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2301.02914
Mikhail Zubkov Dr
M. Selch, J. Miller, M.A.Zubkov
Gravastar-like black hole solutions in $q$-theory
Latex, 14 figures, 28 pages
null
10.1088/1361-6382/ace14b
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a stationary spherically symmetric solution of the Einstein equations, with a source generated by a scalar field of $q$-theory. In this theory Riemannian gravity, as described by the Einstein - Hilbert action, is coupled to a three - form field that describes the dynamical vacuum. Formally it behaves like ...
[ { "created": "Sat, 7 Jan 2023 18:32:20 GMT", "version": "v1" }, { "created": "Tue, 30 May 2023 17:38:15 GMT", "version": "v2" } ]
2023-07-26
[ [ "Selch", "M.", "" ], [ "Miller", "J.", "" ], [ "Zubkov", "M. A.", "" ] ]
We present a stationary spherically symmetric solution of the Einstein equations, with a source generated by a scalar field of $q$-theory. In this theory Riemannian gravity, as described by the Einstein - Hilbert action, is coupled to a three - form field that describes the dynamical vacuum. Formally it behaves like a ...
1603.01465
Hooman Moradpour Hooman
H. Moradpour, Rafael C. Nunes, Everton M. C. Abreu, Jorge Ananias Neto
A note on the relations between thermodynamics, energy definitions and Friedmann equations
The text has been increased
Mod. Phys. Lett. A (2017), Vol. 32, No. 13, 1750078
10.1142/S021773231750078X
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In what follows, we investigate the relation between the Friedmann and thermodynamic pressure equations, through solving the Friedmann and thermodynamic pressure equations simultaneously. Our investigation shows that a perfect fluid, as a suitable solution for the Friedmann equations leading to the standard modelling...
[ { "created": "Mon, 29 Feb 2016 09:37:28 GMT", "version": "v1" }, { "created": "Tue, 17 May 2016 05:58:30 GMT", "version": "v2" }, { "created": "Sat, 6 Aug 2016 12:08:40 GMT", "version": "v3" } ]
2017-04-21
[ [ "Moradpour", "H.", "" ], [ "Nunes", "Rafael C.", "" ], [ "Abreu", "Everton M. C.", "" ], [ "Neto", "Jorge Ananias", "" ] ]
In what follows, we investigate the relation between the Friedmann and thermodynamic pressure equations, through solving the Friedmann and thermodynamic pressure equations simultaneously. Our investigation shows that a perfect fluid, as a suitable solution for the Friedmann equations leading to the standard modelling o...
0903.3088
Xin-Zhou Li
Xin-zhou Li, Chang-bo Sun and Ping Xi
Torsion cosmological dynamics
4 pages, 3 figures
Phys.Rev.D79:027301,2009
10.1103/PhysRevD.79.027301
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, the dynamical attractor and heteroclinic orbit have been employed to make the late-time behaviors of the model insensitive to the initial condition and thus alleviate the fine-tuning problem in the torsion cosmology. The late-time de Sitter attractor indicates that torsion cosmology is an elegant schem...
[ { "created": "Wed, 18 Mar 2009 04:47:48 GMT", "version": "v1" } ]
2010-04-22
[ [ "Li", "Xin-zhou", "" ], [ "Sun", "Chang-bo", "" ], [ "Xi", "Ping", "" ] ]
In this paper, the dynamical attractor and heteroclinic orbit have been employed to make the late-time behaviors of the model insensitive to the initial condition and thus alleviate the fine-tuning problem in the torsion cosmology. The late-time de Sitter attractor indicates that torsion cosmology is an elegant scheme ...
1402.5678
Hoda Farahani
M. Khurshudyan, J. Sadeghi, A. Pasqua, S. Chattopadhyay, R. Myrzakulov, and H. Farahani
Interacting Ricci dark energy models with an effective $\Lambda$-term in Lyra manifold
14 pages
IJTP 54 (2015) 749
10.1007/s10773-014-2266-7
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we consider a universe filled with barotropic dark matter and Ricci dark energy in Lyra geometry with varying Lambda. We assume two different kinds of interactions between dark matter and dark energy. Then, by using numerical analysis, we investigate some cosmological parameters of the models such as eq...
[ { "created": "Sun, 23 Feb 2014 21:28:30 GMT", "version": "v1" } ]
2015-05-12
[ [ "Khurshudyan", "M.", "" ], [ "Sadeghi", "J.", "" ], [ "Pasqua", "A.", "" ], [ "Chattopadhyay", "S.", "" ], [ "Myrzakulov", "R.", "" ], [ "Farahani", "H.", "" ] ]
In this paper we consider a universe filled with barotropic dark matter and Ricci dark energy in Lyra geometry with varying Lambda. We assume two different kinds of interactions between dark matter and dark energy. Then, by using numerical analysis, we investigate some cosmological parameters of the models such as equa...
1010.1143
Mir Faizal
Mir Faizal
BRST and Anti-BRST Symmetries in Perturbative Quantum Gravity
Aversion accepted for publication in Foundations of Physics
Found.Phys.41:270-277,2011
10.1007/s10701-010-9511-6
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In perturbative quantum gravity, the sum of the classical Lagrangian density, a gauge fixing term and a ghost term is invariant under two sets of supersymmetric transformations called the BRST and the anti-BRST transformations. In this paper we will analyse the BRST and the anti-BRST symmetries of perturbative quantu...
[ { "created": "Wed, 6 Oct 2010 12:59:20 GMT", "version": "v1" }, { "created": "Thu, 21 Oct 2010 17:57:53 GMT", "version": "v2" } ]
2011-01-25
[ [ "Faizal", "Mir", "" ] ]
In perturbative quantum gravity, the sum of the classical Lagrangian density, a gauge fixing term and a ghost term is invariant under two sets of supersymmetric transformations called the BRST and the anti-BRST transformations. In this paper we will analyse the BRST and the anti-BRST symmetries of perturbative quantum ...
2303.17364
Charlie Hoy
Connor McIsaac, Charlie Hoy and Ian Harry
A search technique to observe precessing compact binary mergers in the advanced detector era
23 pages, 12 figures. For data release, see https://icg-gravwaves.github.io/precessing_search_paper/
null
null
LIGO-P2300071
gr-qc astro-ph.HE astro-ph.IM
http://creativecommons.org/licenses/by/4.0/
Gravitational-wave signals from compact binary coalescences are most efficiently identified through matched filter searches, which match the data against a pre-generated bank of gravitational-wave templates. Although different techniques for performing the matched filter, as well as generating the template bank, exis...
[ { "created": "Thu, 30 Mar 2023 13:27:43 GMT", "version": "v1" } ]
2023-03-31
[ [ "McIsaac", "Connor", "" ], [ "Hoy", "Charlie", "" ], [ "Harry", "Ian", "" ] ]
Gravitational-wave signals from compact binary coalescences are most efficiently identified through matched filter searches, which match the data against a pre-generated bank of gravitational-wave templates. Although different techniques for performing the matched filter, as well as generating the template bank, exist,...
1801.02026
Izzet Sakalli
G. Tokgoz and I. Sakalli
Spectroscopy of $z=0$ Lifshitz Black Hole
9 pages, 1 figure
Advances in High Energy Physics Volume 2018, Article ID 3270790, 7 pages
10.1155/2018/3270790
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We studied the thermodynamics and spectroscopy of a $4$-dimensional, $z=0$ Lifshitz black hole ($Z0$LBH). Using the Wald's entropy formula and the Hawking temperature, we derived the quasilocal mass of the $Z0$LBH. Based on the exact solution to the near-horizon Zerilli equation of the massive scalar waves, we comput...
