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2208.02557
Leonardo Modesto
Tian Zhou, Leonardo Modesto
Geodesic incompleteness of some popular regular black holes
New version widely extended in accordance with the correct and stimulating suggestions of the referee. This version is conform to the one published on PRD. 8 pages, 9 figures
null
10.1103/PhysRevD.107.044016
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Throughout the study of the geodesics of some popular spherically symmetric regular black holes, we hereby prove that the analytically extended Hayward black hole is geodetically incomplete. The simplest extension of the Culetu-Simpson-Visser's non-analytic smooth black hole is also geodetically incomplete, with the ...
[ { "created": "Thu, 4 Aug 2022 09:56:42 GMT", "version": "v1" }, { "created": "Thu, 23 Mar 2023 09:09:43 GMT", "version": "v2" } ]
2023-03-24
[ [ "Zhou", "Tian", "" ], [ "Modesto", "Leonardo", "" ] ]
Throughout the study of the geodesics of some popular spherically symmetric regular black holes, we hereby prove that the analytically extended Hayward black hole is geodetically incomplete. The simplest extension of the Culetu-Simpson-Visser's non-analytic smooth black hole is also geodetically incomplete, with the ex...
1408.1444
Gabor Kunstatter
Tim Taves, Gabor Kunstatter
Modelling the Evaporation of Non-singular Black Holes
14 pages, 0 figures, references and acknowledgements added, final version to appear in PRD
PhysRevD.90.124062, 2014
10.1103/PhysRevD.90.124062
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a model for studying the formation and evaporation of non-singular (quantum corrected) black holes. The model is based on a generalized form of the dimensionally reduced, spherically symmetric Einstein--Hilbert action and includes a suitably generalized Polyakov action to provide a mechanism for radiation ...
[ { "created": "Thu, 7 Aug 2014 00:23:31 GMT", "version": "v1" }, { "created": "Sun, 17 Aug 2014 12:44:13 GMT", "version": "v2" }, { "created": "Sun, 11 Jan 2015 17:14:42 GMT", "version": "v3" } ]
2015-06-22
[ [ "Taves", "Tim", "" ], [ "Kunstatter", "Gabor", "" ] ]
We present a model for studying the formation and evaporation of non-singular (quantum corrected) black holes. The model is based on a generalized form of the dimensionally reduced, spherically symmetric Einstein--Hilbert action and includes a suitably generalized Polyakov action to provide a mechanism for radiation ba...
1807.00812
Ayan Banerjee
Sudan Hansraj and Ayan Banerjee
Equilibrium stellar configurations in Rastall theory and linear equation of state
9 pages and 2 figures
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Amongst a number of modified theories of gravity, the Rastall theory has been propounded to address some shortcomings of the standard theory of general relativity. Our purpose is to investigate this framework's capacity to analyse stellar structure in the context of elementary requirements for physical plausibility s...
[ { "created": "Sun, 1 Jul 2018 16:11:37 GMT", "version": "v1" } ]
2018-07-04
[ [ "Hansraj", "Sudan", "" ], [ "Banerjee", "Ayan", "" ] ]
Amongst a number of modified theories of gravity, the Rastall theory has been propounded to address some shortcomings of the standard theory of general relativity. Our purpose is to investigate this framework's capacity to analyse stellar structure in the context of elementary requirements for physical plausibility suc...
1803.02779
Celia Escamilla-Rivera
Celia Escamilla-Rivera
Fluctuations of gravitational waves in Eddington inspired Born-Infeld theory
6 pages, 5 figures, under review
Revista Digital Congreso Mesoamericano de Investigacion UNACH 2018. ISSN 2395-8111
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we review the EiBI gravity in the presence of a cosmological constant and its tensor perturbations analysis. We show the existence of gravitational waves in the past-time, seeing as a result the smooth transition between high-energy densities (where the EBI dynamics plays its role) and low-energy densit...
[ { "created": "Wed, 7 Mar 2018 17:26:12 GMT", "version": "v1" } ]
2019-01-23
[ [ "Escamilla-Rivera", "Celia", "" ] ]
In this paper we review the EiBI gravity in the presence of a cosmological constant and its tensor perturbations analysis. We show the existence of gravitational waves in the past-time, seeing as a result the smooth transition between high-energy densities (where the EBI dynamics plays its role) and low-energy densitie...
1907.01580
Vincent Deledicque
Vincent Deledicque
Dark energy explained by an inadequate fitting of the FLRW metric
12 pages, 1 figure
null
null
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Approximating a real manifold by an idealized one requires to calibrate the parameters characterizing the idealized manifold in function of the real one. This calibration is a purely conventional process and can generally be done in several ways, leading to different fittings. In practice, however, all possible fitti...
[ { "created": "Tue, 2 Jul 2019 18:30:58 GMT", "version": "v1" }, { "created": "Thu, 2 Apr 2020 18:44:34 GMT", "version": "v2" } ]
2020-04-06
[ [ "Deledicque", "Vincent", "" ] ]
Approximating a real manifold by an idealized one requires to calibrate the parameters characterizing the idealized manifold in function of the real one. This calibration is a purely conventional process and can generally be done in several ways, leading to different fittings. In practice, however, all possible fitting...
1702.00983
Luis Herrera
L. Herrera, A. Di Prisco, J. Ospino
The transition of a gravitationally radiating, dissipative fluid, to equilibrium
7 pages, latex. arXiv admin note: substantial text overlap with arXiv:1609.02841. Some typos corrected. Published in Canadian Journal of Physics
Can. J. Phys. 96, 1010-1015 (2018)
10.1139/cjp-2017-0651
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe the transition of a graviationally radiating, axially and reflection symmetric dissipative fluid, to a non--radiating state. It is shown that very shortly after the end of the radiating regime, at a time scale of the order the thermal relaxation time, the thermal adjustment time and the hydrostatic time (...
[ { "created": "Fri, 3 Feb 2017 12:14:55 GMT", "version": "v1" }, { "created": "Fri, 31 Aug 2018 14:23:30 GMT", "version": "v2" } ]
2018-10-17
[ [ "Herrera", "L.", "" ], [ "Di Prisco", "A.", "" ], [ "Ospino", "J.", "" ] ]
We describe the transition of a graviationally radiating, axially and reflection symmetric dissipative fluid, to a non--radiating state. It is shown that very shortly after the end of the radiating regime, at a time scale of the order the thermal relaxation time, the thermal adjustment time and the hydrostatic time (wh...
1402.0101
Maurizio Gasperini
M. Gasperini
String theory and primordial cosmology
17 pages, 5 figures, published in "Springer Handbook of Spacetime", ed. by A. Ashtekar and V. Petkov (Springer-Verlag, Berlin Heidelberg, 2014, Chapter 35
null
10.1007/978-3-642-41992-8_35
BA-TH/685-14
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
String cosmology aims at providing a reliable description of the very early Universe in the regime where standard-model physics is no longer appropriate, and where we can safely apply the basic ingredients of superstring models such as dilatonic and axionic forces, duality symmetries, winding modes, limiting sizes an...
[ { "created": "Sat, 1 Feb 2014 16:48:51 GMT", "version": "v1" }, { "created": "Wed, 23 Apr 2014 12:16:37 GMT", "version": "v2" } ]
2014-04-24
[ [ "Gasperini", "M.", "" ] ]
String cosmology aims at providing a reliable description of the very early Universe in the regime where standard-model physics is no longer appropriate, and where we can safely apply the basic ingredients of superstring models such as dilatonic and axionic forces, duality symmetries, winding modes, limiting sizes and ...
0708.4299
Marcello Ortaggio
Marcello Ortaggio, Jiri Podolsky, Martin Zofka
Robinson-Trautman spacetimes with an electromagnetic field in higher dimensions
17 pages
Class.Quant.Grav.25:025006,2008
10.1088/0264-9381/25/2/025006
null
gr-qc hep-th
null
We investigate higher dimensional Robinson-Trautman spacetimes with an electromagnetic field aligned with the hypersurface orthogonal, non-shearing, expanding geodesic null congruence. After integrating the system of Einstein-Maxwell equations with an arbitrary cosmological constant, we present the complete family of...
[ { "created": "Fri, 31 Aug 2007 08:48:20 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ortaggio", "Marcello", "" ], [ "Podolsky", "Jiri", "" ], [ "Zofka", "Martin", "" ] ]
We investigate higher dimensional Robinson-Trautman spacetimes with an electromagnetic field aligned with the hypersurface orthogonal, non-shearing, expanding geodesic null congruence. After integrating the system of Einstein-Maxwell equations with an arbitrary cosmological constant, we present the complete family of s...
gr-qc/0312023
Tran
Rajat K. Bhaduri, Muoi N. Tran, Saurya Das
On the Microcanonical Entropy of a Black Hole
15 pages, 1 figure
Phys.Rev. D69 (2004) 104018
10.1103/PhysRevD.69.104018
null
gr-qc cond-mat.stat-mech hep-th
null
It has been suggested recently that the microcanonical entropy of a system may be accurately reproduced by including a logarithmic correction to the canonical entropy. In this paper we test this claim both analytically and numerically by considering three simple thermodynamic models whose energy spectrum may be defin...
[ { "created": "Wed, 3 Dec 2003 19:13:14 GMT", "version": "v1" } ]
2009-11-10
[ [ "Bhaduri", "Rajat K.", "" ], [ "Tran", "Muoi N.", "" ], [ "Das", "Saurya", "" ] ]
It has been suggested recently that the microcanonical entropy of a system may be accurately reproduced by including a logarithmic correction to the canonical entropy. In this paper we test this claim both analytically and numerically by considering three simple thermodynamic models whose energy spectrum may be defined...
gr-qc/0703058
Jian-Yang Zhu
Cheng-Zhou Liu, Jian-Yang Zhu
Asymptotic quasinormal modes of scalar field in a gravity's rainbow
null
Chin.Phys.B18:4161-4168,2009
10.1088/1674-1056/18/10/015
null
gr-qc
null
In the context of a gravity's rainbow, the asymptotic quasinormal modes of the scalar perturbation in the quantum modified Schwarzschild black holes are investigated. By using the monodromy method, we calculated and obtained the asymptotic quasinormal frequencies, which are dominated not only by the mass parameter of...
[ { "created": "Thu, 8 Mar 2007 13:39:42 GMT", "version": "v1" } ]
2010-11-02
[ [ "Liu", "Cheng-Zhou", "" ], [ "Zhu", "Jian-Yang", "" ] ]
In the context of a gravity's rainbow, the asymptotic quasinormal modes of the scalar perturbation in the quantum modified Schwarzschild black holes are investigated. By using the monodromy method, we calculated and obtained the asymptotic quasinormal frequencies, which are dominated not only by the mass parameter of t...
0911.4180
Hanno Sahlmann
Hanno Sahlmann
Wave propagation on a random lattice
13 pages, 3 figures. v3: Some minor changes and clarifications. Virtually identical with the version published in Physical Review D
Phys.Rev.D82:064018,2010
10.1103/PhysRevD.82.064018
KA-TP-18-2009
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by phenomenological questions in quantum gravity, we consider the propagation of a scalar field on a random lattice. We describe a procedure to calculate the dispersion relation for the field by taking a limit of a periodic lattice. We use this to calculate the lowest order coefficients of the dispersion re...
[ { "created": "Mon, 23 Nov 2009 13:37:35 GMT", "version": "v1" }, { "created": "Tue, 29 Dec 2009 19:55:37 GMT", "version": "v2" }, { "created": "Wed, 15 Sep 2010 14:56:46 GMT", "version": "v3" } ]
2014-11-20
[ [ "Sahlmann", "Hanno", "" ] ]
Motivated by phenomenological questions in quantum gravity, we consider the propagation of a scalar field on a random lattice. We describe a procedure to calculate the dispersion relation for the field by taking a limit of a periodic lattice. We use this to calculate the lowest order coefficients of the dispersion rela...
gr-qc/0105027
Ibrahim Arbab Arbab
Arbab I. Arbab
Cosmological Models With Variable G an Lambda and Bulk viscosity
Ph.D. Thesis(University of Khartoum)
Hadronic Journal Vol. 34, 1 (2011)
null
null
gr-qc
null
We have analyzed a nonsingular model with a variable cosmological term following the Carvalho {\it et al}. ansatz. The model was shown to approximate to the model of Freese {\it et al}. in one direction and to the \"{O}zer-Taha in the other. We have then included the effect of viscosity in this cosmology, as this eff...
[ { "created": "Tue, 8 May 2001 09:54:28 GMT", "version": "v1" } ]
2017-06-15
[ [ "Arbab", "Arbab I.", "" ] ]
We have analyzed a nonsingular model with a variable cosmological term following the Carvalho {\it et al}. ansatz. The model was shown to approximate to the model of Freese {\it et al}. in one direction and to the \"{O}zer-Taha in the other. We have then included the effect of viscosity in this cosmology, as this effec...
gr-qc/9907026
null
Pedro F. Gonzalez-Diaz (IMAFF, CSIC, Madrid)
On the warp drive space-time
7 pages, minor comment on chronology protection added, RevTex, to appear in Phys. Rev. D
Phys.Rev. D62 (2000) 044005
10.1103/PhysRevD.62.044005
IMAFF-RCA-99-04
gr-qc
null
In this paper the problem of the quantum stability of the two-dimensional warp drive spacetime moving with an apparent faster than light velocity is considered. We regard as a maximum extension beyond the event horizon of that spacetime its embedding in a three-dimensional Minkowskian space with the topology of the c...
[ { "created": "Wed, 7 Jul 1999 08:47:19 GMT", "version": "v1" }, { "created": "Mon, 10 Apr 2000 18:25:29 GMT", "version": "v2" } ]
2009-10-31
[ [ "Gonzalez-Diaz", "Pedro F.", "", "IMAFF, CSIC, Madrid" ] ]
In this paper the problem of the quantum stability of the two-dimensional warp drive spacetime moving with an apparent faster than light velocity is considered. We regard as a maximum extension beyond the event horizon of that spacetime its embedding in a three-dimensional Minkowskian space with the topology of the cor...
