are based on dielectric microdroplets on the metal surfaces and on nanoholes drilled in thin metal films. Toy surface plasmon black holes and wormholes are shown to exhi...
1804.06944
Sebasti\'an N\'ajera Valencia
Sebasti\'an N\'ajera and Roberto A. Sussman
Geometric and physical properties of closed ever expanding dust models
18 Pages, 6 figures
General Relativity and Gravitation (2018) 50:94
10.1007/s10714-018-2414-0
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Current observations suggest that our Universe is not incompatible with a small positive spatial curvature that can be associated with rest frames having a "closed" standard topology. We examine a toy model generalisation of the $\Lambda$CDM model in the form of ever expanding Lema\^{i}tre-Tolman-Bondi (LTB) models w...
[ { "created": "Wed, 18 Apr 2018 23:23:49 GMT", "version": "v1" } ]
2018-07-09
[ [ "Nájera", "Sebastián", "" ], [ "Sussman", "Roberto A.", "" ] ]
Current observations suggest that our Universe is not incompatible with a small positive spatial curvature that can be associated with rest frames having a "closed" standard topology. We examine a toy model generalisation of the $\Lambda$CDM model in the form of ever expanding Lema\^{i}tre-Tolman-Bondi (LTB) models wit...
1601.00460
Narayan Banerjee
Sridip Pal and Narayan Banerjee
Anisotropic models are unitary: A rejuvenation of standard quantum cosmology
null
Journal of Mathematical Physics (Vol.57, Issue 12) 2016
10.1063/1.4972292
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The present work proves that the folk-lore of the pathology of non-conservation of probability in quantum anisotropic models is wrong. It is shown in full generality that all operator ordering can lead to a Hamiltonian with a self-adjoint extension as long as it is constructed to be a symmetric operator, thereby maki...
[ { "created": "Mon, 4 Jan 2016 11:31:28 GMT", "version": "v1" } ]
2016-12-30
[ [ "Pal", "Sridip", "" ], [ "Banerjee", "Narayan", "" ] ]
The present work proves that the folk-lore of the pathology of non-conservation of probability in quantum anisotropic models is wrong. It is shown in full generality that all operator ordering can lead to a Hamiltonian with a self-adjoint extension as long as it is constructed to be a symmetric operator, thereby making...
2002.03800
Daniel Berkowitz
Daniel Berkowitz
New Solutions To The Bianchi VIII Wheeler DeWitt Equation And Leading Order Solutions For $\Lambda$ $\ne$ 0 And A Primordial Magnetic Field
11 pages, 6 figures. arXiv admin note: text overlap with arXiv:1910.11970
null
null
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New non trivial solutions to the Lorentzian-signature symmetry reduced Bianchi VIII Wheeler DeWitt equation for Hartle Hawking ordering parameters $ \pm 2\sqrt{33} $ are obtained using an Euclidean-signature semi classical method. Using the aforementioned method we define 'excited' states for the Bianchi VIII wave fu...
[ { "created": "Wed, 5 Feb 2020 20:07:11 GMT", "version": "v1" } ]
2020-02-11
[ [ "Berkowitz", "Daniel", "" ] ]
New non trivial solutions to the Lorentzian-signature symmetry reduced Bianchi VIII Wheeler DeWitt equation for Hartle Hawking ordering parameters $ \pm 2\sqrt{33} $ are obtained using an Euclidean-signature semi classical method. Using the aforementioned method we define 'excited' states for the Bianchi VIII wave func...
gr-qc/0608079
Abel Camacho Mr.
A. Camacho and A. Macias, (Departamento de Fisica, Universidad Autonoma Metropolitana--Mexico D.F., Mexico)
Deformed dispersion relations and the degree of coherence function
null
Gen.Rel.Grav. 38 (2006) 547-551
10.1007/s10714-006-0245-x
null
gr-qc
null
The analysis of the modifications that the presence of a deformed dispersion relation entails in the roots of the so--called degree of coherence function, for a beam embodying two different frequencies and moving in a Michelson interferometer, is carried out. The conditions to be satisfied, in order to detect this ki...
[ { "created": "Wed, 16 Aug 2006 16:48:05 GMT", "version": "v1" } ]
2009-11-11
[ [ "Camacho", "A.", "" ], [ "Macias", "A.", "" ] ]
The analysis of the modifications that the presence of a deformed dispersion relation entails in the roots of the so--called degree of coherence function, for a beam embodying two different frequencies and moving in a Michelson interferometer, is carried out. The conditions to be satisfied, in order to detect this kind...
1808.00080
Brian Seymour
Brian C. Seymour and Kent Yagi
Testing General Relativity with Black Hole-Pulsar Binaries
12 figures, 18 pages, fixed 2 minor typos
Phys. Rev. D 98, 124007 (2018)
10.1103/PhysRevD.98.124007
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Binary pulsars allow us to carry out precision tests of gravity and have placed stringent bounds on a broad class of theories beyond general relativity. Current and future radio telescopes, such as FAST, SKA, and MeerKAT, may find a new astrophysical system, a pulsar orbiting around a black hole, which will provide u...
[ { "created": "Tue, 31 Jul 2018 21:57:17 GMT", "version": "v1" }, { "created": "Tue, 4 Dec 2018 00:17:12 GMT", "version": "v2" }, { "created": "Sat, 21 Mar 2020 19:16:21 GMT", "version": "v3" } ]
2020-03-24
[ [ "Seymour", "Brian C.", "" ], [ "Yagi", "Kent", "" ] ]
Binary pulsars allow us to carry out precision tests of gravity and have placed stringent bounds on a broad class of theories beyond general relativity. Current and future radio telescopes, such as FAST, SKA, and MeerKAT, may find a new astrophysical system, a pulsar orbiting around a black hole, which will provide us ...
2105.04604
Maxime Van De Moortel
Christoph Kehle, Maxime Van de Moortel
Strong Cosmic Censorship in the presence of matter: the decisive effect of horizon oscillations on the black hole interior geometry
Final version, to appear in Analysis & PDE
Analysis & PDE 17 (2024) 1501-1592
10.2140/apde.2024.17.1501
null
gr-qc math-ph math.AP math.DG math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the Strong Cosmic Censorship Conjecture in the presence of matter, we study the Einstein equations coupled with a charged/massive scalar field with spherically symmetric characteristic data relaxing to a Reissner-Nordstr\"om event horizon. Contrary to the vacuum case, the relaxation rate is conjectured t...
[ { "created": "Mon, 10 May 2021 18:41:30 GMT", "version": "v1" }, { "created": "Fri, 23 Dec 2022 12:00:26 GMT", "version": "v2" } ]
2024-06-26
[ [ "Kehle", "Christoph", "" ], [ "Van de Moortel", "Maxime", "" ] ]
Motivated by the Strong Cosmic Censorship Conjecture in the presence of matter, we study the Einstein equations coupled with a charged/massive scalar field with spherically symmetric characteristic data relaxing to a Reissner-Nordstr\"om event horizon. Contrary to the vacuum case, the relaxation rate is conjectured to ...
1610.05281
Robert Mann
Mozhgan Mir and Robert B. Mann
Charged Rotating AdS Black Holes with Chern-Simons coupling
41 pages, Latex, 9 figures; references updated
Phys. Rev. D 95, 024005 (2017)
10.1103/PhysRevD.95.024005
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We obtain a perturbative solution for rotating charged black holes in 5-dimensional Einstein-Maxwell-Chern-Simons theory with a negative cosmological constant. We start from a small undeformed Kerr-AdS solution and use the electric charge as a perturbative parameter to build up black holes with equal-magnitude angula...
[ { "created": "Mon, 17 Oct 2016 19:27:55 GMT", "version": "v1" }, { "created": "Sat, 29 Oct 2016 15:59:06 GMT", "version": "v2" } ]
2017-01-11
[ [ "Mir", "Mozhgan", "" ], [ "Mann", "Robert B.", "" ] ]
We obtain a perturbative solution for rotating charged black holes in 5-dimensional Einstein-Maxwell-Chern-Simons theory with a negative cosmological constant. We start from a small undeformed Kerr-AdS solution and use the electric charge as a perturbative parameter to build up black holes with equal-magnitude angular ...
1408.6435
Jarmo M\"akel\"a Dr.
Jarmo M\"akel\"a
A Model of Inflation
10 pages, no figures. This paper is based on the results obtained in arXiv:1301.0009
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a novel model of cosmic inflation. In our model one does not need any specific matter field to drive inflation, but inflation stems from the microscopic, Planck scale structure of spacetime, thus being of quantum gravitational origin. At a certain temperature spacetime performs a phase transition, where t...
[ { "created": "Tue, 26 Aug 2014 12:17:04 GMT", "version": "v1" } ]
2014-08-28
[ [ "Mäkelä", "Jarmo", "" ] ]
We consider a novel model of cosmic inflation. In our model one does not need any specific matter field to drive inflation, but inflation stems from the microscopic, Planck scale structure of spacetime, thus being of quantum gravitational origin. At a certain temperature spacetime performs a phase transition, where the...
2005.04443
Alessandro Fabbri
Alessandro Fabbri and Roberto Balbinot
Ramp-up of Hawking radiation in Bose-Einstein condensate analogue black holes
6 pages, 5 figures; final version
Phys. Rev. Lett. 126, 111301 (2021)
10.1103/PhysRevLett.126.111301
null
gr-qc cond-mat.quant-gas hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by a recent experiment by Steinhauer and co-workers, we present a simple model which describes the formation of an acoustic black hole in a Bose-Einstein condensate, allowing an analytical computation of the evolution in time of the corresponding density-density correlator. We show the emergence of analog Ha...
[ { "created": "Sat, 9 May 2020 13:33:49 GMT", "version": "v1" }, { "created": "Tue, 19 May 2020 16:12:06 GMT", "version": "v2" }, { "created": "Thu, 18 Mar 2021 17:28:50 GMT", "version": "v3" } ]
2021-03-19
[ [ "Fabbri", "Alessandro", "" ], [ "Balbinot", "Roberto", "" ] ]
Inspired by a recent experiment by Steinhauer and co-workers, we present a simple model which describes the formation of an acoustic black hole in a Bose-Einstein condensate, allowing an analytical computation of the evolution in time of the corresponding density-density correlator. We show the emergence of analog Hawk...
gr-qc/0502049
Yavuz Nutku
Y. Nutku
Electrovac $pp$-waves
null
Class.Quant.Grav. 22 (2005) L43-L46
10.1088/0264-9381/22/9/L01
null
gr-qc
null
New exact solutions of the Einstein-Maxwell field equations that describe $pp$-waves are presented.
[ { "created": "Thu, 10 Feb 2005 20:17:40 GMT", "version": "v1" }, { "created": "Sat, 19 Feb 2005 09:02:16 GMT", "version": "v2" } ]
2009-11-11
[ [ "Nutku", "Y.", "" ] ]
New exact solutions of the Einstein-Maxwell field equations that describe $pp$-waves are presented.
gr-qc/0512050
Bijan Saha
Bijan Saha
Spinor field and accelerated regimes in cosmology
7 pages, 4 figures
Grav.Cosmol.12 (2006) 215 - 218
null
null
gr-qc
null
A self-consistent system of interaction nonlinear spinor and scalar fields within the scope of a BI cosmological model filled with perfect fluid is considered. The role of spinor field in the evolution of the Universe is studied. It is shown that the spinor field nonlinearity can generate a negative effective pressur...
[ { "created": "Thu, 8 Dec 2005 13:12:22 GMT", "version": "v1" } ]
2015-05-01
[ [ "Saha", "Bijan", "" ] ]
A self-consistent system of interaction nonlinear spinor and scalar fields within the scope of a BI cosmological model filled with perfect fluid is considered. The role of spinor field in the evolution of the Universe is studied. It is shown that the spinor field nonlinearity can generate a negative effective pressure,...
gr-qc/9601021
Alberto Saa
Alberto Saa
New no-scalar-hair theorem for black-holes
Revtex, 12 pages
J.Math.Phys. 37 (1996) 2346-2351
10.1063/1.531513
US-FT/2-96
gr-qc
null
A new no-hair theorem is formulated which rules out a very large class of non-minimally coupled finite scalar dressing of an asymptotically flat, static, and spherically symmetric black-hole. The proof is very simple and based in a covariant method for generating solutions for non-minimally coupled scalar fields star...