[ { "created": "Sat, 6 Jan 2018 14:59:11 GMT", "version": "v1" } ]
2018-12-05
[ [ "Tokgoz", "G.", "" ], [ "Sakalli", "I.", "" ] ]
We studied the thermodynamics and spectroscopy of a $4$-dimensional, $z=0$ Lifshitz black hole ($Z0$LBH). Using the Wald's entropy formula and the Hawking temperature, we derived the quasilocal mass of the $Z0$LBH. Based on the exact solution to the near-horizon Zerilli equation of the massive scalar waves, we computed...
1003.5366
Boris Hikin L
Boris Hikin
Einstein-Aether Theory With and Without Einstein
null
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The exact static spherically symmetric solutions for pure-aether theory and Einstein-aether theory are presented. It is shown that both theories can deliver the Schwarzschild metric, but only the Einstein-aether theory contains solutions with "almost-Schwarzschild" metrics that satisfy Einstein's experiments. Two spe...
[ { "created": "Sun, 28 Mar 2010 12:43:30 GMT", "version": "v1" } ]
2010-03-30
[ [ "Hikin", "Boris", "" ] ]
The exact static spherically symmetric solutions for pure-aether theory and Einstein-aether theory are presented. It is shown that both theories can deliver the Schwarzschild metric, but only the Einstein-aether theory contains solutions with "almost-Schwarzschild" metrics that satisfy Einstein's experiments. Two speci...
1005.0790
Alessandro Gruppuso
Roberto Casadio and Alessandro Gruppuso
CMB acoustic scale in the entropic-like accelerating universe
6 pages, 2 figures. Accepted for publication in Physical Review D
Phys.Rev.D84:023503,2011
10.1103/PhysRevD.84.023503
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider generalizations of the entropic accelerating universe recently proposed in Ref. [4,5] and show that their background equations can be made equivalent to a model with a dark energy component with constant parameter of state $w_{X} = -1 + 2\, \gamma /3$, where $\gamma$ is related to the coefficients of the ...
[ { "created": "Wed, 5 May 2010 16:47:13 GMT", "version": "v1" }, { "created": "Sat, 18 Jun 2011 10:06:11 GMT", "version": "v2" } ]
2011-08-08
[ [ "Casadio", "Roberto", "" ], [ "Gruppuso", "Alessandro", "" ] ]
We consider generalizations of the entropic accelerating universe recently proposed in Ref. [4,5] and show that their background equations can be made equivalent to a model with a dark energy component with constant parameter of state $w_{X} = -1 + 2\, \gamma /3$, where $\gamma$ is related to the coefficients of the ne...
gr-qc/0602052
Marc Lachieze-Rey
Marc Lachieze-Rey (APC)
The covariance of GPS coordinates and frames
new version, as to appear in CQG; some equations corrected, redaction improved ; references added
Classical and Quantum Gravity, 23 (2006) 3531-3544
10.1088/0264-9381/23/10/019
null
gr-qc astro-ph
null
We explore, in the general relativistic context, the properties of the recently introduced GPS coordinates, as well as those of the associated frames and coframes. We show that they are covariant, and completely independent of any observer. We show that standard spectroscopic and astrometric observations allow any ob...
[ { "created": "Tue, 14 Feb 2006 10:11:22 GMT", "version": "v1" }, { "created": "Wed, 29 Mar 2006 11:46:20 GMT", "version": "v2" } ]
2009-11-11
[ [ "Lachieze-Rey", "Marc", "", "APC" ] ]
We explore, in the general relativistic context, the properties of the recently introduced GPS coordinates, as well as those of the associated frames and coframes. We show that they are covariant, and completely independent of any observer. We show that standard spectroscopic and astrometric observations allow any obse...
1411.0104
Pedro Pina Avelino
P. P. Avelino
Could the dynamics of the Universe be influenced by what is going on inside black holes?
8 pages, 2 figures. Version 2 (accepted for publication in JCAP): minor typos corrected
JCAP 1504 (2015) 024
10.1088/1475-7516/2015/04/024
null
gr-qc astro-ph.CO hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the potential impact of mass inflation inside black holes on the dynamics of the Universe, considering a recent reformulation of general relativity, proposed in [1], which prevents the vacuum energy from acting as a gravitational source. The interior dynamics of accreting black holes is studied, at the...
[ { "created": "Sat, 1 Nov 2014 11:29:46 GMT", "version": "v1" }, { "created": "Thu, 26 Mar 2015 12:02:25 GMT", "version": "v2" } ]
2015-05-06
[ [ "Avelino", "P. P.", "" ] ]
We investigate the potential impact of mass inflation inside black holes on the dynamics of the Universe, considering a recent reformulation of general relativity, proposed in [1], which prevents the vacuum energy from acting as a gravitational source. The interior dynamics of accreting black holes is studied, at the c...
1707.05862
Jonathan Sorce
Jonathan Sorce and Robert M. Wald
Gedanken Experiments to Destroy a Black Hole II: Kerr-Newman Black Holes Cannot be Over-Charged or Over-Spun
38 pages, 6 figures; minor revisions/corrections; version accepted for publication in PRD
Phys. Rev. D 96, 104014 (2017)
10.1103/PhysRevD.96.104014
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider gedanken experiments to destroy an extremal or nearly extremal Kerr-Newman black hole by causing it to absorb matter with sufficient charge and/or angular momentum as compared with energy that it cannot remain a black hole. It was previously shown by one of us that such gedanken experiments cannot succeed...
[ { "created": "Tue, 18 Jul 2017 21:23:44 GMT", "version": "v1" }, { "created": "Fri, 13 Oct 2017 01:27:59 GMT", "version": "v2" }, { "created": "Wed, 8 Nov 2017 18:43:09 GMT", "version": "v3" } ]
2017-11-15
[ [ "Sorce", "Jonathan", "" ], [ "Wald", "Robert M.", "" ] ]
We consider gedanken experiments to destroy an extremal or nearly extremal Kerr-Newman black hole by causing it to absorb matter with sufficient charge and/or angular momentum as compared with energy that it cannot remain a black hole. It was previously shown by one of us that such gedanken experiments cannot succeed f...
0908.1322
Nadiezhda Montelongo
N. Montelongo Garcia, T. Zannias
On the Structure of the Effective Potential for a Spherical Wormhole
15 pages, 0 figures
Phys. Rev. D 78, 064003 (2008)
10.1103/PhysRevD.78.064003
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The structure of the effective potential $V$ describing causal geodesics near the throat of an arbitrary spherical wormhole is analyzed. Einstein's equations relative to a set of regular coordinates covering a vicinity of the throat imply that any spherical wormhole can be constructed from solutions of an effective i...
[ { "created": "Mon, 10 Aug 2009 13:33:43 GMT", "version": "v1" } ]
2015-05-13
[ [ "Garcia", "N. Montelongo", "" ], [ "Zannias", "T.", "" ] ]
The structure of the effective potential $V$ describing causal geodesics near the throat of an arbitrary spherical wormhole is analyzed. Einstein's equations relative to a set of regular coordinates covering a vicinity of the throat imply that any spherical wormhole can be constructed from solutions of an effective ini...
gr-qc/0207123
Orfeu Bertolami
O. Bertolami and M. Tajmar
Hypothetical Gravity Control and Implications for Spacecraft Propulsion
5 pages, plain Latex
null
null
DF/IST-8.02
gr-qc
null
A scientific analysis of the conditions under which gravity could be controlled and the implications that an hypothetical manipulation of gravity would have for known schemes of space propulsion have been the scope of a recent study carried out for the European Space Agency. The underlying fundamental physical princi...
