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1201.3660
Daniele Malafarina
Pankaj S. Joshi and Daniele Malafarina
Recent developments in gravitational collapse and spacetime singularities
89 pages, 12 figures, Invited review article for Int Jour of Mod Phys D
Int. J. Mod. Phys. D, 20 2641 (2011)
10.1142/S0218271811020792
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is now known that when a massive star collapses under the force of its own gravity, the final fate of such a continual gravitational collapse will be either a black hole or a naked singularity under a wide variety of physically reasonable circumstances within the framework of general theory of relativity. The rese...
[ { "created": "Tue, 17 Jan 2012 22:41:01 GMT", "version": "v1" } ]
2012-04-20
[ [ "Joshi", "Pankaj S.", "" ], [ "Malafarina", "Daniele", "" ] ]
It is now known that when a massive star collapses under the force of its own gravity, the final fate of such a continual gravitational collapse will be either a black hole or a naked singularity under a wide variety of physically reasonable circumstances within the framework of general theory of relativity. The resear...
0910.2820
Sangheon Yun
Sangheon Yun
Toroidal AdS Charged Branes and Toda Equations
The contents are incomplete
null
null
null
gr-qc hep-th
http://creativecommons.org/licenses/by-nc-sa/3.0/
In this note, we consider the equations of motion for charged branes in AdS space and show that they can be cast into one-dimensional coupled Toda type. Then we solve the equations of motion to construct static charged AdS brane solutions which are invariant under translation along $p$ directions and have toroidal sy...
[ { "created": "Thu, 15 Oct 2009 09:30:12 GMT", "version": "v1" }, { "created": "Sun, 6 Sep 2020 04:15:36 GMT", "version": "v2" } ]
2020-09-08
[ [ "Yun", "Sangheon", "" ] ]
In this note, we consider the equations of motion for charged branes in AdS space and show that they can be cast into one-dimensional coupled Toda type. Then we solve the equations of motion to construct static charged AdS brane solutions which are invariant under translation along $p$ directions and have toroidal symm...
1503.07312
Manfred Requardt
Manfred Requardt
About the Incompleteness of the Semiclassical Picture in the BH-Information Paradox and the Quantum Hair emerging from the Coupling of Quantum Matter and Quantum Space-Time Degrees of Freedom
21 pages PDFLatex, Sections and References added, More Details about Coupling of Quantum Matter and Quantum Space Time Degrees of Freedom, Zero Energy Universe, Existence of Quantum Hair
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that the semiclassical analysis of the black hole information paradox is incomplete and has to be completed by an explicit entanglement of matter and quantum gravity degrees of freedom. We study in detail the evaporation process from beginning to end in the light of our extension and show that a pure initial...
[ { "created": "Wed, 25 Mar 2015 09:31:32 GMT", "version": "v1" }, { "created": "Sun, 31 Jul 2022 14:22:42 GMT", "version": "v2" } ]
2022-08-02
[ [ "Requardt", "Manfred", "" ] ]
We argue that the semiclassical analysis of the black hole information paradox is incomplete and has to be completed by an explicit entanglement of matter and quantum gravity degrees of freedom. We study in detail the evaporation process from beginning to end in the light of our extension and show that a pure initial s...
1812.05646
Pratik Wagle
Pratik Wagle, Nicolas Yunes, David Garfinkle and Lydia Bieri
Hair loss in parity violating gravity
10 pages and 2 figures. Published in Classical and Quantum Gravity
2019 Class. Quantum Grav. 36 115004
10.1088/1361-6382/ab0eed
null
gr-qc astro-ph.HE hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent detection of gravitational waves by the LIGO/VIRGO collaboration has allowed for the first tests of Einstein's theory in the extreme gravity regime, where the gravitational interaction is simultaneously strong, non-linear and dynamical. One such test concerns the rate at which the binaries inspiral, or equ...
[ { "created": "Thu, 13 Dec 2018 19:30:25 GMT", "version": "v1" }, { "created": "Mon, 13 May 2019 23:24:44 GMT", "version": "v2" } ]
2019-10-11
[ [ "Wagle", "Pratik", "" ], [ "Yunes", "Nicolas", "" ], [ "Garfinkle", "David", "" ], [ "Bieri", "Lydia", "" ] ]
The recent detection of gravitational waves by the LIGO/VIRGO collaboration has allowed for the first tests of Einstein's theory in the extreme gravity regime, where the gravitational interaction is simultaneously strong, non-linear and dynamical. One such test concerns the rate at which the binaries inspiral, or equiv...
0911.2946
Balakin Alexander
Alexander B. Balakin and Wei-Tou Ni
Non-minimal coupling of photons and axions
31 pages, 2 Tables; replaced with the final version published in Classical and Quantum Gravity
Class.Quant.Grav.27:055003,2010
10.1088/0264-9381/27/5/055003
null
gr-qc astro-ph.CO hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We establish a new self-consistent system of equations accounting for a non-minimal interaction of gravitational, electromagnetic and axion fields. The procedure is based on a non-minimal extension of the standard Einstein-Maxwell-axion action. The general properties of a ten-parameter family of non-minimal linear mo...
[ { "created": "Mon, 16 Nov 2009 03:58:42 GMT", "version": "v1" }, { "created": "Mon, 1 Mar 2010 17:56:38 GMT", "version": "v2" } ]
2014-11-20
[ [ "Balakin", "Alexander B.", "" ], [ "Ni", "Wei-Tou", "" ] ]
We establish a new self-consistent system of equations accounting for a non-minimal interaction of gravitational, electromagnetic and axion fields. The procedure is based on a non-minimal extension of the standard Einstein-Maxwell-axion action. The general properties of a ten-parameter family of non-minimal linear mode...
0704.3368
Thomas Cokelaer
LIGO Scientific Collaboration: B. Abbott, et al
Search for gravitational waves from binary inspirals in S3 and S4 LIGO data
12 pages, 11 figures
Phys.Rev.D77:062002,2008
10.1103/PhysRevD.77.062002
null
gr-qc
null
We report on a search for gravitational waves from the coalescence of compact binaries during the third and fourth LIGO science runs. The search focused on gravitational waves generated during the inspiral phase of the binary evolution. In our analysis, we considered three categories of compact binary systems, ordere...
[ { "created": "Wed, 25 Apr 2007 14:38:17 GMT", "version": "v1" }, { "created": "Thu, 26 Apr 2007 10:56:53 GMT", "version": "v2" }, { "created": "Wed, 23 Jan 2008 16:01:48 GMT", "version": "v3" }, { "created": "Thu, 24 Jan 2008 10:01:17 GMT", "version": "v4" } ]
2008-11-26
[ [ "LIGO Scientific Collaboration", "", "" ], [ "Abbott", "B.", "" ] ]
We report on a search for gravitational waves from the coalescence of compact binaries during the third and fourth LIGO science runs. The search focused on gravitational waves generated during the inspiral phase of the binary evolution. In our analysis, we considered three categories of compact binary systems, ordered ...
1705.04918
Arif Shaikh Md
Md Arif Shaikh
Relativistic sonic geometry for isothermal accretion in the Kerr metric
37 pages, 9 figures, updated to match the published version
Class. Quantum Grav. 35 055002 (2018)
10.1088/1361-6382/aaa5cd
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We linearly perturb advective isothermal transonic accretion onto rotating astrophysical black holes to study the emergence of the relativistic acoustic spacetime and to investigate how the salient features of such spacetime get influenced by the spin angular momentum of the black hole. We have perturbed three differ...
[ { "created": "Sun, 14 May 2017 06:29:12 GMT", "version": "v1" }, { "created": "Fri, 2 Feb 2018 05:25:40 GMT", "version": "v2" } ]
2018-02-05
[ [ "Shaikh", "Md Arif", "" ] ]
We linearly perturb advective isothermal transonic accretion onto rotating astrophysical black holes to study the emergence of the relativistic acoustic spacetime and to investigate how the salient features of such spacetime get influenced by the spin angular momentum of the black hole. We have perturbed three differen...
gr-qc/0111106
Salvatore Capozziello
S. Capozziello, S. Carloni, G. Lambiase, C. Stornaiolo, A. Troisi
Curvature and Torsion Quintessence
12 pages, proceedings of COSMO-01
null
null
null
gr-qc
null
The issues of quintessence and cosmic acceleration can be discussed in the framework of higher order curvature and torsion theories of gravity. We can define effective pressure and energy density directly connected to the curvature or to the torsion fields and then ask for the conditions to get an accelerated expansi...
[ { "created": "Thu, 29 Nov 2001 17:47:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Capozziello", "S.", "" ], [ "Carloni", "S.", "" ], [ "Lambiase", "G.", "" ], [ "Stornaiolo", "C.", "" ], [ "Troisi", "A.", "" ] ]
The issues of quintessence and cosmic acceleration can be discussed in the framework of higher order curvature and torsion theories of gravity. We can define effective pressure and energy density directly connected to the curvature or to the torsion fields and then ask for the conditions to get an accelerated expansion...
gr-qc/0507118
Filimonova Irina V
A.F.Zakharov, A.A.Nucita, F.DePaolis, G.Ingrosso
Observational Features of Black Holes
Plenary talk presented at Workshop on High Energy Physics&Field Theory (Protvino, Russia, 2004)
null
null
HEPFT/2004/2
gr-qc
null
Recently considered a very attracting possibility to detect retro-MACHOs, i.e. retro-images of the Sun by a Schwarzschild black hole. In this paper we discuss glories (mirages) formed near rapidly rotating Kerr black hole horizons and propose a procedure to measure masses and rotation parameters analyzing these forms...
[ { "created": "Thu, 28 Jul 2005 11:15:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zakharov", "A. F.", "" ], [ "Nucita", "A. A.", "" ], [ "DePaolis", "F.", "" ], [ "Ingrosso", "G.", "" ] ]
Recently considered a very attracting possibility to detect retro-MACHOs, i.e. retro-images of the Sun by a Schwarzschild black hole. In this paper we discuss glories (mirages) formed near rapidly rotating Kerr black hole horizons and propose a procedure to measure masses and rotation parameters analyzing these forms o...
2110.07655
Sourav Chowdhury Roy
Sourav Roy Chowdhury and Maxim Khlopov
The stochastic gravitational wave background from magnetars
null
null
10.3390/universe7100381
null
gr-qc astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Magnetars have already been a potential candidate as gravitational wave sources that could be detected by current and future terrestrial as well as ground based gravitational wave detectors. In this article, we focus on the gravitational wave emission from the distorted rotating neutron stars. The deformation is assu...
[ { "created": "Thu, 14 Oct 2021 18:24:54 GMT", "version": "v1" } ]
2021-11-22
[ [ "Chowdhury", "Sourav Roy", "" ], [ "Khlopov", "Maxim", "" ] ]
Magnetars have already been a potential candidate as gravitational wave sources that could be detected by current and future terrestrial as well as ground based gravitational wave detectors. In this article, we focus on the gravitational wave emission from the distorted rotating neutron stars. The deformation is assume...
1801.02033
Ali Kaya
Ali Kaya
Issues about Cosmological Ward Identities
22 pages, revtex4-1, v3: comments and references added, to appear in Phys. Rev. D
Phys. Rev. D 97, 063520 (2018)
10.1103/PhysRevD.97.063520
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we first discuss how a Noether current corresponding to a gauge or a global symmetry can locally be introduced in a path integral irrespective of the boundary conditions defining the theory. We then consider quantization of gravity plus minimally coupled scalar field system in the phase space path integ...
[ { "created": "Sat, 6 Jan 2018 15:27:35 GMT", "version": "v1" }, { "created": "Wed, 24 Jan 2018 19:43:06 GMT", "version": "v2" }, { "created": "Thu, 15 Mar 2018 10:39:23 GMT", "version": "v3" } ]
2018-03-28
[ [ "Kaya", "Ali", "" ] ]
In this paper we first discuss how a Noether current corresponding to a gauge or a global symmetry can locally be introduced in a path integral irrespective of the boundary conditions defining the theory. We then consider quantization of gravity plus minimally coupled scalar field system in the phase space path integra...
2406.10155
Jose Torrente Teruel
Daniel de la Fuente, Rafael M. Rubio and Jose Torrente
On Twisted Spacetimes: a new class of Galilean cosmological models
null
null
null
null
gr-qc math-ph math.MP
http://creativecommons.org/licenses/by/4.0/
Within the generalized Newton-Cartan theory, Galilean Twisted spacetimes are introduced as dual models of the well-known relativistic twisted spacetimes. As a natural generalization, torqued vector fields in Galilean spacetimes are defined, showing that the local structure of a Galilean spacetime admitting a timelike...
[ { "created": "Fri, 14 Jun 2024 16:16:37 GMT", "version": "v1" } ]
2024-06-17
[ [ "de la Fuente", "Daniel", "" ], [ "Rubio", "Rafael M.", "" ], [ "Torrente", "Jose", "" ] ]
Within the generalized Newton-Cartan theory, Galilean Twisted spacetimes are introduced as dual models of the well-known relativistic twisted spacetimes. As a natural generalization, torqued vector fields in Galilean spacetimes are defined, showing that the local structure of a Galilean spacetime admitting a timelike t...
1702.00698
Vladimir Dzhunushaliev
Vladimir Dzhunushaliev, Vladimir Folomeev, Burkhard Kleihau and Jutta Kunz
Dispersion relations for gravitational waves in different models of dark energy
6 pages
null
10.1142/S0218271817501577
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The propagation of weak gravitational waves on the background of dark energy is studied. The consideration is carried out within the framework of an approximate approach where the cosmological scale factor is expanded as a power series for relatively small values of the redshift corresponding to the epoch of the pres...
[ { "created": "Wed, 1 Feb 2017 08:04:23 GMT", "version": "v1" } ]
2018-01-10
[ [ "Dzhunushaliev", "Vladimir", "" ], [ "Folomeev", "Vladimir", "" ], [ "Kleihau", "Burkhard", "" ], [ "Kunz", "Jutta", "" ] ]
The propagation of weak gravitational waves on the background of dark energy is studied. The consideration is carried out within the framework of an approximate approach where the cosmological scale factor is expanded as a power series for relatively small values of the redshift corresponding to the epoch of the presen...