[ { "created": "Mon, 15 Jan 1996 14:29:30 GMT", "version": "v1" } ]
2009-10-28
[ [ "Saa", "Alberto", "" ] ]
A new no-hair theorem is formulated which rules out a very large class of non-minimally coupled finite scalar dressing of an asymptotically flat, static, and spherically symmetric black-hole. The proof is very simple and based in a covariant method for generating solutions for non-minimally coupled scalar fields starti...
2209.11298
James Kennington
Chad Hanna, James Kennington, Shio Sakon, Stephen Privitera, Miguel Fernandez, Jonathan Wang, Cody Messick, Alex Pace, Kipp Cannon, Prathamesh Joshi, Rachael Huxford, Sarah Caudill, Chiwai Chan, Bryce Cousins, Jolien D. E. Creighton, Becca Ewing, Heather Fong, Patrick Godwin, Ryan Magee, Duncan Meacher, Soichir...
A binary tree approach to template placement for searches for gravitational waves from compact binary mergers
null
null
null
null
gr-qc astro-ph.IM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We demonstrate a new geometric method for fast template placement for searches for gravitational waves from the inspiral, merger and ringdown of compact binaries. The method is based on a binary tree decomposition of the template bank parameter space into non-overlapping hypercubes. We use a numerical approximation o...
[ { "created": "Thu, 22 Sep 2022 20:25:23 GMT", "version": "v1" } ]
2022-09-26
[ [ "Hanna", "Chad", "" ], [ "Kennington", "James", "" ], [ "Sakon", "Shio", "" ], [ "Privitera", "Stephen", "" ], [ "Fernandez", "Miguel", "" ], [ "Wang", "Jonathan", "" ], [ "Messick", "Cody", "" ], [ ...
We demonstrate a new geometric method for fast template placement for searches for gravitational waves from the inspiral, merger and ringdown of compact binaries. The method is based on a binary tree decomposition of the template bank parameter space into non-overlapping hypercubes. We use a numerical approximation of ...
gr-qc/9803006
Grigorii A. Vilkovisky
A. G. Mirzabekian, G. A. Vilkovisky (Lebedev Institute)
Particle creation in the effective action method
129 pages including 7 figures. Latex 2.09. Figures by METAFONT, 300 DPI. Execute the file "arttotal.tex"
Ann.Phys.270:391-496,1998
10.1006/aphy.1998.5860
null
gr-qc hep-th
null
The effect of particle creation by nonstationary external fields is considered as a radiation effect in the expectation-value spacetime. The energy of created massless particles is calculated as the vacuum contribution in the energy-momentum tensor of the expectation value of the metric. The calculation is carried ou...
[ { "created": "Mon, 2 Mar 1998 03:37:20 GMT", "version": "v1" } ]
2008-11-26
[ [ "Mirzabekian", "A. G.", "", "Lebedev Institute" ], [ "Vilkovisky", "G. A.", "", "Lebedev Institute" ] ]
The effect of particle creation by nonstationary external fields is considered as a radiation effect in the expectation-value spacetime. The energy of created massless particles is calculated as the vacuum contribution in the energy-momentum tensor of the expectation value of the metric. The calculation is carried out ...
0709.2129
Kevin Vandersloot
Christian G. Boehmer, Kevin Vandersloot
Loop Quantum Dynamics of the Schwarzschild Interior
Update to match version accepted for publication in PRD
Phys.Rev.D76:104030,2007
10.1103/PhysRevD.76.104030
null
gr-qc astro-ph math-ph math.MP
null
We examine the Schwarzschild interior of a black hole, incorporating quantum gravitational modifications due to loop quantum gravity. We consider an improved loop quantization using techniques that have proven successful in loop quantum cosmology. The central Schwarzschild singularity is resolved and the implications...
[ { "created": "Thu, 13 Sep 2007 17:10:18 GMT", "version": "v1" }, { "created": "Mon, 8 Oct 2007 10:07:45 GMT", "version": "v2" } ]
2008-11-26
[ [ "Boehmer", "Christian G.", "" ], [ "Vandersloot", "Kevin", "" ] ]
We examine the Schwarzschild interior of a black hole, incorporating quantum gravitational modifications due to loop quantum gravity. We consider an improved loop quantization using techniques that have proven successful in loop quantum cosmology. The central Schwarzschild singularity is resolved and the implications f...
gr-qc/0511151
Norichika Sago
Norichika Sago, Takahiro Tanaka, Wataru Hikida, Katsuhiko Ganz, Hiroyuki Nakano
The adiabatic evolution of orbital parameters in the Kerr spacetime
34 pages, no figure
Prog.Theor.Phys. 115 (2006) 873-907
10.1143/PTP.115.873
null
gr-qc astro-ph
null
We investigate the adiabatic orbital evolution of a point particle in the Kerr spacetime due to the emission of gravitational waves. In the case that the timescale of the orbital evolution is enough smaller than the typical timescale of orbits, the evolution of orbits is characterized by the change rates of three con...
[ { "created": "Tue, 29 Nov 2005 08:48:26 GMT", "version": "v1" } ]
2009-11-11
[ [ "Sago", "Norichika", "" ], [ "Tanaka", "Takahiro", "" ], [ "Hikida", "Wataru", "" ], [ "Ganz", "Katsuhiko", "" ], [ "Nakano", "Hiroyuki", "" ] ]
We investigate the adiabatic orbital evolution of a point particle in the Kerr spacetime due to the emission of gravitational waves. In the case that the timescale of the orbital evolution is enough smaller than the typical timescale of orbits, the evolution of orbits is characterized by the change rates of three const...
1009.1794
Luca Lusanna
David Alba and Luca Lusanna
The Einstein-Maxwell-Particle System in the York Canonical Basis of ADM Tetrad Gravity: III) The Post-Minkowskian N-Body Problem, its Post-Newtonian Limit in Non-Harmonic 3-Orthogonal Gauges and Dark Matter as an Inertial Effect
86 pages. Deep revision of the second part of the paper with the addition of the center-of-mass problem in GR, with a refined treatment of the PostNewtonian expansion and with the explaination of dark matter as a relativistic inertial effect not only in the rotation curves of galaxies but also in the mass of ga...
null
null
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We conclude the study of the Post-Minkowskian linearization of ADM tetrad gravity in the York canonical basis for asymptotically Minkowskian space-times in the family of non-harmonic 3-orthogonal gauges parametrized by the York time ${}^3K(\tau, \vec \sigma)$ (the inertial gauge variable, not existing in Newton gravi...
[ { "created": "Thu, 9 Sep 2010 14:28:24 GMT", "version": "v1" }, { "created": "Tue, 26 Apr 2011 13:11:24 GMT", "version": "v2" } ]
2011-04-27
[ [ "Alba", "David", "" ], [ "Lusanna", "Luca", "" ] ]
We conclude the study of the Post-Minkowskian linearization of ADM tetrad gravity in the York canonical basis for asymptotically Minkowskian space-times in the family of non-harmonic 3-orthogonal gauges parametrized by the York time ${}^3K(\tau, \vec \sigma)$ (the inertial gauge variable, not existing in Newton gravity...
2207.08864
Jacopo Mazza
Edgardo Franzin, Stefano Liberati, Jacopo Mazza, Vania Vellucci
Stable Rotating Regular Black Holes
15 pages, 8 figures. (v2) Formatting matched to submitted version. (v3) Sec. V.A on causal structure added, sec. V.B on effective matter content expanded, other minor revisions; matches published version
Phys. Rev. D 106, 104060 (2022)
10.1103/PhysRevD.106.104060
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a rotating regular black hole whose inner horizon has zero surface gravity for any value of the spin parameter, and is therefore stable against mass inflation. Our metric is built by combining two successful strategies for regularizing singularities, i.e. by replacing the mass parameter with a function of ...
[ { "created": "Mon, 18 Jul 2022 18:22:16 GMT", "version": "v1" }, { "created": "Mon, 25 Jul 2022 16:27:53 GMT", "version": "v2" }, { "created": "Fri, 2 Dec 2022 17:01:27 GMT", "version": "v3" } ]
2024-03-08
[ [ "Franzin", "Edgardo", "" ], [ "Liberati", "Stefano", "" ], [ "Mazza", "Jacopo", "" ], [ "Vellucci", "Vania", "" ] ]
We present a rotating regular black hole whose inner horizon has zero surface gravity for any value of the spin parameter, and is therefore stable against mass inflation. Our metric is built by combining two successful strategies for regularizing singularities, i.e. by replacing the mass parameter with a function of $r...
1603.03436
Cristian Martinez
Hideki Maeda and Cristian Martinez
All static and electrically charged solutions with Einstein base manifold in the arbitrary-dimensional Einstein-Maxwell system with a massless scalar field
38 pages, 1 figure, 1 table. Some typos fixed. References added
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a simple and complete classification of static solutions in the Einstein-Maxwell system with a massless scalar field in arbitrary $n(\ge 3)$ dimensions. We consider spacetimes which correspond to a warped product $M^2 \times K^{n-2}$, where $K^{n-2}$ is a $(n-2)$-dimensional Einstein space. The scalar fiel...
[ { "created": "Thu, 10 Mar 2016 21:00:03 GMT", "version": "v1" }, { "created": "Mon, 9 Apr 2018 14:39:08 GMT", "version": "v2" }, { "created": "Mon, 6 Aug 2018 15:38:05 GMT", "version": "v3" } ]
2018-08-07
[ [ "Maeda", "Hideki", "" ], [ "Martinez", "Cristian", "" ] ]
We present a simple and complete classification of static solutions in the Einstein-Maxwell system with a massless scalar field in arbitrary $n(\ge 3)$ dimensions. We consider spacetimes which correspond to a warped product $M^2 \times K^{n-2}$, where $K^{n-2}$ is a $(n-2)$-dimensional Einstein space. The scalar field ...
2402.15922
Everton Murilo Carvalho Abreu
Everton M. C. Abreu
Barrow black hole variable parameter model connected to information theory
9 pages
null
null
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
One of the greatest challenges of theoretical physics today is to unveil the quantum information theory concerning what happens when one bit of information enters the black hole (BH) horizon. The Landauer principle showed that a certain amount of energy is generated when one-bit of information is erased as it enters ...
[ { "created": "Sat, 24 Feb 2024 22:33:08 GMT", "version": "v1" } ]
2024-02-27
[ [ "Abreu", "Everton M. C.", "" ] ]
One of the greatest challenges of theoretical physics today is to unveil the quantum information theory concerning what happens when one bit of information enters the black hole (BH) horizon. The Landauer principle showed that a certain amount of energy is generated when one-bit of information is erased as it enters th...
2211.08925
Macarena Lagos
Felipe Sulantay, Macarena Lagos, M\'aximo Ba\~nados
Chiral Gravitational Waves in Palatini Chern-Simons
Published version
null
10.1103/PhysRevD.107.104025
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the parity-breaking higher-curvature gravity theory of Chern-Simons (CS), using the Palatini formulation in which the metric and connection are taken to be independent fields. We first show that Palatini CS gravity leads to first-order derivative equations of motion and thus avoid the typical instabilities o...
[ { "created": "Wed, 16 Nov 2022 14:12:30 GMT", "version": "v1" }, { "created": "Fri, 19 May 2023 18:20:18 GMT", "version": "v2" } ]
2023-05-23
[ [ "Sulantay", "Felipe", "" ], [ "Lagos", "Macarena", "" ], [ "Bañados", "Máximo", "" ] ]
We study the parity-breaking higher-curvature gravity theory of Chern-Simons (CS), using the Palatini formulation in which the metric and connection are taken to be independent fields. We first show that Palatini CS gravity leads to first-order derivative equations of motion and thus avoid the typical instabilities of ...
2311.14052
Luca D'Onofrio
Luca D'Onofrio, Rosario De Rosa, Paola Leaci, Cristiano Palomba
Doppler orbital correction for the targeted search of known pulsars with the 5-vector method
arXiv admin note: substantial text overlap with arXiv:2311.08229
null
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
Pulsars are promising targets for the first detection of continuous gravitational waves (CWs) by the LIGO-Virgo-KAGRA (LVK) Collaboration. Targeted searches leverage critical information derived from continued monitoring of pulsars related to the spin evolution, astrometry, and binary orbit. This information maximize...