[ { "created": "Wed, 31 Jul 2002 12:40:45 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bertolami", "O.", "" ], [ "Tajmar", "M.", "" ] ]
A scientific analysis of the conditions under which gravity could be controlled and the implications that an hypothetical manipulation of gravity would have for known schemes of space propulsion have been the scope of a recent study carried out for the European Space Agency. The underlying fundamental physical principl...
gr-qc/0212129
S. K. Sahay
S.K. Sahay
Matching of the continuous gravitational wave in an all sky search
16 pages, 7 figures, 3 Tables, To appear in Int. J. Mod. Phys. D
Int.J.Mod.Phys.D12:1227-1240,2003
10.1142/S0218271803003578
null
gr-qc astro-ph
null
We investigate the matching of continuous gravitational wave (CGW) signals in an all sky search with reference to Earth based laser interferometric detectors. We consider the source location as the parameters of the signal manifold and templates corresponding to different source locations. It has been found that the ...
[ { "created": "Tue, 31 Dec 2002 14:53:28 GMT", "version": "v1" }, { "created": "Mon, 24 Mar 2003 15:55:03 GMT", "version": "v2" } ]
2014-11-17
[ [ "Sahay", "S. K.", "" ] ]
We investigate the matching of continuous gravitational wave (CGW) signals in an all sky search with reference to Earth based laser interferometric detectors. We consider the source location as the parameters of the signal manifold and templates corresponding to different source locations. It has been found that the ma...
gr-qc/0612139
Christophe Real
Christophe Real
Conservation of energy and Gauss Bonnet gravity
10 pages
null
null
null
gr-qc
null
It is shown how can be made the classification of all tensors constructed from the Riemann tensor that verify the conservation of gravitational energy momentum. More precisely we explain that there exists a unique tensor of degree n in the Riemann tensor and its contractions that verifies the conservation of energy. ...
[ { "created": "Thu, 21 Dec 2006 18:47:25 GMT", "version": "v1" }, { "created": "Wed, 7 Nov 2007 16:59:58 GMT", "version": "v2" } ]
2007-11-07
[ [ "Real", "Christophe", "" ] ]
It is shown how can be made the classification of all tensors constructed from the Riemann tensor that verify the conservation of gravitational energy momentum. More precisely we explain that there exists a unique tensor of degree n in the Riemann tensor and its contractions that verifies the conservation of energy. We...
0811.2832
Ali Shojai
Fatimah Shojai, and Ali Shojai
Geodesic Congruences in the Palatini f(R) Theory
null
Phys.Rev.D78:104011,2008
10.1103/PhysRevD.78.104011
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We shall investigate the properties of a congruence of geodesics in the framework of Palatini f(R) theories. We shall evaluate the modified geodesic deviation equation and the Raychaudhuri's equation and show that f(R) Palatini theories do not necessarily lead to attractive forces. Also we shall study energy conditio...
[ { "created": "Tue, 18 Nov 2008 03:47:22 GMT", "version": "v1" } ]
2008-12-18
[ [ "Shojai", "Fatimah", "" ], [ "Shojai", "Ali", "" ] ]
We shall investigate the properties of a congruence of geodesics in the framework of Palatini f(R) theories. We shall evaluate the modified geodesic deviation equation and the Raychaudhuri's equation and show that f(R) Palatini theories do not necessarily lead to attractive forces. Also we shall study energy condition ...
1003.2481
Stephen Privitera
The LIGO Scientific Collaboration, the Virgo Collaboration: J. Abadie, B. P. Abbott, R. Abbott, M Abernathy, T. Accadia, F. Acernese, C. Adams, R. Adhikari, P. Ajith, B. Allen, G. Allen, E. Amador Ceron, R. S. Amin, S. B. Anderson, W. G. Anderson, F. Antonucci, S. Aoudia, M. A. Arain, M. Araya, M. Aronsson, K. ...
Sensitivity to Gravitational Waves from Compact Binary Coalescences Achieved during LIGO's Fifth and Virgo's First Science Run
12 pages, 5 figures
null
null
LIGO-T0900499-v19, VIR-0171A-10
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We summarize the sensitivity achieved by the LIGO and Virgo gravitational wave detectors for compact binary coalescence (CBC) searches during LIGO's fifth science run and Virgo's first science run. We present noise spectral density curves for each of the four detectors that operated during these science runs which ar...
[ { "created": "Fri, 12 Mar 2010 05:48:36 GMT", "version": "v1" }, { "created": "Sun, 28 Mar 2010 22:46:53 GMT", "version": "v2" }, { "created": "Tue, 1 Jun 2010 04:45:05 GMT", "version": "v3" } ]
2015-03-13
[ [ "The LIGO Scientific Collaboration", "", "" ], [ "the Virgo Collaboration", "", "" ], [ "Abadie", "J.", "" ], [ "Abbott", "B. P.", "" ], [ "Abbott", "R.", "" ], [ "Abernathy", "M", "" ], [ "Accadia", "T.", ...
We summarize the sensitivity achieved by the LIGO and Virgo gravitational wave detectors for compact binary coalescence (CBC) searches during LIGO's fifth science run and Virgo's first science run. We present noise spectral density curves for each of the four detectors that operated during these science runs which are ...
0912.5384
Robert Littlejohn
Hal M. Haggard and Robert G. Littlejohn
Asymptotics of the Wigner 9j symbol
17 pages, 7 figures
Class.Quant.Grav.27:135010,2010
10.1088/0264-9381/27/13/135010
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the asymptotic formula for the Wigner 9j-symbol, valid when all quantum numbers are large, in the classically allowed region. As in the Ponzano-Regge formula for the 6j-symbol, the action is expressed in terms of lengths of edges and dihedral angles of a geometrical figure, but the angles require care in d...
[ { "created": "Tue, 29 Dec 2009 23:06:08 GMT", "version": "v1" } ]
2010-05-25
[ [ "Haggard", "Hal M.", "" ], [ "Littlejohn", "Robert G.", "" ] ]
We present the asymptotic formula for the Wigner 9j-symbol, valid when all quantum numbers are large, in the classically allowed region. As in the Ponzano-Regge formula for the 6j-symbol, the action is expressed in terms of lengths of edges and dihedral angles of a geometrical figure, but the angles require care in def...
2009.10133
Jorge Ananias Neto
Everton M. C. Abreu and Jorge Ananias Neto
Barrow black hole corrected-entropy model and Tsallis nonextensivity
10 pages. To be published in PLB
null
10.1016/j.physletb.2020.135805
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The quantum scenario concerning Hawking radiation, gives us a precious clue that a black hole has its temperature directly connected to its area gravity and that its entropy is proportional to the horizon area. These results have shown that there exist a deep association between thermodynamics and gravity. The recent...
[ { "created": "Mon, 21 Sep 2020 18:54:44 GMT", "version": "v1" } ]
2020-10-28
[ [ "Abreu", "Everton M. C.", "" ], [ "Neto", "Jorge Ananias", "" ] ]
The quantum scenario concerning Hawking radiation, gives us a precious clue that a black hole has its temperature directly connected to its area gravity and that its entropy is proportional to the horizon area. These results have shown that there exist a deep association between thermodynamics and gravity. The recently...
gr-qc/0702087
Raul Horvat
R. Horvat
Renormalization-group running cosmologies and the generalized second law
8 pages, final version to appear in Phys. Lett. B
Phys.Lett.B648:374-377,2007
10.1016/j.physletb.2007.03.037
null
gr-qc astro-ph hep-th
null
We explore some thermodynamical consequences of accelerated universes driven by a running cosmological constant (CC) from the renormalization group (RG). Application of the generalized second law (GSL) of gravitational thermodynamics to a framework where the running of the CC goes at the expense of energy transfer be...