2405.00374
Tayyab Naseer
M. Sharif, Tayyab Naseer
Study of Charged Cylindrical Collapse in $f(\mathcal{R},\mathcal{T},\mathcal{Q})$ Gravity
25 pages, no figure
Chin. J. Phys. 85(2023)41-53
10.1016/j.cjph.2023.06.007
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper investigates the effects of electromagnetic field on the gravitational collapse in $f(\mathcal{R},\mathcal{T},\mathcal{Q})$ theory, where $\mathcal{Q} = \mathcal{R}_{\varphi\vartheta} \mathcal{T}^{\varphi\vartheta}$. For this, we assume dynamical cylindrically symmetric self-gravitating geometry which is c...
[ { "created": "Wed, 1 May 2024 08:03:50 GMT", "version": "v1" } ]
2024-05-02
[ [ "Sharif", "M.", "" ], [ "Naseer", "Tayyab", "" ] ]
This paper investigates the effects of electromagnetic field on the gravitational collapse in $f(\mathcal{R},\mathcal{T},\mathcal{Q})$ theory, where $\mathcal{Q} = \mathcal{R}_{\varphi\vartheta} \mathcal{T}^{\varphi\vartheta}$. For this, we assume dynamical cylindrically symmetric self-gravitating geometry which is cou...
2008.12403
Miguel Cruz
V\'ictor H. C\'ardenas, Miguel Cruz and Samuel Lepe
Cosmic expansion with matter creation and bulk viscosity
Improved version, accepted for publication in Phys. Rev. D. 12 pages, 4 figures
Phys. Rev. D 102, 123543 (2020)
10.1103/PhysRevD.102.123543
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the cosmological implications at effective level of matter creation effects in a dissipative fluid for a FLRW geometry; we also perform a statistical analysis for this kind of model. By considering an inhomogeneous Ansatz for the particle production rate we obtain that for created matter of dark matter typ...
[ { "created": "Thu, 27 Aug 2020 23:04:59 GMT", "version": "v1" }, { "created": "Wed, 9 Dec 2020 21:34:55 GMT", "version": "v2" } ]
2021-01-01
[ [ "Cárdenas", "Víctor H.", "" ], [ "Cruz", "Miguel", "" ], [ "Lepe", "Samuel", "" ] ]
We explore the cosmological implications at effective level of matter creation effects in a dissipative fluid for a FLRW geometry; we also perform a statistical analysis for this kind of model. By considering an inhomogeneous Ansatz for the particle production rate we obtain that for created matter of dark matter type ...
2303.17874
Koji Uryu
Koji Uryu, Shijun Yoshida, Eric Gourgoulhon, Charalampos Markakis, Kotaro Fujisawa, Antonios Tsokaros, Keisuke Taniguchi, Mina Zamani
Equilibriums of extremely magnetized compact stars with force-free magnetotunnels
13 pages, 4 figures
null
10.1103/PhysRevD.107.103016
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We present numerical solutions for stationary and axisymmetric equilibriums of compact stars associated with extremely strong magnetic fields. The interior of the compact stars is assumed to satisfy ideal magnetohydrodynamic (MHD) conditions, while in the region of negligible mass density the force-free conditions or...
[ { "created": "Fri, 31 Mar 2023 08:10:29 GMT", "version": "v1" } ]
2023-06-28
[ [ "Uryu", "Koji", "" ], [ "Yoshida", "Shijun", "" ], [ "Gourgoulhon", "Eric", "" ], [ "Markakis", "Charalampos", "" ], [ "Fujisawa", "Kotaro", "" ], [ "Tsokaros", "Antonios", "" ], [ "Taniguchi", "Keisuke", "...
We present numerical solutions for stationary and axisymmetric equilibriums of compact stars associated with extremely strong magnetic fields. The interior of the compact stars is assumed to satisfy ideal magnetohydrodynamic (MHD) conditions, while in the region of negligible mass density the force-free conditions or e...
gr-qc/0309127
Jiri Bicak
Jiri Bicak, Donald Lynden-Bell, and Joseph Katz
Toroidal Perturbations of Friedmann-Robertson-Walker Universes
13 pages
Phys.Rev. D69 (2004) 064012
10.1103/PhysRevD.69.064012
null
gr-qc astro-ph
null
Explicit expressions are found for the axisymmetric metric perturbations of the closed, flat and open FRW universes caused by toroidal motions of the cosmic fluid. The perturbations are decomposed in vector spherical harmonics on 2-spheres, but the radial dependence is left general. Solutions for general odd-parity $...
[ { "created": "Fri, 26 Sep 2003 12:06:48 GMT", "version": "v1" } ]
2009-11-10
[ [ "Bicak", "Jiri", "" ], [ "Lynden-Bell", "Donald", "" ], [ "Katz", "Joseph", "" ] ]
Explicit expressions are found for the axisymmetric metric perturbations of the closed, flat and open FRW universes caused by toroidal motions of the cosmic fluid. The perturbations are decomposed in vector spherical harmonics on 2-spheres, but the radial dependence is left general. Solutions for general odd-parity $l$...
gr-qc/0112080
Yuri N. Obukhov
Yuri N. Obukhov
On gravitational interaction of fermions
Latex (buckow.sty), 6 pages; Invited talk presented at the Symposium on the Centennial of Werner Heisenberg: Works And Impact, Bamberg, Germany, 26-30 September 2001
Fortsch.Phys.50:711-716,2002
10.1002/1521-3978(200205)50:5/7<711::AID-PROP711>3.0.CO;2-Z
null
gr-qc
null
We discuss some aspects of the gravitational interaction of the relativistic quantum particles with spin 1/2. The exact Foldy-Wouthuysen transformation is constructed for the Dirac particle coupled to the static spacetime metric. The quasi-relativistic limit of the theory is then analyzed. Using the analogous method,...
[ { "created": "Mon, 31 Dec 2001 16:47:19 GMT", "version": "v1" } ]
2015-06-25
[ [ "Obukhov", "Yuri N.", "" ] ]
We discuss some aspects of the gravitational interaction of the relativistic quantum particles with spin 1/2. The exact Foldy-Wouthuysen transformation is constructed for the Dirac particle coupled to the static spacetime metric. The quasi-relativistic limit of the theory is then analyzed. Using the analogous method, w...
2312.16728
Antonios Tsokaros A.
Yufeng Luo, Antonios Tsokaros, Roland Haas, Koji Uryu
General Relativistic Stability and Gravitational Wave Content of Rotating Triaxial Neutron Stars
16 pages, 5 figs
Symmetry 2024, 16(3), 343
10.3390/sym16030343
null
gr-qc astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
Triaxial neutron stars can be sources of continuous gravitational radiation detectable by ground-based interferometers. The amplitude of the emitted gravitational wave can be greatly affected by the state of the hydrodynamical fluid flow inside the neutron star. In this work we examine the most triaxial models along ...
[ { "created": "Wed, 27 Dec 2023 21:50:31 GMT", "version": "v1" } ]
2024-04-24
[ [ "Luo", "Yufeng", "" ], [ "Tsokaros", "Antonios", "" ], [ "Haas", "Roland", "" ], [ "Uryu", "Koji", "" ] ]
Triaxial neutron stars can be sources of continuous gravitational radiation detectable by ground-based interferometers. The amplitude of the emitted gravitational wave can be greatly affected by the state of the hydrodynamical fluid flow inside the neutron star. In this work we examine the most triaxial models along tw...
2104.07281
Peng Liu
Cheng-Yong Zhang, Peng Liu, Yunqi Liu, Chao Niu, Bin Wang
Evolution of Anti-de Sitter black holes in Einstein-Maxwell-dilaton theory
25 pages, 11 figures
null
10.1103/PhysRevD.105.024010
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the nonlinear evolution of the spherical symmetric black holes under a small neutral scalar field perturbation in Einstein-Maxwell-dilaton theory with coupling function $f(\phi)=e^{-b\phi}$ in asymptotic anti-de Sitter spacetime. The non-minimal coupling between scalar and Maxwell fields allows the transmiss...
[ { "created": "Thu, 15 Apr 2021 07:23:48 GMT", "version": "v1" } ]
2022-01-19
[ [ "Zhang", "Cheng-Yong", "" ], [ "Liu", "Peng", "" ], [ "Liu", "Yunqi", "" ], [ "Niu", "Chao", "" ], [ "Wang", "Bin", "" ] ]
We study the nonlinear evolution of the spherical symmetric black holes under a small neutral scalar field perturbation in Einstein-Maxwell-dilaton theory with coupling function $f(\phi)=e^{-b\phi}$ in asymptotic anti-de Sitter spacetime. The non-minimal coupling between scalar and Maxwell fields allows the transmissio...
0911.4923
Alan Coley
A. Coley and S. Hervik
Note on the invariant classification of vacuum type D spacetimes
null
Class. Quant. Grav., v{26} p247001 (2009)
10.1088/0264-9381/26/24/247001
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We illustrate the fact that the class of vacuum type D spacetimes which are $\mathcal{I}$-\emph{non-degenerate} are invariantly classified by their scalar polynomial curvature invariants.
[ { "created": "Wed, 25 Nov 2009 17:22:39 GMT", "version": "v1" } ]
2015-05-14
[ [ "Coley", "A.", "" ], [ "Hervik", "S.", "" ] ]
We illustrate the fact that the class of vacuum type D spacetimes which are $\mathcal{I}$-\emph{non-degenerate} are invariantly classified by their scalar polynomial curvature invariants.
2111.07141
Phongpichit Channuie
Waluka Amake (Walailak U.), Apirak Payaka (Walailak U.), Phongpichit Channuie (Walailak U.)
Warm inflation in general scalar-tensor theory of gravity
v3: 19 pages, 3 captioned figures, version accepted by PRD
Phys. Rev. D 105, 083501 (2022)
10.1103/PhysRevD.105.083501
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
In this work, we investigate warm inflationary models in the context of a general scalar-tensor theory of gravity which is coupled to radiation through a dissipation term. We first derive the potential of exponential and hyperbolic tangent forms. We consider a dissipation parameter of the form $\Gamma = C_{1}T$ with ...
[ { "created": "Sat, 13 Nov 2021 16:11:45 GMT", "version": "v1" }, { "created": "Wed, 17 Nov 2021 04:45:35 GMT", "version": "v2" }, { "created": "Tue, 5 Apr 2022 13:46:49 GMT", "version": "v3" } ]
2022-04-06
[ [ "Amake", "Waluka", "", "Walailak U." ], [ "Payaka", "Apirak", "", "Walailak U." ], [ "Channuie", "Phongpichit", "", "Walailak U." ] ]
In this work, we investigate warm inflationary models in the context of a general scalar-tensor theory of gravity which is coupled to radiation through a dissipation term. We first derive the potential of exponential and hyperbolic tangent forms. We consider a dissipation parameter of the form $\Gamma = C_{1}T$ with $C...
1004.1223
Akira Villar
Akira E. Villar, Eric D. Black, Riccardo DeSalvo, Kenneth G. Libbrecht, Christophe Michel, Nazario Morgado, Laurent Pinard, Innocenzo M. Pinto, Vincenzo Pierro, Vincenzo Galdi, Maria Principe, Ilaria Taurasi
Measurement of Thermal Noise in Multilayer Coatings with Optimized Layer Thickness
8 pages, 14 figures
Phys.Rev.D81:122001,2010
10.1103/PhysRevD.81.122001
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A standard quarter-wavelength multilayer optical coating will produce the highest reflectivity for a given number of coating layers, but in general it will not yield the lowest thermal noise for a prescribed reflectivity. Coatings with the layer thicknesses optimized to minimize thermal noise could be useful in futur...
[ { "created": "Thu, 8 Apr 2010 02:31:07 GMT", "version": "v1" }, { "created": "Sat, 10 Apr 2010 08:15:58 GMT", "version": "v2" } ]
2014-11-20
[ [ "Villar", "Akira E.", "" ], [ "Black", "Eric D.", "" ], [ "DeSalvo", "Riccardo", "" ], [ "Libbrecht", "Kenneth G.", "" ], [ "Michel", "Christophe", "" ], [ "Morgado", "Nazario", "" ], [ "Pinard", "Laurent", ...
A standard quarter-wavelength multilayer optical coating will produce the highest reflectivity for a given number of coating layers, but in general it will not yield the lowest thermal noise for a prescribed reflectivity. Coatings with the layer thicknesses optimized to minimize thermal noise could be useful in future ...
2105.09343
Prashant Kocherlakota
Prashant Kocherlakota, Luciano Rezzolla, Heino Falcke, Christian M. Fromm, Michael Kramer, Yosuke Mizuno, Antonios Nathanail, Hector Olivares, Ziri Younsi, Kazunori Akiyama, Antxon Alberdi, Walter Alef, Juan Carlos Algaba, Richard Anantua, Keiichi Asada, Rebecca Azulay, Anne-Kathrin Baczko, David Ball, Mislav B...
Constraints on black-hole charges with the 2017 EHT observations of M87*
15 pages, 4 figures, published in PRD on May 19
null
10.1103/PhysRevD.103.104047
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Our understanding of strong gravity near supermassive compact objects has recently improved thanks to the measurements made by the Event Horizon Telescope (EHT). We use here the M87* shadow size to infer constraints on the physical charges of a large variety of nonrotating or rotating black holes. For example, we sho...
[ { "created": "Wed, 19 May 2021 18:09:53 GMT", "version": "v1" } ]
2021-06-02
[ [ "Kocherlakota", "Prashant", "" ], [ "Rezzolla", "Luciano", "" ], [ "Falcke", "Heino", "" ], [ "Fromm", "Christian M.", "" ], [ "Kramer", "Michael", "" ], [ "Mizuno", "Yosuke", "" ], [ "Nathanail", "Antonios", ...
Our understanding of strong gravity near supermassive compact objects has recently improved thanks to the measurements made by the Event Horizon Telescope (EHT). We use here the M87* shadow size to infer constraints on the physical charges of a large variety of nonrotating or rotating black holes. For example, we show ...
1112.5873
Alexandre Baranov
Alexandre M.Baranov
On an Extension of a Static Ball Solution
2 pages, Proceedings of the 12th Russian Gravitational Conference, Kazan, 20-36 June 2005
Gravitation & Cosmology, Vol.11 (2005), No.4 (44), pp.313-314
null
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new exact static interior solution of the Einstein equations is obtained for a gravitating ball filled with a Pascal perfect fluid . The solution is an extension of the well-known interior solution with a parabolic distribution of mass density and describes more compact astrophysical objects such as neutron and hyp...