0805.0846
Llu\'is Bel
Ll. Bel
Connecting connections
17 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As true as it is that a bricklayer needs a plumb line and a T-square, so it is that a physicist using general relativity needs how to draw geodesics and use fields of congruent vector frames of reference. While the first part of the preceding statement depends on the Christoffel connection and related metric and curv...
[ { "created": "Wed, 7 May 2008 10:31:02 GMT", "version": "v1" }, { "created": "Tue, 10 Jun 2008 07:25:36 GMT", "version": "v2" } ]
2008-06-10
[ [ "Bel", "Ll.", "" ] ]
As true as it is that a bricklayer needs a plumb line and a T-square, so it is that a physicist using general relativity needs how to draw geodesics and use fields of congruent vector frames of reference. While the first part of the preceding statement depends on the Christoffel connection and related metric and curvat...
gr-qc/9803069
Raul Vera
Jos\'e M. M. Senovilla and Ra\"ul Vera
G_2 cosmological models separable in non-comoving coordinates
latex, 26 pages, accepted for publication in Class. Quantum Grav
Class.Quant.Grav. 15 (1998) 1737-1758
10.1088/0264-9381/15/6/022
null
gr-qc
null
We study new separable orthogonally transitive abelian G_2 on S_2 models with two mutually orthogonal integrable Killing vector fields. For this purpose we consider separability of the metric functions in a coordinate system in which the velocity vector field of the perfect fluid does not take its canonical form, pro...
[ { "created": "Thu, 19 Mar 1998 11:33:35 GMT", "version": "v1" } ]
2009-10-31
[ [ "Senovilla", "José M. M.", "" ], [ "Vera", "Raül", "" ] ]
We study new separable orthogonally transitive abelian G_2 on S_2 models with two mutually orthogonal integrable Killing vector fields. For this purpose we consider separability of the metric functions in a coordinate system in which the velocity vector field of the perfect fluid does not take its canonical form, provi...
1506.08496
Achilleas Porfyriadis
Samuel E. Gralla, Achilleas P. Porfyriadis, Niels Warburton
Particle on the Innermost Stable Circular Orbit of a Rapidly Spinning Black Hole
15 pages, 4 figures, v2: reference added, minor changes, matches published version
Phys. Rev. D 92, 064029 (2015)
10.1103/PhysRevD.92.064029
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the radiation emitted by a particle on the innermost stable circular orbit of a rapidly spinning black hole both (a) analytically, working to leading order in the deviation from extremality and (b) numerically, with a new high-precision Teukolsky code. We find excellent agreement between the two methods. W...
[ { "created": "Mon, 29 Jun 2015 03:13:41 GMT", "version": "v1" }, { "created": "Thu, 24 Sep 2015 03:46:10 GMT", "version": "v2" } ]
2015-09-30
[ [ "Gralla", "Samuel E.", "" ], [ "Porfyriadis", "Achilleas P.", "" ], [ "Warburton", "Niels", "" ] ]
We compute the radiation emitted by a particle on the innermost stable circular orbit of a rapidly spinning black hole both (a) analytically, working to leading order in the deviation from extremality and (b) numerically, with a new high-precision Teukolsky code. We find excellent agreement between the two methods. We ...
1612.06939
Zhi-Chao Zhao
Zhe Chang, Chao-Guang Huang, Zhi-Chao Zhao
Motion of photons in a background of gravitational wave
15 pages, 4 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The photon motion in a Michelson interferometer is re-analyzed in both geometrical optics and wave optics. The classical paths of the photons in the background of gravitational wave are derived from Fermat principle, which is the same as the null geodesics in general relativity. The deformed Maxwell equations and the...
[ { "created": "Wed, 21 Dec 2016 01:29:49 GMT", "version": "v1" } ]
2016-12-22
[ [ "Chang", "Zhe", "" ], [ "Huang", "Chao-Guang", "" ], [ "Zhao", "Zhi-Chao", "" ] ]
The photon motion in a Michelson interferometer is re-analyzed in both geometrical optics and wave optics. The classical paths of the photons in the background of gravitational wave are derived from Fermat principle, which is the same as the null geodesics in general relativity. The deformed Maxwell equations and the w...
gr-qc/0410141
Laurent Freidel
Laurent Freidel and David Louapre
Ponzano-Regge model revisited II: Equivalence with Chern-Simons
27 + 23 pages, many figures
null
null
null
gr-qc hep-th math.QA
null
We provide a mathematical definition of the gauge fixed Ponzano-Regge model showing that it gives a measure on the space of flat connections whose volume is well defined. We then show that the Ponzano-Regge model can be equivalently expressed as Reshetikhin-Turaev evaluation of a colored chain mail link based on D(SU...
[ { "created": "Thu, 28 Oct 2004 14:12:36 GMT", "version": "v1" }, { "created": "Fri, 11 Feb 2005 17:47:39 GMT", "version": "v2" }, { "created": "Mon, 14 Feb 2005 14:25:21 GMT", "version": "v3" } ]
2007-05-23
[ [ "Freidel", "Laurent", "" ], [ "Louapre", "David", "" ] ]
We provide a mathematical definition of the gauge fixed Ponzano-Regge model showing that it gives a measure on the space of flat connections whose volume is well defined. We then show that the Ponzano-Regge model can be equivalently expressed as Reshetikhin-Turaev evaluation of a colored chain mail link based on D(SU(2...
1810.07100
Jakub Mielczarek Ph.D.
Jakub Mielczarek
Spin Foam Vertex Amplitudes on Quantum Computer -- Preliminary Results
35 pages, 9 figures, improved discussion, additional simulations and 2 appendices added
null
null
null
gr-qc hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Vertex amplitudes are elementary contributions to the transition amplitudes in the spin foam models of quantum gravity. The purpose of this article is make the first step towards computing vertex amplitudes with the use of quantum algorithms. In our studies we are focused on a vertex amplitude of 3+1 D gravity, assoc...
[ { "created": "Tue, 16 Oct 2018 15:58:41 GMT", "version": "v1" }, { "created": "Tue, 18 Jun 2019 22:59:15 GMT", "version": "v2" } ]
2019-06-20
[ [ "Mielczarek", "Jakub", "" ] ]
Vertex amplitudes are elementary contributions to the transition amplitudes in the spin foam models of quantum gravity. The purpose of this article is make the first step towards computing vertex amplitudes with the use of quantum algorithms. In our studies we are focused on a vertex amplitude of 3+1 D gravity, associa...
0906.0436
Kamal Nandi
Kamal K. Nandi and Anwarul Islam
Brans wormholes
Uploaded for the use of researchers
Phys.Rev.D55:2497-2500,1997
10.1103/PhysRevD.55.2497
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that three of the four Brans solutions of classes I--IV admit wormhole geometry. Two-way traversable wormholes in the Brans-Dicke theory are allowed not only for the negative values of the coupling parameter w (w<-2), as concluded earlier, but also for arbitrary positive values of w (w<infinity). It also ...
[ { "created": "Tue, 2 Jun 2009 07:47:53 GMT", "version": "v1" } ]
2009-06-30
[ [ "Nandi", "Kamal K.", "" ], [ "Islam", "Anwarul", "" ] ]
It is shown that three of the four Brans solutions of classes I--IV admit wormhole geometry. Two-way traversable wormholes in the Brans-Dicke theory are allowed not only for the negative values of the coupling parameter w (w<-2), as concluded earlier, but also for arbitrary positive values of w (w<infinity). It also fo...
gr-qc/0310098
Sachiko Ogushi
Nathalie Deruelle, Joseph Katz, Sachiko Ogushi
Conserved Charges in Einstein Gauss-Bonnet theory
17 pages, LaTeX, references added, typos corrected, version to appear in Class. Quant. Grav
Class.Quant.Grav.21:1971,2004
10.1088/0264-9381/21/8/004
YITP-03-67
gr-qc hep-th
null
Using Noether's identities, we define a superpotential with respect to a background for the Einstein Gauss-Bonnet theory of gravity. As an example, we show that its associated conserved charge yields the mass-energy of a D-dimensional Gauss-Bonnet black hole in an anti-de Sitter spacetime.
[ { "created": "Mon, 20 Oct 2003 07:08:44 GMT", "version": "v1" }, { "created": "Mon, 23 Feb 2004 01:00:12 GMT", "version": "v2" } ]
2010-12-03
[ [ "Deruelle", "Nathalie", "" ], [ "Katz", "Joseph", "" ], [ "Ogushi", "Sachiko", "" ] ]
Using Noether's identities, we define a superpotential with respect to a background for the Einstein Gauss-Bonnet theory of gravity. As an example, we show that its associated conserved charge yields the mass-energy of a D-dimensional Gauss-Bonnet black hole in an anti-de Sitter spacetime.
gr-qc/0002021
Ulf Nilsson
U. S. Nilsson and C. Uggla
General Relativistic Stars: Linear Equations of State
17 pages, 3 figures, uses ajour.cls
Annals Phys. 286 (2001) 278-291
10.1006/aphy.2000.6089
null
gr-qc
null
In this paper Einstein's field equations, for static spherically symmetric perfect fluid models with a linear barotropic equation of state, are recast into a 3-dimensional regular system of ordinary differential equations on a compact state space. The system is analyzed qualitatively, using the theory of dynamical sy...
[ { "created": "Fri, 4 Feb 2000 12:24:09 GMT", "version": "v1" } ]
2009-10-31
[ [ "Nilsson", "U. S.", "" ], [ "Uggla", "C.", "" ] ]
In this paper Einstein's field equations, for static spherically symmetric perfect fluid models with a linear barotropic equation of state, are recast into a 3-dimensional regular system of ordinary differential equations on a compact state space. The system is analyzed qualitatively, using the theory of dynamical syst...
2406.02639
Moli Ghosh
Moli Ghosh, Prabir Rudra, Surajit Chattopadhyay
Warm Inflation with Barrow Holographic Dark Energy
15 pages, 8 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we study the warm inflation mechanism in the presence of the Barrow holographic dark energy model. Warm inflation differs from other forms of inflation primarily in that it makes the assumption that radiation and inflaton exist and interact throughout the inflationary process. After the warming process,...
[ { "created": "Tue, 4 Jun 2024 09:15:32 GMT", "version": "v1" } ]
2024-06-06
[ [ "Ghosh", "Moli", "" ], [ "Rudra", "Prabir", "" ], [ "Chattopadhyay", "Surajit", "" ] ]
In this work, we study the warm inflation mechanism in the presence of the Barrow holographic dark energy model. Warm inflation differs from other forms of inflation primarily in that it makes the assumption that radiation and inflaton exist and interact throughout the inflationary process. After the warming process, e...
1906.00485
Hector O. Silva
Hector O. Silva, Nicol\'as Yunes
More than the sum of its parts: combining parameterized tests of extreme gravity
(v1) 11 pages, 4 figures, 1 appendix; (v2) 12 pages, new appendix. Matches published version
Phys. Rev. D 100, 084034 (2019)
10.1103/PhysRevD.100.084034
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We connect two formalisms that describe deformations away from general relativity, one valid in the strong-field regime of neutrons stars and another valid in the radiative regime of gravitational waves: the post-Tolman-Oppenheimer-Volkoff and the parametrized-post-Einsteinian formalisms respectively. We find that po...
[ { "created": "Sun, 2 Jun 2019 21:03:46 GMT", "version": "v1" }, { "created": "Fri, 8 Nov 2019 03:22:05 GMT", "version": "v2" } ]
2019-11-11
[ [ "Silva", "Hector O.", "" ], [ "Yunes", "Nicolás", "" ] ]
We connect two formalisms that describe deformations away from general relativity, one valid in the strong-field regime of neutrons stars and another valid in the radiative regime of gravitational waves: the post-Tolman-Oppenheimer-Volkoff and the parametrized-post-Einsteinian formalisms respectively. We find that post...
gr-qc/9710076
Jacob D. Bekenstein
Jacob D. Bekenstein (Hebrew Universiy, Jerusalem)
Quantum Black Holes as Atoms
20 pages, latex, uses mprocl.sty. Plenary talk at VIII Marcel Grossmann Meeting on General Relativity, Jerusalem, June 1997. Added and corrected references
Prodeedings of the Eight Marcel Grossmann Meeting, T. Piran and R. Ruffini, eds. (World Scientific Singapore 1999), pp. 92-111
null
null
gr-qc astro-ph hep-th quant-ph
null
In some respects the black hole plays the same role in gravitation that the atom played in the nascent quantum mechanics. This analogy suggests that black hole mass $M$ might have a discrete spectrum. I review the physical arguments for the expectation that black hole horizon area eigenvalues are uniformly spaced, or...
[ { "created": "Wed, 15 Oct 1997 07:15:04 GMT", "version": "v1" }, { "created": "Tue, 10 Mar 1998 14:44:42 GMT", "version": "v2" } ]
2007-05-23
[ [ "Bekenstein", "Jacob D.", "", "Hebrew Universiy, Jerusalem" ] ]
In some respects the black hole plays the same role in gravitation that the atom played in the nascent quantum mechanics. This analogy suggests that black hole mass $M$ might have a discrete spectrum. I review the physical arguments for the expectation that black hole horizon area eigenvalues are uniformly spaced, or e...
1912.07630
Shahar Hod
Shahar Hod
Spontaneous scalarization of Gauss-Bonnet black holes: Analytic treatment in the linearized regime
6 pages
Physical Review D 100, 064039 (2019)
10.1103/PhysRevD.100.064039
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has recently been proved that nontrivial couplings between scalar fields and the Gauss-Bonnet invariant of a curved spacetime may allow a central black hole to support spatially regular scalar hairy configurations. Interestingly, former numerical studies of the intriguing black-hole spontaneous scalarization pheno...