[ { "created": "Thu, 15 Feb 2007 11:21:00 GMT", "version": "v1" }, { "created": "Mon, 19 Feb 2007 16:07:24 GMT", "version": "v2" }, { "created": "Thu, 22 Mar 2007 09:14:32 GMT", "version": "v3" } ]
2008-11-26
[ [ "Horvat", "R.", "" ] ]
We explore some thermodynamical consequences of accelerated universes driven by a running cosmological constant (CC) from the renormalization group (RG). Application of the generalized second law (GSL) of gravitational thermodynamics to a framework where the running of the CC goes at the expense of energy transfer betw...
gr-qc/9904032
T. Damour
T. Damour
Equivalence Principle and Clocks
7 pages, latex, uses moriond.sty, to appear in the Proceedings of the 34th Rencontres de Moriond, "Gravitational Waves and Experimental Gravity", January 1999
null
null
IHES/P/99/11
gr-qc
null
String theory suggests the existence of gravitational-strength scalar fields ("dilaton" and "moduli") whose couplings to matter violate the equivalence principle. This provides a new motivation for high-precision clock experiments, as well as a generic theoretical framework for analyzing their significance.
[ { "created": "Wed, 14 Apr 1999 13:09:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Damour", "T.", "" ] ]
String theory suggests the existence of gravitational-strength scalar fields ("dilaton" and "moduli") whose couplings to matter violate the equivalence principle. This provides a new motivation for high-precision clock experiments, as well as a generic theoretical framework for analyzing their significance.
1003.5640
Alexander Kouretsis
A.P.Kouretsis, M.Stathakopoulos and P.C.Stavrinos
Imperfect fluids, Lorentz violations and Finsler Cosmology
v1:16 pages v2: extended version; section, several comments, clarifications and references added; to appear on prd
Phys.Rev.D82:064035,2010
10.1103/PhysRevD.82.064035
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct a cosmological toy model based on a Finslerian structure of space-time. In particular, we are interested in a specific Finslerian Lorentz violating theory based on a curved version of Cohen and Glashow's Very Special Relativity. The osculation of a Finslerian manifold to a Riemannian leads to the limit o...
[ { "created": "Mon, 29 Mar 2010 19:02:41 GMT", "version": "v1" }, { "created": "Mon, 6 Sep 2010 14:42:51 GMT", "version": "v2" } ]
2014-11-20
[ [ "Kouretsis", "A. P.", "" ], [ "Stathakopoulos", "M.", "" ], [ "Stavrinos", "P. C.", "" ] ]
We construct a cosmological toy model based on a Finslerian structure of space-time. In particular, we are interested in a specific Finslerian Lorentz violating theory based on a curved version of Cohen and Glashow's Very Special Relativity. The osculation of a Finslerian manifold to a Riemannian leads to the limit of ...
1212.0432
Ahmet Baykal
Ahmet Baykal
Energy definition for quadratic curvature gravities
7 pages
Phys. Rev. D 86, 127501 (2012)
10.1103/PhysRevD.86.127501
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A conserved current for generic quadratic curvature gravitational models is defined, and it is shown that, at the linearized level, it corresponds to the Deser-Tekin charges. An explicit expression for the charge for new massive gravity in three dimensions is given. Some implications of the linearized equations are d...
[ { "created": "Mon, 3 Dec 2012 16:20:08 GMT", "version": "v1" } ]
2012-12-04
[ [ "Baykal", "Ahmet", "" ] ]
A conserved current for generic quadratic curvature gravitational models is defined, and it is shown that, at the linearized level, it corresponds to the Deser-Tekin charges. An explicit expression for the charge for new massive gravity in three dimensions is given. Some implications of the linearized equations are dis...
1604.08039
Sudipto Roy
Sudipto Roy, Mohsin Islam
A Study of Cosmic Expansion Generated by Non-conservation of Matter in the Framework of Brans-Dicke Theory
12 pages, 8 figures
International Journal of Physics and Mathematical Sciences, Volume 6, Number 2, pages 1-10, 2016
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The present study, on the expansion of universe, is based on an assumption regarding the possibility of inter-conversion between matter and dark energy, through some interaction of matter with the scalar field in the framework of Brans-Dicke theory. The field equations for a spatially flat space-time have been solved...
[ { "created": "Mon, 25 Apr 2016 20:00:11 GMT", "version": "v1" } ]
2017-11-07
[ [ "Roy", "Sudipto", "" ], [ "Islam", "Mohsin", "" ] ]
The present study, on the expansion of universe, is based on an assumption regarding the possibility of inter-conversion between matter and dark energy, through some interaction of matter with the scalar field in the framework of Brans-Dicke theory. The field equations for a spatially flat space-time have been solved u...
1103.0983
Umberto Cannella
Umberto Cannella
Effective Field Theory Methods in Gravitational Physics and Tests of Gravity
This PhD Thesis has been conducted at the University of Geneva (Switzerland) under the direction of Professor Michele Maggiore and the codirection of Doctor Riccardo Sturani. Version 2: abstract slightly changed; one typo corrected; layout issue fixed
null
null
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this PhD thesis I make use of the "Effective Field Theory of Gravity for Extended Objects" by Goldberger and Rothstein in order to investigate theories of gravity and to take a different point of view on the physical information that can be extracted from experiments. In the first work I present, I study a scalar-...
[ { "created": "Sat, 5 Mar 2011 20:34:05 GMT", "version": "v1" }, { "created": "Tue, 19 Apr 2011 16:11:32 GMT", "version": "v2" } ]
2015-03-19
[ [ "Cannella", "Umberto", "" ] ]
In this PhD thesis I make use of the "Effective Field Theory of Gravity for Extended Objects" by Goldberger and Rothstein in order to investigate theories of gravity and to take a different point of view on the physical information that can be extracted from experiments. In the first work I present, I study a scalar-te...
0812.0428
Prasanta Mahato Prin.
Prasanta Mahato
Torsion and Axial Current
13 pages, no figure
ICFAI Univ. Jour. of Phys.,2,(2009),92-104
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The role of torsion and a scalar field $\phi$ in gravitation, especially, in the presence of a Dirac field in the background of a particular class of the Riemann-Cartan geometry is considered here. Recently, a Lagrangian density with Lagrange multipliers has been proposed by the author which has been obtained by pick...
[ { "created": "Tue, 2 Dec 2008 04:52:39 GMT", "version": "v1" }, { "created": "Sat, 6 Dec 2008 17:16:40 GMT", "version": "v2" } ]
2009-09-04
[ [ "Mahato", "Prasanta", "" ] ]
The role of torsion and a scalar field $\phi$ in gravitation, especially, in the presence of a Dirac field in the background of a particular class of the Riemann-Cartan geometry is considered here. Recently, a Lagrangian density with Lagrange multipliers has been proposed by the author which has been obtained by pickin...
1012.0953
Francisco Lobo
Nadiezhda Montelongo Garc\'ia, Tiberiu Harko, Francisco S. N. Lobo, Jos\'e P. Mimoso
f(G) modified gravity and the energy conditions
4 pages. Prepared for the proceedings of the Spanish Relativity meeting (ERE2010), Granada, Spain, 6-10 Sep 2010
J.Phys.Conf.Ser.314:012060,2011
10.1088/1742-6596/314/1/012056
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by string/M-theory predictions that scalar field couplings with the Gauss-Bonnet invariant, G, are essential in the appearance of non-singular early time cosmologies, we discuss the viability of an interesting alternative gravitational theory, namely, modified Gauss-Bonnet gravity, and present the viability...
[ { "created": "Sat, 4 Dec 2010 22:24:39 GMT", "version": "v1" } ]
2015-03-17
[ [ "García", "Nadiezhda Montelongo", "" ], [ "Harko", "Tiberiu", "" ], [ "Lobo", "Francisco S. N.", "" ], [ "Mimoso", "José P.", "" ] ]
Motivated by string/M-theory predictions that scalar field couplings with the Gauss-Bonnet invariant, G, are essential in the appearance of non-singular early time cosmologies, we discuss the viability of an interesting alternative gravitational theory, namely, modified Gauss-Bonnet gravity, and present the viability b...