[ { "created": "Mon, 26 Dec 2011 16:52:07 GMT", "version": "v1" } ]
2020-07-17
[ [ "Baranov", "Alexandre M.", "" ] ]
A new exact static interior solution of the Einstein equations is obtained for a gravitating ball filled with a Pascal perfect fluid . The solution is an extension of the well-known interior solution with a parabolic distribution of mass density and describes more compact astrophysical objects such as neutron and hyper...
gr-qc/0301128
S. Kalyana Rama
Romesh K. Kaul and S. Kalyana Rama
Black Hole Entropy from Spin One Punctures
4 pages. RevTex
Phys.Rev. D68 (2003) 024001
10.1103/PhysRevD.68.024001
null
gr-qc hep-th
null
Recent suggestion, that the emission of a quantum of energy corresponding to the asymptotic value of quasinormal modes of a Schwarzschild black hole should be associated with the loss of spin one punctures from the black hole horizon, fixes the Immirzi parameter to a definite value. We show that saturating the horizo...
[ { "created": "Fri, 31 Jan 2003 10:35:41 GMT", "version": "v1" } ]
2009-11-10
[ [ "Kaul", "Romesh K.", "" ], [ "Rama", "S. Kalyana", "" ] ]
Recent suggestion, that the emission of a quantum of energy corresponding to the asymptotic value of quasinormal modes of a Schwarzschild black hole should be associated with the loss of spin one punctures from the black hole horizon, fixes the Immirzi parameter to a definite value. We show that saturating the horizon ...
gr-qc/0111041
Jorge Stephany
D.E. Diaz and J. Stephany
Rindler Particles and Classical Radiation
8 pages, 2 figures
Class.Quant.Grav. 19 (2002) 3753-3760
10.1088/0264-9381/19/14/314
SB/F/01-293
gr-qc hep-th
null
We describe the quantum and classical radiation by a uniformly accelerating point source in terms of the elementary processes of absorption and emission of Rindler scalar photons of the Fulling-Davies-Unruh bath observed by a co-accelerating observer.To this end we compute the emission rate by a DeWitt detector of a ...
[ { "created": "Tue, 13 Nov 2001 22:49:17 GMT", "version": "v1" }, { "created": "Tue, 19 Feb 2002 21:35:50 GMT", "version": "v2" } ]
2009-11-07
[ [ "Diaz", "D. E.", "" ], [ "Stephany", "J.", "" ] ]
We describe the quantum and classical radiation by a uniformly accelerating point source in terms of the elementary processes of absorption and emission of Rindler scalar photons of the Fulling-Davies-Unruh bath observed by a co-accelerating observer.To this end we compute the emission rate by a DeWitt detector of a Mi...
1411.4401
Prado Martin-Moruno
Prado Martin-Moruno
Semiclassical energy conditions and wormholes
6 pages; contribution to the proceedings of the Spanish Relativity Meeting 2014 (ERE 2014), Valencia, 1-5 September 2014
null
10.1088/1742-6596/600/1/012036
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the nonlinear energy conditions and their quantum extensions. These new energy conditions behave much better than the usual pointwise energy conditions in the presence of semiclassical quantum effects. Analogous quantum extensions for the linear energy conditions are not always satisfied as one enters the...
[ { "created": "Mon, 17 Nov 2014 09:36:39 GMT", "version": "v1" } ]
2015-05-20
[ [ "Martin-Moruno", "Prado", "" ] ]
We consider the nonlinear energy conditions and their quantum extensions. These new energy conditions behave much better than the usual pointwise energy conditions in the presence of semiclassical quantum effects. Analogous quantum extensions for the linear energy conditions are not always satisfied as one enters the q...
0910.5836
Claus Kiefer
Claus Kiefer
Can the Arrow of Time be understood from Quantum Cosmology?
14 pages, to appear in "The Arrow of Time", ed. by L. Mersini-Houghton and R. Vaas
The Arrows of Time (Springer, Heidelberg 2012), pp. 191-203
10.1007/978-3-642-23259-6_10
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I address the question whether the origin of the observed arrow of time can be derived from quantum cosmology. After a general discussion of entropy in cosmology and some numerical estimates, I give a brief introduction into quantum geometrodynamics and argue that this may provide a sufficient framework for studying ...
[ { "created": "Fri, 30 Oct 2009 10:31:42 GMT", "version": "v1" } ]
2012-07-27
[ [ "Kiefer", "Claus", "" ] ]
I address the question whether the origin of the observed arrow of time can be derived from quantum cosmology. After a general discussion of entropy in cosmology and some numerical estimates, I give a brief introduction into quantum geometrodynamics and argue that this may provide a sufficient framework for studying th...
2408.03241
Sunny Vagnozzi
Mohsen Khodadi, Sunny Vagnozzi, Javad T. Firouzjaee
Event Horizon Telescope observations exclude compact objects in baseline mimetic gravity
12 pages, 5 sub-figures arranged into 3 figures, key summary figure of our results (diagrammatic synopsis) is Fig. 3
null
null
null
gr-qc astro-ph.CO hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mimetic gravity has gained significant appeal in cosmological contexts, but static spherically symmetric space-times within the baseline theory are highly non-trivial: the two natural solutions are a naked singularity and a black hole space-time obtained through an appropriate gluing procedure. We study the shadow pr...
[ { "created": "Tue, 6 Aug 2024 15:02:43 GMT", "version": "v1" } ]
2024-08-12
[ [ "Khodadi", "Mohsen", "" ], [ "Vagnozzi", "Sunny", "" ], [ "Firouzjaee", "Javad T.", "" ] ]
Mimetic gravity has gained significant appeal in cosmological contexts, but static spherically symmetric space-times within the baseline theory are highly non-trivial: the two natural solutions are a naked singularity and a black hole space-time obtained through an appropriate gluing procedure. We study the shadow prop...
gr-qc/9902061
Eric Woolgar
G.J. Galloway, K. Schleich, D.M. Witt, and E. Woolgar
Topological Censorship and Higher Genus Black Holes
20 pages, Plain TeX
Phys.Rev.D60:104039,1999
10.1103/PhysRevD.60.104039
null
gr-qc hep-th
null
Motivated by recent interest in black holes whose asymptotic geometry approaches that of anti-de Sitter spacetime, we give a proof of topological censorship applicable to spacetimes with such asymptotic behavior. Employing a useful rephrasing of topological censorship as a property of homotopies of arbitrary loops, w...
[ { "created": "Sat, 20 Feb 1999 00:26:22 GMT", "version": "v1" }, { "created": "Sat, 19 Jun 1999 22:05:27 GMT", "version": "v2" } ]
2008-11-26
[ [ "Galloway", "G. J.", "" ], [ "Schleich", "K.", "" ], [ "Witt", "D. M.", "" ], [ "Woolgar", "E.", "" ] ]
Motivated by recent interest in black holes whose asymptotic geometry approaches that of anti-de Sitter spacetime, we give a proof of topological censorship applicable to spacetimes with such asymptotic behavior. Employing a useful rephrasing of topological censorship as a property of homotopies of arbitrary loops, we ...
1405.0705
Peng Xu
Li-E Qiang (1), Peng Xu (2) ((1) Chang'an University, Xi'an, China, (2) Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, China.)
Signature of biased range in the non-dynamical Chern-Simons modified gravity and its measurements with satellite-satellite tracking missions: Theoretical studies
19 pages, 4 figures
European Physical Journal C, Vol 75, 390 (2015)
10.1140/epjc/s10052-015-3610-7
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Having great accuracy in the range and range rate measurements,he GRACE mission and the planed GRACE Follow On mission can in principle be employed to place strong constraints on certain relativistic gravitational theories. In this paper, we work out the range observable of the non-dynamical Chern-Simons modified gra...
[ { "created": "Sun, 4 May 2014 15:12:56 GMT", "version": "v1" }, { "created": "Mon, 24 Nov 2014 07:23:56 GMT", "version": "v2" }, { "created": "Mon, 27 Jul 2015 18:50:32 GMT", "version": "v3" }, { "created": "Sun, 30 Aug 2015 04:53:32 GMT", "version": "v4" } ]
2015-09-01
[ [ "Qiang", "Li-E", "" ], [ "Xu", "Peng", "" ] ]
Having great accuracy in the range and range rate measurements,he GRACE mission and the planed GRACE Follow On mission can in principle be employed to place strong constraints on certain relativistic gravitational theories. In this paper, we work out the range observable of the non-dynamical Chern-Simons modified gravi...
0705.1179
Uri Keshet
Uri Keshet and Shahar Hod
Analytic Study of Rotating Black-Hole Quasinormal Modes
Shortened and typos fixed; to appear in PRD Rapid communications
Phys.Rev.D76:061501,2007
10.1103/PhysRevD.76.061501
null
gr-qc astro-ph hep-th
null
A Bohr-Sommerfeld equation is derived for the highly-damped quasinormal mode frequencies omega(n>>1) of rotating black holes. It may be written as 2\int_C(p_r+ip_0)dr=(n+1/2)h, where p_r is the canonical momentum conjugate to the radial coordinate r along null geodesics of energy hbar*omega and angular momentum hbar*...
[ { "created": "Tue, 8 May 2007 22:15:41 GMT", "version": "v1" }, { "created": "Fri, 24 Aug 2007 05:25:57 GMT", "version": "v2" } ]
2008-11-26
[ [ "Keshet", "Uri", "" ], [ "Hod", "Shahar", "" ] ]
A Bohr-Sommerfeld equation is derived for the highly-damped quasinormal mode frequencies omega(n>>1) of rotating black holes. It may be written as 2\int_C(p_r+ip_0)dr=(n+1/2)h, where p_r is the canonical momentum conjugate to the radial coordinate r along null geodesics of energy hbar*omega and angular momentum hbar*m,...
1010.5435
Zhaoyan Wu
Zhaoyan Wu
Pseudotensor problem of gravitational energy-momentum and Noether's theorem revisited
35 pages. The new version contains one more theorem and a few more examples to make it more convincing
null
null
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Based on a general variational principle, Noether's theorem is revisited. It is shown that the so called pseudotensor problem of the gravitational energy-momentum is a result of mis-reading Noether's theorem, and in fact, all the Noether's conserved quantities are scalars. It is also shown, by using a counter-example...
[ { "created": "Tue, 26 Oct 2010 15:42:06 GMT", "version": "v1" }, { "created": "Wed, 4 May 2011 01:52:29 GMT", "version": "v2" }, { "created": "Sat, 11 Jun 2011 04:05:31 GMT", "version": "v3" }, { "created": "Fri, 8 Nov 2013 17:54:29 GMT", "version": "v4" } ]
2013-11-11
[ [ "Wu", "Zhaoyan", "" ] ]
Based on a general variational principle, Noether's theorem is revisited. It is shown that the so called pseudotensor problem of the gravitational energy-momentum is a result of mis-reading Noether's theorem, and in fact, all the Noether's conserved quantities are scalars. It is also shown, by using a counter-example, ...
2106.05678
Cyril Renevey
Cyril Renevey, Ryan McManus, Charles Dalang, Lucas Lombriser
The effect of screening mechanisms on black hole binary inspiral waveforms
26 pages, 1 figure
null
10.1103/PhysRevD.105.084059
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Scalar-tensor theories leaving significant modifications of gravity at cosmological scales rely on screening mechanisms to recover General Relativity (GR) in high-density regions and pass stringent tests with astrophysical objects. Much focus has been placed on the signatures of such modifications of gravity on the p...
[ { "created": "Thu, 10 Jun 2021 11:50:19 GMT", "version": "v1" }, { "created": "Mon, 6 Dec 2021 13:01:49 GMT", "version": "v2" } ]
2022-05-11
[ [ "Renevey", "Cyril", "" ], [ "McManus", "Ryan", "" ], [ "Dalang", "Charles", "" ], [ "Lombriser", "Lucas", "" ] ]
Scalar-tensor theories leaving significant modifications of gravity at cosmological scales rely on screening mechanisms to recover General Relativity (GR) in high-density regions and pass stringent tests with astrophysical objects. Much focus has been placed on the signatures of such modifications of gravity on the pro...
1606.08586
Genly Le\'on
Joey Latta (Dalhousie U., Math. Dept.), Genly Leon (Valparaiso U., Catolica) and Andronikos Paliathanasis (Chile Austral U., Valdivia)
Kantowski-Sachs Einstein-{\ae}ther perfect fluid models
28 pages, 12 eps figures (4 compound figures). Minor revision of previous version. Matches the published version
JCAP11(2016)051
10.1088/1475-7516/2016/11/051
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate Kantowski-Sachs models in Einstein-{\ae}ther theory with a perfect fluid source using the singularity analysis to prove the integrability of the field equations and dynamical system tools to study the evolution. We find an inflationary source at early times, and an inflationary sink at late times, for ...
[ { "created": "Tue, 28 Jun 2016 07:33:52 GMT", "version": "v1" }, { "created": "Mon, 10 Oct 2016 21:57:21 GMT", "version": "v2" }, { "created": "Wed, 23 Nov 2016 16:33:41 GMT", "version": "v3" } ]
2016-11-24
[ [ "Latta", "Joey", "", "Dalhousie U., Math. Dept." ], [ "Leon", "Genly", "", "Valparaiso U.,\n Catolica" ], [ "Paliathanasis", "Andronikos", "", "Chile Austral U., Valdivia" ] ]
We investigate Kantowski-Sachs models in Einstein-{\ae}ther theory with a perfect fluid source using the singularity analysis to prove the integrability of the field equations and dynamical system tools to study the evolution. We find an inflationary source at early times, and an inflationary sink at late times, for a ...
0812.4742
Branislav Cvetkovi\'c
M. Blagojevi\'c and B. Cvetkovi\'c
Canonical structure of topologically massive gravity with a cosmological constant
LATEX, 19 pages, v2: Extended version of v1
JHEP 0905:073,2009
10.1088/1126-6708/2009/05/073
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the canonical structure of three-dimensional topologically massive gravity with a cosmological constant, using the full power of Dirac's method for constrained Hamiltonian systems. It is found that the dimension of the physical phase space is two per spacetime point, which corresponds to a single Lagrangian ...
[ { "created": "Sat, 27 Dec 2008 12:38:31 GMT", "version": "v1" }, { "created": "Thu, 29 Jan 2009 18:50:59 GMT", "version": "v2" }, { "created": "Wed, 20 May 2009 15:45:34 GMT", "version": "v3" } ]
2009-05-29
[ [ "Blagojević", "M.", "" ], [ "Cvetković", "B.", "" ] ]
We study the canonical structure of three-dimensional topologically massive gravity with a cosmological constant, using the full power of Dirac's method for constrained Hamiltonian systems. It is found that the dimension of the physical phase space is two per spacetime point, which corresponds to a single Lagrangian de...