[ { "created": "Mon, 16 Dec 2019 19:00:20 GMT", "version": "v1" } ]
2020-01-08
[ [ "Hod", "Shahar", "" ] ]
It has recently been proved that nontrivial couplings between scalar fields and the Gauss-Bonnet invariant of a curved spacetime may allow a central black hole to support spatially regular scalar hairy configurations. Interestingly, former numerical studies of the intriguing black-hole spontaneous scalarization phenome...
2301.06764
Subhajit Barman
Subhajit Barman, Bibhas Ranjan Majhi
Optimization of entanglement depends on whether a black hole is extremal
A modified version, to appear in General Relativity and Gravitation
null
null
null
gr-qc hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider two Unruh-DeWitt detectors interacting with a massless, minimally coupled scalar field in a $(1+1)$ dimensional Reissner-Nordstr\"om black hole spacetime. In particular, one of the detectors, corresponding to $Alice$, is moving along an outgoing null trajectory. While the other detector carried by $Bob$ i...
[ { "created": "Tue, 17 Jan 2023 08:59:12 GMT", "version": "v1" }, { "created": "Thu, 30 May 2024 12:51:01 GMT", "version": "v2" } ]
2024-05-31
[ [ "Barman", "Subhajit", "" ], [ "Majhi", "Bibhas Ranjan", "" ] ]
We consider two Unruh-DeWitt detectors interacting with a massless, minimally coupled scalar field in a $(1+1)$ dimensional Reissner-Nordstr\"om black hole spacetime. In particular, one of the detectors, corresponding to $Alice$, is moving along an outgoing null trajectory. While the other detector carried by $Bob$ is ...
gr-qc/0501003
Alena Pravdov\'a
V. Pravda, A. Pravdova
WANDs of the Black Ring
9 pages, 3 figures
Gen.Rel.Grav.37:1277-1287,2005
10.1007/s10714-005-0110-3
null
gr-qc hep-th
null
Necessary conditions for various algebraic types of the Weyl tensor are determined. These conditions are then used to find Weyl aligned null directions for the black ring solution. It is shown that the black ring solution is algebraically special, of type I_i, while locally on the horizon the type is II. One exceptio...
[ { "created": "Sat, 1 Jan 2005 22:56:18 GMT", "version": "v1" } ]
2008-11-26
[ [ "Pravda", "V.", "" ], [ "Pravdova", "A.", "" ] ]
Necessary conditions for various algebraic types of the Weyl tensor are determined. These conditions are then used to find Weyl aligned null directions for the black ring solution. It is shown that the black ring solution is algebraically special, of type I_i, while locally on the horizon the type is II. One exceptiona...
1705.02747
Woei Chet Lim
Daniele Gregoris, Woei Chet Lim, Alan Coley
Stiff fluid spike solutions from Bianchi type V seed solutions
24 pages. 11 figures. Matches accepted version
null
10.1088/1361-6382/aa924f
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we expand upon our previous work [1] by using the entire family of Bianchi type V stiff fluid solutions as seed solutions of the Stephani transformation. Among the new exact solutions generated, we observe a number of important physical phenomena. The most interesting phenomenon is exact solutions with ...
[ { "created": "Mon, 8 May 2017 05:29:43 GMT", "version": "v1" }, { "created": "Thu, 19 Oct 2017 04:20:06 GMT", "version": "v2" } ]
2017-12-06
[ [ "Gregoris", "Daniele", "" ], [ "Lim", "Woei Chet", "" ], [ "Coley", "Alan", "" ] ]
In this paper we expand upon our previous work [1] by using the entire family of Bianchi type V stiff fluid solutions as seed solutions of the Stephani transformation. Among the new exact solutions generated, we observe a number of important physical phenomena. The most interesting phenomenon is exact solutions with in...
2201.06521
Pardyumn Kumar Sahoo
Raja Solanki, Avik De, Sanjay Mandal, P.K. Sahoo
Accelerating expansion of the universe in modified symmetric teleparallel gravity
PDU revised version
Physics of the Dark Universe 36 (2022) 101053
10.1016/j.dark.2022.101053
null
gr-qc astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
The fundamental nature and origin of dark energy are one of the premier mysteries of theoretical physics. In General Relativity Theory, the cosmological constant $\Lambda$ is the simplest explanation for dark energy. On the other hand, the cosmological constant $\Lambda$ suffers from a delicate issue so-called fine-t...
[ { "created": "Mon, 17 Jan 2022 16:54:40 GMT", "version": "v1" }, { "created": "Wed, 9 Feb 2022 16:58:29 GMT", "version": "v2" }, { "created": "Mon, 21 Feb 2022 09:28:47 GMT", "version": "v3" }, { "created": "Thu, 12 May 2022 15:28:38 GMT", "version": "v4" } ]
2022-05-27
[ [ "Solanki", "Raja", "" ], [ "De", "Avik", "" ], [ "Mandal", "Sanjay", "" ], [ "Sahoo", "P. K.", "" ] ]
The fundamental nature and origin of dark energy are one of the premier mysteries of theoretical physics. In General Relativity Theory, the cosmological constant $\Lambda$ is the simplest explanation for dark energy. On the other hand, the cosmological constant $\Lambda$ suffers from a delicate issue so-called fine-tun...
0901.0590
Alfredo Sandoval-Villalbazo
A. Sandoval-Villalbazo, A. L. Garcia-Perciante and L.S. Garcia-Colin
The heat flux from a relativistic kinetic equation with a simplified collision kernel
4 pages, one figure. To appear in the AIP conference proceedings of the XXXI Spanish Relativity Meeting: Physics and Mathematics of Gravitation. Salamanca Spain, 15-19 September 2008
AIP Conf.Proc.1122:388-391,2009
10.1063/1.3141333
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show how using a special relativistic kinetic equation with a BGK- like collision operator the ensuing expression for the heat flux can be casted in the form required by Classical Irreversible Thermodynamics. Indeed, it is linearly related to the temperature and number density gradients and not to the acceleration...
[ { "created": "Tue, 6 Jan 2009 02:50:02 GMT", "version": "v1" } ]
2009-06-12
[ [ "Sandoval-Villalbazo", "A.", "" ], [ "Garcia-Perciante", "A. L.", "" ], [ "Garcia-Colin", "L. S.", "" ] ]
We show how using a special relativistic kinetic equation with a BGK- like collision operator the ensuing expression for the heat flux can be casted in the form required by Classical Irreversible Thermodynamics. Indeed, it is linearly related to the temperature and number density gradients and not to the acceleration a...
gr-qc/0703001
Lars Samuelsson
Max Karlovini and Lars Samuelsson
Elastic stars in general relativity: IV. Axial perturbations
18 pages, no figures
Class.Quant.Grav.24:3171-3190,2007
10.1088/0264-9381/24/13/003
null
gr-qc astro-ph
null
This is the fourth paper in a series that attempt to put forward a consistent framework for modelling solid regions in neutron stars. Here we turn our attention to axial perturbations of spherically symmetric spacetimes using a gauge invariant approach due to one of us. Using the formalism developed in the first pape...
[ { "created": "Wed, 28 Feb 2007 21:41:38 GMT", "version": "v1" } ]
2008-11-26
[ [ "Karlovini", "Max", "" ], [ "Samuelsson", "Lars", "" ] ]
This is the fourth paper in a series that attempt to put forward a consistent framework for modelling solid regions in neutron stars. Here we turn our attention to axial perturbations of spherically symmetric spacetimes using a gauge invariant approach due to one of us. Using the formalism developed in the first paper ...
1603.05987
Gandalf Lechner
Stefan Hollands and Gandalf Lechner
SO(d,1)-invariant Yang-Baxter operators and the dS/CFT correspondence
Minor changes in formulations and presentation. 48 pages
null
10.1007/s00220-017-2942-6
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a model for the dS/CFT correspondence. The model is constructed in terms of a "Yang-Baxter operator" $R$ for unitary representations of the deSitter group $SO(d,1)$. This $R$-operator is shown to satisfy the Yang-Baxter equation, unitarity, as well as certain analyticity relations, including in particular ...
[ { "created": "Fri, 18 Mar 2016 20:25:44 GMT", "version": "v1" }, { "created": "Tue, 30 May 2017 11:06:43 GMT", "version": "v2" } ]
2017-09-13
[ [ "Hollands", "Stefan", "" ], [ "Lechner", "Gandalf", "" ] ]
We propose a model for the dS/CFT correspondence. The model is constructed in terms of a "Yang-Baxter operator" $R$ for unitary representations of the deSitter group $SO(d,1)$. This $R$-operator is shown to satisfy the Yang-Baxter equation, unitarity, as well as certain analyticity relations, including in particular a ...
1506.07061
Jinn-Ouk Gong
Inyong Cho and Jinn-Ouk Gong
Spectral indices in Eddington-inspired Born-Infeld inflation
(v1) 9 pages, 1 figure; (v2) references added, to appear in Physical Review D
Phys. Rev. D 92, 064046 (2015)
10.1103/PhysRevD.92.064046
APCTP-Pre2015-013
gr-qc astro-ph.CO hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the scalar and tensor spectral indices of the quadratic inflation model in Eddington-inspired Born-Infeld (EiBI) gravity. We find that the EiBI corrections to the spectral indices are of second and first order in the slow-roll approximation for the scalar and tensor perturbations respectively. This is ...
[ { "created": "Tue, 23 Jun 2015 15:58:14 GMT", "version": "v1" }, { "created": "Mon, 21 Sep 2015 14:49:04 GMT", "version": "v2" } ]
2015-09-30
[ [ "Cho", "Inyong", "" ], [ "Gong", "Jinn-Ouk", "" ] ]
We investigate the scalar and tensor spectral indices of the quadratic inflation model in Eddington-inspired Born-Infeld (EiBI) gravity. We find that the EiBI corrections to the spectral indices are of second and first order in the slow-roll approximation for the scalar and tensor perturbations respectively. This is ve...
2405.03492
Hong-Bo Jin
Hong-Bo Jin, Cong-Feng Qiao
Gravitational Wave Polarization Detection with Pyramid Constellation of Gravitational Wave Observatory
12 pages, 5 figures
null
null
null
gr-qc astro-ph.IM
http://creativecommons.org/licenses/by/4.0/
For the first time, we have introduced the Pyramid Constellation of Gravitational Wave Observatory (PCGO) for GW polarization detection. The PCGO is composed of four identical spacecrafts (S/Cs). The laser telescopes and their pointing structures are mounted on the S/C platform and are evenly distributed at three loc...
[ { "created": "Mon, 6 May 2024 14:02:59 GMT", "version": "v1" }, { "created": "Wed, 8 May 2024 14:32:20 GMT", "version": "v2" } ]
2024-05-09
[ [ "Jin", "Hong-Bo", "" ], [ "Qiao", "Cong-Feng", "" ] ]
For the first time, we have introduced the Pyramid Constellation of Gravitational Wave Observatory (PCGO) for GW polarization detection. The PCGO is composed of four identical spacecrafts (S/Cs). The laser telescopes and their pointing structures are mounted on the S/C platform and are evenly distributed at three locat...
2210.05383
Marcos Vinicius de Sousa Silva
Manuel E. Rodrigues, Marcos V. de S. Silva
Embedding regular black holes and black bounces in a cloud of strings
14 pages, 2 figures, accepted for publication in PRD
null
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
A string is the one-dimensional generalization of a point particle. In this sense, the analog of a cloud of dust would be a cloud of strings. In this work, we consider a cloud of strings around a regular solution in general gelativity. We consider the Bardeen solution and the Simpson--Visser solution, analyzing the c...
[ { "created": "Sat, 8 Oct 2022 16:33:06 GMT", "version": "v1" } ]
2022-10-12
[ [ "Rodrigues", "Manuel E.", "" ], [ "Silva", "Marcos V. de S.", "" ] ]
A string is the one-dimensional generalization of a point particle. In this sense, the analog of a cloud of dust would be a cloud of strings. In this work, we consider a cloud of strings around a regular solution in general gelativity. We consider the Bardeen solution and the Simpson--Visser solution, analyzing the con...
2403.09576
Stuart Dowker
J.S.Dowker
On the high-temperature expansion of the thermal energy on Einstein cylinders
5 pages
null
null
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
Some exact high temperature expansions are derived using a temperature inversion symmetry of the internal energy for conformal scalars and spinors on the Einstein Universe.
[ { "created": "Thu, 14 Mar 2024 17:11:48 GMT", "version": "v1" } ]
2024-03-15
[ [ "Dowker", "J. S.", "" ] ]
Some exact high temperature expansions are derived using a temperature inversion symmetry of the internal energy for conformal scalars and spinors on the Einstein Universe.
1705.02496
Maxim Makukov
Eduard G. Mychelkin, Maxim A. Makukov
Coordinate effect: Vaidya solutions without integrating the field equations
Accepted in GRG
null
10.1007/s10714-020-02767-y
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend Vaidya's algorithm for the description of a central mass losing or gaining energy due to electromagnetic-type radiation (`null dust') to the case of arbitrary radial corpuscular radiation. We also demonstrate the remarkable possibility of purely algebraic deduction of the Vaidya solution without integrating...
[ { "created": "Sat, 6 May 2017 16:08:58 GMT", "version": "v1" }, { "created": "Wed, 18 Nov 2020 13:20:31 GMT", "version": "v2" } ]
2020-11-19
[ [ "Mychelkin", "Eduard G.", "" ], [ "Makukov", "Maxim A.", "" ] ]
We extend Vaidya's algorithm for the description of a central mass losing or gaining energy due to electromagnetic-type radiation (`null dust') to the case of arbitrary radial corpuscular radiation. We also demonstrate the remarkable possibility of purely algebraic deduction of the Vaidya solution without integrating t...
2107.14195
Arnab Dhani
Arnab Dhani and B. S. Sathyaprakash
Overtones, mirror modes, and mode-mixing in binary black hole mergers
null
null
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
Gravitational waves emitted in the aftermath of a black hole binary coalescence have characteristic complex frequencies called quasinormal modes (QNMs). These can be used to test the nature of the merger remnant, e.g. a test of the black hole "no-hair" theorem. The relative excitation amplitudes of the QNMs contain i...