2301.05083
Karim Mosani
Karim Mosani, Koushiki, Pankaj S. Joshi, Jay Verma Trivedi, and Tapobroto Bhanja
Gravitational collapse of scalar and vector fields
null
null
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We study here the unhindered gravitational collapse of spatially homogeneous (SH) scalar fields $\phi$ with a potential $V_{s}(\phi)$, as well as vector fields $\tilde{A}$ with a potential $V_{v}(B)$ where $B=g(\tilde{A},\tilde{A})$ and $g$ is the metric tensor. We show that in both cases, classes of potentials exist...
[ { "created": "Thu, 12 Jan 2023 15:33:21 GMT", "version": "v1" } ]
2023-01-13
[ [ "Mosani", "Karim", "" ], [ "Koushiki", "", "" ], [ "Joshi", "Pankaj S.", "" ], [ "Trivedi", "Jay Verma", "" ], [ "Bhanja", "Tapobroto", "" ] ]
We study here the unhindered gravitational collapse of spatially homogeneous (SH) scalar fields $\phi$ with a potential $V_{s}(\phi)$, as well as vector fields $\tilde{A}$ with a potential $V_{v}(B)$ where $B=g(\tilde{A},\tilde{A})$ and $g$ is the metric tensor. We show that in both cases, classes of potentials exist t...
gr-qc/9812045
Massar Serge
S. Massar and R. Parentani
Unitary and non-unitary evolution in quantum cosmology
26 pages, latex; minor corrections, final version to appear in Phys. Rev. D
Phys. Rev. D 59, 123519 (1999)
10.1103/PhysRevD.59.123519
ULB-TH/98-17
gr-qc
null
We analyse when and why unitarity violations might occur in quantum cosmology restricted to minisuperspace. To this end we discuss in detail backscattering transitions between expanding and contracting solutions of the Wheeler-DeWitt equation. We first show that upon neglecting only backscattering, one obtains an int...
[ { "created": "Mon, 14 Dec 1998 11:26:46 GMT", "version": "v1" }, { "created": "Wed, 21 Apr 1999 07:56:16 GMT", "version": "v2" } ]
2016-08-25
[ [ "Massar", "S.", "" ], [ "Parentani", "R.", "" ] ]
We analyse when and why unitarity violations might occur in quantum cosmology restricted to minisuperspace. To this end we discuss in detail backscattering transitions between expanding and contracting solutions of the Wheeler-DeWitt equation. We first show that upon neglecting only backscattering, one obtains an inter...
2401.11273
Vasilis Oikonomou
V.K. Oikonomou, Pyotr Tsyba, Olga Razina
Einstein-Gauss-Bonnet Cosmological Theories at Reheating and at the End of the Inflationary Era
AoP accepted
null
null
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we study the GW170817-compatible Einstein-Gauss-Bonnet theories during the reheating and the end of inflationary era. Given the scalar field potential $V(\phi)$ which can have some intrinsic importance for the theory, determining the scalar coupling function $\xi(\phi)$ can be cumbersome due to lack of a...
[ { "created": "Sat, 20 Jan 2024 17:03:04 GMT", "version": "v1" } ]
2024-01-23
[ [ "Oikonomou", "V. K.", "" ], [ "Tsyba", "Pyotr", "" ], [ "Razina", "Olga", "" ] ]
In this work we study the GW170817-compatible Einstein-Gauss-Bonnet theories during the reheating and the end of inflationary era. Given the scalar field potential $V(\phi)$ which can have some intrinsic importance for the theory, determining the scalar coupling function $\xi(\phi)$ can be cumbersome due to lack of ana...
1707.00255
Thomas Cailleteau Mr
Thomas Cailleteau
Langton's Ant from the Ant's referential
First part of the work
null
null
null
gr-qc nlin.CG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The evolution of the Langton's ant on a 2D lattice is studied from the "ant's framework". The aim of this article is twofold. Firstly, to see if one can explain the emergent behaviour of the ant as an analogous sytem of a particle crossing an horizon. Secondly, pointing toward some directions for an explanation, the ...
[ { "created": "Sun, 2 Jul 2017 08:18:05 GMT", "version": "v1" } ]
2017-07-04
[ [ "Cailleteau", "Thomas", "" ] ]
The evolution of the Langton's ant on a 2D lattice is studied from the "ant's framework". The aim of this article is twofold. Firstly, to see if one can explain the emergent behaviour of the ant as an analogous sytem of a particle crossing an horizon. Secondly, pointing toward some directions for an explanation, the ev...
2404.05677
Bruce Allen
Bruce Allen
Pulsar Timing Array Harmonic Analysis and Source Angular Correlations
Updated with citations to recent work by others; shifted to covariance C(O.O') to unify notation with [51]. 22 pages, 1 figure
null
null
null
gr-qc astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Gravitational waves (GWs) influence the arrival times of radio signals coming from pulsars. Here, we investigate the harmonic space approach to describing a pulsar's response to GWs. We derive and discuss the "diagonalized form" of the response, which is a sum of spin-2-weighted spherical harmonics of the GW directio...
[ { "created": "Mon, 8 Apr 2024 16:56:45 GMT", "version": "v1" }, { "created": "Mon, 29 Apr 2024 16:42:34 GMT", "version": "v2" } ]
2024-04-30
[ [ "Allen", "Bruce", "" ] ]
Gravitational waves (GWs) influence the arrival times of radio signals coming from pulsars. Here, we investigate the harmonic space approach to describing a pulsar's response to GWs. We derive and discuss the "diagonalized form" of the response, which is a sum of spin-2-weighted spherical harmonics of the GW direction ...
1208.3796
Stanley P. Gudder
Stanley P Gudder
The Causal Poset is Directed but not Lattice Ordered
The counterexample is incorrect. Thanks to Rafael Sorkin and David Rideout for pointing this out
null
null
null
gr-qc quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the causal set approach to discrete quantum gravity the universe grows one element at a time in discrete steps. At each step the process has the form of a causal set (causet) and the "completed" universe is given by a path through a discretely growing chain of causets. The collection of causets forms a partially o...
[ { "created": "Sun, 19 Aug 2012 01:10:24 GMT", "version": "v1" }, { "created": "Sat, 28 Sep 2013 18:49:40 GMT", "version": "v2" } ]
2013-10-01
[ [ "Gudder", "Stanley P", "" ] ]
In the causal set approach to discrete quantum gravity the universe grows one element at a time in discrete steps. At each step the process has the form of a causal set (causet) and the "completed" universe is given by a path through a discretely growing chain of causets. The collection of causets forms a partially ord...
0811.4129
Martin Bojowald
Martin Bojowald
Consistent Loop Quantum Cosmology
13 pages
Class.Quant.Grav.26:075020,2009
10.1088/0264-9381/26/7/075020
IGC-08/11-5
gr-qc astro-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A consistent combination of quantum geometry effects rules out a large class of models of loop quantum cosmology and their critical densities as they have been used in the recent literature. In particular, the critical density at which an isotropic universe filled with a free, massless scalar field would bounce must ...
[ { "created": "Tue, 25 Nov 2008 16:58:46 GMT", "version": "v1" } ]
2009-03-27
[ [ "Bojowald", "Martin", "" ] ]
A consistent combination of quantum geometry effects rules out a large class of models of loop quantum cosmology and their critical densities as they have been used in the recent literature. In particular, the critical density at which an isotropic universe filled with a free, massless scalar field would bounce must be...
0709.3302
Salvador Robles-Perez
S. Robles-Perez, Y. Hassouni and P. F. Gonzalez-Diaz
Coherent states in quantum cosmology
6 pages, 2 figures
null
null
null
gr-qc
null
In the realm of a quantum cosmological model for dark energy in which we have been able to construct a well-defined Hilbert space, a consistent coherent state representation has been formulated that may describe the quantum state of the universe and has a well-behaved semiclassical limit.