2401.03553
Finnian Gray
Finnian Gray and David Kubiznak
Homogeneous Symmetry Operators in Kerr--NUT--AdS Spacetimes
null
Phys. Rev. D 109, 084027, April 2024
10.1103/PhysRevD.109.084027
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
It is well known that the Kerr--NUT--AdS spacetimes possess hidden symmetries encoded in the so-called principal Killing--Yano tensor. In this paper, focusing on the four-dimensional case, we obtain a number of symmetry operators for scalar, vector, and tensor perturbations, that are of degree two (to be defined belo...
[ { "created": "Sun, 7 Jan 2024 17:27:20 GMT", "version": "v1" }, { "created": "Thu, 4 Jul 2024 08:30:42 GMT", "version": "v2" } ]
2024-07-08
[ [ "Gray", "Finnian", "" ], [ "Kubiznak", "David", "" ] ]
It is well known that the Kerr--NUT--AdS spacetimes possess hidden symmetries encoded in the so-called principal Killing--Yano tensor. In this paper, focusing on the four-dimensional case, we obtain a number of symmetry operators for scalar, vector, and tensor perturbations, that are of degree two (to be defined below)...
gr-qc/0405146
Emanuele Berti
Emanuele Berti, Frances White, Asimina Maniopoulou, Marco Bruni
Rotating neutron stars: an invariant comparison of approximate and numerical spacetime models
19 pages, 9 figures, accepted in MNRAS; improved presentation, some new analytical results in Section 5.2
Mon.Not.Roy.Astron.Soc.358:923-938,2005
10.1111/j.1365-2966.2005.08812.x/abs/
null
gr-qc astro-ph
null
We compare three different models of rotating neutron star spacetimes: the Hartle-Thorne (HT) slow-rotation approximation at second order in rotation, the exact analytic vacuum solution of Manko et al. and a numerical solution of the full Einstein equations. We integrate the HT structure equations for five representa...
[ { "created": "Sat, 29 May 2004 21:47:59 GMT", "version": "v1" }, { "created": "Tue, 11 Jan 2005 11:09:43 GMT", "version": "v2" } ]
2011-05-23
[ [ "Berti", "Emanuele", "" ], [ "White", "Frances", "" ], [ "Maniopoulou", "Asimina", "" ], [ "Bruni", "Marco", "" ] ]
We compare three different models of rotating neutron star spacetimes: the Hartle-Thorne (HT) slow-rotation approximation at second order in rotation, the exact analytic vacuum solution of Manko et al. and a numerical solution of the full Einstein equations. We integrate the HT structure equations for five representati...
2006.14176
Hernando Quevedo
Walter Pulido and Hernando Quevedo
Black shells and naked shells
Typos corrected; references added; new sections and comments added
null
10.1142/S0219887821502005
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the collapse of a thin dust shell from the point of view of the horizon dynamics. We identify the critical surfaces at which time and space coordinates interchange their roles and investigate their properties by using the formalism of trapped surfaces. We show the existence of marginally outer trapped surfac...
[ { "created": "Thu, 25 Jun 2020 05:01:12 GMT", "version": "v1" }, { "created": "Wed, 8 Jul 2020 13:58:26 GMT", "version": "v2" }, { "created": "Tue, 1 Jun 2021 18:04:47 GMT", "version": "v3" } ]
2021-11-10
[ [ "Pulido", "Walter", "" ], [ "Quevedo", "Hernando", "" ] ]
We study the collapse of a thin dust shell from the point of view of the horizon dynamics. We identify the critical surfaces at which time and space coordinates interchange their roles and investigate their properties by using the formalism of trapped surfaces. We show the existence of marginally outer trapped surfaces...
2102.00017
Matteo Breschi
Matteo Breschi, Rossella Gamba, Sebastiano Bernuzzi
${\tt bajes}$: Bayesian inference of multimessenger astrophysical data, methods and application to gravitational-waves
null
Phys. Rev. D 104, 042001 (2021)
10.1103/PhysRevD.104.042001
null
gr-qc astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
We present ${\tt bajes}$, a parallel and lightweight framework for Bayesian inference of multimessenger transients. ${\tt bajes}$ is a Python modular package with minimal dependencies on external libraries adaptable to the majority of the Bayesian models and to various sampling methods. We describe the general workfl...
[ { "created": "Fri, 29 Jan 2021 19:00:13 GMT", "version": "v1" }, { "created": "Tue, 10 Aug 2021 14:40:19 GMT", "version": "v2" } ]
2021-08-18
[ [ "Breschi", "Matteo", "" ], [ "Gamba", "Rossella", "" ], [ "Bernuzzi", "Sebastiano", "" ] ]
We present ${\tt bajes}$, a parallel and lightweight framework for Bayesian inference of multimessenger transients. ${\tt bajes}$ is a Python modular package with minimal dependencies on external libraries adaptable to the majority of the Bayesian models and to various sampling methods. We describe the general workflow...
0805.1792
Tiberiu Harko
T. Harko, W. F. Choi, K. C. Wong, K. S. Cheng
Reheating the Universe in Braneworld Cosmological Models with bulk-brane energy transfer
29 pages, 9 figures, accepted for publication in JCAP
JCAP 0806:002,2008
10.1088/1475-7516/2008/06/002
null
gr-qc astro-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The emergence of the cosmological composition (the reheating era) after the inflationary period is analyzed in the framework of the braneworld models, in which our Universe is a three-brane embedded in a five-dimensional bulk, by assuming the possibility of the brane-bulk energy exchange. The inflaton field is assume...
[ { "created": "Tue, 13 May 2008 07:14:13 GMT", "version": "v1" }, { "created": "Wed, 28 May 2008 04:55:38 GMT", "version": "v2" } ]
2009-11-18
[ [ "Harko", "T.", "" ], [ "Choi", "W. F.", "" ], [ "Wong", "K. C.", "" ], [ "Cheng", "K. S.", "" ] ]
The emergence of the cosmological composition (the reheating era) after the inflationary period is analyzed in the framework of the braneworld models, in which our Universe is a three-brane embedded in a five-dimensional bulk, by assuming the possibility of the brane-bulk energy exchange. The inflaton field is assumed ...
0912.0628
Luis Manuel Gonzalez-Romero
L. M. Gonz\'alez-Romero, J. L. Bl\'azquez-Salcedo
Core-crust transition pressure evolution in post-glitch epoch for a Vela-type pulsar
4 pages, 5 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose that the \textit{post-glitch} epoch in a Vela-type pulsar corresponds to a transition time in which the broken \textit{crust} is readjusting its temperature and core-\textit{crust} transition pressure after the changes produced by the \textit{glitch}. To describe the evolution of the pulsar in this epoch w...
[ { "created": "Thu, 3 Dec 2009 11:41:06 GMT", "version": "v1" } ]
2009-12-04
[ [ "González-Romero", "L. M.", "" ], [ "Blázquez-Salcedo", "J. L.", "" ] ]
We propose that the \textit{post-glitch} epoch in a Vela-type pulsar corresponds to a transition time in which the broken \textit{crust} is readjusting its temperature and core-\textit{crust} transition pressure after the changes produced by the \textit{glitch}. To describe the evolution of the pulsar in this epoch we ...
gr-qc/0612045
Aurelien Barrau
A. Barrau
World-making with extended gravity black holes for cosmic natural selection in the multiverse scenario
5 pages, 1 figure. Proceedings of the Eleventh Marcel Grossmann Meeting on General Relativity, edited by H. Kleinert, R.T. Jantzen and R. Ruffini, World Scientific, Singapore, 2007
null
10.1142/9789812834300_0149
LPSC-06.118
gr-qc astro-ph hep-ph hep-th math-ph math.MP
null
Physics is facing contingency. Not only in facts but also in laws (the frontier becoming extremely narrow). Cosmic natural selection is a tantalizing idea to explain the apparently highly improbable structure of our Universe. In this brief note I will study the creation of Universes by black holes in -string inspired...
[ { "created": "Thu, 7 Dec 2006 14:53:08 GMT", "version": "v1" }, { "created": "Fri, 9 Feb 2007 15:53:33 GMT", "version": "v2" } ]
2018-12-19
[ [ "Barrau", "A.", "" ] ]
Physics is facing contingency. Not only in facts but also in laws (the frontier becoming extremely narrow). Cosmic natural selection is a tantalizing idea to explain the apparently highly improbable structure of our Universe. In this brief note I will study the creation of Universes by black holes in -string inspired- ...
1212.5731
S. Hamid Mehdipour
S. Hamid Mehdipour
Gravitational energy of a noncommutative Vaidya black hole
10 pages, no figure, to appear in Can. J. Phys
Can. J. Phys., Vol. 91, No. 3 (2013) 242-245
10.1139/cjp-2012-0485
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we evaluate the components of the energy-momentum pseudotensors of Landau and Lifshitz for the noncommutative Vaidya spacetime. The effective gravitational mass experienced by a neutral test particle present at any finite distance in the gravitational field of the noncommutative Vaidya black hole is der...
[ { "created": "Sat, 22 Dec 2012 21:53:32 GMT", "version": "v1" } ]
2013-04-04
[ [ "Mehdipour", "S. Hamid", "" ] ]
In this paper we evaluate the components of the energy-momentum pseudotensors of Landau and Lifshitz for the noncommutative Vaidya spacetime. The effective gravitational mass experienced by a neutral test particle present at any finite distance in the gravitational field of the noncommutative Vaidya black hole is deriv...
1111.3807
Hamid Reza Sepangi
A. S. Sefiedgar and H. R. Sepangi
Corrections to the Cardy-Verlinde formula from the modified dispersion relation in extra dimensions
9 pages, to appear in PLB
Phys. Lett. B 706 (2012) 431
10.1016/j.physletb.2011.11.027
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The modified dispersion relation as a common feature of all quantum gravity scenarios provides a perturbation framework upon which the black hole thermodynamics can be corrected. In this letter, we obtain the corrections to the $d$-dimensional Schwarzschild black hole thermodynamics by utilizing the extra dimensional...
[ { "created": "Wed, 16 Nov 2011 14:11:19 GMT", "version": "v1" }, { "created": "Mon, 21 Nov 2011 12:01:29 GMT", "version": "v2" } ]
2015-06-03
[ [ "Sefiedgar", "A. S.", "" ], [ "Sepangi", "H. R.", "" ] ]
The modified dispersion relation as a common feature of all quantum gravity scenarios provides a perturbation framework upon which the black hole thermodynamics can be corrected. In this letter, we obtain the corrections to the $d$-dimensional Schwarzschild black hole thermodynamics by utilizing the extra dimensional f...
1007.4669
Jonathan Middleton
Jonathan Middleton
On The Existence Of Anisotropic Cosmological Models In Higher-Order Theories Of Gravity
24 pages, submitted to CQG
Class.Quant.Grav.27:225013,2010
10.1088/0264-9381/27/22/225013
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the behaviour on approach to the initial singularity in higher-order extensions of general relativity by finding exact cosmological solutions for a wide class of models in which the Lagrangian is allowed to depend nonlinearly upon the three possible linear and quadratic scalars built from the Riemann t...
[ { "created": "Tue, 27 Jul 2010 10:41:39 GMT", "version": "v1" } ]
2014-11-21
[ [ "Middleton", "Jonathan", "" ] ]
We investigate the behaviour on approach to the initial singularity in higher-order extensions of general relativity by finding exact cosmological solutions for a wide class of models in which the Lagrangian is allowed to depend nonlinearly upon the three possible linear and quadratic scalars built from the Riemann ten...
gr-qc/9907098
Thomas W. Baumgarte
T. W. Baumgarte, S. A. Hughes, L. Rezzolla, S. L. Shapiro and M. Shibata
Implementing fully relativistic hydrodynamics in three dimensions
5 Pages, 4 Figures, submitted to Proceedings of the 8th Canadian Conference on General Relativity and Relativistic Astrophysics
null
10.1063/1.1301563
null
gr-qc astro-ph
null
We report on our numerical implementation of fully relativistic hydrodynamics coupled to Einstein's field equations in three spatial dimensions. We briefly review several steps in our code development, including our recasting of Einstein's equations and several tests which demonstrate its advantages for numerical int...
[ { "created": "Wed, 28 Jul 1999 18:25:01 GMT", "version": "v1" } ]
2009-10-31
[ [ "Baumgarte", "T. W.", "" ], [ "Hughes", "S. A.", "" ], [ "Rezzolla", "L.", "" ], [ "Shapiro", "S. L.", "" ], [ "Shibata", "M.", "" ] ]
We report on our numerical implementation of fully relativistic hydrodynamics coupled to Einstein's field equations in three spatial dimensions. We briefly review several steps in our code development, including our recasting of Einstein's equations and several tests which demonstrate its advantages for numerical integ...
1505.06260
Paulo Luz
Paulo Luz, Jos\'e P. S. Lemos
Newtonian wormholes with spherical symmetry and tidal forces on test particles
12 pages, 2 figures. Accepted for publication in International Journal of Modern Physics D
International Journal of Modern Physics D 24, 1550054 (2015)
null
null
gr-qc astro-ph.SR hep-th physics.class-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A spherically symmetric wormhole in Newtonian gravitation in curved space, enhanced with a connection between the mass density and the Ricci scalar, is presented. The wormhole, consisting of two connected asymptotically flat regions, inhabits a spherically symmetric curved space. The gravitational potential, gravitat...
[ { "created": "Sat, 23 May 2015 01:54:47 GMT", "version": "v1" } ]
2016-03-23
[ [ "Luz", "Paulo", "" ], [ "Lemos", "José P. S.", "" ] ]
A spherically symmetric wormhole in Newtonian gravitation in curved space, enhanced with a connection between the mass density and the Ricci scalar, is presented. The wormhole, consisting of two connected asymptotically flat regions, inhabits a spherically symmetric curved space. The gravitational potential, gravitatio...
0710.3415
Viktor Toth
J. W. Moffat and V. T. Toth
Modified gravity and the origin of inertia
4 pages, 3 figures; published version with updated references
MNRAS 395 (2009) L25-L28
10.1111/j.1745-3933.2009.00633.x
null
gr-qc astro-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Modified gravity theory is known to violate Birkhoff's theorem. We explore a key consequence of this violation, the effect of distant matter in the Universe on the motion of test particles. We find that when a particle is accelerated, a force is experienced that is proportional to the particle's mass and acceleration...