[ { "created": "Thu, 23 Nov 2023 15:10:01 GMT", "version": "v1" } ]
2023-11-27
[ [ "D'Onofrio", "Luca", "" ], [ "De Rosa", "Rosario", "" ], [ "Leaci", "Paola", "" ], [ "Palomba", "Cristiano", "" ] ]
Pulsars are promising targets for the first detection of continuous gravitational waves (CWs) by the LIGO-Virgo-KAGRA (LVK) Collaboration. Targeted searches leverage critical information derived from continued monitoring of pulsars related to the spin evolution, astrometry, and binary orbit. This information maximizes ...
2308.07363
Ignacio A. Reyes
Ignacio A. Reyes
Trace anomaly and compact stars
6 pages, 1 figure. Minor modifications: added comment on the equation of state, shortened the section on the wave equation
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A widespread assumption states that quantum effects of matter in curved spacetimes become relevant only when the inverse curvature radius approaches the Planck mass $m_{\text{P}}$. We challenge this view by showing that, relying solely on universal properties of QFTs at high energies, the trace anomaly becomes macros...
[ { "created": "Mon, 14 Aug 2023 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 11 Sep 2023 17:44:02 GMT", "version": "v2" } ]
2023-09-12
[ [ "Reyes", "Ignacio A.", "" ] ]
A widespread assumption states that quantum effects of matter in curved spacetimes become relevant only when the inverse curvature radius approaches the Planck mass $m_{\text{P}}$. We challenge this view by showing that, relying solely on universal properties of QFTs at high energies, the trace anomaly becomes macrosco...
1410.2301
Hristu Culetu
Hristu Culetu
Negative $\Lambda$ induced by accelerated motion
title changed, 6 pages, version published in EPJ Plus 130 (4), 2015; DOI 10.1140/epjp/i2015-15065-9
EPJ Plus (2015) 130 (4)
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A correlation between accelerated motion and a noncompact 5th dimension is proposed. The curvature invariants and the stress energy tensor in the bulk depend only on the 5th dimension $w$ and vanish asymptotically while the proper acceleration of a static observer is proportional to $1/w$. The brane (located at $w = ...
[ { "created": "Wed, 8 Oct 2014 22:20:13 GMT", "version": "v1" }, { "created": "Thu, 16 Apr 2015 15:28:57 GMT", "version": "v2" } ]
2015-04-17
[ [ "Culetu", "Hristu", "" ] ]
A correlation between accelerated motion and a noncompact 5th dimension is proposed. The curvature invariants and the stress energy tensor in the bulk depend only on the 5th dimension $w$ and vanish asymptotically while the proper acceleration of a static observer is proportional to $1/w$. The brane (located at $w = w_...
1610.01968
Lee Smolin
Lee Smolin
Four principles for quantum gravity
26 pages, one figure and caption taken from McGaugh, Lelli, Schombert, arXiv:1609.05917v1
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Four principles are proposed to underlie the quantum theory of gravity. We show that these suffice to recover the Einstein equations. We also suggest that MOND results from a modification of the classical equivalence principle, due to quantum gravity effects.
[ { "created": "Thu, 6 Oct 2016 17:46:33 GMT", "version": "v1" } ]
2016-10-07
[ [ "Smolin", "Lee", "" ] ]
Four principles are proposed to underlie the quantum theory of gravity. We show that these suffice to recover the Einstein equations. We also suggest that MOND results from a modification of the classical equivalence principle, due to quantum gravity effects.
1007.1031
Frank Wilczek
Achilleas P. Porfyriadis and Frank Wilczek
Effective Action, Boundary Conditions, and Virasoro Algebra for AdS$_3$
12 pages, no figures
null
null
MIT-CTP/4160
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct, to second order, the effective action of General Relativity for small excitations generated by a vector field and use it to study conformal symmetry in the boundary of AdS$_3$. By requiring finiteness of the boundary effective action(s) for certain asymptotic transformations, we derive the well-known Vi...
[ { "created": "Wed, 7 Jul 2010 01:08:56 GMT", "version": "v1" } ]
2010-07-08
[ [ "Porfyriadis", "Achilleas P.", "" ], [ "Wilczek", "Frank", "" ] ]
We construct, to second order, the effective action of General Relativity for small excitations generated by a vector field and use it to study conformal symmetry in the boundary of AdS$_3$. By requiring finiteness of the boundary effective action(s) for certain asymptotic transformations, we derive the well-known Vira...
1109.4400
Andrea Nerozzi
Andrea Nerozzi
A new approach to the Newman-Penrose formalism
5 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Newman-Penrose formalism in transverse tetrads, namely those tetrads where \Psi_1=\Psi_3=0, is studied. In particular it is shown that the equations governing the dynamics within this formalism can be recast in a particularly compact way, leading to a better understanding of the formalism itself. The particular c...
[ { "created": "Tue, 20 Sep 2011 19:26:30 GMT", "version": "v1" } ]
2011-09-21
[ [ "Nerozzi", "Andrea", "" ] ]
The Newman-Penrose formalism in transverse tetrads, namely those tetrads where \Psi_1=\Psi_3=0, is studied. In particular it is shown that the equations governing the dynamics within this formalism can be recast in a particularly compact way, leading to a better understanding of the formalism itself. The particular cho...
1503.03370
Aghil Alaee
Aghil Alaee, Hari K. Kunduri
Proof of the local mass-angular momenta inequality for $U(1)^2$ invariant black holes
v2. statement of main theorem clarified, various minor improvements and clarifications
Class.Quant.Grav. 32 (2015) 16, 165020
10.1088/0264-9381/32/16/165020
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider initial data for extreme vacuum asymptotically flat black holes with $\mathbb{R} \times U(1)^2$ symmetry. Such geometries are critical points of a mass functional defined for a wide class of asymptotically flat, `$(t-\phi^i)$' symmetric maximal initial data for the vacuum Einstein equations. We prove that...
[ { "created": "Wed, 11 Mar 2015 15:16:43 GMT", "version": "v1" }, { "created": "Wed, 12 Aug 2015 15:16:31 GMT", "version": "v2" } ]
2015-08-13
[ [ "Alaee", "Aghil", "" ], [ "Kunduri", "Hari K.", "" ] ]
We consider initial data for extreme vacuum asymptotically flat black holes with $\mathbb{R} \times U(1)^2$ symmetry. Such geometries are critical points of a mass functional defined for a wide class of asymptotically flat, `$(t-\phi^i)$' symmetric maximal initial data for the vacuum Einstein equations. We prove that t...
gr-qc/0007052
Moncy John
Moncy V. John and K. Babu Joseph
A Low Matter Density Decaying Vacuum Cosmology from Complex Metric
21 pages, no figures
Class.Quant.Grav.14:1115,1997
10.1088/0264-9381/14/5/016
null
gr-qc astro-ph hep-th
null
A low matter density decaying vacuum cosmology is proposed on the assumption that the universe's radius is a complex quantity \hat{R} if it is regarded as having a zero energy-momentum tensor. But we find that when the radius is real, it contains matter. Using the Einstein-Hilbert action principle, the physical scale...
[ { "created": "Thu, 20 Jul 2000 17:09:30 GMT", "version": "v1" } ]
2008-11-26
[ [ "John", "Moncy V.", "" ], [ "Joseph", "K. Babu", "" ] ]
A low matter density decaying vacuum cosmology is proposed on the assumption that the universe's radius is a complex quantity \hat{R} if it is regarded as having a zero energy-momentum tensor. But we find that when the radius is real, it contains matter. Using the Einstein-Hilbert action principle, the physical scale f...
1007.2024
David Nichols
David A. Nichols and Yanbei Chen
A hybrid method for understanding black-hole mergers: head-on case
14 pages, 6 figures, 1 table, revtex4 format, v2 references added, v3 expanded discussion of comparison with numerical relativity, and small changes to match published version
Phys.Rev.D82:104020,2010
10.1103/PhysRevD.82.104020
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Black-hole-binary coalescence is often divided into three stages: inspiral, merger and ringdown. The post-Newtonian (PN) approximation treats the inspiral phase, black-hole perturbation (BHP) theory describes the ringdown, and the nonlinear dynamics of spacetime characterize the merger. In this paper, we introduce a ...
[ { "created": "Tue, 13 Jul 2010 02:34:30 GMT", "version": "v1" }, { "created": "Mon, 26 Jul 2010 06:12:52 GMT", "version": "v2" }, { "created": "Mon, 15 Nov 2010 22:53:19 GMT", "version": "v3" } ]
2010-12-13
[ [ "Nichols", "David A.", "" ], [ "Chen", "Yanbei", "" ] ]
Black-hole-binary coalescence is often divided into three stages: inspiral, merger and ringdown. The post-Newtonian (PN) approximation treats the inspiral phase, black-hole perturbation (BHP) theory describes the ringdown, and the nonlinear dynamics of spacetime characterize the merger. In this paper, we introduce a hy...
gr-qc/9803081
Justino Martinez
L. Herrera, A. Di Prisco and J. Martinez
Breakdown of the linear approximation in the perturbative analysis of heat conduction in relativistic systems
11 pages (Latex2.09) To appear in Physics Letters A
Phys.Lett.A243:7-12,1998
10.1016/S0375-9601(98)00222-9
null
gr-qc astro-ph
null
We analyze the effects of thermal conduction in a relativistic fluid just after its departure from spherical symmetry, on a time scale of the order of relaxation time. Using first order perturbation theory, it is shown that, as in spherical systems, at a critical point the effective inertial mass density of a fluid e...
[ { "created": "Wed, 25 Mar 1998 08:05:46 GMT", "version": "v1" } ]
2008-11-26
[ [ "Herrera", "L.", "" ], [ "Di Prisco", "A.", "" ], [ "Martinez", "J.", "" ] ]
We analyze the effects of thermal conduction in a relativistic fluid just after its departure from spherical symmetry, on a time scale of the order of relaxation time. Using first order perturbation theory, it is shown that, as in spherical systems, at a critical point the effective inertial mass density of a fluid ele...
2204.04519
Junji Jia
Haotian Liu, Jinning Liang and Junji Jia
Deflection and Gravitational lensing of null and timelike signals in the Kiselev black hole spacetime in the weak field limit
19 pages, 7 figures; to match the version to appear in Classical and Quantum Gravity
null
10.1088/1361-6382/ac8b56
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we study the deflection and gravitational lensing of null and timelike signals in the Kiselev spacetime in the weak field limit, to investigate the effects of the equation of state parameter $\omega$ and the matter amount parameter $\alpha$. In doing this, we extend a perturbative method previously devel...
[ { "created": "Sat, 9 Apr 2022 17:50:22 GMT", "version": "v1" }, { "created": "Sun, 28 Aug 2022 15:12:42 GMT", "version": "v2" } ]
2022-09-21
[ [ "Liu", "Haotian", "" ], [ "Liang", "Jinning", "" ], [ "Jia", "Junji", "" ] ]
In this work we study the deflection and gravitational lensing of null and timelike signals in the Kiselev spacetime in the weak field limit, to investigate the effects of the equation of state parameter $\omega$ and the matter amount parameter $\alpha$. In doing this, we extend a perturbative method previously develop...
gr-qc/0212065
Kirill Bronnikov
K.A. Bronnikov, S.B. Fadeev and A.V. Michtchenko
Scalar fields in multidimensional gravity. No-hair and other no-go theorems
10 pages, Latex-2e. Submitted to Gen. Rel. Grav
Gen.Rel.Grav. 35 (2003) 505-525
10.1023/A:1022952314050
null
gr-qc hep-th
null
Global properties of static, spherically symmetric configurations of scalar fields of sigma-model type with arbitrary potentials are studied in $D$ dimensions, including space-times containing multiple internal factor spaces. The latter are assumed to be Einstein spaces, not necessarily Ricci-flat, and the potential ...
[ { "created": "Sun, 15 Dec 2002 17:44:51 GMT", "version": "v1" } ]
2015-06-25
[ [ "Bronnikov", "K. A.", "" ], [ "Fadeev", "S. B.", "" ], [ "Michtchenko", "A. V.", "" ] ]
Global properties of static, spherically symmetric configurations of scalar fields of sigma-model type with arbitrary potentials are studied in $D$ dimensions, including space-times containing multiple internal factor spaces. The latter are assumed to be Einstein spaces, not necessarily Ricci-flat, and the potential $V...