[ { "created": "Thu, 20 Sep 2007 20:16:17 GMT", "version": "v1" } ]
2007-09-24
[ [ "Robles-Perez", "S.", "" ], [ "Hassouni", "Y.", "" ], [ "Gonzalez-Diaz", "P. F.", "" ] ]
In the realm of a quantum cosmological model for dark energy in which we have been able to construct a well-defined Hilbert space, a consistent coherent state representation has been formulated that may describe the quantum state of the universe and has a well-behaved semiclassical limit.
gr-qc/9508027
Yoav Peleg
Sukanta Bose, Leonard Parker and Yoav Peleg (UWM)
Hawking Radiation and Unitary evolution
LaTex file + uuencoded ps version including 4 figures
Phys.Rev.Lett. 76 (1996) 861-864
10.1103/PhysRevLett.76.861
WISC-MILW-95-TH-17
gr-qc hep-th
null
We find a family of exact solutions to the semi-classical equations (including back-reaction) of two-dimensional dilaton gravity, describing infalling null matter that becomes outgoing and returns to infinity without forming a black hole. When a black hole almost forms, the radiation reaching infinity in advance of t...
[ { "created": "Thu, 10 Aug 1995 21:55:43 GMT", "version": "v1" }, { "created": "Fri, 11 Aug 1995 16:10:39 GMT", "version": "v2" } ]
2009-10-28
[ [ "Bose", "Sukanta", "", "UWM" ], [ "Parker", "Leonard", "", "UWM" ], [ "Peleg", "Yoav", "", "UWM" ] ]
We find a family of exact solutions to the semi-classical equations (including back-reaction) of two-dimensional dilaton gravity, describing infalling null matter that becomes outgoing and returns to infinity without forming a black hole. When a black hole almost forms, the radiation reaching infinity in advance of the...
2105.10178
Pedro Bargue\~no
Pedro Bargueno, Ernesto Contreras and Angel Rincon
Thermodynamics of scale-dependent Friedmann equations
To be published in EPJC
null
10.1140/epjc/s10052-021-09274-7
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
In this work, the role of a time-varying Newton constant under the scale-dependent approach is investigated in the thermodynamics of the Friedman equations. In particular, we show that the extended Friedman equations can be derived either from equilibrium thermodynamics when the non-matter energy momentum tensor is i...
[ { "created": "Fri, 21 May 2021 07:37:53 GMT", "version": "v1" } ]
2021-06-16
[ [ "Bargueno", "Pedro", "" ], [ "Contreras", "Ernesto", "" ], [ "Rincon", "Angel", "" ] ]
In this work, the role of a time-varying Newton constant under the scale-dependent approach is investigated in the thermodynamics of the Friedman equations. In particular, we show that the extended Friedman equations can be derived either from equilibrium thermodynamics when the non-matter energy momentum tensor is int...
2207.14652
Mikhail Altaisky
Mikhail Altaisky and Robin Raj
Can our spacetime emerge from anti -- de Sitter space?
LaTeX, 4 pages, 2 eps figures
Physics of Particles and Nuclei Letters, 2022, vol.19, No 4, pp.313-316
10.1134/S1547477122040033
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We present a model showing that our four-dimensional spacetime with the signature $(+,-,-,-)$ and almost vanishing positive curvature may have originated from a $b$-ary tree-like branching of a single discrete entity, and the $AdS_5$ space related to this branching process.
[ { "created": "Wed, 27 Jul 2022 05:23:35 GMT", "version": "v1" } ]
2022-08-01
[ [ "Altaisky", "Mikhail", "" ], [ "Raj", "Robin", "" ] ]
We present a model showing that our four-dimensional spacetime with the signature $(+,-,-,-)$ and almost vanishing positive curvature may have originated from a $b$-ary tree-like branching of a single discrete entity, and the $AdS_5$ space related to this branching process.
0801.4584
Abel Camacho Mr.
Alfredo Macias, Abel Camacho, Jutta Kunz, Claus Laemmerzahl
Midisuperspace Supersymmetric Quantum Cosmology
Accepted in Physical Review D
Phys.Rev.D77:064009,2008
10.1103/PhysRevD.77.064009
null
gr-qc
null
We investigate the canonical quantization in the framework of N=1 simple supergravity for the case of a very simple gravitational midisuperspace described by Gowdy $T^3$ cosmological models. We consider supersymmetric quantum cosmology in the mentioned midisuperspace, where a matrix representation for the gravitino c...
[ { "created": "Tue, 29 Jan 2008 23:58:42 GMT", "version": "v1" } ]
2008-11-26
[ [ "Macias", "Alfredo", "" ], [ "Camacho", "Abel", "" ], [ "Kunz", "Jutta", "" ], [ "Laemmerzahl", "Claus", "" ] ]
We investigate the canonical quantization in the framework of N=1 simple supergravity for the case of a very simple gravitational midisuperspace described by Gowdy $T^3$ cosmological models. We consider supersymmetric quantum cosmology in the mentioned midisuperspace, where a matrix representation for the gravitino cov...
gr-qc/0611022
Kirill Bronnikov
K.A. Bronnikov, H. Dehnen, V.N. Melnikov
Regular black holes and black universes
13 pages, 1 figure. 6 referenses and some discussion added, misprints corrected
Gen.Rel.Grav.39:973-987,2007
10.1007/s10714-007-0430-6
null
gr-qc
null
We give a comparative description of different types of regular static, spherically symmetric black holes (BHs) and discuss in more detail their particular type, which we suggest to call black universes. The latter have a Schwarzschild-like causal structure, but inside the horizon there is an expanding Kantowski-Sach...
[ { "created": "Fri, 3 Nov 2006 15:28:27 GMT", "version": "v1" }, { "created": "Sun, 12 Nov 2006 18:08:31 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bronnikov", "K. A.", "" ], [ "Dehnen", "H.", "" ], [ "Melnikov", "V. N.", "" ] ]
We give a comparative description of different types of regular static, spherically symmetric black holes (BHs) and discuss in more detail their particular type, which we suggest to call black universes. The latter have a Schwarzschild-like causal structure, but inside the horizon there is an expanding Kantowski-Sachs ...
2103.10555
Jens Boos
Jens Boos, Ivan Kol\'a\v{r}
Non-locality and gravitoelectromagnetic duality
8 pages, comments welcome!
Phys. Rev. D 104, 024018 (2021)
10.1103/PhysRevD.104.024018
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The weak-field Schwarzschild and NUT solutions of general relativity are gravitoelectromagnetically dual to each other, except on the positive $z$-axis. The presence of non-locality weakens this duality and violates it within a smeared region around the positive $z$-axis, whose typical transverse size is given by the...
[ { "created": "Thu, 18 Mar 2021 22:51:38 GMT", "version": "v1" } ]
2021-07-14
[ [ "Boos", "Jens", "" ], [ "Kolář", "Ivan", "" ] ]
The weak-field Schwarzschild and NUT solutions of general relativity are gravitoelectromagnetically dual to each other, except on the positive $z$-axis. The presence of non-locality weakens this duality and violates it within a smeared region around the positive $z$-axis, whose typical transverse size is given by the s...
gr-qc/9705085
Alexander L. Gromov
Vladik Kreinovich and R. R. Zapatrin
An operationalistic reformulation of Einstein's equivalence principle
latex
null
null
IRB-MSP-970530
gr-qc
null
The Einstein's equivalence principle is formulated in terms of the accuracy of measurements and its dependence of the size of the area of measurement. It is shown that different refinements of the statement 'the spacetime is locally flat' lead to different conculsions about the spacetime geometry.