[ { "created": "Thu, 18 Oct 2007 00:55:13 GMT", "version": "v1" }, { "created": "Tue, 27 Nov 2007 15:49:25 GMT", "version": "v2" }, { "created": "Mon, 5 May 2008 22:34:50 GMT", "version": "v3" }, { "created": "Fri, 6 Jun 2008 16:33:37 GMT", "version": "v4" }, { "cre...
2009-04-10
[ [ "Moffat", "J. W.", "" ], [ "Toth", "V. T.", "" ] ]
Modified gravity theory is known to violate Birkhoff's theorem. We explore a key consequence of this violation, the effect of distant matter in the Universe on the motion of test particles. We find that when a particle is accelerated, a force is experienced that is proportional to the particle's mass and acceleration a...
1803.01119
Suddhasattwa Brahma
Martin Bojowald, Suddhasattwa Brahma and Dong-han Yeom
Effective line elements and black-hole models in canonical (loop) quantum gravity
27 pages; v2: matches published version
Phys. Rev. D 98, 046015 (2018)
10.1103/PhysRevD.98.046015
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Canonical quantization is often used to suggest new effects in quantum gravity, in the dynamics as well as the structure of space-time. Usually, possible phenomena are first seen in a modified version of the classical dynamics, for instance in an effective Friedmann equation, but there should also be implications for...
[ { "created": "Sat, 3 Mar 2018 07:18:09 GMT", "version": "v1" }, { "created": "Thu, 8 Nov 2018 23:07:14 GMT", "version": "v2" } ]
2018-11-12
[ [ "Bojowald", "Martin", "" ], [ "Brahma", "Suddhasattwa", "" ], [ "Yeom", "Dong-han", "" ] ]
Canonical quantization is often used to suggest new effects in quantum gravity, in the dynamics as well as the structure of space-time. Usually, possible phenomena are first seen in a modified version of the classical dynamics, for instance in an effective Friedmann equation, but there should also be implications for a...
1108.3237
Erico Goulart
E. Goulart, Santiago Esteban Perez Bergliaffa
Effective metric in nonlinear scalar field theories
null
null
10.1103/PhysRevD.84.105027
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss several features of the propagation of perturbations in nonlinear scalar field theories using the effective metric. It is shown that the effective metric can be classified according to whether the gradient of the scalar field is timelike, null, or spacelike, and this classification is illustrated with two ...
[ { "created": "Tue, 16 Aug 2011 13:19:18 GMT", "version": "v1" } ]
2015-05-30
[ [ "Goulart", "E.", "" ], [ "Bergliaffa", "Santiago Esteban Perez", "" ] ]
We discuss several features of the propagation of perturbations in nonlinear scalar field theories using the effective metric. It is shown that the effective metric can be classified according to whether the gradient of the scalar field is timelike, null, or spacelike, and this classification is illustrated with two ex...
2002.09429
Derek Davis
Derek Davis, Laurel V. White, Peter R. Saulson
Utilizing aLIGO Glitch Classifications to Validate Gravitational-Wave Candidates
16 pages, 6 figures
null
10.1088/1361-6382/ab91e6
null
gr-qc astro-ph.IM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Advanced LIGO data contains numerous noise transients, or "glitches", that have been shown to reduce the sensitivity of matched filter searches for gravitational waves from compact binaries by increasing the rate at which random coincidences occur. The presence of these transients has precipitated extensive work to e...
[ { "created": "Fri, 21 Feb 2020 17:22:25 GMT", "version": "v1" } ]
2020-08-26
[ [ "Davis", "Derek", "" ], [ "White", "Laurel V.", "" ], [ "Saulson", "Peter R.", "" ] ]
Advanced LIGO data contains numerous noise transients, or "glitches", that have been shown to reduce the sensitivity of matched filter searches for gravitational waves from compact binaries by increasing the rate at which random coincidences occur. The presence of these transients has precipitated extensive work to est...
gr-qc/0612013
Kishore Ananda N
Kishore N. Ananda, Chris Clarkson, David Wands (ICG, Portsmouth)
The cosmological gravitational wave background from primordial density perturbations
8 Pages
Phys.Rev.D75:123518,2007
10.1103/PhysRevD.75.123518
null
gr-qc astro-ph hep-ph
null
We discuss the gravitational wave background generated by primordial density perturbations evolving during the radiation era. At second-order in a perturbative expansion, density fluctuations produce gravitational waves. We calculate the power spectra of gravitational waves from this mechanism, and show that, in prin...
[ { "created": "Fri, 1 Dec 2006 17:54:02 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ananda", "Kishore N.", "", "ICG, Portsmouth" ], [ "Clarkson", "Chris", "", "ICG, Portsmouth" ], [ "Wands", "David", "", "ICG, Portsmouth" ] ]
We discuss the gravitational wave background generated by primordial density perturbations evolving during the radiation era. At second-order in a perturbative expansion, density fluctuations produce gravitational waves. We calculate the power spectra of gravitational waves from this mechanism, and show that, in princi...
gr-qc/0702011
F\'abio Dahia
F. Dahia and C. Romero
Confinement and stability of the motion of test particles in thick branes
1 figure. Extended analysis to treat general thick branes RSII-type. Added references
Phys.Lett.B651:232-238,2007
10.1016/j.physletb.2007.06.004
null
gr-qc
null
We consider the motion of test particles in a thick brane version of Randall-Sundrum type II model. It is known that gravity alone cannot explain the confinement of test particles in this kind of brane. In this paper we show that a stable confinement in a domain wall is possible by admitting a direct interaction betw...
[ { "created": "Fri, 2 Feb 2007 01:52:34 GMT", "version": "v1" }, { "created": "Fri, 7 Dec 2007 19:20:15 GMT", "version": "v2" } ]
2008-11-26
[ [ "Dahia", "F.", "" ], [ "Romero", "C.", "" ] ]
We consider the motion of test particles in a thick brane version of Randall-Sundrum type II model. It is known that gravity alone cannot explain the confinement of test particles in this kind of brane. In this paper we show that a stable confinement in a domain wall is possible by admitting a direct interaction betwee...
gr-qc/9609037
null
Sunme Kim and Freydoon Mansouri
The Structure of Space-Time Emerging from the Two-Superbody Problem in Chern Simons Supergravity
10 pages, LaTex
Phys.Lett.B397:81-87,1997
10.1016/S0370-2693(97)00148-2
UCTP104.96
gr-qc
null
We show that the exact solution of the two_superbody problem in N=2 Chern Simons Supergravity in 2+1 dimensions leads to a supermultiplet of space-times. This supersymmetric space-time is characterized by the two gauge invariant observables of the super Poincare' group, which may be viewed as the Casimir invariants o...
[ { "created": "Thu, 12 Sep 1996 22:08:49 GMT", "version": "v1" } ]
2014-11-17
[ [ "Kim", "Sunme", "" ], [ "Mansouri", "Freydoon", "" ] ]
We show that the exact solution of the two_superbody problem in N=2 Chern Simons Supergravity in 2+1 dimensions leads to a supermultiplet of space-times. This supersymmetric space-time is characterized by the two gauge invariant observables of the super Poincare' group, which may be viewed as the Casimir invariants of ...
gr-qc/0003027
Carlos Lousto
J. Baker, B. Bruegmann, M. Campanelli and C. O. Lousto (AEI-Golm)
Gravitational waves from black hole collisions via an eclectic approach
4 pages, 3 eps figures, Revtex
Class.Quant.Grav.17:L149-L156,2000
10.1088/0264-9381/17/20/102
AEI-2000-015
gr-qc astro-ph hep-th
null
We present the first results in a new program intended to make the best use of all available technologies to provide an effective understanding of waves from inspiralling black hole binaries in time for imminent observations. In particular, we address the problem of combining the close-limit approximation describing ...
[ { "created": "Wed, 8 Mar 2000 16:17:00 GMT", "version": "v1" } ]
2010-04-06
[ [ "Baker", "J.", "", "AEI-Golm" ], [ "Bruegmann", "B.", "", "AEI-Golm" ], [ "Campanelli", "M.", "", "AEI-Golm" ], [ "Lousto", "C. O.", "", "AEI-Golm" ] ]
We present the first results in a new program intended to make the best use of all available technologies to provide an effective understanding of waves from inspiralling black hole binaries in time for imminent observations. In particular, we address the problem of combining the close-limit approximation describing ri...
2402.16136
Francesco Marino
Samuel L. Braunstein, Mir Faizal, Lawrence M. Krauss, Francesco Marino, Naveed A. Shah
Analogue simulations of quantum gravity with fluids
Accepted version in Nature Reviews Physics. A view-only version of the manuscript with edited figures and additional references can be accessed at the link https://rdcu.be/dj6CN
Nature Reviews Physics 5, 612-622 (2023)
10.1038/s42254-023-00630-y
null
gr-qc cond-mat.quant-gas hep-th physics.flu-dyn quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent technological advances in controlling and manipulating fluids have enabled the experimental realization of acoustic analogues of gravitational black holes. A flowing fluid provides an effective curved spacetime on which sound waves can propagate, allowing the simulation of gravitational geometries and rela...
[ { "created": "Sun, 25 Feb 2024 16:21:43 GMT", "version": "v1" } ]
2024-02-27
[ [ "Braunstein", "Samuel L.", "" ], [ "Faizal", "Mir", "" ], [ "Krauss", "Lawrence M.", "" ], [ "Marino", "Francesco", "" ], [ "Shah", "Naveed A.", "" ] ]
The recent technological advances in controlling and manipulating fluids have enabled the experimental realization of acoustic analogues of gravitational black holes. A flowing fluid provides an effective curved spacetime on which sound waves can propagate, allowing the simulation of gravitational geometries and relate...
gr-qc/0003022
Bahram Mashhoon
Bahram Mashhoon
Gravitational Couplings of Intrinsic Spin
LaTeX file, no figures, 16 pages
Class.Quant.Grav. 17 (2000) 2399-2410
10.1088/0264-9381/17/12/312
null
gr-qc
null
The gravitational couplings of intrinsic spin are briefly reviewed. A consequence of the Dirac equation in the exterior gravitational field of a rotating mass is considered in detail, namely, the difference in the energy of a spin-1/2 particle polarized vertically up and down near the surface of a rotating body is $\...
[ { "created": "Tue, 7 Mar 2000 23:14:42 GMT", "version": "v1" } ]
2009-10-31
[ [ "Mashhoon", "Bahram", "" ] ]
The gravitational couplings of intrinsic spin are briefly reviewed. A consequence of the Dirac equation in the exterior gravitational field of a rotating mass is considered in detail, namely, the difference in the energy of a spin-1/2 particle polarized vertically up and down near the surface of a rotating body is $\hb...
2404.03095
Christopher Helmerich
Christopher Helmerich, Jared Fuchs, Alexey Bobrick, Luke Sellers, Brandon Melcher, Gianni Martire
Analyzing Warp Drive Spacetimes with Warp Factory
36 pages, 22 figures, Accepted in Classical and Quantum Gravity, For supplementary material, see https://doi.org/10.1088/1361-6382/ad2e42
null
10.1088/1361-6382/ad2e42
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
The field of warp research has been dominated by analytical methods to investigate potential solutions. However, these approaches often favor simple metric forms that facilitate analysis but ultimately limit the range of exploration of novel solutions. So far the proposed solutions have been unphysical, requiring ene...
[ { "created": "Wed, 3 Apr 2024 22:18:49 GMT", "version": "v1" }, { "created": "Wed, 10 Apr 2024 17:18:19 GMT", "version": "v2" } ]
2024-04-11
[ [ "Helmerich", "Christopher", "" ], [ "Fuchs", "Jared", "" ], [ "Bobrick", "Alexey", "" ], [ "Sellers", "Luke", "" ], [ "Melcher", "Brandon", "" ], [ "Martire", "Gianni", "" ] ]
The field of warp research has been dominated by analytical methods to investigate potential solutions. However, these approaches often favor simple metric forms that facilitate analysis but ultimately limit the range of exploration of novel solutions. So far the proposed solutions have been unphysical, requiring energ...
2407.15347
Leo Rodriguez
Shanshan Rodriguez, Alex Sidler, Leo Rodriguez, L. R. Ram-Mohan
Energy extraction through Comisso-Asenjo process from a Kerr-Newman black hole in perfect fluid dark matter
11 pages, 7 figures
null
null
null
gr-qc astro-ph.HE hep-th
http://creativecommons.org/licenses/by/4.0/
In this work, we provide a thorough analysis of energy extraction via magnetic reconnection, a novel mechanism recently proposed by Comisso and Asenjo, for a Kerr-Newman black hole immersed in a perfect fluid dark matter (PFDM) background. Our studies focus on the impact of black hole spin $a$, electric charge $Q$ an...
[ { "created": "Mon, 22 Jul 2024 03:14:47 GMT", "version": "v1" } ]
2024-07-23
[ [ "Rodriguez", "Shanshan", "" ], [ "Sidler", "Alex", "" ], [ "Rodriguez", "Leo", "" ], [ "Ram-Mohan", "L. R.", "" ] ]
In this work, we provide a thorough analysis of energy extraction via magnetic reconnection, a novel mechanism recently proposed by Comisso and Asenjo, for a Kerr-Newman black hole immersed in a perfect fluid dark matter (PFDM) background. Our studies focus on the impact of black hole spin $a$, electric charge $Q$ and ...
1011.3940
Bijan Saha Dr.
Hassan Amirhashchi, Anirudh Pradhan and Bijan Saha
An Interacting Two-Fluid Scenario for Dark Energy in FRW Universe
11 pages, accepted for publication in Chinese Physics Letters. Unlike the previous version the new one contains the time depending deceleration parameter
Chin. Phys. Lett. 28(3), (2011) 039801-4
10.1088/0256-307X/28/3/039801
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the evolution of the dark energy parameter within the scope of a spatially flat and isotropic Friedmann-Robertson-Walker (FRW) model filled with barotropic fluid and dark energy. To obtain the deterministic solution we choose the scale factor $a(t) = \sqrt{t e^{t}}$ which yields a time dependent deceleration...
[ { "created": "Wed, 17 Nov 2010 10:59:03 GMT", "version": "v1" }, { "created": "Fri, 14 Jan 2011 12:25:40 GMT", "version": "v2" } ]
2015-05-01
[ [ "Amirhashchi", "Hassan", "" ], [ "Pradhan", "Anirudh", "" ], [ "Saha", "Bijan", "" ] ]
We study the evolution of the dark energy parameter within the scope of a spatially flat and isotropic Friedmann-Robertson-Walker (FRW) model filled with barotropic fluid and dark energy. To obtain the deterministic solution we choose the scale factor $a(t) = \sqrt{t e^{t}}$ which yields a time dependent deceleration p...