1906.08288
Ashoke Sen
Alok Laddha and Ashoke Sen
A Classical Proof of the Classical Soft Graviton Theorem in D>4
LaTeX; 32 pages
Phys. Rev. D 101, 084011 (2020)
10.1103/PhysRevD.101.084011
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Classical soft graviton theorem gives an expression for the spectrum of low frequency gravitational radiation, emitted during a classical scattering process, in terms of the trajectories and spin angular momenta of ingoing and outgoing objects, including hard radiation. This has been proved to subleading order in the...
[ { "created": "Wed, 19 Jun 2019 18:14:17 GMT", "version": "v1" } ]
2020-04-15
[ [ "Laddha", "Alok", "" ], [ "Sen", "Ashoke", "" ] ]
Classical soft graviton theorem gives an expression for the spectrum of low frequency gravitational radiation, emitted during a classical scattering process, in terms of the trajectories and spin angular momenta of ingoing and outgoing objects, including hard radiation. This has been proved to subleading order in the e...
0910.0490
Bennie F. L. Ward
B.F.L. Ward (Department of Physics, Baylor University, Waco, TX, USA)
Planck Scale Cosmology and Resummed Quantum Gravity
6 pages, 2 figures. To be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C090726; 3 typo's corrected
null
null
BU-HEPP-09-05
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that, by using amplitude-based resummation techniques for Feynman's formulation of Einstein's theory, we get quantum field theoretic 'first principles' predictions for the UV fixed-point values of the dimensionless gravitational and cosmological constants. Connections to the phenomenological asymptotic safety...
[ { "created": "Fri, 2 Oct 2009 21:25:20 GMT", "version": "v1" }, { "created": "Tue, 13 Oct 2009 19:48:31 GMT", "version": "v2" } ]
2009-10-13
[ [ "Ward", "B. F. L.", "", "Department of Physics, Baylor University, Waco, TX, USA" ] ]
We show that, by using amplitude-based resummation techniques for Feynman's formulation of Einstein's theory, we get quantum field theoretic 'first principles' predictions for the UV fixed-point values of the dimensionless gravitational and cosmological constants. Connections to the phenomenological asymptotic safety a...
2401.06931
Jan Ambjorn
Jan Ambjorn and Yoshiyuki Watabiki
Late time acceleration of our Universe caused by the absorption of baby universes
Contribution to the proceedings volume for Gravity, Strings and Fields: A conference in honour of Gordon Semenoff
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If our Universe is allowed to absorb baby universes, one obtains a modified Friedmann equation that can explain the late time acceleration of our Universe and there is no need for a cosmological constant. In addition the modified Friedmann equation favors the value of the Hubble constant obtained by local measurement...
[ { "created": "Fri, 12 Jan 2024 23:47:06 GMT", "version": "v1" } ]
2024-01-17
[ [ "Ambjorn", "Jan", "" ], [ "Watabiki", "Yoshiyuki", "" ] ]
If our Universe is allowed to absorb baby universes, one obtains a modified Friedmann equation that can explain the late time acceleration of our Universe and there is no need for a cosmological constant. In addition the modified Friedmann equation favors the value of the Hubble constant obtained by local measurements.
2210.15640
D. Ghilencea
Dumitru Ghilencea, Christopher T. Hill
Renormalization Group for Non-minimal $\phi^2 R$ Couplings and Gravitational Contact Interactions
11 pages, 4 figures. arXiv admin note: text overlap with arXiv:2009.14782
null
10.1103/PhysRevD.107.085013
null
gr-qc astro-ph.CO hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Theories of scalars and gravity, with an Einstein-Hilbert term and non-minimal interactions, $M^2R/2 -\alpha\phi^2R/12 $, have graviton exchange induced contact interactions. These modify the renormalization group, leading to a discrepancy between the conventional calculations in the Jordan frame that ignore this eff...
[ { "created": "Thu, 27 Oct 2022 17:31:11 GMT", "version": "v1" } ]
2023-05-03
[ [ "Ghilencea", "Dumitru", "" ], [ "Hill", "Christopher T.", "" ] ]
Theories of scalars and gravity, with an Einstein-Hilbert term and non-minimal interactions, $M^2R/2 -\alpha\phi^2R/12 $, have graviton exchange induced contact interactions. These modify the renormalization group, leading to a discrepancy between the conventional calculations in the Jordan frame that ignore this effec...
gr-qc/0306095
Jorge Pullin
Rodolfo Gambini, Jorge Pullin
Discrete quantum gravity: a mechanism for selecting the value of fundamental constants
5 pages, RevTex, 4 figures, honorable mention in the 2003 Gravity Research Foundation Essays, to appear in Int. J. Mod. Phys. D
Int.J.Mod.Phys. D12 (2003) 1775-1782
10.1142/S0218271803004018
LSU-REL-062003
gr-qc astro-ph hep-th
null
Smolin has put forward the proposal that the universe fine tunes the values of its physical constants through a Darwinian selection process. Every time a black hole forms, a new universe is developed inside it that has different values for its physical constants from the ones in its progenitor. The most likely univer...
[ { "created": "Fri, 20 Jun 2003 18:49:24 GMT", "version": "v1" } ]
2009-11-10
[ [ "Gambini", "Rodolfo", "" ], [ "Pullin", "Jorge", "" ] ]
Smolin has put forward the proposal that the universe fine tunes the values of its physical constants through a Darwinian selection process. Every time a black hole forms, a new universe is developed inside it that has different values for its physical constants from the ones in its progenitor. The most likely universe...
1003.3782
Branislav Cvetkovi\'c
M. Blagojevi\'c and B. Cvetkovi\'c
Conserved charges in 3D gravity
LATEX, 14 pages; v2: minor corrections, two references added
Phys.Rev.D81:124024,2010
10.1103/PhysRevD.81.124024
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The covariant canonical expression for the conserved charges, proposed by Nester, is tested on several solutions in 3D gravity with or without torsion and topologically massive gravity. In each of these cases, the calculated values of energy-momentum and angular momentum are found to satisfy the first law of black ho...
[ { "created": "Fri, 19 Mar 2010 12:07:12 GMT", "version": "v1" }, { "created": "Thu, 10 Jun 2010 08:09:41 GMT", "version": "v2" } ]
2010-06-11
[ [ "Blagojević", "M.", "" ], [ "Cvetković", "B.", "" ] ]
The covariant canonical expression for the conserved charges, proposed by Nester, is tested on several solutions in 3D gravity with or without torsion and topologically massive gravity. In each of these cases, the calculated values of energy-momentum and angular momentum are found to satisfy the first law of black hole...
2303.18074
Silvia Pla Garc\'ia
Antonio Ferreiro and Silvia Pla
Instantaneous vacuum and States of Low Energy for a scalar field in cosmological backgrounds
10 pages, 4 figures, contribution to the proceedings of the "Avenues of Quantum Field Theory in Curved Space-time" conference, Genova, September 2022
null
null
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We construct the instantaneous vacuum state for a quantum scalar field coupled to another classical scalar field as described in [1]. We then compare it with the state of low energy constructed for a particular solution. We show that under physically motivated conditions they become very similar.
[ { "created": "Fri, 31 Mar 2023 14:06:09 GMT", "version": "v1" } ]
2023-04-03
[ [ "Ferreiro", "Antonio", "" ], [ "Pla", "Silvia", "" ] ]
We construct the instantaneous vacuum state for a quantum scalar field coupled to another classical scalar field as described in [1]. We then compare it with the state of low energy constructed for a particular solution. We show that under physically motivated conditions they become very similar.
1205.1096
Ahmet Baykal
Ahmet Baykal
Quadratic Curvature Gravity with Second Order Trace and Massive Gravity Models in Three Dimensions
24 pages, to appear in GRG
Gen.Rel.Grav. 44 (2012) 1993-2017
10.1007/s10714-012-1377-9
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The quadratic curvature lagrangians having metric field equations with second order trace are constructed relative to an orthonormal coframe. In $n>4$ dimensions, pure quadratic curvature lagrangian having second order trace constructed contains three free parameters in the most general case. The fourth order field e...
[ { "created": "Sat, 5 May 2012 03:59:30 GMT", "version": "v1" } ]
2012-07-17
[ [ "Baykal", "Ahmet", "" ] ]
The quadratic curvature lagrangians having metric field equations with second order trace are constructed relative to an orthonormal coframe. In $n>4$ dimensions, pure quadratic curvature lagrangian having second order trace constructed contains three free parameters in the most general case. The fourth order field equ...
1701.00564
Tetsuya Shiromizu
Tetsuya Shiromizu, Yoshimune Tomikawa, Keisuke Izumi and Hirotaka Yoshino
Area bound for a surface in a strong gravity region
5 pages, a reference added, minor changes, accepted for publication in PTEP
Prog. Theor. Exp. Phys. (2017) 033E01
10.1093/ptep/ptx022
OCU-PHYS-456; AP-GR-135
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For asymptotically flat spacetimes, using the inverse mean curvature flow, we show that any compact $2$-surface, $S_0$, whose mean curvature and its derivative for outward direction are positive in spacelike hypersurface with non-negative Ricci scalar satisfies the inequality $A_0 \leq 4 \pi (3Gm)^2$, where $A_0$ is ...
[ { "created": "Tue, 3 Jan 2017 01:25:54 GMT", "version": "v1" }, { "created": "Thu, 23 Feb 2017 06:04:42 GMT", "version": "v2" } ]
2017-04-19
[ [ "Shiromizu", "Tetsuya", "" ], [ "Tomikawa", "Yoshimune", "" ], [ "Izumi", "Keisuke", "" ], [ "Yoshino", "Hirotaka", "" ] ]
For asymptotically flat spacetimes, using the inverse mean curvature flow, we show that any compact $2$-surface, $S_0$, whose mean curvature and its derivative for outward direction are positive in spacelike hypersurface with non-negative Ricci scalar satisfies the inequality $A_0 \leq 4 \pi (3Gm)^2$, where $A_0$ is th...
1402.1437
Bernard J. Carr
B. J. Carr
Primordial Black Holes and Quantum Effects
8 pages, 6 figures, to appear in Proceedings of 2013 Karl Schwarzschild Meeting on Gravitational Physics, eds. P. Nicolini, J. Mureika, M. Kaminski, M. Bleicher
null
null
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Primordial black holes (PBHs) are of special interest because of the crucial role of quantum effects in their formation and evaporation. This means that they provide a unique probe of the early universe, high-energy physics and quantum gravity. We highlight some recent developments in the subject, including improved ...
[ { "created": "Thu, 6 Feb 2014 17:52:12 GMT", "version": "v1" } ]
2014-02-07
[ [ "Carr", "B. J.", "" ] ]
Primordial black holes (PBHs) are of special interest because of the crucial role of quantum effects in their formation and evaporation. This means that they provide a unique probe of the early universe, high-energy physics and quantum gravity. We highlight some recent developments in the subject, including improved li...
2311.11926
Jainendra Kumar Singh Dr.
J. K. Singh, Shaily, Harshna Balhara, Sushant G. Ghosh and Sunil D. Maharaj
EDSFD parametrization in $ f(R,T) $ gravity with linear curvature terms
16 pages, 18 figures
Physics of the Dark Universe, 2024
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
This paper investigates the flat Friedmann-Lema$\hat{\imath}$tre-Robertson-Walker (FLRW) cosmological model using a suitable parameterization represented as a differential equation concerning the energy density of the scalar field, $\rho_{\phi}$, in the context of $f(R,T)$ gravity theory. This parameterization is kno...
[ { "created": "Wed, 15 Nov 2023 15:37:07 GMT", "version": "v1" }, { "created": "Sun, 28 Apr 2024 19:37:28 GMT", "version": "v2" } ]
2024-04-30
[ [ "Singh", "J. K.", "" ], [ "Shaily", "", "" ], [ "Balhara", "Harshna", "" ], [ "Ghosh", "Sushant G.", "" ], [ "Maharaj", "Sunil D.", "" ] ]
This paper investigates the flat Friedmann-Lema$\hat{\imath}$tre-Robertson-Walker (FLRW) cosmological model using a suitable parameterization represented as a differential equation concerning the energy density of the scalar field, $\rho_{\phi}$, in the context of $f(R,T)$ gravity theory. This parameterization is known...