[ { "created": "Fri, 30 May 1997 20:30:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kreinovich", "Vladik", "" ], [ "Zapatrin", "R. R.", "" ] ]
The Einstein's equivalence principle is formulated in terms of the accuracy of measurements and its dependence of the size of the area of measurement. It is shown that different refinements of the statement 'the spacetime is locally flat' lead to different conculsions about the spacetime geometry.
1604.00075
Jonah Miller
Jonah M. Miller and Erik Schnetter
An Operator-Based Local Discontinuous Galerkin Method Compatible With the BSSN Formulation of the Einstein Equations
Incorporated referee comments during peer-review. Added several references pointed out to us. Added a figure and discussion comparing pointwise error for 4th- and 5th-order stencils for wave equation
Class. Quantum Grav. 34 (2017) 1
10.1088/1361-6382/34/1/015003
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Discontinuous Galerkin Finite Element (DGFE) methods offer a mathematically beautiful, computationally efficient, and efficiently parallelizable way to solve hyperbolic partial differential equations. These properties make them highly desirable for numerical calculations in relativistic astrophysics and many other fi...
[ { "created": "Thu, 31 Mar 2016 23:06:49 GMT", "version": "v1" }, { "created": "Thu, 14 Apr 2016 16:24:58 GMT", "version": "v2" }, { "created": "Mon, 14 Nov 2016 23:00:37 GMT", "version": "v3" } ]
2016-12-12
[ [ "Miller", "Jonah M.", "" ], [ "Schnetter", "Erik", "" ] ]
Discontinuous Galerkin Finite Element (DGFE) methods offer a mathematically beautiful, computationally efficient, and efficiently parallelizable way to solve hyperbolic partial differential equations. These properties make them highly desirable for numerical calculations in relativistic astrophysics and many other fiel...
0710.5656
Sergey Sushkov
P.E. Kashargin and S.V. Sushkov
Slowly rotating wormholes: the first order approximation
7 pages, 2 figures, submitted to Gravitation and Cosmology
Grav.Cosmol.14:80-85,2008
10.1007/s12267-008-1010-y
null
gr-qc
null
We discuss a solution describing a rotating wormhole in the theory of gravity with a scalar field with negative kinetic energy. To solve the problem we use the assumption about slow rotation. The role of a small dimensionless parameter plays the ratio of the linear velocity of rotation of the wormhole's throat and th...
[ { "created": "Tue, 30 Oct 2007 14:26:53 GMT", "version": "v1" } ]
2009-11-13
[ [ "Kashargin", "P. E.", "" ], [ "Sushkov", "S. V.", "" ] ]
We discuss a solution describing a rotating wormhole in the theory of gravity with a scalar field with negative kinetic energy. To solve the problem we use the assumption about slow rotation. The role of a small dimensionless parameter plays the ratio of the linear velocity of rotation of the wormhole's throat and the ...
2111.05732
Javier Bad\'ia
Javier Bad\'ia, Ernesto F. Eiroa
Shadow of a charged black hole surrounded by an anisotropic matter field
8 pages, 5 figures; prepared for the Proceedings of the Sixteenth Marcel Grossmann Meeting - MG16
Proceedings of the Sixteenth Marcel Grossmann Meeting (MG16), pages 1343-1350 (World Scientific, Singapore, 2023)
10.1142/9789811269776_0108
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A certain type of matter with anisotropic pressures can add to the Reissner-Nordstr\"om metric a term proportional to a power of the radial coordinate. Using the standard method of separating variables for the Hamilton-Jacobi equation, we study the shadow of the corresponding rotating solution, obtained through the N...
[ { "created": "Wed, 10 Nov 2021 15:13:43 GMT", "version": "v1" } ]
2023-01-30
[ [ "Badía", "Javier", "" ], [ "Eiroa", "Ernesto F.", "" ] ]
A certain type of matter with anisotropic pressures can add to the Reissner-Nordstr\"om metric a term proportional to a power of the radial coordinate. Using the standard method of separating variables for the Hamilton-Jacobi equation, we study the shadow of the corresponding rotating solution, obtained through the New...
gr-qc/0201087
Sergey Alexandrov
Sergei Alexandrov
Hilbert space structure of covariant loop quantum gravity
20 pages, RevTEX
Phys.Rev. D66 (2002) 024028
10.1103/PhysRevD.66.024028
null
gr-qc
null
We investigate the Hilbert space in the Lorentz covariant approach to loop quantum gravity. We restrict ourselves to the space where all area operators are simultaneously diagonalizable, assuming that it exists. In this sector quantum states are realized by a generalization of spin network states based on Lorentz Wil...
[ { "created": "Mon, 28 Jan 2002 21:33:37 GMT", "version": "v1" } ]
2009-11-07
[ [ "Alexandrov", "Sergei", "" ] ]
We investigate the Hilbert space in the Lorentz covariant approach to loop quantum gravity. We restrict ourselves to the space where all area operators are simultaneously diagonalizable, assuming that it exists. In this sector quantum states are realized by a generalization of spin network states based on Lorentz Wilso...
2105.13260
Marcus Khuri
Marcus Khuri, Gilbert Weinstein, Sumio Yamada
Balancing Static Vacuum Black Holes with Signed Masses in 4 and 5 Dimensions
35 pages, 7 figures
Phys. Rev. D 104, 044063 (2021)
10.1103/PhysRevD.104.044063
null
gr-qc hep-th math.DG
http://creativecommons.org/licenses/by/4.0/
We construct a new set of asymptotically flat, static vacuum solutions to the Einstein equations in dimensions 4 and 5, which may be interpreted as a superposition of positive and negative mass black holes. The resulting spacetimes are axisymmetric in 4-dimensions and bi-axisymmetric in 5-dimensions, and are regular ...
[ { "created": "Thu, 27 May 2021 15:56:54 GMT", "version": "v1" }, { "created": "Thu, 26 Aug 2021 19:22:05 GMT", "version": "v2" } ]
2021-09-01
[ [ "Khuri", "Marcus", "" ], [ "Weinstein", "Gilbert", "" ], [ "Yamada", "Sumio", "" ] ]
We construct a new set of asymptotically flat, static vacuum solutions to the Einstein equations in dimensions 4 and 5, which may be interpreted as a superposition of positive and negative mass black holes. The resulting spacetimes are axisymmetric in 4-dimensions and bi-axisymmetric in 5-dimensions, and are regular aw...
gr-qc/9804056
George Lavrelashvili
George Lavrelashvili
On the quadratic action of the Hawking-Turok instanton
8 pages, REVTeX, 4 eps figures (included); statement concerning the CD solution is corrected and few other minor changes are made
Phys. Rev. D 58, 063505 (1998)
10.1103/PhysRevD.58.063505
BUTP-98/12
gr-qc hep-th
null
Positive definiteness of the quadratic part of the action of the Hawking-Turok instanton is investigated. The Euclidean quadratic action for scalar perturbations is expressed in terms of a single gauge invariant quantity $q$. The mode functions satisfy a Schr\"odinger type equation with a potential $U$. It is shown t...
[ { "created": "Wed, 22 Apr 1998 18:12:39 GMT", "version": "v1" }, { "created": "Fri, 1 May 1998 21:32:00 GMT", "version": "v2" } ]
2016-08-25
[ [ "Lavrelashvili", "George", "" ] ]
Positive definiteness of the quadratic part of the action of the Hawking-Turok instanton is investigated. The Euclidean quadratic action for scalar perturbations is expressed in terms of a single gauge invariant quantity $q$. The mode functions satisfy a Schr\"odinger type equation with a potential $U$. It is shown tha...