1509.01772
George F. R. Ellis
George F. R. Ellis
100 Years of General Relativity
36 pages, 4 figures. This version corrects incorrect remarks made regarding the use of the post-Newtonian approximation in Section 6.4 of the printed version
null
null
null
gr-qc physics.hist-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is Chapter 1 in the book General Relativity and Gravitation: A Centennial Perspective, Edited by Abhay Ashtekar (Editor in Chief), Beverly Berger, James Isenberg, Malcolm MacCallum. Publisher: Cambridge University Press (June, 2015). It gives a survey of themes that have been developed during the 100 years of pr...
[ { "created": "Sun, 6 Sep 2015 06:11:40 GMT", "version": "v1" } ]
2015-09-08
[ [ "Ellis", "George F. R.", "" ] ]
This is Chapter 1 in the book General Relativity and Gravitation: A Centennial Perspective, Edited by Abhay Ashtekar (Editor in Chief), Beverly Berger, James Isenberg, Malcolm MacCallum. Publisher: Cambridge University Press (June, 2015). It gives a survey of themes that have been developed during the 100 years of prog...
1507.05312
Phuc Nguyen
Phuc H. Nguyen, Richard Matzner
Modelling LARES temperature distribution and thermal drag
24 pages, multiple figures. v4: typos in footnote 1 corrected
Eur. Phys. J. Plus (2015) 130: 206
10.1140/epjp/i2015-15206-2
UTTG-16-15, TCC-006-15
gr-qc physics.space-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The LARES satellite, a laser-ranged space experiment to contribute to geophysics observation, and to measure the general relativistic Lense-Thirring effect, has been observed to undergo an anomalous along-track orbital acceleration of -0.4 pm/s$^2$ (pm := picometer). This "drag" is not surprising; along track drag ha...
[ { "created": "Sun, 19 Jul 2015 17:48:56 GMT", "version": "v1" }, { "created": "Sat, 25 Jul 2015 22:09:52 GMT", "version": "v2" }, { "created": "Tue, 13 Oct 2015 17:08:54 GMT", "version": "v3" }, { "created": "Fri, 4 Mar 2016 15:09:44 GMT", "version": "v4" } ]
2016-03-07
[ [ "Nguyen", "Phuc H.", "" ], [ "Matzner", "Richard", "" ] ]
The LARES satellite, a laser-ranged space experiment to contribute to geophysics observation, and to measure the general relativistic Lense-Thirring effect, has been observed to undergo an anomalous along-track orbital acceleration of -0.4 pm/s$^2$ (pm := picometer). This "drag" is not surprising; along track drag has ...
gr-qc/0106047
Manoelito M. de Souza
Manoelito M. de Souza
Discrete interactions and the Pioneer anomalous acceleration: Alternative II
8 pages with calculation details of alternative II of gr-qc/0106096
null
null
null
gr-qc astro-ph hep-th
null
The dominant contributions from a discrete gravitational interaction produce the standard potential as an effective continuous field. The sub-dominant contributions are, in a first approximation, linear on $n$, the accumulated number of (discrete) interaction events along the test-body trajectory. For a nearly radial...
[ { "created": "Thu, 14 Jun 2001 13:30:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "de Souza", "Manoelito M.", "" ] ]
The dominant contributions from a discrete gravitational interaction produce the standard potential as an effective continuous field. The sub-dominant contributions are, in a first approximation, linear on $n$, the accumulated number of (discrete) interaction events along the test-body trajectory. For a nearly radial t...
1410.6152
She-Sheng Xue
She-Sheng Xue
How universe evolves with cosmological and gravitational constants
typo corrections, the final version to appear in Nucl. Phys. B (2015). 24 pages and 6 figures
Nuclear Physics B897 (2015) 326
10.1016/j.nuclphysb.2015.05.022
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With a basic varying space-time cutoff $\tilde\ell$, we study a regularized and quantized Einstein-Cartan gravitational field theory and its domains of ultraviolet-unstable fixed point $g_{\rm ir}\gtrsim 0$ and ultraviolet-stable fixed point $g_{\rm uv}\approx 4/3$ of the gravitational gauge coupling $g=(4/3)G/G_{\rm...
[ { "created": "Tue, 21 Oct 2014 08:01:42 GMT", "version": "v1" }, { "created": "Thu, 19 Mar 2015 09:07:09 GMT", "version": "v2" }, { "created": "Wed, 3 Jun 2015 16:13:04 GMT", "version": "v3" } ]
2015-09-09
[ [ "Xue", "She-Sheng", "" ] ]
With a basic varying space-time cutoff $\tilde\ell$, we study a regularized and quantized Einstein-Cartan gravitational field theory and its domains of ultraviolet-unstable fixed point $g_{\rm ir}\gtrsim 0$ and ultraviolet-stable fixed point $g_{\rm uv}\approx 4/3$ of the gravitational gauge coupling $g=(4/3)G/G_{\rm N...
1012.2560
Bin Liu
Bin Liu, Yun-Chuan Dai, Xian-Ru Hu, Jian-Bo Deng
The Klein-Gordon equation in Machian model
10 pages, accepted for publication in IJTP
null
10.1007/s10773-011-0862-3
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The non-local Machian model is regarded as an alternative theory of gravitation which states that all particles in the Universe as a 'gravitationally entangled' statistical ensemble. It is shown that the Klein-Gordon equation can be derived within this Machian model of the universe. The crucial point of the derivatio...
[ { "created": "Sun, 12 Dec 2010 17:16:12 GMT", "version": "v1" }, { "created": "Wed, 20 Jul 2011 12:32:20 GMT", "version": "v2" } ]
2011-07-21
[ [ "Liu", "Bin", "" ], [ "Dai", "Yun-Chuan", "" ], [ "Hu", "Xian-Ru", "" ], [ "Deng", "Jian-Bo", "" ] ]
The non-local Machian model is regarded as an alternative theory of gravitation which states that all particles in the Universe as a 'gravitationally entangled' statistical ensemble. It is shown that the Klein-Gordon equation can be derived within this Machian model of the universe. The crucial point of the derivation ...
0812.0272
Madhavan Varadarajan
Madhavan Varadarajan
On the resolution of the big bang singularity in isotropic Loop Quantum Cosmology
26 pages, no figures
Class.Quant.Grav. 26 (2009) 085006
10.1088/0264-9381/26/8/085006
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In contrast to previous work in the field, we construct the Loop Quantum Cosmology (LQC) of the flat isotropic model with a massless scalar field in the absence of higher order curvature corrections to the gravitational part of the Hamiltonian constraint. The matter part of the constraint contains the inverse triad o...
[ { "created": "Mon, 1 Dec 2008 11:56:49 GMT", "version": "v1" } ]
2015-01-30
[ [ "Varadarajan", "Madhavan", "" ] ]
In contrast to previous work in the field, we construct the Loop Quantum Cosmology (LQC) of the flat isotropic model with a massless scalar field in the absence of higher order curvature corrections to the gravitational part of the Hamiltonian constraint. The matter part of the constraint contains the inverse triad ope...
gr-qc/0005132
A. A. Shatskiy , A. Yu. Andreev
A. A. Shatskiy, A. Yu. Andreev
Dynamics of the formation of an event horizon
17 pages, 4 figures
Zh.Eksp.Teor.Fiz.116:353-368(1999)
null
null
gr-qc
null
The radial motion of matter in a centrally symmetric gravitational field in a comoving reference frame is investigated for a realistic equation of state of matter. The dynamics of the formation of an event horizon are investigated.
[ { "created": "Wed, 31 May 2000 11:53:45 GMT", "version": "v1" }, { "created": "Wed, 4 Oct 2000 08:07:29 GMT", "version": "v2" }, { "created": "Wed, 25 Oct 2000 08:54:29 GMT", "version": "v3" }, { "created": "Wed, 8 Nov 2000 13:09:55 GMT", "version": "v4" }, { "cre...
2010-11-19
[ [ "Shatskiy", "A. A.", "" ], [ "Andreev", "A. Yu.", "" ] ]
The radial motion of matter in a centrally symmetric gravitational field in a comoving reference frame is investigated for a realistic equation of state of matter. The dynamics of the formation of an event horizon are investigated.
gr-qc/0306040
Ujjal Debnath
Subenoy Chakraborty, N.C.Chakraborty and Ujjal Debnath
Quintessence Problem and Brans-Dicke Theory
6 Latex pages, No figure, Revtex style
Mod.Phys.Lett. A18 (2003) 1549-1556
10.1142/S0217732303009630
null
gr-qc
null
It has been shown that Brans-Dicke (BD) theory in anisotropic cosmological model can alone solve the quintessence problem and we have accelerated expanding universe without any quintessence matter. Also the flatness problem has been discussed in this context.
[ { "created": "Tue, 10 Jun 2003 12:01:34 GMT", "version": "v1" } ]
2009-11-10
[ [ "Chakraborty", "Subenoy", "" ], [ "Chakraborty", "N. C.", "" ], [ "Debnath", "Ujjal", "" ] ]
It has been shown that Brans-Dicke (BD) theory in anisotropic cosmological model can alone solve the quintessence problem and we have accelerated expanding universe without any quintessence matter. Also the flatness problem has been discussed in this context.
gr-qc/0402090
Alexander Petrov Nikolaevich
A.N.Petrov
Perturbations in the Einstein theory of gravity: Conserved currents
LATEX, 8 pages
Moscow Univ.Phys.Bull. 59 (2004) 1:24-28; Vestn.Mosk.Univ.Fiz.Astron. 1 (2004) 18-22
null
null
gr-qc
null
General relativity in the form where gravitational perturbations together with other physical fields propagate on an auxiliary background is considered. With using the Katz-Bi{\v{c}}\'ak-Lynden-Bell technique new conserved currents, divergences of antisymmetric tensor densities(superpotentials), in an arbitrary curve...
[ { "created": "Sun, 22 Feb 2004 09:26:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Petrov", "A. N.", "" ] ]
General relativity in the form where gravitational perturbations together with other physical fields propagate on an auxiliary background is considered. With using the Katz-Bi{\v{c}}\'ak-Lynden-Bell technique new conserved currents, divergences of antisymmetric tensor densities(superpotentials), in an arbitrary curved ...
1406.3201
Jeroen Meidam
J. Meidam, M. Agathos, C. Van Den Broeck, J. Veitch, B.S. Sathyaprakash
Testing the no-hair theorem with black hole ringdowns using TIGER
11 pages, 20 figures. Matches version in PRD
Phys. Rev. D 90, 064009 (2014)
10.1103/PhysRevD.90.064009
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Einstein Telescope (ET), a proposed third-generation gravitational wave observatory, would enable tests of the no-hair theorem by looking at the characteristic frequencies and damping times of black hole ringdown signals. In previous work it was shown that with a single $500 - 1000\,M_\odot$ black hole at distanc...
[ { "created": "Thu, 12 Jun 2014 11:47:26 GMT", "version": "v1" }, { "created": "Wed, 24 Sep 2014 15:44:17 GMT", "version": "v2" } ]
2015-06-19
[ [ "Meidam", "J.", "" ], [ "Agathos", "M.", "" ], [ "Broeck", "C. Van Den", "" ], [ "Veitch", "J.", "" ], [ "Sathyaprakash", "B. S.", "" ] ]
The Einstein Telescope (ET), a proposed third-generation gravitational wave observatory, would enable tests of the no-hair theorem by looking at the characteristic frequencies and damping times of black hole ringdown signals. In previous work it was shown that with a single $500 - 1000\,M_\odot$ black hole at distance ...
gr-qc/0304086
Reinhard Meinel
G. Neugebauer and R. Meinel
Progress in relativistic gravitational theory using the inverse scattering method
31 pages, 5 figures, to appear in J. Math. Phys
J.Math.Phys.44:3407,2003
10.1063/1.1590419
null
gr-qc hep-th math-ph math.MP
null
The increasing interest in compact astrophysical objects (neutron stars, binaries, galactic black holes) has stimulated the search for rigorous methods, which allow a systematic general relativistic description of such objects. This paper is meant to demonstrate the use of the inverse scattering method, which allows,...
[ { "created": "Wed, 23 Apr 2003 08:23:25 GMT", "version": "v1" } ]
2008-11-26
[ [ "Neugebauer", "G.", "" ], [ "Meinel", "R.", "" ] ]
The increasing interest in compact astrophysical objects (neutron stars, binaries, galactic black holes) has stimulated the search for rigorous methods, which allow a systematic general relativistic description of such objects. This paper is meant to demonstrate the use of the inverse scattering method, which allows, i...
2407.07820
Alexandra Eleni Koloniari
Alexandra E. Koloniari, Evdokia C. Koursoumpa, Paraskevi Nousi, Paraskevas Lampropoulos, Nikolaos Passalis, Anastasios Tefas, Nikolaos Stergioulas
New Gravitational Wave Discoveries Enabled by Machine Learning
30 pages, 42 figures
null
null
null
gr-qc astro-ph.HE astro-ph.IM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The detection of gravitational waves has revolutionized our understanding of the universe, offering unprecedented insights into its dynamics. A major goal of gravitational wave data analysis is to speed up the detection and parameter estimation process using machine learning techniques, in light of an anticipated sur...
[ { "created": "Wed, 10 Jul 2024 16:44:08 GMT", "version": "v1" } ]
2024-07-11
[ [ "Koloniari", "Alexandra E.", "" ], [ "Koursoumpa", "Evdokia C.", "" ], [ "Nousi", "Paraskevi", "" ], [ "Lampropoulos", "Paraskevas", "" ], [ "Passalis", "Nikolaos", "" ], [ "Tefas", "Anastasios", "" ], [ "Stergioul...
The detection of gravitational waves has revolutionized our understanding of the universe, offering unprecedented insights into its dynamics. A major goal of gravitational wave data analysis is to speed up the detection and parameter estimation process using machine learning techniques, in light of an anticipated surge...
gr-qc/9612038
Alexander L. Gromov
Alexander Gromov (St-Petersburg State Thechnical University, Russia)
The Tolman-Bondi Model in the Ruban-Chernin Coordinates. 1. Equations and Solutions
LaTeX,12 pages, submitted to New Astronomy
null
null
null
gr-qc
null
The Tolman-Bondi (TB) model is defined up to some transformation of a co-moving coordinate but the transformation is not fixed. The use of an arbitrary co-moving system of coordinates leads to the solution dependent on three functions $f, F, {\bf F}$ which are chosen independently in applications. The article studi...