[ { "created": "Thu, 29 Jul 2021 17:30:05 GMT", "version": "v1" }, { "created": "Fri, 6 Aug 2021 13:59:42 GMT", "version": "v2" } ]
2021-08-09
[ [ "Dhani", "Arnab", "" ], [ "Sathyaprakash", "B. S.", "" ] ]
Gravitational waves emitted in the aftermath of a black hole binary coalescence have characteristic complex frequencies called quasinormal modes (QNMs). These can be used to test the nature of the merger remnant, e.g. a test of the black hole "no-hair" theorem. The relative excitation amplitudes of the QNMs contain inf...
2103.01258
Antoine Folacci
Antoine Folacci and Aditya Tamar
Quasinormal mode frequencies of Kerr black holes from Regge trajectories
null
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A large portion of the studies concerning the quasinormal mode frequencies of a Kerr black hole have focused only on achieving higher numerical accuracy with limited emphasis on providing their physical interpretation. In this article, we partially address this issue by computing the quasinormal mode frequency spectr...
[ { "created": "Mon, 1 Mar 2021 19:11:12 GMT", "version": "v1" } ]
2021-03-03
[ [ "Folacci", "Antoine", "" ], [ "Tamar", "Aditya", "" ] ]
A large portion of the studies concerning the quasinormal mode frequencies of a Kerr black hole have focused only on achieving higher numerical accuracy with limited emphasis on providing their physical interpretation. In this article, we partially address this issue by computing the quasinormal mode frequency spectrum...
gr-qc/0310060
Albert V. Minkevich
A. V. Minkevich, A. S. Garkun, Yu. G. Vasilevski
Scalar fields superdense gravitating systems
7 pages, Latex2e, report at XII Annual International Seminar NPCS-2003, Minsk, 22--25 September, 2003
Nonlin.Phenom.Complex Syst. 7 (2004) 78-84
null
null
gr-qc
null
Solutions for scalar fields superdense gravitating systems of flat, open and closed type obtained in the frame of gauge theories of gravitation are discussed. Properties of these systems in dependence on parameter $\beta$ and initial conditions are analyzed.
[ { "created": "Fri, 10 Oct 2003 19:27:44 GMT", "version": "v1" } ]
2007-05-23
[ [ "Minkevich", "A. V.", "" ], [ "Garkun", "A. S.", "" ], [ "Vasilevski", "Yu. G.", "" ] ]
Solutions for scalar fields superdense gravitating systems of flat, open and closed type obtained in the frame of gauge theories of gravitation are discussed. Properties of these systems in dependence on parameter $\beta$ and initial conditions are analyzed.
1504.07022
Kirill Bronnikov
K.A. Bronnikov, O.B. Zaslavskii
Quasi-black holes: general features and purely field configurations
6 revtex 2-column pages
Mod. Phys. Lett. A 30, No. 30, 1550154 (2015)
10.1142/S0217732315501540
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Objects that are on the threshold of forming the horizon but never collapse are called quasi-black holes (QBHs). We discuss the properties of the general spherically symmetric QBH metric without addressing its material source, including its limiting cases as the corresponding small parameter tends to zero. We then sh...
[ { "created": "Mon, 27 Apr 2015 10:54:40 GMT", "version": "v1" } ]
2015-09-07
[ [ "Bronnikov", "K. A.", "" ], [ "Zaslavskii", "O. B.", "" ] ]
Objects that are on the threshold of forming the horizon but never collapse are called quasi-black holes (QBHs). We discuss the properties of the general spherically symmetric QBH metric without addressing its material source, including its limiting cases as the corresponding small parameter tends to zero. We then show...
2209.01574
Ruben Campos Delgado
Ruben Campos Delgado and Sergei V. Ketov
Schwarzschild-type black holes in Starobinsky-Bel-Robinson gravity
10 pages; v3: one more reference added, final version accepted for publication in Physics Letters B
Physics Letters B 838 (2023) 137690
10.1016/j.physletb.2023.137690
IPMU22-0059
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We study physical properties of a Schwarzschild-type black hole in the framework of the recently proposed Starobinsky-Bel-Robinson (SBR) modified theory of gravity, working perturbatively in the new coupling constant. In particular, we compute the temperature, entropy, pressure and lifetime of a Schwarzschild-type bl...
[ { "created": "Sun, 4 Sep 2022 09:06:52 GMT", "version": "v1" }, { "created": "Thu, 10 Nov 2022 11:04:24 GMT", "version": "v2" }, { "created": "Tue, 10 Jan 2023 11:33:32 GMT", "version": "v3" } ]
2023-01-24
[ [ "Delgado", "Ruben Campos", "" ], [ "Ketov", "Sergei V.", "" ] ]
We study physical properties of a Schwarzschild-type black hole in the framework of the recently proposed Starobinsky-Bel-Robinson (SBR) modified theory of gravity, working perturbatively in the new coupling constant. In particular, we compute the temperature, entropy, pressure and lifetime of a Schwarzschild-type blac...
2201.00035
Thanasis Karakasis
Thanasis Karakasis, Eleftherios Papantonopoulos, Zi-Yu Tang, Bin Wang
$(2+1)$-Dimensional Black Holes in $f(R,\phi)$ Gravity
Accepted for publication in PRD
Phys. Rev. D 105, 044038 (2022)
10.1103/PhysRevD.105.044038
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We consider a $f(R)$ gravity theory in $(2+1)$-dimensions with a self-interacting scalar field non-minimally coupled to gravity. Without specifying the form of the $f(R)$ function, solving the field equations we find that the Ricci scalar receives a non-linear correction term which breaks the conformal invariance and...
[ { "created": "Fri, 31 Dec 2021 19:29:37 GMT", "version": "v1" }, { "created": "Wed, 2 Feb 2022 16:29:25 GMT", "version": "v2" } ]
2022-02-18
[ [ "Karakasis", "Thanasis", "" ], [ "Papantonopoulos", "Eleftherios", "" ], [ "Tang", "Zi-Yu", "" ], [ "Wang", "Bin", "" ] ]
We consider a $f(R)$ gravity theory in $(2+1)$-dimensions with a self-interacting scalar field non-minimally coupled to gravity. Without specifying the form of the $f(R)$ function, solving the field equations we find that the Ricci scalar receives a non-linear correction term which breaks the conformal invariance and l...
gr-qc/0212001
Louapre
Laurent Freidel (ENS-Lyon, PI), David Louapre (ENS-Lyon)
Diffeomorphisms and spin foam models
19 pages
Nucl.Phys. B662 (2003) 279-298
10.1016/S0550-3213(03)00306-7
null
gr-qc hep-th
null
We study the action of diffeomorphisms on spin foam models. We prove that in 3 dimensions, there is a residual action of the diffeomorphisms that explains the naive divergences of state sum models. We present the gauge fixing of this symmetry and show that it explains the original renormalization of Ponzano-Regge mod...
[ { "created": "Fri, 29 Nov 2002 23:38:40 GMT", "version": "v1" }, { "created": "Wed, 29 Jan 2003 14:32:17 GMT", "version": "v2" } ]
2009-11-07
[ [ "Freidel", "Laurent", "", "ENS-Lyon, PI" ], [ "Louapre", "David", "", "ENS-Lyon" ] ]
We study the action of diffeomorphisms on spin foam models. We prove that in 3 dimensions, there is a residual action of the diffeomorphisms that explains the naive divergences of state sum models. We present the gauge fixing of this symmetry and show that it explains the original renormalization of Ponzano-Regge model...
gr-qc/0308063
Marcelo J. Reboucas
B. Mota, M.J. Reboucas, R. Tavakol
Constraints on the Detectability of Cosmic Topology from Observational Uncertainties
16 pages, 1 figure, LaTeX2e
Class.Quant.Grav. 20 (2003) 4837-4850
10.1088/0264-9381/20/22/008
null
gr-qc astro-ph hep-th
null
Recent observational results suggest that our universe is nearly flat and well modelled within a $\Lambda$CDM framework. The observed values of $\Omega_{m}$ and $\Omega_{\Lambda}$ inevitably involve uncertainties. Motivated by this, we make a systematic study of the necessary and sufficient conditions for undetectabi...
[ { "created": "Tue, 19 Aug 2003 23:39:39 GMT", "version": "v1" }, { "created": "Thu, 16 Oct 2003 01:57:38 GMT", "version": "v2" } ]
2009-11-10
[ [ "Mota", "B.", "" ], [ "Reboucas", "M. J.", "" ], [ "Tavakol", "R.", "" ] ]
Recent observational results suggest that our universe is nearly flat and well modelled within a $\Lambda$CDM framework. The observed values of $\Omega_{m}$ and $\Omega_{\Lambda}$ inevitably involve uncertainties. Motivated by this, we make a systematic study of the necessary and sufficient conditions for undetectabili...
1710.07267
Orr Sela
Assaf Lanir, Adam Levi, Amos Ori and Orr Sela
Two-point function of a quantum scalar field in the interior region of a Reissner-Nordstrom black hole
14 pages, 1 figure; Minor modifications; Accepted for publication in PRD
Phys. Rev. D 97, 024033 (2018)
10.1103/PhysRevD.97.024033
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive explicit expressions for the two-point function of a massless scalar field in the interior region of a Reissner-Nordstrom black hole, in both the Unruh and Hartle-Hawking quantum states. The two-point function is expressed in terms of the standard $lm\omega$ modes of the scalar field (those associated with ...
[ { "created": "Thu, 19 Oct 2017 17:51:35 GMT", "version": "v1" }, { "created": "Sun, 14 Jan 2018 12:42:50 GMT", "version": "v2" } ]
2018-01-25
[ [ "Lanir", "Assaf", "" ], [ "Levi", "Adam", "" ], [ "Ori", "Amos", "" ], [ "Sela", "Orr", "" ] ]
We derive explicit expressions for the two-point function of a massless scalar field in the interior region of a Reissner-Nordstrom black hole, in both the Unruh and Hartle-Hawking quantum states. The two-point function is expressed in terms of the standard $lm\omega$ modes of the scalar field (those associated with a ...
1802.03293
Ahmadjon Abdujabbarov
Bobur Turimov, Bobomurat Ahmedov, Ahmadjon Abdujabbarov, Cosimo Bambi
Gravitational lensing by magnetized compact object in the presence of plasma
21 pages, 8 figures
null
10.1142/S0218271820400131
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the gravitational lensing in the weak field approximation assuming the presence of a plasma and of a magnetic field around a compact gravitational source. The external magnetic field causes the split of the image, as the counterpart of the Zeeman effect. The magnetic field affects the magnification of images...
[ { "created": "Thu, 8 Feb 2018 10:36:22 GMT", "version": "v1" }, { "created": "Mon, 12 Feb 2018 08:13:45 GMT", "version": "v2" } ]
2020-02-19
[ [ "Turimov", "Bobur", "" ], [ "Ahmedov", "Bobomurat", "" ], [ "Abdujabbarov", "Ahmadjon", "" ], [ "Bambi", "Cosimo", "" ] ]
We study the gravitational lensing in the weak field approximation assuming the presence of a plasma and of a magnetic field around a compact gravitational source. The external magnetic field causes the split of the image, as the counterpart of the Zeeman effect. The magnetic field affects the magnification of images, ...
2106.04393
Robert John McLeod
Robert J. McLeod
A Brief Review Noether's Theorems and their Application to General Relativity
null
null
null
null
gr-qc
http://creativecommons.org/licenses/by-nc-sa/4.0/
In this article, we will review Noether's Theorems and their application in General Relativity. We will present Noether's Theorems in their original form and restate them as they are usually applied to physics. Some basic equations of Special Relativity will be reviewed and contrasted with the equations in General Re...
[ { "created": "Sun, 6 Jun 2021 00:49:26 GMT", "version": "v1" } ]
2021-06-09
[ [ "McLeod", "Robert J.", "" ] ]
In this article, we will review Noether's Theorems and their application in General Relativity. We will present Noether's Theorems in their original form and restate them as they are usually applied to physics. Some basic equations of Special Relativity will be reviewed and contrasted with the equations in General Rela...
1909.07852
Kenta Hioki
Kenta Hioki and Tomohiro Harada
Dynamical Transition from a Naked Singularity to a Black Hole
10 pages, 13 figures, accepted for publication in International Journal of Modern Physics A
null
10.1142/S0217751X20502012
RUP-19-25
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that a Reissner-Nordstr\"{o}m (RN) black hole can be formed by dropping a charged thin dust shell onto a RN naked singularity. This is in contrast to the fact that a RN naked singularity is prohibited from forming by dropping a charged thin dust shell onto a RN black hole. This implies the strong tendency of ...
[ { "created": "Tue, 17 Sep 2019 14:41:16 GMT", "version": "v1" }, { "created": "Tue, 10 Mar 2020 14:36:20 GMT", "version": "v2" }, { "created": "Mon, 17 Aug 2020 13:51:01 GMT", "version": "v3" }, { "created": "Sun, 8 Nov 2020 04:28:55 GMT", "version": "v4" } ]
2020-12-02
[ [ "Hioki", "Kenta", "" ], [ "Harada", "Tomohiro", "" ] ]
We show that a Reissner-Nordstr\"{o}m (RN) black hole can be formed by dropping a charged thin dust shell onto a RN naked singularity. This is in contrast to the fact that a RN naked singularity is prohibited from forming by dropping a charged thin dust shell onto a RN black hole. This implies the strong tendency of th...
2102.00972
Horst R. Beyer
Horst Reinhard Beyer, Miguel Alcubierre and Miguel Megevand
Stability study of a model for the Klein-Gordon equation in Kerr space-time II
33 pages, 4 figures
null
10.1016/S0034-4877(21)00059-8
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The present paper is a follow-up of our previous paper that derives a slightly simplified model equation for the Klein-Gordon equation, describing the propagation of a scalar field of mass $\mu$ in the background of a rotating black hole and, among others, supports the instability of the field down to $a/M \approx 0....