1511.06307
Lucila Kraiselburd
Lucila Kraiselburd, Susana J. Landau, Marcelo Salgado, Daniel Sudarsky and H\'ector Vucetich
Equivalence Principle in Chameleon Models
42 pages, 15 figures Accepted for publication in PRD
Phys. Rev. D 97, 104044 (2018)
10.1103/PhysRevD.97.104044
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most theories that predict time and/or space variation of fundamental constants also predict violations of the Weak Equivalence Principle. In 2004 Khoury and Weltman proposed the so called chameleon field arguing that it could help avoiding experimental bounds on the WEP while having a non-trivial cosmological impact...
[ { "created": "Thu, 19 Nov 2015 18:56:15 GMT", "version": "v1" }, { "created": "Wed, 8 Jun 2016 00:16:42 GMT", "version": "v2" }, { "created": "Fri, 10 Jun 2016 17:27:13 GMT", "version": "v3" }, { "created": "Thu, 9 Nov 2017 12:36:12 GMT", "version": "v4" }, { "cre...
2018-05-30
[ [ "Kraiselburd", "Lucila", "" ], [ "Landau", "Susana J.", "" ], [ "Salgado", "Marcelo", "" ], [ "Sudarsky", "Daniel", "" ], [ "Vucetich", "Héctor", "" ] ]
Most theories that predict time and/or space variation of fundamental constants also predict violations of the Weak Equivalence Principle. In 2004 Khoury and Weltman proposed the so called chameleon field arguing that it could help avoiding experimental bounds on the WEP while having a non-trivial cosmological impact. ...
1606.04980
Swati Singh
S. Singh, L.A. De Lorenzo, I. Pikovski and K.C. Schwab
Detecting continuous gravitational waves with superfluid $^4$He
null
null
10.1088/1367-2630/aa78cb
null
gr-qc astro-ph.IM cond-mat.other quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Direct detection of gravitational waves is opening a new window onto our universe. Here, we study the sensitivity to continuous-wave strain fields of a kg-scale optomechanical system formed by the acoustic motion of superfluid helium-4 parametrically coupled to a superconducting microwave cavity. This narrowband dete...
[ { "created": "Wed, 15 Jun 2016 21:10:15 GMT", "version": "v1" } ]
2017-08-02
[ [ "Singh", "S.", "" ], [ "De Lorenzo", "L. A.", "" ], [ "Pikovski", "I.", "" ], [ "Schwab", "K. C.", "" ] ]
Direct detection of gravitational waves is opening a new window onto our universe. Here, we study the sensitivity to continuous-wave strain fields of a kg-scale optomechanical system formed by the acoustic motion of superfluid helium-4 parametrically coupled to a superconducting microwave cavity. This narrowband detect...
2009.03778
Yuan Chen
Yuan Chen, He-Xu Zhang, Tian-Chi Ma and Jian-Bo Deng
Optical properties of a nonlinear magnetic charged rotating black hole surrounded by quintessence with a cosmological constant
null
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper,we discuss optical properties of the nonlinear magnetic charged black hole surrounded by quintessence with a non-zero cosmological constant $\Lambda$. Setting the state parameter $\omega=-3/2$ , we studied the horizon, the photon region and the shadow of this black hole. It turned out that for a fixed q...
[ { "created": "Sun, 6 Sep 2020 11:07:05 GMT", "version": "v1" } ]
2021-04-26
[ [ "Chen", "Yuan", "" ], [ "Zhang", "He-Xu", "" ], [ "Ma", "Tian-Chi", "" ], [ "Deng", "Jian-Bo", "" ] ]
In this paper,we discuss optical properties of the nonlinear magnetic charged black hole surrounded by quintessence with a non-zero cosmological constant $\Lambda$. Setting the state parameter $\omega=-3/2$ , we studied the horizon, the photon region and the shadow of this black hole. It turned out that for a fixed qui...
1812.03376
Bahram Mashhoon
Alireza Allahyari, Hassan Firouzjahi, and Bahram Mashhoon
Quasinormal Modes of a Black Hole with Quadrupole Moment
45 pages; v2: presentation improved, matches published version
Phys. Rev. D 99, 044005 (2019)
10.1103/PhysRevD.99.044005
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analytically determine the quasinormal mode (QNM) frequencies of a black hole with quadrupole moment in the eikonal limit using the light-ring method. The generalized black holes that are discussed in this work possess arbitrary quadrupole and higher mass moments in addition to mass and angular momentum. Static co...
[ { "created": "Sat, 8 Dec 2018 19:29:01 GMT", "version": "v1" }, { "created": "Wed, 6 Feb 2019 17:28:38 GMT", "version": "v2" } ]
2019-02-13
[ [ "Allahyari", "Alireza", "" ], [ "Firouzjahi", "Hassan", "" ], [ "Mashhoon", "Bahram", "" ] ]
We analytically determine the quasinormal mode (QNM) frequencies of a black hole with quadrupole moment in the eikonal limit using the light-ring method. The generalized black holes that are discussed in this work possess arbitrary quadrupole and higher mass moments in addition to mass and angular momentum. Static coll...
1609.02751
Chandra Prakash Singh
Pankaj Kumar, C.P. Singh
New agegraphic dark energy in Brans-Dicke theory with logarithmic form of scalar field
11 pages
Astrophys. Space Sci. 362, 52 (2017)
10.1007/s10509-017-3032-0
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a very recent paper, the current authors (arXiv:gr-qc/1609.01477) have proposed and analyzed in detail the logarithmic form of Brans-Dicke scalar field $\phi$ as $\phi \propto ln(\alpha+\beta a)$, where $\alpha$ and $\beta$ are positive constants, to alleviate the problems of interacting holographic dark energy mo...
[ { "created": "Fri, 9 Sep 2016 11:51:27 GMT", "version": "v1" } ]
2017-06-13
[ [ "Kumar", "Pankaj", "" ], [ "Singh", "C. P.", "" ] ]
In a very recent paper, the current authors (arXiv:gr-qc/1609.01477) have proposed and analyzed in detail the logarithmic form of Brans-Dicke scalar field $\phi$ as $\phi \propto ln(\alpha+\beta a)$, where $\alpha$ and $\beta$ are positive constants, to alleviate the problems of interacting holographic dark energy mode...
gr-qc/9806015
Robert Mann
I. S. Booth and R. B. Mann
Complex Instantons and Charged Rotating Black Hole Pair Creation
11 pages, 1 figure, Latex, text shortened with only minor changes in content, accepted for Phys Rev Letters
Phys.Rev.Lett.81:5052-5055,1998
10.1103/PhysRevLett.81.5052
WATPHY-TH98/04
gr-qc
null
We consider the general process of pair-creation of charged rotating black holes. We find that instantons which describe this process are necessarily complex due to regularity requirements. However their associated probabilities are real, and fully consistent with the interpretation that the entropy of a charged rota...
[ { "created": "Wed, 3 Jun 1998 16:23:50 GMT", "version": "v1" }, { "created": "Mon, 26 Oct 1998 22:08:06 GMT", "version": "v2" } ]
2010-11-19
[ [ "Booth", "I. S.", "" ], [ "Mann", "R. B.", "" ] ]
We consider the general process of pair-creation of charged rotating black holes. We find that instantons which describe this process are necessarily complex due to regularity requirements. However their associated probabilities are real, and fully consistent with the interpretation that the entropy of a charged rotati...
1208.2984
Bijunath Patla
Bijunath R. Patla
Small Angle Approximation for Non-parallel Plate Capacitors with Applications in Experimental Gravitation
An error in Fig.3 fixed now. 14 pages, 5 figures. Submitted to Journal of Electrostatics
null
null
null
gr-qc physics.class-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An approximate analytical formula for the capacitance of a non-parallel plate capacitor with small values of inclination angles and distance separations of the plates is presented. Most applications involving position sensing that are employed in precision experiments and micromechanical devices often use a parallel ...
[ { "created": "Tue, 14 Aug 2012 21:59:44 GMT", "version": "v1" }, { "created": "Fri, 31 Aug 2012 17:02:17 GMT", "version": "v2" }, { "created": "Thu, 16 May 2013 21:47:18 GMT", "version": "v3" } ]
2013-05-20
[ [ "Patla", "Bijunath R.", "" ] ]
An approximate analytical formula for the capacitance of a non-parallel plate capacitor with small values of inclination angles and distance separations of the plates is presented. Most applications involving position sensing that are employed in precision experiments and micromechanical devices often use a parallel pl...
gr-qc/0002038
null
A.I.Nikishov (Lebedev Physics Institute)
Weinberg's energy-momentum pseudotensor for Schwarzschild field
5 pages, Latex, no figures
null
null
null
gr-qc
null
Weinberg's energy-momentum pseudotensor is obtained for Schwarzschild metric in harmonic coordinates. On the horizon it possesses unintegrable singularities. For this reason the total energy of a collapsar can't be obtained by integrating energy density over the system's volume. The implication for gravity theories i...
[ { "created": "Thu, 10 Feb 2000 14:53:37 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nikishov", "A. I.", "", "Lebedev Physics Institute" ] ]
Weinberg's energy-momentum pseudotensor is obtained for Schwarzschild metric in harmonic coordinates. On the horizon it possesses unintegrable singularities. For this reason the total energy of a collapsar can't be obtained by integrating energy density over the system's volume. The implication for gravity theories is ...
1206.0658
Derek Wise
Steffen Gielen and Derek K. Wise
Linking Covariant and Canonical General Relativity via Local Observers
8 pages; Essay written for the 2012 Gravity Research Foundation Awards for Essays on Gravitation
Gen. Relativ. Gravit. 44 (2012) 3103-3109
10.1007/s10714-012-1443-3
pi-qg-288
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hamiltonian gravity, relying on arbitrary choices of "space," can obscure spacetime symmetries. We present an alternative, manifestly spacetime covariant formulation that nonetheless distinguishes between "spatial" and "temporal" variables. The key is viewing dynamical fields from the perspective of a field of observ...
[ { "created": "Mon, 4 Jun 2012 16:01:21 GMT", "version": "v1" } ]
2012-11-12
[ [ "Gielen", "Steffen", "" ], [ "Wise", "Derek K.", "" ] ]
Hamiltonian gravity, relying on arbitrary choices of "space," can obscure spacetime symmetries. We present an alternative, manifestly spacetime covariant formulation that nonetheless distinguishes between "spatial" and "temporal" variables. The key is viewing dynamical fields from the perspective of a field of observer...
0912.1285
Christian Reisswig
C. Reisswig, N. T. Bishop, D. Pollney, B. Szilagyi
Characteristic extraction in numerical relativity: binary black hole merger waveforms at null infinity
41 pages, 8 figures, 2 tables, added references, fixed typos. Version matches published version.
Class. Quantum Grav. 27 075014 (2010)
10.1088/0264-9381/27/7/075014
null
gr-qc astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The accurate modeling of gravitational radiation is a key issue for gravitational wave astronomy. As simulation codes reach higher accuracy, systematic errors inherent in current numerical relativity wave-extraction methods become evident, and may lead to a wrong astrophysical interpretation of the data. In this pape...
[ { "created": "Mon, 7 Dec 2009 16:05:47 GMT", "version": "v1" }, { "created": "Wed, 10 Mar 2010 17:52:48 GMT", "version": "v2" } ]
2010-03-26
[ [ "Reisswig", "C.", "" ], [ "Bishop", "N. T.", "" ], [ "Pollney", "D.", "" ], [ "Szilagyi", "B.", "" ] ]
The accurate modeling of gravitational radiation is a key issue for gravitational wave astronomy. As simulation codes reach higher accuracy, systematic errors inherent in current numerical relativity wave-extraction methods become evident, and may lead to a wrong astrophysical interpretation of the data. In this paper,...
1202.3256
Joshua Logue
J. Logue (1), C. D. Ott (2), I. S. Heng (1), P. Kalmus (2), J. Scargill (3) ((1) Glasgow, (2) Caltech, (3) Oxford)
Inferring Core-Collapse Supernova Physics with Gravitational Waves
22 pages, 9 figures
null
10.1103/PhysRevD.86.044023
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Stellar collapse and the subsequent development of a core-collapse supernova explosion emit bursts of gravitational waves (GWs) that might be detected by the advanced generation of laser interferometer gravitational-wave observatories such as Advanced LIGO, Advanced Virgo, and LCGT. GW bursts from core-collapse super...