[ { "created": "Sun, 15 Dec 1996 17:22:20 GMT", "version": "v1" }, { "created": "Tue, 18 Mar 1997 21:24:12 GMT", "version": "v2" }, { "created": "Wed, 7 May 1997 12:07:14 GMT", "version": "v3" } ]
2008-02-03
[ [ "Gromov", "Alexander", "", "St-Petersburg State Thechnical University, Russia" ] ]
The Tolman-Bondi (TB) model is defined up to some transformation of a co-moving coordinate but the transformation is not fixed. The use of an arbitrary co-moving system of coordinates leads to the solution dependent on three functions $f, F, {\bf F}$ which are chosen independently in applications. The article studies t...
gr-qc/0601023
Soon-Tae Hong
Soon-Tae Hong
Warped products and black holes
6 pages
Nuovo Cim. B120 (2005) 1227-1234
10.1393/ncb/i2005-10150-0
null
gr-qc
null
We apply the warped product spacetime scheme to the Banados-Teitelboim-Zanelli black holes and the Reissner-Nordstr\"om-anti-de Sitter black hole to investigate their interior solutions in terms of warped products. It is shown that there exist no discontinuities of the Ricci and Einstein curvatures across event horiz...
[ { "created": "Fri, 6 Jan 2006 05:23:10 GMT", "version": "v1" } ]
2009-11-11
[ [ "Hong", "Soon-Tae", "" ] ]
We apply the warped product spacetime scheme to the Banados-Teitelboim-Zanelli black holes and the Reissner-Nordstr\"om-anti-de Sitter black hole to investigate their interior solutions in terms of warped products. It is shown that there exist no discontinuities of the Ricci and Einstein curvatures across event horizon...
1903.07685
Andrea Giusti
Roberto Casadio, Andrea Giugno, Andrea Giusti, Valerio Faraoni
Is de Sitter space always excluded in semiclassical f(R) gravity?
9 pages, no figures
JCAP 1906 (2019) no.06, 005
10.1088/1475-7516/2019/06/005
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that the recent corpuscular description of gravity generically excludes de Sitter spacetime in any semiclassical version of f(R) gravity. A phantom phenomenology of the cosmic dynamics is also naturally excluded.
[ { "created": "Mon, 18 Mar 2019 19:28:39 GMT", "version": "v1" }, { "created": "Tue, 18 Jun 2019 17:53:43 GMT", "version": "v2" } ]
2019-06-19
[ [ "Casadio", "Roberto", "" ], [ "Giugno", "Andrea", "" ], [ "Giusti", "Andrea", "" ], [ "Faraoni", "Valerio", "" ] ]
It is shown that the recent corpuscular description of gravity generically excludes de Sitter spacetime in any semiclassical version of f(R) gravity. A phantom phenomenology of the cosmic dynamics is also naturally excluded.
0708.2018
Peter D'Eath
A.N.St.J.Farley, P.D.D'Eath
Quantum amplitudes in black-hole evaporation: coherent and squeezed states
null
Class.Quant.Grav.24:105-127,2007
10.1088/0264-9381/24/1/006
null
gr-qc
null
The quantum amplitude for processes involving the formation and evaporation of black holes was previously calculated by means of a complex-time approach. In that treatment, we followed Feynman's $+i\epsilon$ approach in quantum field theory. The Lorentzian time interval $T$, measured at spatial infinity between a pai...
[ { "created": "Wed, 15 Aug 2007 09:54:42 GMT", "version": "v1" } ]
2008-11-26
[ [ "Farley", "A. N. St. J.", "" ], [ "D'Eath", "P. D.", "" ] ]
The quantum amplitude for processes involving the formation and evaporation of black holes was previously calculated by means of a complex-time approach. In that treatment, we followed Feynman's $+i\epsilon$ approach in quantum field theory. The Lorentzian time interval $T$, measured at spatial infinity between a pair ...
2011.06148
Cosimo Bambi
Bakhtiyor Narzilloev, Javlon Rayimbaev, Sanjar Shaymatov, Ahmadjon Abdujabbarov, Bobomurat Ahmedov, Cosimo Bambi
Dynamics of test particles around a Bardeen black hole surrounded by perfect fluid dark matter
17 pages, 16 figures. Accepted for publication in Phys. Rev. D
Phys. Rev. D 102, 104062 (2020)
10.1103/PhysRevD.102.104062
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the dynamics of (i) neutral test particles, (ii) magnetically charged test particles, and (iii) test magnetic dipole around a regular Bardeen black hole surrounded by perfect fluid dark matter (PFDM). It has been shown how the magnetic charge of the black hole and the parameter of the surrounding PFDM can in...
[ { "created": "Thu, 12 Nov 2020 01:16:46 GMT", "version": "v1" } ]
2020-11-25
[ [ "Narzilloev", "Bakhtiyor", "" ], [ "Rayimbaev", "Javlon", "" ], [ "Shaymatov", "Sanjar", "" ], [ "Abdujabbarov", "Ahmadjon", "" ], [ "Ahmedov", "Bobomurat", "" ], [ "Bambi", "Cosimo", "" ] ]
We study the dynamics of (i) neutral test particles, (ii) magnetically charged test particles, and (iii) test magnetic dipole around a regular Bardeen black hole surrounded by perfect fluid dark matter (PFDM). It has been shown how the magnetic charge of the black hole and the parameter of the surrounding PFDM can infl...
1909.11267
Ling Sun
Ling Sun, Richard Brito, Maximiliano Isi
Search for ultralight bosons in Cygnus X-1 with Advanced LIGO
9 pages, 4 figures; In the latest version, we integrated the changes reported in the published erratum (DOI: 10.1103/PhysRevD.102.089902). A missing coefficient when comparing the numerically estimated signal strain to the strain upper limit is fixed. An alternative choice of the black hole age and the correspo...
Phys. Rev. D 101, 063020 (2020)
10.1103/PhysRevD.101.063020
null
gr-qc astro-ph.HE hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ultralight scalars, if they exist as theorized, could form clouds around rapidly rotating black holes. Such clouds are expected to emit continuous, quasimonochromatic gravitational waves that could be detected by LIGO and Virgo. Here we present results of a directed search for such signals from the Cygnus X-1 binary,...
[ { "created": "Wed, 25 Sep 2019 03:20:21 GMT", "version": "v1" }, { "created": "Mon, 2 Mar 2020 19:38:30 GMT", "version": "v2" }, { "created": "Tue, 27 Oct 2020 22:58:14 GMT", "version": "v3" } ]
2020-10-29
[ [ "Sun", "Ling", "" ], [ "Brito", "Richard", "" ], [ "Isi", "Maximiliano", "" ] ]
Ultralight scalars, if they exist as theorized, could form clouds around rapidly rotating black holes. Such clouds are expected to emit continuous, quasimonochromatic gravitational waves that could be detected by LIGO and Virgo. Here we present results of a directed search for such signals from the Cygnus X-1 binary, u...
gr-qc/0405020
Ruth Lazkoz
Luis P. Chimento and Ruth Lazkoz
On big rip singularities
8 pages
Mod.Phys.Lett. A19 (2004) 2479-2484
10.1142/S0217732304015646
null
gr-qc
null
In this comment we discuss big rip singularities occurring in typical phantom models by violation of the weak energy condition. After that, we compare them with future late-time singularities arising in models where the scale factor ends in a constant value and there is no violation of the strong energy condition. In...
[ { "created": "Wed, 5 May 2004 11:05:08 GMT", "version": "v1" } ]
2009-11-10
[ [ "Chimento", "Luis P.", "" ], [ "Lazkoz", "Ruth", "" ] ]
In this comment we discuss big rip singularities occurring in typical phantom models by violation of the weak energy condition. After that, we compare them with future late-time singularities arising in models where the scale factor ends in a constant value and there is no violation of the strong energy condition. In p...
gr-qc/9803082
Saul A. Teukolsky
Saul A. Teukolsky
Irrotational Binary Neutron Stars in Quasiequilibrium in General Relativity
14 pages, AASTeX, accepted in ApJ. Simplified final form of equation (eq. 52). Added Shibata ref
null
10.1086/306082
SAT-101
gr-qc astro-ph
null
Neutron stars in binary orbit emit gravitational waves and spiral slowly together. During this inspiral, they are expected to have very little vorticity. It is in fact a good approximation to treat the system as having zero vorticity, i.e., as irrotational. Because the orbital period is much shorter than the radiatio...
[ { "created": "Wed, 25 Mar 1998 18:43:35 GMT", "version": "v1" }, { "created": "Mon, 4 May 1998 17:50:37 GMT", "version": "v2" } ]
2009-10-31
[ [ "Teukolsky", "Saul A.", "" ] ]
Neutron stars in binary orbit emit gravitational waves and spiral slowly together. During this inspiral, they are expected to have very little vorticity. It is in fact a good approximation to treat the system as having zero vorticity, i.e., as irrotational. Because the orbital period is much shorter than the radiation ...
gr-qc/9502022
Sardanashvily Gennadi
G.Sardanashvily (Moscow State University)
Composite Spinor Bundles in Gravitation Theory
26 pp, LaTeX file
null
null
TP\95\021
gr-qc
null
In gravitation theory, the realistic fermion matter is described by spinor bundles associated with the cotangent bundle of a world manifold $X$. In this case, the Dirac operator can be introduced. There is the 1:1 correspondence between these spinor bundles and the tetrad gravitational fields represented by sections ...
[ { "created": "Wed, 8 Feb 1995 07:12:06 GMT", "version": "v1" } ]
2016-08-31
[ [ "Sardanashvily", "G.", "", "Moscow State University" ] ]
In gravitation theory, the realistic fermion matter is described by spinor bundles associated with the cotangent bundle of a world manifold $X$. In this case, the Dirac operator can be introduced. There is the 1:1 correspondence between these spinor bundles and the tetrad gravitational fields represented by sections of...
2301.00639
Abra\~ao Mendes
Gregory J. Galloway, Abra\~ao Mendes
Some rigidity results for compact initial data sets
19 pages. All comments welcome. Small update
null
null
null
gr-qc math.DG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we prove several rigidity results for compact initial data sets, in both the boundary and no boundary cases. In particular, under natural energy, boundary, and topological conditions, we obtain a global version of the main result in [15]. We also obtain some extensions of results in [12]. A number of e...
[ { "created": "Mon, 2 Jan 2023 13:02:19 GMT", "version": "v1" }, { "created": "Wed, 1 Feb 2023 19:18:20 GMT", "version": "v2" } ]
2023-02-03
[ [ "Galloway", "Gregory J.", "" ], [ "Mendes", "Abraão", "" ] ]
In this paper, we prove several rigidity results for compact initial data sets, in both the boundary and no boundary cases. In particular, under natural energy, boundary, and topological conditions, we obtain a global version of the main result in [15]. We also obtain some extensions of results in [12]. A number of exa...
1911.11232
Roger Hurtado M.Sc.
Roger A. Hurtado and Robel Arenas
Scalar-field potential for viable models in $f(R)$ theory
20 pages, 8 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The $f(R)$ theory of gravity can be expressed as a scalar tensor theory with a scalar degree of freedom $\phi$. By a conformal transformation, the action and its Gibbons-York-Hawking boundary term are written in the Einstein frame and the field equations are found. An effective potential is defined from part of the t...
[ { "created": "Mon, 25 Nov 2019 21:08:23 GMT", "version": "v1" } ]
2019-11-27
[ [ "Hurtado", "Roger A.", "" ], [ "Arenas", "Robel", "" ] ]
The $f(R)$ theory of gravity can be expressed as a scalar tensor theory with a scalar degree of freedom $\phi$. By a conformal transformation, the action and its Gibbons-York-Hawking boundary term are written in the Einstein frame and the field equations are found. An effective potential is defined from part of the tra...
gr-qc/9501019
Hans-Juergen Schmidt
Hans - J\"urgen Schmidt
An alternate Hamiltonian formulation of fourth-order theories and its application to cosmology
29 pages, latex, no figures, hjschmi@rz.uni-potsdam.de
null
null
Uni Potsdam Math-94/12
gr-qc
null
An alternate Hamiltonian H different from Ostrogradski's one is found for the Lagrangian L = L(q, \dot q, \ddot q). We add a suitable divergence to L and insert a=q and b=\ddot q. Contrary to other approaches no constraint is needed because \ddot a = b is one of the canonical equations. Another canonical equation bec...
[ { "created": "Wed, 18 Jan 1995 11:19:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Schmidt", "Hans - Jürgen", "" ] ]
An alternate Hamiltonian H different from Ostrogradski's one is found for the Lagrangian L = L(q, \dot q, \ddot q). We add a suitable divergence to L and insert a=q and b=\ddot q. Contrary to other approaches no constraint is needed because \ddot a = b is one of the canonical equations. Another canonical equation becom...
gr-qc/9801082
Toporenskij A. V.
A.Yu.Kamenshchik, I.M.Khalatnikov, A.V.Toporensky
Simplest cosmological model with the scalar field II. Influence of cosmological constant
12 pages with 2 gif figures and 2 eps figures, mprocl.sty, To appear in International Journal of Modern Physics D
Int.J.Mod.Phys. D7 (1998) 129-138
10.1142/S0218271898000127
null
gr-qc
null
Continuing the investigation of the simplest cosmological model with the massive real scalar non-interacting inflaton field minimally coupled to gravity we study an influence of the cosmological constant on the behaviour of trajectories in closed minisuperspace Friedmann-Robertson-Walker model. The transition from ch...
[ { "created": "Fri, 23 Jan 1998 15:22:28 GMT", "version": "v1" } ]
2009-10-31
[ [ "Kamenshchik", "A. Yu.", "" ], [ "Khalatnikov", "I. M.", "" ], [ "Toporensky", "A. V.", "" ] ]
Continuing the investigation of the simplest cosmological model with the massive real scalar non-interacting inflaton field minimally coupled to gravity we study an influence of the cosmological constant on the behaviour of trajectories in closed minisuperspace Friedmann-Robertson-Walker model. The transition from chao...
gr-qc/0103078
M. G. Jackson
Mark G. Jackson
Two Black Hole Holography, Lensing and Intensity
10 pages
Phys.Rev. D64 (2001) 044020
10.1103/PhysRevD.64.044020
CU-TP-1013
gr-qc hep-th
null
We numerically verify the analysis of the "expanding horizon" theory of Susskind in relation to the 't Hooft holographic conjecture. By using a numerical simulation to work out the image formed by two black holes upon a screen very far away, it is seen that it is impossible for a horizon to hide behind another. We al...