[ { "created": "Mon, 1 Feb 2021 16:55:21 GMT", "version": "v1" } ]
2021-09-15
[ [ "Beyer", "Horst Reinhard", "" ], [ "Alcubierre", "Miguel", "" ], [ "Megevand", "Miguel", "" ] ]
The present paper is a follow-up of our previous paper that derives a slightly simplified model equation for the Klein-Gordon equation, describing the propagation of a scalar field of mass $\mu$ in the background of a rotating black hole and, among others, supports the instability of the field down to $a/M \approx 0.97...
gr-qc/9804062
Jose Socorro Garcia Diaz
Jos\'e Socorro, Claus L\"ammerzahl, Alfredo Mac\'ias and Eckehard W. Mielke
Multipole solutions in metric--affine gravity
13 pages, Revtex, to appear in Phys. Lett. A
Phys.Lett. A244 (1998) 317-323
10.1016/S0375-9601(98)00360-0
IFUG-98-05
gr-qc
null
Above Planck energies, the spacetime might become non--Riemannian, as it is known fron string theory and inflation. Then geometries arise in which nonmetricity and torsion appear as field strengths, side by side with curvature. By gauging the affine group, a metric affine gauge theory emerges as dynamical framework. ...
[ { "created": "Thu, 23 Apr 1998 23:18:04 GMT", "version": "v1" } ]
2016-08-15
[ [ "Socorro", "José", "" ], [ "Lämmerzahl", "Claus", "" ], [ "Macías", "Alfredo", "" ], [ "Mielke", "Eckehard W.", "" ] ]
Above Planck energies, the spacetime might become non--Riemannian, as it is known fron string theory and inflation. Then geometries arise in which nonmetricity and torsion appear as field strengths, side by side with curvature. By gauging the affine group, a metric affine gauge theory emerges as dynamical framework. He...
2010.13558
Kyriakos Papadopoulos
Kyriakos Papadopoulos, Nazli Kurt
On Completeness of the Alexandrov Topology on a Spacetime: remarks and some corrections
null
null
10.1142/S0219887821501024
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We clarify and discuss a misunderstanding between uniform completeness and metric completeness, that has appeared in the literature in a study on the Alexandrov topology for a spacetime.
[ { "created": "Fri, 23 Oct 2020 05:49:56 GMT", "version": "v1" }, { "created": "Sat, 21 Nov 2020 12:31:11 GMT", "version": "v2" } ]
2021-06-30
[ [ "Papadopoulos", "Kyriakos", "" ], [ "Kurt", "Nazli", "" ] ]
We clarify and discuss a misunderstanding between uniform completeness and metric completeness, that has appeared in the literature in a study on the Alexandrov topology for a spacetime.
1808.01288
B\'eatrice Bonga
B\'eatrice Bonga and Eric Poisson
Coulombic contribution to the flux of angular momentum in general relativity
accepted for publication in PRD; major revision of previous version (conclusion altered); 10 pages + 6 pages as appendix
Phys. Rev. D 99, 064024 (2019)
10.1103/PhysRevD.99.064024
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The flux of angular momentum in electromagnetism cannot be expressed entirely in terms of the field's radiative degrees of freedom. Its expression also involves Coulombic pieces of the field, in the form of a charge aspect $q(\theta,\phi)$, a function of polar angles whose integral gives the total charge of the syste...
[ { "created": "Fri, 3 Aug 2018 18:00:29 GMT", "version": "v1" }, { "created": "Mon, 4 Mar 2019 14:16:15 GMT", "version": "v2" } ]
2019-03-27
[ [ "Bonga", "Béatrice", "" ], [ "Poisson", "Eric", "" ] ]
The flux of angular momentum in electromagnetism cannot be expressed entirely in terms of the field's radiative degrees of freedom. Its expression also involves Coulombic pieces of the field, in the form of a charge aspect $q(\theta,\phi)$, a function of polar angles whose integral gives the total charge of the system....
1302.5407
Muhammad Sharif
M. Sharif and Rabia Saleem
Dark Energy Models and Laws of Thermodynamics in Bianchi I Model
12 pages, 2 figures
Mod. Phys. Lett. A 27(2012)1250187
10.1142/S0217732312501878
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper is devoted to check validity of the laws of thermodynamics for LRS Bianchi type I universe model which is filled with combination of dark matter and dark energy. We take two types of dark energy models, i.e., generalized holographic dark energy and generalized Ricci dark energy. It is proved that the first...
[ { "created": "Wed, 20 Feb 2013 02:40:08 GMT", "version": "v1" } ]
2015-06-15
[ [ "Sharif", "M.", "" ], [ "Saleem", "Rabia", "" ] ]
This paper is devoted to check validity of the laws of thermodynamics for LRS Bianchi type I universe model which is filled with combination of dark matter and dark energy. We take two types of dark energy models, i.e., generalized holographic dark energy and generalized Ricci dark energy. It is proved that the first a...
gr-qc/0404009
Oleg Zaslavskii
O.B. Zaslavskii
Near-extremal and extremal quantum-corrected two-dimensional charged black holes
25 pages. Typos corrected. To appear in Class. Quant. Grav
Class.Quant.Grav. 21 (2004) 2687-2701
10.1088/0264-9381/21/11/012
ESI - 1479
gr-qc hep-th
null
We consider charged black holes within dilaton gravity with exponential-linear dependence of action coefficients on dilaton and minimal coupling to quantum scalar fields. This includes, in particular, CGHS and RST black holes in the uncharged limit. For non-extremal configuration quantum correction to the total mass,...
[ { "created": "Thu, 1 Apr 2004 16:52:12 GMT", "version": "v1" }, { "created": "Tue, 13 Apr 2004 19:27:19 GMT", "version": "v2" } ]
2009-11-10
[ [ "Zaslavskii", "O. B.", "" ] ]
We consider charged black holes within dilaton gravity with exponential-linear dependence of action coefficients on dilaton and minimal coupling to quantum scalar fields. This includes, in particular, CGHS and RST black holes in the uncharged limit. For non-extremal configuration quantum correction to the total mass, H...
gr-qc/0506094
Dilek Ciftci
M. Arik and D. Ciftci
Brane World Cosmology In Jordan-Brans-Dicke Theory
11 pages
Gen.Rel.Grav. 37 (2005) 2211-2221
10.1007/s10714-005-0201-1
null
gr-qc
null
We consider the embedding of 3+1 dimensional cosmology in 4+1 dimensional Jordan-Brans-Dicke theory. We show that exponentially growing and power law scale factors are implied. Whereas the 4+1 dimensional scalar field is approximately constant for each, the effective 3+1 dimensional scalar field is constant for expon...
[ { "created": "Fri, 17 Jun 2005 12:43:11 GMT", "version": "v1" } ]
2009-11-11
[ [ "Arik", "M.", "" ], [ "Ciftci", "D.", "" ] ]
We consider the embedding of 3+1 dimensional cosmology in 4+1 dimensional Jordan-Brans-Dicke theory. We show that exponentially growing and power law scale factors are implied. Whereas the 4+1 dimensional scalar field is approximately constant for each, the effective 3+1 dimensional scalar field is constant for exponen...
1106.2831
John Ward
Narit Pidokrajt, John Ward
Thermodynamic Geometry and Type 0A Black Holes
13 pages, 2 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this note we study thermodynamic geometry of the type 0A black hole solution in string theory using a variety of different methods (Ruppeiner, Weinhold and Geometrothermodynamics). Our results indicate that the curvature invariants are finite for all physical solutions, suggesting that there is no phase transition...
[ { "created": "Tue, 14 Jun 2011 22:04:11 GMT", "version": "v1" } ]
2011-06-16
[ [ "Pidokrajt", "Narit", "" ], [ "Ward", "John", "" ] ]
In this note we study thermodynamic geometry of the type 0A black hole solution in string theory using a variety of different methods (Ruppeiner, Weinhold and Geometrothermodynamics). Our results indicate that the curvature invariants are finite for all physical solutions, suggesting that there is no phase transition. ...
1901.00167
Supriya Pan
Jaume Haro, Jaume Amor\'os and Supriya Pan
The Peebles -- Vilenkin quintessential inflation model revisited
28 pages; 7 captioned figures; version published in The European Physical Journal C
Eur.Phys.J. C79 (2019) no.6, 505
10.1140/epjc/s10052-019-7012-0
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the well-known Peebles-Vilenkin (PV) quintessential inflation model and discuss its possible improvements in agreement with the recent observations. The improved PV model depends only on two parameters: the inflaton mass $m$, and another smaller mass $M$; where the latter has to be chosen in order to undert...
[ { "created": "Tue, 1 Jan 2019 15:34:12 GMT", "version": "v1" }, { "created": "Sun, 2 Jun 2019 19:06:58 GMT", "version": "v2" }, { "created": "Wed, 26 Jun 2019 16:23:30 GMT", "version": "v3" } ]
2019-06-27
[ [ "Haro", "Jaume", "" ], [ "Amorós", "Jaume", "" ], [ "Pan", "Supriya", "" ] ]
We review the well-known Peebles-Vilenkin (PV) quintessential inflation model and discuss its possible improvements in agreement with the recent observations. The improved PV model depends only on two parameters: the inflaton mass $m$, and another smaller mass $M$; where the latter has to be chosen in order to undertak...
2108.07210
Masoud Ghezelbash
Masoud Ghezelbash
Bianchi IX geometry and the Einstein-Maxwell theory
38 pages, 16 figures, new contents, figures and four appendices added, references added, to appear in classical and quantum gravity
Class. Quantum Grav. 39 (2022) 075012
10.1088/1361-6382/ac504e
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct numerical solutions to the higher-dimensional Einstein-Maxwell theory. The solutions are based on embedding the four dimensional Bianchi type IX space in the theory. We find the solutions as superposition of two functions, which one of them can be found numerically. We show that the solutions in any dime...
[ { "created": "Mon, 16 Aug 2021 16:37:53 GMT", "version": "v1" }, { "created": "Sun, 6 Feb 2022 18:05:04 GMT", "version": "v2" } ]
2022-04-14
[ [ "Ghezelbash", "Masoud", "" ] ]
We construct numerical solutions to the higher-dimensional Einstein-Maxwell theory. The solutions are based on embedding the four dimensional Bianchi type IX space in the theory. We find the solutions as superposition of two functions, which one of them can be found numerically. We show that the solutions in any dimens...
gr-qc/0202006
Harold Blas
A. Accioly, H. Blas and H. Mukai
Nonminimal coupling, equivalence principle and exact Foldy-Wouthuysen transformation
9 pages, LaTex
null
null
null
gr-qc
null
It is shown that the exact Foldy-Wouthuysen transformation for spin-0 particles on spacetimes described by the metrics $ds^2 = V^2 dt^2 - W^2 d {\bf{x}}^2$, where $V=V({\bf{x}})$ and $W=W({\bf{x}})$, only exists if the scalar field is nonminimally coupled to the Ricci scalar field with a coupling constant equal to 1/...
[ { "created": "Sat, 2 Feb 2002 18:48:44 GMT", "version": "v1" } ]
2007-05-23
[ [ "Accioly", "A.", "" ], [ "Blas", "H.", "" ], [ "Mukai", "H.", "" ] ]
It is shown that the exact Foldy-Wouthuysen transformation for spin-0 particles on spacetimes described by the metrics $ds^2 = V^2 dt^2 - W^2 d {\bf{x}}^2$, where $V=V({\bf{x}})$ and $W=W({\bf{x}})$, only exists if the scalar field is nonminimally coupled to the Ricci scalar field with a coupling constant equal to 1/6....
gr-qc/9408008
null
J. Schirmer
Hamiltonian reduction of Bianchi Cosmologies
14 pages, Latex, Freiburg preprint THEP 94/21
Class.Quant.Grav.12:1099-1110,1995
10.1088/0264-9381/12/4/017
null
gr-qc
null
It was noted recently that the ADM-diffeomorphism-constraint does not generate all observed symmetries for several Bianchi-models. We will suggest not to use the ADM-constraint restricted to homogeneous variables, but some equivalent which is derived from a restricted action principle. This will generate all homogene...
[ { "created": "Thu, 4 Aug 1994 22:00:31 GMT", "version": "v1" } ]
2010-04-06
[ [ "Schirmer", "J.", "" ] ]
It was noted recently that the ADM-diffeomorphism-constraint does not generate all observed symmetries for several Bianchi-models. We will suggest not to use the ADM-constraint restricted to homogeneous variables, but some equivalent which is derived from a restricted action principle. This will generate all homogeneit...
0711.1584
Mikhail V. Gorbatenko
Mikhail V.Gorbatenko
Conformal Geometrodynamics: Exact Nonstationary Spherically Symmetric Solutions
13 pages
null
null
null
gr-qc
null
A nonstationary spherically symmetric problem for conformal geometrodynamics equations is considered and general exact solutions in quadratures are obtained. Involvement of Weyl degrees of freedom allows us to consider the problem with arbitrary initial data, as for the conformal geometrodynamics equations the Cauchy...
[ { "created": "Sat, 10 Nov 2007 10:29:12 GMT", "version": "v1" } ]
2007-11-13
[ [ "Gorbatenko", "Mikhail V.", "" ] ]
A nonstationary spherically symmetric problem for conformal geometrodynamics equations is considered and general exact solutions in quadratures are obtained. Involvement of Weyl degrees of freedom allows us to consider the problem with arbitrary initial data, as for the conformal geometrodynamics equations the Cauchy p...