[ { "created": "Wed, 15 Feb 2012 10:08:35 GMT", "version": "v1" }, { "created": "Thu, 23 Feb 2012 11:02:09 GMT", "version": "v2" } ]
2015-06-04
[ [ "Logue", "J.", "", "Glasgow" ], [ "Ott", "C. D.", "", "Caltech" ], [ "Heng", "I. S.", "", "Glasgow" ], [ "Kalmus", "P.", "", "Caltech" ], [ "Scargill", "J.", "", "Oxford" ] ]
Stellar collapse and the subsequent development of a core-collapse supernova explosion emit bursts of gravitational waves (GWs) that might be detected by the advanced generation of laser interferometer gravitational-wave observatories such as Advanced LIGO, Advanced Virgo, and LCGT. GW bursts from core-collapse superno...
gr-qc/9911080
Dzhunushaliev Vladimir
V. Dzhunushaliev and H.-J. Schmidt
Wormholes and Flux Tubes in the 7D Gravity on the Principal Bundle with SU(2) Gauge Group as the Extra Dimensions
20 pages, 8 figures, the quality of the figures are improved
Phys.Rev.D62:044035,2000
10.1103/PhysRevD.62.044035
UNIPO-MATH-99-November-18
gr-qc hep-th
null
Vacuum solutions for multidimensional gravity on the principal bundle with the SU(2) structural group as the extra dimensions are found and discussed. This generalizes the results of Ref. \cite{vds3} from U(1) to the SU(2) gauge group. The spherically symmetric solution with the off-diagonal components of the multidi...
[ { "created": "Mon, 22 Nov 1999 09:07:34 GMT", "version": "v1" }, { "created": "Fri, 4 Feb 2000 08:51:24 GMT", "version": "v2" } ]
2010-11-19
[ [ "Dzhunushaliev", "V.", "" ], [ "Schmidt", "H. -J.", "" ] ]
Vacuum solutions for multidimensional gravity on the principal bundle with the SU(2) structural group as the extra dimensions are found and discussed. This generalizes the results of Ref. \cite{vds3} from U(1) to the SU(2) gauge group. The spherically symmetric solution with the off-diagonal components of the multidime...
1601.06789
Stephen Green
Stephen R. Green and Robert M. Wald
A Simple, Heuristic Derivation of our "No Backreaction" Results
13 pages
null
10.1088/0264-9381/33/12/125027
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide a simple discussion of our results on the backreaction effects of density inhomogeneities in cosmology, without mentioning one-parameter families or weak limits. Emphasis is placed on the manner in which "averaging" is done and the fact that one is solving Einstein's equation. The key assumptions and resul...
[ { "created": "Mon, 25 Jan 2016 21:00:10 GMT", "version": "v1" } ]
2016-06-01
[ [ "Green", "Stephen R.", "" ], [ "Wald", "Robert M.", "" ] ]
We provide a simple discussion of our results on the backreaction effects of density inhomogeneities in cosmology, without mentioning one-parameter families or weak limits. Emphasis is placed on the manner in which "averaging" is done and the fact that one is solving Einstein's equation. The key assumptions and results...
2112.15038
Misba Afrin
Misba Afrin and Sushant G. Ghosh
Estimating the cosmological constant from shadows of Kerr--de Sitter black holes
10 figures, 1 table. Matched to the published version
Universe 2022, 8(1), 52
10.3390/universe8010052
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
The Event Horizon Telescope collaboration has revealed the first direct image of a black hole, as per the shadow of a Kerr black hole of general relativity. However, other Kerr-like rotating black holes of modified gravity theories cannot be ignored, and they are essential as they offer an arena in which these theori...
[ { "created": "Thu, 30 Dec 2021 12:55:33 GMT", "version": "v1" }, { "created": "Thu, 20 Jan 2022 12:15:00 GMT", "version": "v2" } ]
2022-01-21
[ [ "Afrin", "Misba", "" ], [ "Ghosh", "Sushant G.", "" ] ]
The Event Horizon Telescope collaboration has revealed the first direct image of a black hole, as per the shadow of a Kerr black hole of general relativity. However, other Kerr-like rotating black holes of modified gravity theories cannot be ignored, and they are essential as they offer an arena in which these theories...
2404.12028
Federico De Santi
Federico De Santi, Massimiliano Razzano, Francesco Fidecaro, Luca Muccillo, Lucia Papalini, and Barbara Patricelli
Deep learning to detect gravitational waves from binary close encounters: Fast parameter estimation using normalizing flows
49 pages, 14 figures, accepted for publication in Physical Review D (PRD)
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A yet undetected class of GW signals is represented by the close encounters between compact objects in highly-eccentric e~1 orbits, that can occur in binary systems formed in dense environments such as globular clusters. The expected gravitational signals are short-duration pulses that would repeat over a much longer...
[ { "created": "Thu, 18 Apr 2024 09:26:23 GMT", "version": "v1" } ]
2024-04-19
[ [ "De Santi", "Federico", "" ], [ "Razzano", "Massimiliano", "" ], [ "Fidecaro", "Francesco", "" ], [ "Muccillo", "Luca", "" ], [ "Papalini", "Lucia", "" ], [ "Patricelli", "Barbara", "" ] ]
A yet undetected class of GW signals is represented by the close encounters between compact objects in highly-eccentric e~1 orbits, that can occur in binary systems formed in dense environments such as globular clusters. The expected gravitational signals are short-duration pulses that would repeat over a much longer t...
0804.2778
Orest Hrycyna
Orest Hrycyna, Jakub Mielczarek, Marek Szydlowski
Effects of the quantisation ambiguities on the Big Bounce dynamics
RevTeX4, 28 pages, 11 figs; rev.2 new section on exact solutions; (v3) published version
Gen.Rel.Grav.41:1025-1049,2009
10.1007/s10714-008-0689-2
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we investigate dynamics of the modified loop quantum cosmology models using dynamical systems methods. Modifications considered come from the choice of the different field strength operator $\hat{F}$ and result in different forms of the effective Hamiltonian. Such an ambiguity of the choice of this expr...
[ { "created": "Thu, 17 Apr 2008 11:42:53 GMT", "version": "v1" }, { "created": "Sat, 26 Apr 2008 11:32:02 GMT", "version": "v2" }, { "created": "Mon, 4 May 2009 17:23:12 GMT", "version": "v3" } ]
2014-11-18
[ [ "Hrycyna", "Orest", "" ], [ "Mielczarek", "Jakub", "" ], [ "Szydlowski", "Marek", "" ] ]
In this paper we investigate dynamics of the modified loop quantum cosmology models using dynamical systems methods. Modifications considered come from the choice of the different field strength operator $\hat{F}$ and result in different forms of the effective Hamiltonian. Such an ambiguity of the choice of this expres...
gr-qc/0404078
Valerio Faraoni
Valerio Faraoni
Coupled oscillators as models of phantom and scalar field cosmologies
18 pages, LaTeX, to appear in Physical Review D
Phys.Rev. D69 (2004) 123520
10.1103/PhysRevD.69.123520
null
gr-qc
null
We study a toy model for phantom cosmology recently introduced in the literature and consisting of two oscillators, one of which carries negative kinetic energy. The results are compared with the exact phase space picture obtained for similar dynamical systems describing, respectively, a massive canonical scalar fiel...
[ { "created": "Sat, 17 Apr 2004 00:42:39 GMT", "version": "v1" } ]
2009-11-10
[ [ "Faraoni", "Valerio", "" ] ]
We study a toy model for phantom cosmology recently introduced in the literature and consisting of two oscillators, one of which carries negative kinetic energy. The results are compared with the exact phase space picture obtained for similar dynamical systems describing, respectively, a massive canonical scalar field ...
2311.08304
Dmitriy Ovchinnikov
Dmitriy Ovchinnikov
Quasinormal ringing of Bardeen spacetime
Report prepared for the 25th RAGtime conference in Opava
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review recent calculations of quasinormal modes and asymptotic tails of the Bardeen spacetime interpreted as a quantum corrected Schwarzschild-like black holes. Massless electromagnetic and Dirac fields and massive scalar field are considered. The first few overtones are much more sensitive to the change of the qu...
[ { "created": "Tue, 14 Nov 2023 16:46:29 GMT", "version": "v1" } ]
2023-11-15
[ [ "Ovchinnikov", "Dmitriy", "" ] ]
We review recent calculations of quasinormal modes and asymptotic tails of the Bardeen spacetime interpreted as a quantum corrected Schwarzschild-like black holes. Massless electromagnetic and Dirac fields and massive scalar field are considered. The first few overtones are much more sensitive to the change of the quan...
1903.01227
Kimet Jusufi
Kimet Jusufi, Mubasher Jamil, Muhammad Rizwan
On the possibility of wormhole formation in the galactic halo due to dark matter Bose-Einstein condensates
15 pages, 9 figures. Accepted for publication in General Relativity and Gravitation
Gen Relativ Gravit (2019) 51: 102
10.1007/s10714-019-2586-2
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been recently claimed that dark matter could be in the form of a Bose-Einstein condensate (BEC) in order to explain the dynamics at large distances from the galactic center [Boehmer, Harko, JCAP {\bf 0706}, 025 (2007)]. In this paper we explore the possibility of wormhole formation in galactic halos due to the...
[ { "created": "Mon, 4 Mar 2019 13:34:55 GMT", "version": "v1" }, { "created": "Mon, 12 Aug 2019 06:50:20 GMT", "version": "v2" } ]
2019-08-27
[ [ "Jusufi", "Kimet", "" ], [ "Jamil", "Mubasher", "" ], [ "Rizwan", "Muhammad", "" ] ]
It has been recently claimed that dark matter could be in the form of a Bose-Einstein condensate (BEC) in order to explain the dynamics at large distances from the galactic center [Boehmer, Harko, JCAP {\bf 0706}, 025 (2007)]. In this paper we explore the possibility of wormhole formation in galactic halos due to the d...
2205.05903
Yu Hao
Hao Yu, Yu-Xiao Liu, Jin Li
Entropies of the various components of the universe
25pages, 3figures
Chin.Phys.C 47 (2023) 5, 055105
10.1088/1674-1137/acc2ad
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we study the entropies of photons, dust (baryonic matter), dark matter, and dark energy in the context of cosmology. When these components expand freely with the universe, we calculate the entropy and specific entropy of each component from the perspective of statistics. Under specific assumptions and c...
[ { "created": "Thu, 12 May 2022 06:53:31 GMT", "version": "v1" }, { "created": "Fri, 23 Feb 2024 09:09:30 GMT", "version": "v2" } ]
2024-02-26
[ [ "Yu", "Hao", "" ], [ "Liu", "Yu-Xiao", "" ], [ "Li", "Jin", "" ] ]
In this work, we study the entropies of photons, dust (baryonic matter), dark matter, and dark energy in the context of cosmology. When these components expand freely with the universe, we calculate the entropy and specific entropy of each component from the perspective of statistics. Under specific assumptions and con...
gr-qc/0507108
Ricardo Rosas
R. Rosas-Rodriguez
A Hamiltonian functional for the linearized Einstein vacuum field equations
5 pages, accepted in J. Phys.: Conf. Series
J.Phys.Conf.Ser.24:231-235,2005
10.1088/1742-6596/24/1/027
null
gr-qc
null
By considering the Einstein vacuum field equations linearized about the Minkowski metric, the evolution equations for the gauge-invariant quantities characterizing the gravitational field are written in a Hamiltonian form by using a conserved functional as Hamiltonian; this Hamiltonian is not the analog of the energy...
[ { "created": "Tue, 26 Jul 2005 00:49:48 GMT", "version": "v1" } ]
2014-11-17
[ [ "Rosas-Rodriguez", "R.", "" ] ]
By considering the Einstein vacuum field equations linearized about the Minkowski metric, the evolution equations for the gauge-invariant quantities characterizing the gravitational field are written in a Hamiltonian form by using a conserved functional as Hamiltonian; this Hamiltonian is not the analog of the energy o...
gr-qc/9312037
Kawai
Toshiharu Kawai
Poincar\'{e} gauge theory of gravity
27pages, RevTeX, OCU-PHYS-152
Phys.Rev. D49 (1994) 2862-2871
10.1103/PhysRevD.49.2862
null
gr-qc
null
A Poincar\'{e} gauge theory of (2+1)-dimensional gravity is developed. Fundamental gravitational field variables are dreibein fields and Lorentz gauge potentials, and the theory is underlain with the Riemann-Cartan space-time. The most general gravitational Lagrangian density, which is at most quadratic in curvature ...