[ { "created": "Thu, 22 Mar 2001 10:18:39 GMT", "version": "v1" }, { "created": "Mon, 3 Sep 2001 04:36:03 GMT", "version": "v2" } ]
2009-11-07
[ [ "Jackson", "Mark G.", "" ] ]
We numerically verify the analysis of the "expanding horizon" theory of Susskind in relation to the 't Hooft holographic conjecture. By using a numerical simulation to work out the image formed by two black holes upon a screen very far away, it is seen that it is impossible for a horizon to hide behind another. We also...
1205.2365
Ramon Herrera
Ramon Herrera and Marco Olivares
Warm-Logamediate inflationary universe model
16 pages, 2 figures. Accepted for publication in IJMPD. arXiv admin note: text overlap with arXiv:1108.1371
null
10.1142/S0218271812500472
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Warm inflationary universe models in the context of logamediate expansion are studied. General conditions required for these models to be realizable and discussed. This study is done in the weak and strong dissipative regimes. The parameters of our models are constrained from the observational data.
[ { "created": "Thu, 10 May 2012 19:51:32 GMT", "version": "v1" } ]
2015-06-05
[ [ "Herrera", "Ramon", "" ], [ "Olivares", "Marco", "" ] ]
Warm inflationary universe models in the context of logamediate expansion are studied. General conditions required for these models to be realizable and discussed. This study is done in the weak and strong dissipative regimes. The parameters of our models are constrained from the observational data.
2107.08506
Abhay Ashtekar
Abhay Ashtekar, Tommaso De Lorenzo, Marc Schneider
Probing the Big Bang with quantum fields
38 pages; Three small clarifications added and minor typos corrected. Version to appear in Advances in Mathematical and Theoretical Physics
Advances in Theoretical and Mathematical Physics, 25, 7, 1651-1702 (2021)
10.4310/ATMP.2021.v25.n7.a1
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By carrying out a systematic investigation of linear, test quantum fields $\hat{\phi}(x)$ in cosmological space-times, we show that $\hat{\phi}(x)$ remain well-defined across the big bang as operator valued distributions in a large class of Friedmann, Lema\^itre, Robertson, Walker space-times, including radiation and...
[ { "created": "Sun, 18 Jul 2021 18:00:03 GMT", "version": "v1" }, { "created": "Fri, 1 Oct 2021 15:40:28 GMT", "version": "v2" } ]
2022-07-14
[ [ "Ashtekar", "Abhay", "" ], [ "De Lorenzo", "Tommaso", "" ], [ "Schneider", "Marc", "" ] ]
By carrying out a systematic investigation of linear, test quantum fields $\hat{\phi}(x)$ in cosmological space-times, we show that $\hat{\phi}(x)$ remain well-defined across the big bang as operator valued distributions in a large class of Friedmann, Lema\^itre, Robertson, Walker space-times, including radiation and d...
0804.2327
Miodrag Krmar
Vladan Pankovic, Simo Ciganovic, Rade Glavatovic
The Simplest Determination of the Thermodynamical Characteristics of Kerr-Newman Black Hole
5 pages, no figures
null
null
F-NS/02-08
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, generalizing our previous results, we determine in an original and the simplest way three most important thermodynamical characteristics (Bekenstein-Hawking entropy, Bekenstein quantization of the entropy or (outer) horizon surface area and Hawking temperature) of Kerr-Newman black hole. We start physic...
[ { "created": "Tue, 15 Apr 2008 08:32:46 GMT", "version": "v1" } ]
2008-04-16
[ [ "Pankovic", "Vladan", "" ], [ "Ciganovic", "Simo", "" ], [ "Glavatovic", "Rade", "" ] ]
In this work, generalizing our previous results, we determine in an original and the simplest way three most important thermodynamical characteristics (Bekenstein-Hawking entropy, Bekenstein quantization of the entropy or (outer) horizon surface area and Hawking temperature) of Kerr-Newman black hole. We start physical...
1910.06350
T. P. Singh
Tejinder P. Singh
Quantum gravity, minimum length, and holography
v2. 15 pages, one figure, title changed, introductory remarks added, references updated, to appear in Pramana - Journal of Physics
Pramana - J. Phys. 95, 40 (2021)
10.1007/s12043-020-02045-1
null
gr-qc hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Karolyhazy uncertainty relation is the statement that if a device is used to measure a length $l$, there will be a minimum uncertainty $\delta l$ in the measurement, given by $(\delta l)^3 \sim L_P^2\; l$. This is a consequence of combining the principles of quantum mechanics and general relativity. In this note ...
[ { "created": "Mon, 14 Oct 2019 18:00:29 GMT", "version": "v1" }, { "created": "Wed, 7 Oct 2020 06:40:50 GMT", "version": "v2" } ]
2021-03-03
[ [ "Singh", "Tejinder P.", "" ] ]
The Karolyhazy uncertainty relation is the statement that if a device is used to measure a length $l$, there will be a minimum uncertainty $\delta l$ in the measurement, given by $(\delta l)^3 \sim L_P^2\; l$. This is a consequence of combining the principles of quantum mechanics and general relativity. In this note we...
1601.01055
Jibitesh Dutta
Sourav Haldar, Jibitesh Dutta, Subenoy Chakraborty
A Comparative Study of Different Entropies in Fractal Universe
Revised throughly
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Here we make an attempt to extend the idea of generalized Hawking temperature and modified Bekenstein entropy at the event horizon in a fractal universe. The modified Hawking temperature and Bekenstein entropy are considered in the governing Friedmann equations, which is modified in the background of a fractal univer...
[ { "created": "Wed, 6 Jan 2016 02:34:08 GMT", "version": "v1" }, { "created": "Thu, 1 Dec 2016 09:19:45 GMT", "version": "v2" } ]
2016-12-02
[ [ "Haldar", "Sourav", "" ], [ "Dutta", "Jibitesh", "" ], [ "Chakraborty", "Subenoy", "" ] ]
Here we make an attempt to extend the idea of generalized Hawking temperature and modified Bekenstein entropy at the event horizon in a fractal universe. The modified Hawking temperature and Bekenstein entropy are considered in the governing Friedmann equations, which is modified in the background of a fractal universe...
1803.01712
Muhammad Sharif
M. Sharif and Ayesha Ikram
Thermodynamics in $f(\mathcal{G},T)$ Gravity
20 pages, 8 figures
Ad. High Energy Phys. 2018(2018)2563871
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper explores the non-equilibrium behavior of thermodynamics at the apparent horizon of isotropic and homogeneous universe model in $f(\mathcal{G},T)$ gravity ($\mathcal{G}$ and $T$ represent the Gauss-Bonnet invariant and trace of the energy-momentum tensor, respectively). We construct the corresponding field ...
[ { "created": "Thu, 1 Mar 2018 09:36:31 GMT", "version": "v1" } ]
2018-03-13
[ [ "Sharif", "M.", "" ], [ "Ikram", "Ayesha", "" ] ]
This paper explores the non-equilibrium behavior of thermodynamics at the apparent horizon of isotropic and homogeneous universe model in $f(\mathcal{G},T)$ gravity ($\mathcal{G}$ and $T$ represent the Gauss-Bonnet invariant and trace of the energy-momentum tensor, respectively). We construct the corresponding field eq...
1311.6963
Mustapha Azreg-A\"inou
Mustapha Azreg-A\"inou
Geometrothermodynamics: Comments, critics, and supports
7 pages, no figures, more extended version: new equations added (European Physical Journal C)
Eur. Phys. J. C (2014) 74:2930
10.1140/epjc/s10052-014-2930-3
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We write explicitly the Euler identity and the Gibbs-Duhem relation for thermodynamic potentials that are not homogeneous first-order functions of their natural extensive variables. We apply the rules to the theory of geometrothermodynamics and show how the use of the natural extensive variables, instead of the modif...
[ { "created": "Wed, 27 Nov 2013 13:17:53 GMT", "version": "v1" }, { "created": "Wed, 11 Dec 2013 11:03:28 GMT", "version": "v2" }, { "created": "Fri, 28 Mar 2014 13:04:20 GMT", "version": "v3" }, { "created": "Mon, 2 Jun 2014 07:09:43 GMT", "version": "v4" } ]
2014-06-26
[ [ "Azreg-Aïnou", "Mustapha", "" ] ]
We write explicitly the Euler identity and the Gibbs-Duhem relation for thermodynamic potentials that are not homogeneous first-order functions of their natural extensive variables. We apply the rules to the theory of geometrothermodynamics and show how the use of the natural extensive variables, instead of the modifie...
1806.04614
Andreas Lymperis
Andreas Lymperis and Emmanuel N. Saridakis
Modified cosmology through nonextensive horizon thermodynamics
11 pages, 4 figures
Eur.Phys.J. C78 (2018) no.12, 993
10.1140/epjc/s10052-018-6480-y
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct modified cosmological scenarios through the application of the first law of thermodynamics in the universe horizon, but using the generalized, nonextensive Tsallis entropy instead of the usual Bekenstein-Hawking one. We result to modified cosmological equations that possess the usual ones as a particular...
[ { "created": "Tue, 12 Jun 2018 15:45:17 GMT", "version": "v1" }, { "created": "Thu, 6 Dec 2018 08:51:04 GMT", "version": "v2" } ]
2018-12-07
[ [ "Lymperis", "Andreas", "" ], [ "Saridakis", "Emmanuel N.", "" ] ]
We construct modified cosmological scenarios through the application of the first law of thermodynamics in the universe horizon, but using the generalized, nonextensive Tsallis entropy instead of the usual Bekenstein-Hawking one. We result to modified cosmological equations that possess the usual ones as a particular l...
1907.12049
Qiming Fu
Qi-Ming Fu, Hao Yu, Li Zhao, and Yu-Xiao Liu
Thick brane in reduced Horndeski theory
null
Phys. Rev. D 100, 124057 (2019)
10.1103/PhysRevD.100.124057
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Horndeski theory is the most general scalar-tensor theory retaining second-order field equations, although the action includes higher-order terms. This is achieved by a special choice of coupling constants. In this paper, we investigate thick brane system in reduced Horndeski theory, especially the effect of the non-...
[ { "created": "Sun, 28 Jul 2019 09:06:19 GMT", "version": "v1" } ]
2020-01-01
[ [ "Fu", "Qi-Ming", "" ], [ "Yu", "Hao", "" ], [ "Zhao", "Li", "" ], [ "Liu", "Yu-Xiao", "" ] ]
Horndeski theory is the most general scalar-tensor theory retaining second-order field equations, although the action includes higher-order terms. This is achieved by a special choice of coupling constants. In this paper, we investigate thick brane system in reduced Horndeski theory, especially the effect of the non-mi...
gr-qc/9706074
Roberto Casadio
Roberto Casadio, Fabio Finelli and Giovanni Venturi (Dipartimento di Fisica, Universita' di Bologna and INFN, Bologna)
Adiabatic Invariant Treatment of a Collapsing Sphere of Quantized Dust
LaTeX, 16 pages, no figures, final version to appear in Class. and Quantum Gravity
Class.Quant.Grav. 15 (1998) 2451-2464
10.1088/0264-9381/15/8/021
null
gr-qc hep-th
null
The semiclassical collapse of a sphere of quantized dust is studied. A Born-Oppenheimer decomposition is performed for the wave function of the system and the semiclassical limit is considered for the gravitational part. The method of adiabatic invariants for time dependent Hamiltonians is then employed to find (appr...
[ { "created": "Tue, 24 Jun 1997 10:10:32 GMT", "version": "v1" }, { "created": "Tue, 19 May 1998 10:50:20 GMT", "version": "v2" } ]
2009-10-30
[ [ "Casadio", "Roberto", "", "Dipartimento di\n Fisica, Universita' di Bologna and INFN, Bologna" ], [ "Finelli", "Fabio", "", "Dipartimento di\n Fisica, Universita' di Bologna and INFN, Bologna" ], [ "Venturi", "Giovanni", "", "Dipartimento di\n Fisica, Uni...
The semiclassical collapse of a sphere of quantized dust is studied. A Born-Oppenheimer decomposition is performed for the wave function of the system and the semiclassical limit is considered for the gravitational part. The method of adiabatic invariants for time dependent Hamiltonians is then employed to find (approx...
gr-qc/0202023
Remo Garattini
Remo Garattini
Can Reissner-Nordstr\"{o}m wormholes be considered for Spacetime Foam formation?
18 pages. RevTeX with package epsf and four eps figures. Submitted to International Journal of Theoretical Physics, Group Theory and Nonlinear Optics
Int.J.Theor.Phys.9:129,2002
null
null
gr-qc hep-th
null
A simple model of spacetime foam, made by $N$ Reissner-Nordstr\"{o}m wormholes with a magnetic and electric charge in a semiclassical approximation, is taken under examination. The Casimir-like energy of the quantum fluctuation of such a model is computed and compared with that one obtained with a foamy space modeled...
[ { "created": "Thu, 7 Feb 2002 11:56:49 GMT", "version": "v1" } ]
2014-11-17
[ [ "Garattini", "Remo", "" ] ]
A simple model of spacetime foam, made by $N$ Reissner-Nordstr\"{o}m wormholes with a magnetic and electric charge in a semiclassical approximation, is taken under examination. The Casimir-like energy of the quantum fluctuation of such a model is computed and compared with that one obtained with a foamy space modeled b...
0909.0459
Jorge Pullin
Rodolfo Gambini, Jorge Pullin and Saeed Rastgoo
New variables for 1+1 dimensional gravity
8 pages, no figures, added references, corrected some misleading statements
Class.Quant.Grav.27:025002,2010
10.1088/0264-9381/27/2/025002
LSU-REL-090209
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the canonical formulation of a generic action for 1+1-dimensional models of gravity coupled to matter admits a description in terms of Ashtekar-type variables. This includes the CGHS model and spherically symmetric reductions of 3+1 gravity as particular cases. This opens the possibility of discussing mo...
[ { "created": "Wed, 2 Sep 2009 15:37:11 GMT", "version": "v1" }, { "created": "Fri, 4 Sep 2009 15:44:06 GMT", "version": "v2" } ]
2010-03-25
[ [ "Gambini", "Rodolfo", "" ], [ "Pullin", "Jorge", "" ], [ "Rastgoo", "Saeed", "" ] ]
We show that the canonical formulation of a generic action for 1+1-dimensional models of gravity coupled to matter admits a description in terms of Ashtekar-type variables. This includes the CGHS model and spherically symmetric reductions of 3+1 gravity as particular cases. This opens the possibility of discussing mode...