2310.17311
Suddhasattwa Brahma
Suddhasattwa Brahma and Abhinove Nagarajan Seenivasan
Gravity-induced entanglement as a probe of spacetime curvature
Honorable Mention in the 2023 Essay Competition of the Gravity Research Foundation; comments welcome
null
10.1142/S0218271823420208
null
gr-qc hep-th quant-ph
http://creativecommons.org/licenses/by/4.0/
It is now widely believed that if the gravitational field is (perturbatively) quantum, it would entangle two massive objects (in spatial superpositions) which were otherwise unentangled to begin with. Recently, actual table-top experiments have been proposed to test this idea in what would be the first detection of p...
[ { "created": "Thu, 26 Oct 2023 11:16:35 GMT", "version": "v1" } ]
2023-10-27
[ [ "Brahma", "Suddhasattwa", "" ], [ "Seenivasan", "Abhinove Nagarajan", "" ] ]
It is now widely believed that if the gravitational field is (perturbatively) quantum, it would entangle two massive objects (in spatial superpositions) which were otherwise unentangled to begin with. Recently, actual table-top experiments have been proposed to test this idea in what would be the first detection of per...
gr-qc/0608078
Roland Triay
Roland Triay (CPT), Henri-Hugues Fliche (LMMT)
Spherical Voids in Newton-Friedmann Universe
to appear
Proceedings of the Eleventh Marcel Grossmann Meeting on General Relativity, Allemagne (2007)
null
null
gr-qc astro-ph
null
We show that the cosmological constant favours significantly the growth of voids in the universe. This dynamical effect is investigated within a newtonian approach with an extension to Friedmann-Lema\^{\i}tre model.
[ { "created": "Wed, 16 Aug 2006 15:40:40 GMT", "version": "v1" } ]
2007-05-23
[ [ "Triay", "Roland", "", "CPT" ], [ "Fliche", "Henri-Hugues", "", "LMMT" ] ]
We show that the cosmological constant favours significantly the growth of voids in the universe. This dynamical effect is investigated within a newtonian approach with an extension to Friedmann-Lema\^{\i}tre model.
2206.13672
Matheus Filipe Santos Alves
Matheus F. S. Alves, Lu\'is F. M. A. M. Reis, L. G. Medeiros
Gravitational waves from inspiraling black holes in quadratic gravity
19 pages, 9 figures
Phys. Rev. D 107, 044017 (2023)
10.1103/PhysRevD.107.044017
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We peform a study of gravitational waves emitted by inspiraling black holes in the context of quadratic gravity. By linearizing the field equations around a flat background, we demonstrate that all degrees of freedom satisfy wave-like equations. These degrees of freedom split into three modes: a massive spin-$2$ mode...
[ { "created": "Tue, 28 Jun 2022 00:23:14 GMT", "version": "v1" }, { "created": "Thu, 9 Feb 2023 23:03:01 GMT", "version": "v2" } ]
2023-02-13
[ [ "Alves", "Matheus F. S.", "" ], [ "Reis", "Luís F. M. A. M.", "" ], [ "Medeiros", "L. G.", "" ] ]
We peform a study of gravitational waves emitted by inspiraling black holes in the context of quadratic gravity. By linearizing the field equations around a flat background, we demonstrate that all degrees of freedom satisfy wave-like equations. These degrees of freedom split into three modes: a massive spin-$2$ mode, ...
1202.5157
W{\l}odzimierz Natorf
W{\l}odzimierz Natorf
Asymptotic stability of vacuum type II metrics
some typos removed in v2
J. Math. Phys. 53, 022503 (2012);
10.1063/1.3682273
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We generalize the result of Lukacs {\it et al.} on asymptotic stability of the Schwarzschild metric with respect to perturbations in the Robinson-Trautman class of metrics to the case of Petrov type II twisting metrics, uder the condition of asymptotic flatness at future null infinity. The Bondi energy is used as the...
[ { "created": "Thu, 23 Feb 2012 12:22:32 GMT", "version": "v1" }, { "created": "Thu, 12 Apr 2012 10:27:45 GMT", "version": "v2" } ]
2012-04-13
[ [ "Natorf", "Włodzimierz", "" ] ]
We generalize the result of Lukacs {\it et al.} on asymptotic stability of the Schwarzschild metric with respect to perturbations in the Robinson-Trautman class of metrics to the case of Petrov type II twisting metrics, uder the condition of asymptotic flatness at future null infinity. The Bondi energy is used as the L...
2401.07662
Charis Anastopoulos
Charis Anastopoulos
Final States in Quantum Cosmology: Cosmic Acceleration as a Quantum Post-Selection Effect
33 pages, 5 figures. Greatly extended and restructured; it now contains a derivation of post-selected quasi-classical equations of motion for generic systems, and more examples
null
null
null
gr-qc astro-ph.CO quant-ph
http://creativecommons.org/licenses/by/4.0/
Standard quantum theory admits naturally statistical ensembles that are both pre-selected and post-selected, i.e., they involve both an initial and a final state. We argue that there is no compelling physical reason to preclude a probability assignment with a final quantum state at the cosmological level. We therefor...
[ { "created": "Mon, 15 Jan 2024 13:05:28 GMT", "version": "v1" }, { "created": "Sun, 28 Jul 2024 10:54:17 GMT", "version": "v2" } ]
2024-07-30
[ [ "Anastopoulos", "Charis", "" ] ]
Standard quantum theory admits naturally statistical ensembles that are both pre-selected and post-selected, i.e., they involve both an initial and a final state. We argue that there is no compelling physical reason to preclude a probability assignment with a final quantum state at the cosmological level. We therefore ...
1811.08852
Isaac Torres
Isaac Torres, J\'ulio C\'esar Fabris, and Oliver Fabio Piattella
Classical and quantum cosmology of Fab Four John theories
null
Physics Letters B 798 (2019) 135003
10.1016/j.physletb.2019.135003
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We present here a quantum cosmological model with Bohm-de Broglie interpretation of the theory described by a combination of two terms of the Fab Four cosmological theory. The first term is the John Lagrangian and the second is a potential representing matter content to avoid classical trivial solutions. This model h...
[ { "created": "Wed, 21 Nov 2018 17:57:06 GMT", "version": "v1" }, { "created": "Wed, 28 Nov 2018 22:03:33 GMT", "version": "v2" }, { "created": "Fri, 11 Oct 2019 21:34:53 GMT", "version": "v3" } ]
2019-10-15
[ [ "Torres", "Isaac", "" ], [ "Fabris", "Júlio César", "" ], [ "Piattella", "Oliver Fabio", "" ] ]
We present here a quantum cosmological model with Bohm-de Broglie interpretation of the theory described by a combination of two terms of the Fab Four cosmological theory. The first term is the John Lagrangian and the second is a potential representing matter content to avoid classical trivial solutions. This model has...
1606.07041
Pierre-Henri Chavanis
Pierre-Henri Chavanis and Tonatiuh Matos
Covariant theory of Bose-Einstein condensates in curved spacetimes with electromagnetic interactions: the hydrodynamic approach
null
Eur. Phys. J. Plus, 132, 30 (2017)
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a hydrodynamic representation of the Klein-Gordon-Maxwell-Einstein equations. These equations combine quantum mechanics, electromagnetism, and general relativity. We consider the case of an arbitrary curved spacetime, the case of weak gravitational fields in a static or expanding background, and the nonrel...
[ { "created": "Wed, 22 Jun 2016 18:56:54 GMT", "version": "v1" } ]
2017-11-27
[ [ "Chavanis", "Pierre-Henri", "" ], [ "Matos", "Tonatiuh", "" ] ]
We develop a hydrodynamic representation of the Klein-Gordon-Maxwell-Einstein equations. These equations combine quantum mechanics, electromagnetism, and general relativity. We consider the case of an arbitrary curved spacetime, the case of weak gravitational fields in a static or expanding background, and the nonrelat...
gr-qc/9805017
Fodor Gyula
G. Fodor, M. Marklund, and Z. Perj\'es
Axistationary perfect fluids -- a tetrad approach
12 pages
Class.Quant.Grav. 16 (1999) 453-463
10.1088/0264-9381/16/2/010
null
gr-qc
null
Stationary axisymmetric perfect fluid space-times are investigated using the curvature description of geometries. Attention is focused on space-times with a vanishing electric part of the Weyl tensor. It is shown that the only incompressible axistationary magnetic perfect fluid is the interior Schwarzschild solution....
[ { "created": "Wed, 6 May 1998 13:18:56 GMT", "version": "v1" } ]
2009-10-31
[ [ "Fodor", "G.", "" ], [ "Marklund", "M.", "" ], [ "Perjés", "Z.", "" ] ]
Stationary axisymmetric perfect fluid space-times are investigated using the curvature description of geometries. Attention is focused on space-times with a vanishing electric part of the Weyl tensor. It is shown that the only incompressible axistationary magnetic perfect fluid is the interior Schwarzschild solution. T...
2002.06059
Roger Hurtado PhD
Roger A. Hurtado and Jose R. Arenas
Spherically symmetric and static solutions in $f(R)$ gravity coupled with EM fields
14 pages, 2 figures
Phys. Rev. D 102, 104019 (2020)
10.1103/PhysRevD.102.104019
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Solutions of field equations in $f(R)$ gravity are found for a spherically symmetric and static spacetime in the Born-Infeld (BI) non-linear electrodynamics. It is found that the models supported in this configuration must have the parametric form $f'(R)|_{r}=m+n r$, with $m,n$ constants, whose value and sign have a ...
[ { "created": "Fri, 14 Feb 2020 14:46:39 GMT", "version": "v1" } ]
2020-11-18
[ [ "Hurtado", "Roger A.", "" ], [ "Arenas", "Jose R.", "" ] ]
Solutions of field equations in $f(R)$ gravity are found for a spherically symmetric and static spacetime in the Born-Infeld (BI) non-linear electrodynamics. It is found that the models supported in this configuration must have the parametric form $f'(R)|_{r}=m+n r$, with $m,n$ constants, whose value and sign have a st...
1707.02216
Yi-Shi Duan
Yi-Shi Duan
Generalized Nonsingular Solutions for the Scalar Meson Field of a Point Charge in General Relativity Theory
2 pages
Soviet Physics JETP Vol 31, 1098-1099 (1956)
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been shown that in investigating the electromagnetic and meson fields of elementary particles, the effects of gravitational interaction cannot be neglected. The present note is an attempt to find solutions to the equations of the general relativistic gravitational and scalar meson fields of a point nuclear cha...
[ { "created": "Wed, 24 May 2017 03:39:38 GMT", "version": "v1" } ]
2017-07-10
[ [ "Duan", "Yi-Shi", "" ] ]
It has been shown that in investigating the electromagnetic and meson fields of elementary particles, the effects of gravitational interaction cannot be neglected. The present note is an attempt to find solutions to the equations of the general relativistic gravitational and scalar meson fields of a point nuclear charg...
gr-qc/9906070
Piotr Bizon
P. Bizo\'n and T. Chmaj
Remark on formation of colored black holes via fine tuning
2 pages, RevTex, 2 postscript figures
Phys.Rev. D61 (2000) 067501
10.1103/PhysRevD.61.067501
null
gr-qc
null
In a recent paper (gr-qc/9903081) Choptuik, Hirschmann, and Marsa have discovered the scaling law for the lifetime of an intermediate attractor in the formation of n=1 colored black holes via fine tuning. We show that their result is in agreement with the prediction of linear perturbation analysis. We also briefly co...
[ { "created": "Thu, 17 Jun 1999 06:26:58 GMT", "version": "v1" } ]
2009-10-31
[ [ "Bizoń", "P.", "" ], [ "Chmaj", "T.", "" ] ]
In a recent paper (gr-qc/9903081) Choptuik, Hirschmann, and Marsa have discovered the scaling law for the lifetime of an intermediate attractor in the formation of n=1 colored black holes via fine tuning. We show that their result is in agreement with the prediction of linear perturbation analysis. We also briefly comm...
gr-qc/0103044
John Baez
John C. Baez and Emory F. Bunn
The Meaning of Einstein's Equation
23 pages LaTeX, 8 encapsulated Postscript figures; unlike the published version this includes a derivation of the inverse-square force law
Amer. Jour. Phys. 73 (2005), 644-652
10.1119/1.1852541
null
gr-qc astro-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is a brief introduction to general relativity, designed for both students and teachers of the subject. While there are many excellent expositions of general relativity, few adequately explain the geometrical meaning of the basic equation of the theory: Einstein's equation. Here we give a simple formulation of th...
[ { "created": "Tue, 13 Mar 2001 22:38:05 GMT", "version": "v1" }, { "created": "Fri, 6 Apr 2001 01:30:30 GMT", "version": "v2" }, { "created": "Wed, 18 Aug 2004 17:39:22 GMT", "version": "v3" }, { "created": "Thu, 5 Jan 2006 18:23:17 GMT", "version": "v4" }, { "cre...
2015-06-15
[ [ "Baez", "John C.", "" ], [ "Bunn", "Emory F.", "" ] ]
This is a brief introduction to general relativity, designed for both students and teachers of the subject. While there are many excellent expositions of general relativity, few adequately explain the geometrical meaning of the basic equation of the theory: Einstein's equation. Here we give a simple formulation of this...
gr-qc/0306061
Miguel Gustavo de Campos Batista
M. de Campos
Adiabatic decaying vacuum model for the universe
10 pages, 2 figures
Gen.Rel.Grav.35:899-906,2003
10.1023/A:1022907506957
null
gr-qc
null
We study a model that the entropy per particle in the universe is constant. The sources for the entropy are the particle creation and a lambda decaying term. We find exact solutions for the Einstein field equations and show the compatibilty of the model with respect to the age and the acceleration of the universe.
[ { "created": "Sun, 15 Jun 2003 20:53:50 GMT", "version": "v1" }, { "created": "Tue, 17 Jun 2003 22:22:50 GMT", "version": "v2" } ]
2009-04-17
[ [ "de Campos", "M.", "" ] ]
We study a model that the entropy per particle in the universe is constant. The sources for the entropy are the particle creation and a lambda decaying term. We find exact solutions for the Einstein field equations and show the compatibilty of the model with respect to the age and the acceleration of the universe.