[ { "created": "Mon, 27 Dec 1993 09:09:16 GMT", "version": "v1" } ]
2009-10-22
[ [ "Kawai", "Toshiharu", "" ] ]
A Poincar\'{e} gauge theory of (2+1)-dimensional gravity is developed. Fundamental gravitational field variables are dreibein fields and Lorentz gauge potentials, and the theory is underlain with the Riemann-Cartan space-time. The most general gravitational Lagrangian density, which is at most quadratic in curvature an...
1302.0724
Hal Haggard
Hal M. Haggard and Carlo Rovelli
Death and resurrection of the zeroth principle of thermodynamics
5 pages, 2 figures
Phys. Rev. D 87, 084001 (2013)
10.1103/PhysRevD.87.084001
null
gr-qc physics.class-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The zeroth principle of thermodynamics in the form "temperature is uniform at equilibrium" is notoriously violated in relativistic gravity. Temperature uniformity is often derived from the maximization of the total number of microstates of two interacting systems under energy exchanges. Here we discuss a generalized ...
[ { "created": "Mon, 4 Feb 2013 15:36:07 GMT", "version": "v1" } ]
2014-03-12
[ [ "Haggard", "Hal M.", "" ], [ "Rovelli", "Carlo", "" ] ]
The zeroth principle of thermodynamics in the form "temperature is uniform at equilibrium" is notoriously violated in relativistic gravity. Temperature uniformity is often derived from the maximization of the total number of microstates of two interacting systems under energy exchanges. Here we discuss a generalized ve...
2002.04055
Richard Brito
Richard Brito, Sara Grillo, Paolo Pani
Black hole superradiant instability from ultralight spin-2 fields
13 pages, 4 Figures; v3: minor changes to match published version in Physical Review Letters
Phys. Rev. Lett. 124, 211101 (2020)
10.1103/PhysRevLett.124.211101
null
gr-qc astro-ph.HE hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ultralight bosonic fields are compelling dark-matter candidates and arise in a variety of beyond-Standard-Model scenarios. These fields can tap energy and angular momentum from spinning black holes through superradiant instabilities, during which a macroscopic bosonic condensate develops around the black hole. Striki...
[ { "created": "Mon, 10 Feb 2020 19:18:14 GMT", "version": "v1" }, { "created": "Sun, 10 May 2020 16:01:10 GMT", "version": "v2" }, { "created": "Wed, 3 Jun 2020 10:21:33 GMT", "version": "v3" } ]
2020-06-04
[ [ "Brito", "Richard", "" ], [ "Grillo", "Sara", "" ], [ "Pani", "Paolo", "" ] ]
Ultralight bosonic fields are compelling dark-matter candidates and arise in a variety of beyond-Standard-Model scenarios. These fields can tap energy and angular momentum from spinning black holes through superradiant instabilities, during which a macroscopic bosonic condensate develops around the black hole. Striking...
2206.07574
Antonio Gallerati
Antonio Gallerati, Giovanni Modanese, Giovanni Ummarino
Interaction between macroscopic quantum systems and gravity
59 pages
Frontiers in Physics 10 (2022) 941858
10.3389/fphy.2022.941858
null
gr-qc cond-mat.supr-con hep-ph hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review experiments and theoretical models about the possible mutual interplay between the gravitational field and materials in the superconducting state or other macroscopic quantum states. More generally, we focus on the possibility for quantum macrosystems in a coherent state to produce local alterations of the ...
[ { "created": "Wed, 15 Jun 2022 14:57:11 GMT", "version": "v1" }, { "created": "Fri, 17 Jun 2022 09:03:15 GMT", "version": "v2" }, { "created": "Thu, 30 Jun 2022 14:09:15 GMT", "version": "v3" } ]
2022-07-01
[ [ "Gallerati", "Antonio", "" ], [ "Modanese", "Giovanni", "" ], [ "Ummarino", "Giovanni", "" ] ]
We review experiments and theoretical models about the possible mutual interplay between the gravitational field and materials in the superconducting state or other macroscopic quantum states. More generally, we focus on the possibility for quantum macrosystems in a coherent state to produce local alterations of the gr...
gr-qc/0507081
Patrick Sutton
LIGO Scientific Collaboration and TAMA Collaboration
Upper limits from the LIGO and TAMA detectors on the rate of gravitational-wave bursts
15 pages, 11 figures, to be submitted to Phys Rev D. Updated author list
Phys.Rev.D72:122004,2005
10.1103/PhysRevD.72.122004
LIGO-P040050-06-Z
gr-qc
null
We report on the first joint search for gravitational waves by the TAMA and LIGO collaborations. We looked for millisecond-duration unmodelled gravitational-wave bursts in 473 hr of coincident data collected during early 2003. No candidate signals were found. We set an upper limit of 0.12 events per day on the rate o...
[ { "created": "Tue, 19 Jul 2005 01:43:57 GMT", "version": "v1" }, { "created": "Wed, 20 Jul 2005 00:37:41 GMT", "version": "v2" }, { "created": "Tue, 26 Jul 2005 17:49:15 GMT", "version": "v3" } ]
2012-08-27
[ [ "LIGO Scientific Collaboration", "", "" ], [ "TAMA Collaboration", "", "" ] ]
We report on the first joint search for gravitational waves by the TAMA and LIGO collaborations. We looked for millisecond-duration unmodelled gravitational-wave bursts in 473 hr of coincident data collected during early 2003. No candidate signals were found. We set an upper limit of 0.12 events per day on the rate of ...
1204.2450
Tadashi Takayanagi
Tadashi Takayanagi
Entanglement Entropy from a Holographic Viewpoint
Latex, 30 pages, invited review for Classical and Quantum Gravity, minor corrections
Class.Quant.Grav. 29 (2012) 153001
10.1088/0264-9381/29/15/153001
YITP-12-31; IPMU12-0067
gr-qc cond-mat.str-el hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The entanglement entropy has been historically studied by many authors in order to obtain quantum mechanical interpretations of the gravitational entropy. The discovery of AdS/CFT correspondence leads to the idea of holographic entanglement entropy, which is a clear solution to this important problem in gravity. In t...
[ { "created": "Wed, 11 Apr 2012 13:49:01 GMT", "version": "v1" }, { "created": "Sun, 22 Apr 2012 05:08:30 GMT", "version": "v2" } ]
2015-06-04
[ [ "Takayanagi", "Tadashi", "" ] ]
The entanglement entropy has been historically studied by many authors in order to obtain quantum mechanical interpretations of the gravitational entropy. The discovery of AdS/CFT correspondence leads to the idea of holographic entanglement entropy, which is a clear solution to this important problem in gravity. In thi...
gr-qc/0610013
Sigbjorn Hervik
John D. Barrow and Sigbjorn Hervik
On the evolution of universes in quadratic theories of gravity
18 pages, 2 figures, v2: matches published version
Phys.Rev.D74:124017,2006
10.1103/PhysRevD.74.124017
null
gr-qc astro-ph hep-th
null
We use a dynamical systems approach to investigate Bianchi type I and II universes in quadratic theories of gravity. Due to the complicated nature of the equations of motion we focus on the stability of exact solutions and find that there exists an isotropic FRW universe acting as a past attractor. This may indicate ...
[ { "created": "Tue, 3 Oct 2006 18:47:49 GMT", "version": "v1" }, { "created": "Tue, 19 Dec 2006 14:06:17 GMT", "version": "v2" } ]
2008-11-26
[ [ "Barrow", "John D.", "" ], [ "Hervik", "Sigbjorn", "" ] ]
We use a dynamical systems approach to investigate Bianchi type I and II universes in quadratic theories of gravity. Due to the complicated nature of the equations of motion we focus on the stability of exact solutions and find that there exists an isotropic FRW universe acting as a past attractor. This may indicate th...
2105.01548
Adrian Lim
Adrian P.C. Lim
Loop representation of Quantum Gravity
null
null
null
null
gr-qc math-ph math.MP
http://creativecommons.org/licenses/by/4.0/
A hyperlink is a finite set of non-intersecting simple closed curves in $\mathbb{R}^4 \equiv \mathbb{R} \times \mathbb{R}^3$, each curve is either a matter or geometric loop. We consider an equivalence class of such hyperlinks, up to time-like isotopy, preserving time-ordering. Using an equivalence class and after co...
[ { "created": "Sat, 1 May 2021 05:47:38 GMT", "version": "v1" } ]
2021-05-05
[ [ "Lim", "Adrian P. C.", "" ] ]
A hyperlink is a finite set of non-intersecting simple closed curves in $\mathbb{R}^4 \equiv \mathbb{R} \times \mathbb{R}^3$, each curve is either a matter or geometric loop. We consider an equivalence class of such hyperlinks, up to time-like isotopy, preserving time-ordering. Using an equivalence class and after colo...
1908.11742
Joao Paulo Manoel Pitelli
J. P. M. Pitelli, Vitor S. Barroso
Particle Production Between Isometric Frames on a Poincar\'e Patch of $\text{AdS}_2$
4 pages. Accepted for publication in J. Math. Phys
null
10.1063/1.5117832
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a recent paper [J. P. M. Pitelli, Phys. Rev. D {\bf 99}, 108701 (2019)], one of us showed that the vacuum state associated to conformal fields on a Poicar\'e patch of anti-de Sitter spacetime is not $\text{AdS}$ invariant for fields satisfying non-trivial boundary conditions (by non-trivial we mean neither Dirichl...
[ { "created": "Fri, 30 Aug 2019 13:55:06 GMT", "version": "v1" } ]
2019-10-02
[ [ "Pitelli", "J. P. M.", "" ], [ "Barroso", "Vitor S.", "" ] ]
In a recent paper [J. P. M. Pitelli, Phys. Rev. D {\bf 99}, 108701 (2019)], one of us showed that the vacuum state associated to conformal fields on a Poicar\'e patch of anti-de Sitter spacetime is not $\text{AdS}$ invariant for fields satisfying non-trivial boundary conditions (by non-trivial we mean neither Dirichlet...
gr-qc/9508047
Animals have rights
Kamilla Piotrkowska
Averaging, renormalization group and criticality in cosmology
12 pages. Latex. Talk given at the South African Relativity Workshop, Cape Town, June 1995
null
null
null
gr-qc
null
Several problems in physics, in particular the averaging problem in gravity, can be described in a formalism derived from the real-space Renormalization Group (RG) methods. It is shown that the RG flow is provided by the Ricci-Hamilton equations which are thereby provided with a {\it physical} interpretation. The con...
[ { "created": "Tue, 22 Aug 1995 11:37:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Piotrkowska", "Kamilla", "" ] ]
Several problems in physics, in particular the averaging problem in gravity, can be described in a formalism derived from the real-space Renormalization Group (RG) methods. It is shown that the RG flow is provided by the Ricci-Hamilton equations which are thereby provided with a {\it physical} interpretation. The conne...
2006.00669
Kiyoshi Shiraishi
Kiyoshi Shiraishi
Evaluation of vacuum energy density around geometrical defects by the WKB method
11 pages, one figure
Soryushiron Kenkyu (Kyoto) 90 (1995), No. 4, pp. 95-106
10.24532/soken.90.4_95
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The energy density of a conformally invariant scalar field around a cosmic string is estimated by the WKB method. This approach reproduces the precise value obtained by the other authors using the exact mode-sum method or the method of mirror images. The approximation is also in good agreement with the exact result i...
[ { "created": "Mon, 1 Jun 2020 02:10:32 GMT", "version": "v1" } ]
2020-07-02
[ [ "Shiraishi", "Kiyoshi", "" ] ]
The energy density of a conformally invariant scalar field around a cosmic string is estimated by the WKB method. This approach reproduces the precise value obtained by the other authors using the exact mode-sum method or the method of mirror images. The approximation is also in good agreement with the exact result in ...
gr-qc/0011074
L. Sriramkumar
L. Sriramkumar
Fluctuations in the current and energy densities around a magnetic flux carrying cosmic string
RevTeX, 13 Pages, 3 Figures
Class.Quant.Grav. 18 (2001) 1015-1025
10.1088/0264-9381/18/6/304
null
gr-qc
null
We calculate the fluctuations in the current and energy densities for the case of a quantized, minimally coupled, massless, complex scalar field around a straight and infinitesimally thin cosmic string carrying magnetic flux. At zero temperature, we evaluate the fluctuations in the current and energy densities for ar...
[ { "created": "Wed, 22 Nov 2000 00:08:43 GMT", "version": "v1" } ]
2009-10-31
[ [ "Sriramkumar", "L.", "" ] ]
We calculate the fluctuations in the current and energy densities for the case of a quantized, minimally coupled, massless, complex scalar field around a straight and infinitesimally thin cosmic string carrying magnetic flux. At zero temperature, we evaluate the fluctuations in the current and energy densities for arbi...
0912.3474
Piotr Bizon
Piotr Bizo\'n and Andrzej Rostworowski
A note about late-time wave tails on a dynamical background
4 pages
Phys.Rev.D81:084047,2010
10.1103/PhysRevD.81.084047
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Consider a spherically symmetric spacetime generated by a self-gravitating massless scalar field $\phi$ and let $\psi$ be a test (nonspherical) massless scalar field propagating on this dynamical background. Gundlach, Price, and Pullin \cite{gpp2} computed numerically the late-time tails for different multipoles of t...
[ { "created": "Thu, 17 Dec 2009 18:09:03 GMT", "version": "v1" } ]
2010-05-11
[ [ "Bizoń", "Piotr", "" ], [ "Rostworowski", "Andrzej", "" ] ]
Consider a spherically symmetric spacetime generated by a self-gravitating massless scalar field $\phi$ and let $\psi$ be a test (nonspherical) massless scalar field propagating on this dynamical background. Gundlach, Price, and Pullin \cite{gpp2} computed numerically the late-time tails for different multipoles of the...
gr-qc/0101024
Scott A. Hughes
Scott A. Hughes
Comment on "Gravity Waves, Chaos, and Spinning Compact Binaries"
1 page, comment on gr-qc/9910040
Phys.Rev.Lett.85:5480,2000
10.1103/PhysRevLett.85.5480
null
gr-qc astro-ph
null
In this comment, I argue that chaotic effects in binary black hole inspiral will not strongly impact the detection of gravitational waves from such systems.
[ { "created": "Fri, 5 Jan 2001 22:17:28 GMT", "version": "v1" } ]
2016-08-31
[ [ "Hughes", "Scott A.", "" ] ]
In this comment, I argue that chaotic effects in binary black hole inspiral will not strongly impact the detection of gravitational waves from such systems.
1801.01274
Andronikos Paliathanasis
G. Papagiannopoulos, Spyros Basilakos, John D. Barrow and Andronikos Paliathanasis
New integrable models and analytical solutions in $f(R)$~cosmology with an ideal gas
14 pages, 2 figures, to appear in Physical Review D
Phys. Rev. D 97, 024026 (2018)
10.1103/PhysRevD.97.024026
null
gr-qc astro-ph.CO hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the context of $f\left( R\right) $-gravity with a spatially flat FLRW metric containing an ideal fluid, we use the method of invariant transformations to specify families of models which are integrable. We find three families of $f(R)$ theories for which new analytical solutions are given and closed-form solutions...
[ { "created": "Thu, 4 Jan 2018 08:29:45 GMT", "version": "v1" } ]
2018-01-25
[ [ "Papagiannopoulos", "G.", "" ], [ "Basilakos", "Spyros", "" ], [ "Barrow", "John D.", "" ], [ "Paliathanasis", "Andronikos", "" ] ]
In the context of $f\left( R\right) $-gravity with a spatially flat FLRW metric containing an ideal fluid, we use the method of invariant transformations to specify families of models which are integrable. We find three families of $f(R)$ theories for which new analytical solutions are given and closed-form solutions a...
1811.01260
Rahul Kumar
Rahul Kumar, Sushant G. Ghosh
Black Hole Parameter Estimation from Its Shadow
18 pages, 14 figures, and 3 tables. Matched with the published version
ApJ 892, 78 (2020)
10.3847/1538-4357/ab77b0
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Event Horizon Telescope (EHT), a global submillimeter wavelength very long baseline interferometry array, unveiled event-horizon-scale images of the supermassive black hole M87* as an asymmetric bright emission ring with a diameter of $ 42 \pm 3\; \mu$as, and it is consistent with the shadow of a Kerr black hole ...
[ { "created": "Sat, 3 Nov 2018 18:04:33 GMT", "version": "v1" }, { "created": "Wed, 27 Feb 2019 16:02:21 GMT", "version": "v2" }, { "created": "Tue, 18 Feb 2020 16:27:53 GMT", "version": "v3" }, { "created": "Sun, 10 May 2020 11:00:45 GMT", "version": "v4" } ]
2020-05-12
[ [ "Kumar", "Rahul", "" ], [ "Ghosh", "Sushant G.", "" ] ]
The Event Horizon Telescope (EHT), a global submillimeter wavelength very long baseline interferometry array, unveiled event-horizon-scale images of the supermassive black hole M87* as an asymmetric bright emission ring with a diameter of $ 42 \pm 3\; \mu$as, and it is consistent with the shadow of a Kerr black hole of...
2004.11357
Adri\`a Delhom
Jose Beltr\'an Jim\'enez and Adri\`a Delhom
Instabilities in Metric-Affine Theories of Gravity
27 pp
null
10.1140/epjc/s10052-020-8143-z
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the presence of ghostly instabilities for metric-affine theories constructed with higher order curvature terms. We mainly focus on theories containing only the Ricci tensor and show the crucial role played by the projective symmetry. The pathological modes arise from the absence of a pure kinetic term for ...
[ { "created": "Thu, 23 Apr 2020 17:55:54 GMT", "version": "v1" } ]
2021-04-23
[ [ "Jiménez", "Jose Beltrán", "" ], [ "Delhom", "Adrià", "" ] ]
We discuss the presence of ghostly instabilities for metric-affine theories constructed with higher order curvature terms. We mainly focus on theories containing only the Ricci tensor and show the crucial role played by the projective symmetry. The pathological modes arise from the absence of a pure kinetic term for th...
1006.1834
Khaled Saaidi
Kh. Saaidi, A.Aghamohammadi, M. R. Setare
Holographic dark energy with time depend gravitational constant in the non-flat Ho$\check{r}$ava-Lifshitz cosmology
11 pages
Astrophys. Space Sci. 332 (2011) 503
10.1007/s10509-010-0531-7
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the holographic dark energy on the subject of Ho$\check{r}$ava-Lifshitz gravity with a time dependent gravitational constant (G(t)), in the non-flat space-time. We obtain the differential equation that specify the evolution of the dark energy density parameter based on varying gravitational constant. we find...
[ { "created": "Wed, 9 Jun 2010 15:34:38 GMT", "version": "v1" }, { "created": "Mon, 25 Oct 2010 07:06:13 GMT", "version": "v2" } ]
2014-01-20
[ [ "Saaidi", "Kh.", "" ], [ "Aghamohammadi", "A.", "" ], [ "Setare", "M. R.", "" ] ]
We study the holographic dark energy on the subject of Ho$\check{r}$ava-Lifshitz gravity with a time dependent gravitational constant (G(t)), in the non-flat space-time. We obtain the differential equation that specify the evolution of the dark energy density parameter based on varying gravitational constant. we find o...
gr-qc/9702039
Ulf Nilsson
Ulf S. Nilsson, C. Uggla
Stationary Bianchi type II perfect fluid models
6 pages, 1 figure LaTeX. To appear in JMP
null
10.1063/1.531998
null
gr-qc
null
Einstein's field equations for stationary Bianchi type II models with a perfect fluid source are investigated. The field equations are rewritten as a system of autonomous first order differential equations. Dimensionless variables are subsequently introduced for which the reduced phase space is compact. The system is...
[ { "created": "Thu, 20 Feb 1997 15:10:28 GMT", "version": "v1" } ]
2009-10-30
[ [ "Nilsson", "Ulf S.", "" ], [ "Uggla", "C.", "" ] ]
Einstein's field equations for stationary Bianchi type II models with a perfect fluid source are investigated. The field equations are rewritten as a system of autonomous first order differential equations. Dimensionless variables are subsequently introduced for which the reduced phase space is compact. The system is t...
1904.09244
Ward Struyve
Thibaut Demaerel, Ward Struyve
Elimination of cosmological singularities in quantum cosmology by suitable operator orderings
9 pages, no figures, Latex; v2 minor improvements
Phys. Rev. D 100, 046008 (2019)
10.1103/PhysRevD.100.046008
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Canonical quantization of general relativity does not yield a unique quantum theory for gravity. This is in part due to operator ordering ambiguities. In this paper, we investigate the role of different operator orderings on the question of whether a big bang or big crunch singularity occurs. We do this in the contex...
[ { "created": "Fri, 19 Apr 2019 15:53:08 GMT", "version": "v1" }, { "created": "Thu, 15 Aug 2019 17:50:12 GMT", "version": "v2" } ]
2019-08-21
[ [ "Demaerel", "Thibaut", "" ], [ "Struyve", "Ward", "" ] ]
Canonical quantization of general relativity does not yield a unique quantum theory for gravity. This is in part due to operator ordering ambiguities. In this paper, we investigate the role of different operator orderings on the question of whether a big bang or big crunch singularity occurs. We do this in the context ...
2408.01468
Faizuddin Ahmed
Faizuddin Ahmed
Higher-dimensional topologically charged traversable defect wormhole with non-exotic matter
12 pages, accepted in IJMPA (https://doi.org/10.1142/S0217751X24500878)
null
10.1142/S0217751X24500878
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
In this study, we explore a topologically charged higher-dimensional traversable defect wormhole, with a specific emphasis on five dimensions. Particularly noteworthy is the fact that the matter-energy distribution attributed to this charged wormhole configuration adheres to the weak energy condition, thus presenting...
[ { "created": "Thu, 1 Aug 2024 05:19:27 GMT", "version": "v1" } ]
2024-08-06
[ [ "Ahmed", "Faizuddin", "" ] ]
In this study, we explore a topologically charged higher-dimensional traversable defect wormhole, with a specific emphasis on five dimensions. Particularly noteworthy is the fact that the matter-energy distribution attributed to this charged wormhole configuration adheres to the weak energy condition, thus presenting a...
0710.3677
Peng Xu
Peng Xu and Yongge Ma
Five-dimensional PPN formalism and experimental test of Kaluza-Klein theory
4 pages, 1 table, accepted for publication in Physics Letters B
Phys.Lett.B656:165-168,2007
10.1016/j.physletb.2007.09.035
null
gr-qc astro-ph hep-th
null
The parametrized post Newtonian formalism for 5-dimensional metric theories with a compact extra dimension is developed. The relation of the 5-dimensional and 4-dimensional formulations is then analyzed, in order to compare the higher dimensional theories of gravity with experiments. It turns out that the value of po...
[ { "created": "Fri, 19 Oct 2007 11:27:31 GMT", "version": "v1" } ]
2008-11-26
[ [ "Xu", "Peng", "" ], [ "Ma", "Yongge", "" ] ]
The parametrized post Newtonian formalism for 5-dimensional metric theories with a compact extra dimension is developed. The relation of the 5-dimensional and 4-dimensional formulations is then analyzed, in order to compare the higher dimensional theories of gravity with experiments. It turns out that the value of post...
1412.1725
Oleg Zaslavskii
O. B. Zaslavskii
On geodesics with negative energies in the ergoregions of dirty black holes
6 pages
Mod. Phys. Lett. A, 30, 1550055 (2015)
10.1142/S0217732315500558
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider behavior of equatorial geodesics with the negative energy in the ergoregion of a generic rotating "dirty" (surrounded by matter) black hole. It is shown that under very simple and generic conditions on the metric coefficients, there are no such circular orbits. This entails that such geodesic must origina...
[ { "created": "Thu, 4 Dec 2014 16:45:47 GMT", "version": "v1" } ]
2015-03-27
[ [ "Zaslavskii", "O. B.", "" ] ]
We consider behavior of equatorial geodesics with the negative energy in the ergoregion of a generic rotating "dirty" (surrounded by matter) black hole. It is shown that under very simple and generic conditions on the metric coefficients, there are no such circular orbits. This entails that such geodesic must originate...