1712.04834
Giorgio Papini
Giorgio Papini
Spin and maximal acceleration
8 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the spin current tensor of a Dirac particle at accelerations close to the upper limit introduced by Caianiello. Continual interchange between particle spin and angular momentum is possible only when the acceleration is time-dependent. This represents a stringent limit on the effect that maximal acceleration ...
[ { "created": "Wed, 13 Dec 2017 16:06:08 GMT", "version": "v1" } ]
2017-12-14
[ [ "Papini", "Giorgio", "" ] ]
We study the spin current tensor of a Dirac particle at accelerations close to the upper limit introduced by Caianiello. Continual interchange between particle spin and angular momentum is possible only when the acceleration is time-dependent. This represents a stringent limit on the effect that maximal acceleration ma...
gr-qc/9908025
Jorma Louko
Jorma Louko, Hans-Juergen Matschull
(2+1)-dimensional Einstein-Kepler problem in the centre-of-mass frame
38 pages, REVTeX v3.1 with amsfonts and epsf, 12 eps figures. (v2: Presentational improvement, references added, typos corrected.)
Class.Quant.Grav. 17 (2000) 1847-1873
10.1088/0264-9381/17/8/307
AEI 1999-015, MZ-TH/99-31
gr-qc
null
We formulate and analyze the Hamiltonian dynamics of a pair of massive spinless point particles in (2+1)-dimensional Einstein gravity by anchoring the system to a conical infinity, isometric to the infinity generated by a single massive but possibly spinning particle. The reduced phase space \Gamma_{red} has dimensio...
[ { "created": "Sun, 8 Aug 1999 13:31:32 GMT", "version": "v1" }, { "created": "Mon, 6 Mar 2000 19:40:06 GMT", "version": "v2" } ]
2009-10-31
[ [ "Louko", "Jorma", "" ], [ "Matschull", "Hans-Juergen", "" ] ]
We formulate and analyze the Hamiltonian dynamics of a pair of massive spinless point particles in (2+1)-dimensional Einstein gravity by anchoring the system to a conical infinity, isometric to the infinity generated by a single massive but possibly spinning particle. The reduced phase space \Gamma_{red} has dimension ...
gr-qc/0312039
Kostas Kokkotas
Kostas D. Kokkotas
High frequency sources of gravitational waves
7 pages, Class. Quantum Grav. in press. Proceedings of the 5th Amaldi Conference
Nucl.Phys.Proc.Suppl.138:433-435,2005
10.1016/j.nuclphysbps.2004.11.099
null
gr-qc
null
Sources of high frequency gravitational waves are reviewed. Gravitational collapse, rotational instabilities and oscillations of the remnant compact objects are potentially important sources of gravitational waves. Significant and unique information for the various stages of the collapse, the evolution of protoneutro...
[ { "created": "Sun, 7 Dec 2003 18:25:02 GMT", "version": "v1" } ]
2010-11-19
[ [ "Kokkotas", "Kostas D.", "" ] ]
Sources of high frequency gravitational waves are reviewed. Gravitational collapse, rotational instabilities and oscillations of the remnant compact objects are potentially important sources of gravitational waves. Significant and unique information for the various stages of the collapse, the evolution of protoneutron ...
0801.1562
S Habib Mazharimousavi
S. Habib Mazharimousavi and M. Halilsoy
5D-Black Hole Solution in Einstein-Yang-Mills-Gauss-Bonnet Theory
5 pages, no figures
Phys.Rev.D76:087501,2007
10.1103/PhysRevD.76.087501
null
gr-qc
null
By adopting the 5D version of the Wu-Yang Ansatz we present in closed form a black hole solution in the Einstein-Yang-Mills-Gauss-Bonnet (EYMGB) theory. In the EYM limit, we recover the 5D black hole solution already known.
[ { "created": "Thu, 10 Jan 2008 08:34:54 GMT", "version": "v1" } ]
2008-11-26
[ [ "Mazharimousavi", "S. Habib", "" ], [ "Halilsoy", "M.", "" ] ]
By adopting the 5D version of the Wu-Yang Ansatz we present in closed form a black hole solution in the Einstein-Yang-Mills-Gauss-Bonnet (EYMGB) theory. In the EYM limit, we recover the 5D black hole solution already known.
gr-qc/0505163
Todd Fugleberg
K. Choy, T. Kruk, M.E. Carrington, T. Fugleberg, J. Zahn, R. Kobes, G. Kunstatter, D. Pickering
Energy Flow in Acoustic Black Holes
8 pages, 9 figures, Comments added to discussion of energy flow and introductory section abbreviated
Phys.Rev. D73 (2006) 104011
10.1103/PhysRevD.73.104011
null
gr-qc hep-th
null
We present the results of an analysis of superradiant energy flow due to scalar fields incident on an acoustic black hole. In addition to providing independent confirmation of the recent results in [5], we determine in detail the profile of energy flow everywhere outside the horizon. We confirm explicitly that in a s...
[ { "created": "Tue, 31 May 2005 18:45:35 GMT", "version": "v1" }, { "created": "Tue, 11 Oct 2005 17:07:15 GMT", "version": "v2" } ]
2009-11-11
[ [ "Choy", "K.", "" ], [ "Kruk", "T.", "" ], [ "Carrington", "M. E.", "" ], [ "Fugleberg", "T.", "" ], [ "Zahn", "J.", "" ], [ "Kobes", "R.", "" ], [ "Kunstatter", "G.", "" ], [ "Pickering", "D.", ...
We present the results of an analysis of superradiant energy flow due to scalar fields incident on an acoustic black hole. In addition to providing independent confirmation of the recent results in [5], we determine in detail the profile of energy flow everywhere outside the horizon. We confirm explicitly that in a sui...
gr-qc/0006078
Joshua A. Faber
Joshua A. Faber, Frederic A. Rasio, and Justin B. Manor
Post-Newtonian SPH calculations of binary neutron star coalescence. II. Binary mass ratio, equation of state, and spin dependence
RevTeX, 38 pages, 24 figures, Minor Corrections, to appear in Phys. Rev. D
Phys.Rev. D63 (2001) 044012
10.1103/PhysRevD.63.044012
null
gr-qc astro-ph
null
Using our new Post-Newtonian SPH (smoothed particle hydrodynamics) code, we study the final coalescence and merging of neutron star (NS) binaries. We vary the stiffness of the equation of state (EOS) as well as the initial binary mass ratio and stellar spins. Results are compared to those of Newtonian calculations, w...
[ { "created": "Thu, 22 Jun 2000 00:02:40 GMT", "version": "v1" }, { "created": "Sun, 15 Oct 2000 21:12:42 GMT", "version": "v2" } ]
2009-10-31
[ [ "Faber", "Joshua A.", "" ], [ "Rasio", "Frederic A.", "" ], [ "Manor", "Justin B.", "" ] ]
Using our new Post-Newtonian SPH (smoothed particle hydrodynamics) code, we study the final coalescence and merging of neutron star (NS) binaries. We vary the stiffness of the equation of state (EOS) as well as the initial binary mass ratio and stellar spins. Results are compared to those of Newtonian calculations, wit...
1306.1527
Joan Sola
Joan Sola
Cosmological constant and vacuum energy: old and new ideas
86 pages, substantially extended discussion, many new references added
J.Phys.Conf.Ser. 453 (2013) 012015
10.1088/1742-6596/453/1/012015
null
gr-qc astro-ph.CO hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The cosmological constant (CC) term in Einstein's equations, Lambda, was first associated to the idea of vacuum energy density. Notwithstanding, it is well-known that there is a huge, in fact appalling, discrepancy between the theoretical prediction and the observed value picked from the modern cosmological data. Thi...
[ { "created": "Thu, 6 Jun 2013 19:58:11 GMT", "version": "v1" }, { "created": "Sun, 30 Jun 2013 19:08:16 GMT", "version": "v2" }, { "created": "Sun, 21 Jul 2013 19:58:21 GMT", "version": "v3" } ]
2015-03-19
[ [ "Sola", "Joan", "" ] ]
The cosmological constant (CC) term in Einstein's equations, Lambda, was first associated to the idea of vacuum energy density. Notwithstanding, it is well-known that there is a huge, in fact appalling, discrepancy between the theoretical prediction and the observed value picked from the modern cosmological data. This ...
gr-qc/0511112
Luis Herrera
L. Herrera, N.O. Santos and J. Carot
Gravitational radiation, vorticity and the electric and magnetic part of Weyl tensor
17 pages Latex. Typos corrected
J.Math.Phys. 47 (2006) 052502
10.1063/1.2199027
null
gr-qc
null
The electric and the magnetic part of the Weyl tensor, as well as the invariants obtained from them, are calculated for the Bondi vacuum metric. One of the invariants vanishes identically and the other only exhibits contributions from terms of the Weyl tensor containing the static part of the field. It is shown that ...
[ { "created": "Sun, 20 Nov 2005 21:07:55 GMT", "version": "v1" }, { "created": "Thu, 30 Mar 2006 19:21:31 GMT", "version": "v2" }, { "created": "Mon, 15 May 2006 20:35:07 GMT", "version": "v3" } ]
2009-11-11
[ [ "Herrera", "L.", "" ], [ "Santos", "N. O.", "" ], [ "Carot", "J.", "" ] ]
The electric and the magnetic part of the Weyl tensor, as well as the invariants obtained from them, are calculated for the Bondi vacuum metric. One of the invariants vanishes identically and the other only exhibits contributions from terms of the Weyl tensor containing the static part of the field. It is shown that th...
1605.07205
Antonios Tsokaros A.
Antonios Tsokaros, Bruno C. Mundim, Filippo Galeazzi, Luciano Rezzolla, K\=oji Ury\=u
Initial-data contribution to the error budget of gravitational waves from neutron-star binaries
17 pages, 11 figures
Phys. Rev. D 94, 044049 (2016)
10.1103/PhysRevD.94.044049
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As numerical calculations of inspiralling neutron-star binaries reach values of accuracy that are comparable with those of binary black holes, a fine budgeting of the various sources of error becomes increasingly important. Among such sources, the initial data is normally not accounted for, the rationale being that t...
[ { "created": "Mon, 23 May 2016 20:17:05 GMT", "version": "v1" } ]
2016-08-31
[ [ "Tsokaros", "Antonios", "" ], [ "Mundim", "Bruno C.", "" ], [ "Galeazzi", "Filippo", "" ], [ "Rezzolla", "Luciano", "" ], [ "Uryū", "Kōji", "" ] ]
As numerical calculations of inspiralling neutron-star binaries reach values of accuracy that are comparable with those of binary black holes, a fine budgeting of the various sources of error becomes increasingly important. Among such sources, the initial data is normally not accounted for, the rationale being that the...
2405.15874
Himanshu Chaudhary
Ujjal Debnath, Himanshu Chaudhary, Niyaz Uddin Molla, S. K. J. Pacif and G.Mustafa
Dark Energy Model in Einstein and Horava-Lifshitz Gravity with a new Parametrization of $\omega(z)$: Model Comparison, Analysis and Observational Constraint
19 pages, 5 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a novel dynamical dark energy model within the frameworks of both Einstein gravity and Horava-Lifshitz gravity. Utilizing a new parametrization of the dark energy equation of state $\omega(z)$, we derive solutions to the field equations. By employing recent cosmological datasets, such as cosmic chronometer...
[ { "created": "Fri, 24 May 2024 18:39:57 GMT", "version": "v1" } ]
2024-05-28
[ [ "Debnath", "Ujjal", "" ], [ "Chaudhary", "Himanshu", "" ], [ "Molla", "Niyaz Uddin", "" ], [ "Pacif", "S. K. J.", "" ], [ "Mustafa", "G.", "" ] ]
We present a novel dynamical dark energy model within the frameworks of both Einstein gravity and Horava-Lifshitz gravity. Utilizing a new parametrization of the dark energy equation of state $\omega(z)$, we derive solutions to the field equations. By employing recent cosmological datasets, such as cosmic chronometer d...
2112.12861
Shahn Majid
Chengcheng Liu and Shahn Majid
Quantum geodesics on $\lambda$-Minkowski spacetime
28 pages amslatex, 3 pdf figures; some small corrections and clarified the notation in a couple of places
null
10.1088/1751-8121/ac7593
null
gr-qc hep-th math.QA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply a recent formalism of quantum geodesics to the well-known bicrossproduct model $\lambda$-Minkowski quantum spacetime $[x^i,t]=\imath\lambda_p x^i$ with its flat quantum metric as a model of quantum gravity effects, with $\lambda_p$ the Planck scale. As examples, quantum geodesic flow of a plane wave gets an ...
[ { "created": "Wed, 22 Dec 2021 18:36:04 GMT", "version": "v1" }, { "created": "Thu, 10 Feb 2022 20:55:33 GMT", "version": "v2" } ]
2022-11-23
[ [ "Liu", "Chengcheng", "" ], [ "Majid", "Shahn", "" ] ]
We apply a recent formalism of quantum geodesics to the well-known bicrossproduct model $\lambda$-Minkowski quantum spacetime $[x^i,t]=\imath\lambda_p x^i$ with its flat quantum metric as a model of quantum gravity effects, with $\lambda_p$ the Planck scale. As examples, quantum geodesic flow of a plane wave gets an or...
2003.14088
Iver Brevik
I. Brevik and A. V. Timoshkin
Rip brane cosmology from a viscous holographic dark fluid
11 pages, to appear in Int. J. Geom. Methods in Mod. Phys
Int. J. Geom. Meth. Mod. Phys. 17(2020)2050087
10.1142/S0219887820500875
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This article is devoted to the application of the holographic principle to describe Rip brane cosmological models in the presence of a bulk viscosity. We make use of the generalized infrared-cutoff holographic dark energy, introduced by Nojiri and Odintsov We consider various examples: Rip brane cosmology correspondi...
[ { "created": "Tue, 31 Mar 2020 10:53:53 GMT", "version": "v1" } ]
2020-06-05
[ [ "Brevik", "I.", "" ], [ "Timoshkin", "A. V.", "" ] ]
This article is devoted to the application of the holographic principle to describe Rip brane cosmological models in the presence of a bulk viscosity. We make use of the generalized infrared-cutoff holographic dark energy, introduced by Nojiri and Odintsov We consider various examples: Rip brane cosmology corresponding...
0903.2128
Matt Visser
Jozef Skakala (Victoria University of Wellington) and Matt Visser (Victoria University of Wellington)
Birkhoff-like theorem for rotating stars in (2+1) dimensions
4 pages; uses revtex4; V2: added 1 very important reference; significantly expanded discussion; many small changes in the text but no significant change in physics conclusions; V3: minor typos fixed
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Consider a rotating and possibly pulsating "star" in (2+1) dimensions. If the star is axially symmetric, then in the vacuum region surrounding the star, (a region that we assume at most contains a cosmological constant), the Einstein equations imply that under physically plausible conditions the geometry is in fact s...
[ { "created": "Thu, 12 Mar 2009 09:37:46 GMT", "version": "v1" }, { "created": "Tue, 17 Mar 2009 05:07:10 GMT", "version": "v2" }, { "created": "Sun, 22 Mar 2009 19:26:26 GMT", "version": "v3" } ]
2009-03-22
[ [ "Skakala", "Jozef", "", "Victoria University of Wellington" ], [ "Visser", "Matt", "", "Victoria University of Wellington" ] ]
Consider a rotating and possibly pulsating "star" in (2+1) dimensions. If the star is axially symmetric, then in the vacuum region surrounding the star, (a region that we assume at most contains a cosmological constant), the Einstein equations imply that under physically plausible conditions the geometry is in fact sta...
0704.1802
Comelli Denis
Denis Comelli
A Way to Dynamically Overcome the Cosmological Constant Problem
5 pages
Int.J.Mod.Phys.A23:4133-4143,2008
10.1142/S0217751X08041359
null
gr-qc astro-ph
null
The Cosmological Constant problem can be solved once we require that the full standard Einstein Hilbert lagrangian, gravity plus matter, is multiplied by a total derivative. We analyze such a picture writing the total derivative as the covariant gradient of a new vector field (b_mu). The dynamics of this b_mu field c...
[ { "created": "Fri, 13 Apr 2007 17:29:06 GMT", "version": "v1" } ]
2009-01-06
[ [ "Comelli", "Denis", "" ] ]
The Cosmological Constant problem can be solved once we require that the full standard Einstein Hilbert lagrangian, gravity plus matter, is multiplied by a total derivative. We analyze such a picture writing the total derivative as the covariant gradient of a new vector field (b_mu). The dynamics of this b_mu field can...
0806.2415
Yungui Gong
Ximing Chen, Jie Liu, Yungui Gong
Constraints on Dark Energy Models from Weak Gravity Conjecture
4 two column pages, 3 figures, accepted by Chin. Phys. Lett
Chin.Phys.Lett.25:3086-3089,2008
10.1088/0256-307X/25/8/094
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the constraints on the dark energy model with constant equation of state parameter $w=p/\rho$ and the holographic dark energy model by using the weak gravity conjecture. The combination of weak gravity conjecture and the observational data gives $w<-0.7$ at the $3\sigma$ confidence level. The holographic dar...
[ { "created": "Sun, 15 Jun 2008 04:16:46 GMT", "version": "v1" } ]
2008-11-26
[ [ "Chen", "Ximing", "" ], [ "Liu", "Jie", "" ], [ "Gong", "Yungui", "" ] ]
We study the constraints on the dark energy model with constant equation of state parameter $w=p/\rho$ and the holographic dark energy model by using the weak gravity conjecture. The combination of weak gravity conjecture and the observational data gives $w<-0.7$ at the $3\sigma$ confidence level. The holographic dark ...
2006.09026
Sergey Paston
S.A. Paston
Dark matter from non-relativistic embedding gravity
LaTeX, 11 pages. This version corresponds to the published one
Modern Physics Letters A, Vol. 36, No. 15, 2150101 (2021)
10.1142/S0217732321501017
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the possibility to explain the mystery of the dark matter through the transition from General Relativity to embedding gravity. This modification of gravity, which was proposed by Regge and Teitelboim, is based on a simple string-inspired geometrical principle: our spacetime is considered here as a 4-dimensio...
[ { "created": "Tue, 16 Jun 2020 09:46:56 GMT", "version": "v1" }, { "created": "Sun, 6 Jun 2021 09:19:03 GMT", "version": "v2" } ]
2021-06-08
[ [ "Paston", "S. A.", "" ] ]
We study the possibility to explain the mystery of the dark matter through the transition from General Relativity to embedding gravity. This modification of gravity, which was proposed by Regge and Teitelboim, is based on a simple string-inspired geometrical principle: our spacetime is considered here as a 4-dimensiona...
2107.10682
Fei-Quan Tu
Fei-Quan Tu, Yi-Xin Chen, Qi-Hong Huang
A cosmic accelerated scenario based on degrees of freedom of the spacetime
11 pages, 1 figure
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Several recent investigations have shown that there is a holographic relationship between the bulk degrees of freedom and the surface degrees of freedom in the spacetime. Furthermore, the entropy on the horizon can produce an entropic force effect on the bulk degrees of freedom. In this paper, we explore the dynamic ...
[ { "created": "Thu, 22 Jul 2021 13:41:14 GMT", "version": "v1" } ]
2021-07-23
[ [ "Tu", "Fei-Quan", "" ], [ "Chen", "Yi-Xin", "" ], [ "Huang", "Qi-Hong", "" ] ]
Several recent investigations have shown that there is a holographic relationship between the bulk degrees of freedom and the surface degrees of freedom in the spacetime. Furthermore, the entropy on the horizon can produce an entropic force effect on the bulk degrees of freedom. In this paper, we explore the dynamic ev...
1611.02932
Manuel Kraemer
David Brizuela, Claus Kiefer, Manuel Kraemer
Quantum-gravitational effects on gauge-invariant scalar and tensor perturbations during inflation: The slow-roll approximation
16 pages, 7 figures, clarifications and references added
Phys. Rev. D 94, 123527 (2016)
10.1103/PhysRevD.94.123527
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We continue our study on corrections from canonical quantum gravity to the power spectra of gauge-invariant inflationary scalar and tensor perturbations. A direct canonical quantization of a perturbed inflationary universe model is implemented, which leads to a Wheeler-DeWitt equation. For this equation, a semiclassi...
[ { "created": "Wed, 9 Nov 2016 13:51:30 GMT", "version": "v1" }, { "created": "Fri, 30 Dec 2016 17:00:06 GMT", "version": "v2" } ]
2017-01-02
[ [ "Brizuela", "David", "" ], [ "Kiefer", "Claus", "" ], [ "Kraemer", "Manuel", "" ] ]
We continue our study on corrections from canonical quantum gravity to the power spectra of gauge-invariant inflationary scalar and tensor perturbations. A direct canonical quantization of a perturbed inflationary universe model is implemented, which leads to a Wheeler-DeWitt equation. For this equation, a semiclassica...
1907.09201
Euaggelos E. Zotos
Euaggelos E. Zotos, Fredy L. Dubeibe, Jan Nagler, Emilio Tejeda
Orbit classification in a pseudo-Newtonian Copenhagen problem with Schwarzschild-like primaries
Published in Monthly Notices of the Royal Astronomical Society (MNRAS) journal
MNRAS, vol. 487, 2340-2353 (2019)
10.1093/mnras/stz1432
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the orbital dynamics of the planar pseudo-Newtonian Copenhagen problem, in the case of a binary system of Schwarzschild-like primaries, such as super-massive black holes. In particular, we investigate how the Jacobi constant (which is directly connected with the energy of the orbits) influences several asp...
[ { "created": "Mon, 22 Jul 2019 09:42:48 GMT", "version": "v1" } ]
2019-07-23
[ [ "Zotos", "Euaggelos E.", "" ], [ "Dubeibe", "Fredy L.", "" ], [ "Nagler", "Jan", "" ], [ "Tejeda", "Emilio", "" ] ]
We examine the orbital dynamics of the planar pseudo-Newtonian Copenhagen problem, in the case of a binary system of Schwarzschild-like primaries, such as super-massive black holes. In particular, we investigate how the Jacobi constant (which is directly connected with the energy of the orbits) influences several aspec...
gr-qc/9603002
Masafumi Seriu
Masafumi Seriu
The spectral representation of the spacetime structure: The `distance' between universes with different topologies
47 pages
Phys.Rev.D53:6902-6920,1996
10.1103/PhysRevD.53.6902
YITP-96-9
gr-qc
null
We investigate the representation of the geometrical information of the universe in terms of the eigenvalues of the Laplacian defined on the universe. We concentrate only on one specific problem along this line: To introduce a concept of distance between universes in terms of the difference in the spectra. We can f...
[ { "created": "Fri, 1 Mar 1996 14:28:19 GMT", "version": "v1" } ]
2014-11-17
[ [ "Seriu", "Masafumi", "" ] ]
We investigate the representation of the geometrical information of the universe in terms of the eigenvalues of the Laplacian defined on the universe. We concentrate only on one specific problem along this line: To introduce a concept of distance between universes in terms of the difference in the spectra. We can find ...
gr-qc/0402044
Simon F. Ross
Tim Clunan, Simon F. Ross and Douglas J. Smith
On Gauss-Bonnet black hole entropy
14 pages, no figures. v2: references added; v3,v4: more references added
Class.Quant.Grav. 21 (2004) 3447-3458
10.1088/0264-9381/21/14/009
null
gr-qc hep-th
null
We investigate the entropy of black holes in Gauss-Bonnet and Lovelock gravity using the Noether charge approach, in which the entropy is given as the integral of a suitable (n-2) form charge over the event horizon. We compare the results to those obtained in other approaches. We also comment on the appearance of neg...
[ { "created": "Tue, 10 Feb 2004 09:47:09 GMT", "version": "v1" }, { "created": "Fri, 13 Feb 2004 14:33:54 GMT", "version": "v2" }, { "created": "Fri, 20 Feb 2004 17:26:41 GMT", "version": "v3" }, { "created": "Fri, 10 Dec 2004 16:10:15 GMT", "version": "v4" } ]
2009-11-10
[ [ "Clunan", "Tim", "" ], [ "Ross", "Simon F.", "" ], [ "Smith", "Douglas J.", "" ] ]
We investigate the entropy of black holes in Gauss-Bonnet and Lovelock gravity using the Noether charge approach, in which the entropy is given as the integral of a suitable (n-2) form charge over the event horizon. We compare the results to those obtained in other approaches. We also comment on the appearance of negat...
2006.05242
W{\l}odzimierz Piechocki
W{\l}odzimierz Piechocki
Generic singularity of general relativity and its quantum fate
9 pages, no figures, extended version of essay
null
null
null
gr-qc hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Belinski-Khalatnikov-Lifshitz scenario concerns the existence of generic singularity of general relativity. At the singularity, there is a breakdown of all known laws of physics. Quantization of this scenario leads, however, to regular quantum evolution. The singularity is avoided by a quantum bounce. It is fairl...
[ { "created": "Tue, 9 Jun 2020 13:27:59 GMT", "version": "v1" }, { "created": "Fri, 17 Jul 2020 04:27:12 GMT", "version": "v2" } ]
2020-07-20
[ [ "Piechocki", "Włodzimierz", "" ] ]
The Belinski-Khalatnikov-Lifshitz scenario concerns the existence of generic singularity of general relativity. At the singularity, there is a breakdown of all known laws of physics. Quantization of this scenario leads, however, to regular quantum evolution. The singularity is avoided by a quantum bounce. It is fairly ...
gr-qc/0201103
Giovanni Imponente
Giovanni Imponente and Giovanni Montani
Covariant Mixmaster Dynamics
null
in ''Similarities and Universality in Relativistic Flows'', Ed. by Logos Verlag, Berlin (2001)
null
null
gr-qc
null
We provide a Hamiltonian analysis of the Mixmaster Universe dynamics on the base of a standard Arnowitt-Deser-Misner Hamiltonian approach, showing the covariant nature of its chaotic behaviour with respect to the choice of any time variable, from the point of view either of the dynamical systems theory, either of the...
[ { "created": "Thu, 31 Jan 2002 14:30:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Imponente", "Giovanni", "" ], [ "Montani", "Giovanni", "" ] ]
We provide a Hamiltonian analysis of the Mixmaster Universe dynamics on the base of a standard Arnowitt-Deser-Misner Hamiltonian approach, showing the covariant nature of its chaotic behaviour with respect to the choice of any time variable, from the point of view either of the dynamical systems theory, either of the s...
gr-qc/9606059
Roland Steinbauer
Roland Steinbauer
The ultrarelativistic Reissner-Nordstrom field in the Colombeau algebra
final version, minor grammatical changes
J.Math.Phys. 38 (1997) 1614-1622
10.1063/1.531819
null
gr-qc math-ph math.MP
null
The electromagnetic field of the ultrarelativistic Reissner-Nordstrom solution shows the physically highly unsatisfactory property of a vanishing field tensor but a nonzero, i.e., delta-like, energy density. The aim of this work is to analyze this situation from a mathematical point of view, using the framework of Co...
[ { "created": "Wed, 19 Jun 1996 10:01:09 GMT", "version": "v1" }, { "created": "Mon, 24 Feb 1997 11:08:09 GMT", "version": "v2" } ]
2009-10-28
[ [ "Steinbauer", "Roland", "" ] ]
The electromagnetic field of the ultrarelativistic Reissner-Nordstrom solution shows the physically highly unsatisfactory property of a vanishing field tensor but a nonzero, i.e., delta-like, energy density. The aim of this work is to analyze this situation from a mathematical point of view, using the framework of Colo...