2106.10425
Pramit Rej
Piyali Bhar, Pramit Rej, P. Mafa Takisa, and M. Zubair
Relativistic compact stars in Tolman spacetime via an anisotropic approach
18 Pages, 8 Figures, Accepted in European Physical Journal C on 12.06.2021
The European Physical Journal C 81, 531 (2021)
10.1140/epjc/s10052-021-09340-0
null
gr-qc astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this present work, we have obtained a singularity-free spherically symmetric stellar model with anisotropic pressure in the background of Einstein's general theory of relativity. The Einstein's field equations have been solved by exploiting Tolman {\em ansatz} [Richard C Tolman, Phys. Rev. 55:364, 1939] in $(3+1)$...
[ { "created": "Sat, 19 Jun 2021 05:22:30 GMT", "version": "v1" } ]
2021-06-23
[ [ "Bhar", "Piyali", "" ], [ "Rej", "Pramit", "" ], [ "Takisa", "P. Mafa", "" ], [ "Zubair", "M.", "" ] ]
In this present work, we have obtained a singularity-free spherically symmetric stellar model with anisotropic pressure in the background of Einstein's general theory of relativity. The Einstein's field equations have been solved by exploiting Tolman {\em ansatz} [Richard C Tolman, Phys. Rev. 55:364, 1939] in $(3+1)$-d...
1502.04640
Jonathan Engle
Jonathan Engle and Antonia Zipfel
The Lorentzian proper vertex amplitude: Classical analysis and quantum derivation
36 pages; references corrected
Phys. Rev. D 94, 064024 (2016)
10.1103/PhysRevD.94.064024
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Spin foam models, an approach to defining the dynamics of loop quantum gravity, make use of the Plebanski formulation of gravity, in which gravity is recovered from a topological field theory via certain constraints called simplicity constraints. However, the simplicity constraints in their usual form select more tha...
[ { "created": "Mon, 16 Feb 2015 17:28:27 GMT", "version": "v1" }, { "created": "Tue, 31 May 2016 12:20:16 GMT", "version": "v2" } ]
2016-09-14
[ [ "Engle", "Jonathan", "" ], [ "Zipfel", "Antonia", "" ] ]
Spin foam models, an approach to defining the dynamics of loop quantum gravity, make use of the Plebanski formulation of gravity, in which gravity is recovered from a topological field theory via certain constraints called simplicity constraints. However, the simplicity constraints in their usual form select more than ...
1206.5413
Jose Socorro Garcia
Juan M. Ram\'irez and J. Socorro
FRW in cosmological self-creation theory
10 pages in latex, 4 figures
acepted in Int. J. of Theor. Phys. (2013)
10.1007/s10773-013-1580-9
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use the Brans-Dicke theory from the framework of General Relativity (Einstein frame), but now the total energy momentum tensor fulfills the following condition $\rm <[\{1}{\phi}T^{\mu \nu M}+T^{\mu \nu}(\phi)>]_{;\nu}=0$. We take as a first model the flat FRW metric and with the law of variation for Hubble's param...
[ { "created": "Sat, 23 Jun 2012 17:02:10 GMT", "version": "v1" }, { "created": "Tue, 7 May 2013 20:45:16 GMT", "version": "v2" } ]
2013-05-09
[ [ "Ramírez", "Juan M.", "" ], [ "Socorro", "J.", "" ] ]
We use the Brans-Dicke theory from the framework of General Relativity (Einstein frame), but now the total energy momentum tensor fulfills the following condition $\rm <[\{1}{\phi}T^{\mu \nu M}+T^{\mu \nu}(\phi)>]_{;\nu}=0$. We take as a first model the flat FRW metric and with the law of variation for Hubble's paramet...
2005.01784
Olesya Galkina
Olesya Galkina, Alexander Yu. Kamenshchik
Future soft singularities, Born-Infeld-like fields and particles
13 pages, 1 figure. Final version to be published in PRD
Phys. Rev. D 102, 024078 (2020)
10.1103/PhysRevD.102.024078
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider different scenarios of the evolution of the universe, where the singularities or some non-analyticities in the geometry of the spacetime are present, trying to answer the following question: is it possible to conserve some kind of notion of particle corresponding to a chosen quantum field present in the u...
[ { "created": "Mon, 4 May 2020 18:43:35 GMT", "version": "v1" }, { "created": "Tue, 21 Jul 2020 18:45:48 GMT", "version": "v2" } ]
2020-08-05
[ [ "Galkina", "Olesya", "" ], [ "Kamenshchik", "Alexander Yu.", "" ] ]
We consider different scenarios of the evolution of the universe, where the singularities or some non-analyticities in the geometry of the spacetime are present, trying to answer the following question: is it possible to conserve some kind of notion of particle corresponding to a chosen quantum field present in the uni...
2311.17993
Mehrab Momennia
Diego A. Martinez-Valera, Mehrab Momennia, Alfredo Herrera-Aguilar
Observational redshift from general spherically symmetric black holes
9 pages with 3 captioned figures. Comments are welcome; V2: Published version
Eur. Phys. J. C 84 (2024) 288
10.1140/epjc/s10052-024-12649-1
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
In this work, we obtain an expression for the total observational frequency shift of photons emitted by massive geodesic particles circularly orbiting a black hole in a general spherically symmetric background. Our general relations are presented in terms of the metric components and their derivatives that characteri...
[ { "created": "Wed, 29 Nov 2023 19:00:00 GMT", "version": "v1" }, { "created": "Sun, 24 Mar 2024 22:32:17 GMT", "version": "v2" } ]
2024-03-26
[ [ "Martinez-Valera", "Diego A.", "" ], [ "Momennia", "Mehrab", "" ], [ "Herrera-Aguilar", "Alfredo", "" ] ]
In this work, we obtain an expression for the total observational frequency shift of photons emitted by massive geodesic particles circularly orbiting a black hole in a general spherically symmetric background. Our general relations are presented in terms of the metric components and their derivatives that characterize...
1904.05109
Kodai Ueda
Vitor Cardoso, Takahisa Igata, Akihiro Ishibashi and Kodai Ueda
Massive tensor field perturbations on extremal and near-extremal static black holes
no figure, 24 pages
Phys. Rev. D 100, 044013 (2019)
10.1103/PhysRevD.100.044013
RUP-19-12
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a new perturbation method to study the dynamics of massive tensor fields on extremal and near-extremal static black hole spacetimes in arbitrary dimensions. On such backgrounds, one can classify the components of massive tensor fields into the tensor, vector, and scalar-type components. For the tensor-type...
[ { "created": "Wed, 10 Apr 2019 11:07:39 GMT", "version": "v1" } ]
2019-08-14
[ [ "Cardoso", "Vitor", "" ], [ "Igata", "Takahisa", "" ], [ "Ishibashi", "Akihiro", "" ], [ "Ueda", "Kodai", "" ] ]
We develop a new perturbation method to study the dynamics of massive tensor fields on extremal and near-extremal static black hole spacetimes in arbitrary dimensions. On such backgrounds, one can classify the components of massive tensor fields into the tensor, vector, and scalar-type components. For the tensor-type c...
2201.12295
Jan Sbierski
Jan Sbierski
Instability of the Kerr Cauchy horizon under linearised gravitational perturbations
102 pages, 9 figures; v2 accepted for publication in Annals of PDE
null
null
null
gr-qc math-ph math.AP math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper establishes a mathematical proof of the blue-shift instability at the sub-extremal Kerr Cauchy horizon for the linearised vacuum Einstein equations. More precisely, we exhibit conditions on the $s=+2$ Teukolsky field, consisting of suitable integrated upper and lower bounds on the decay along the event hor...
[ { "created": "Fri, 28 Jan 2022 18:00:05 GMT", "version": "v1" }, { "created": "Tue, 21 Mar 2023 09:38:27 GMT", "version": "v2" } ]
2023-03-22
[ [ "Sbierski", "Jan", "" ] ]
This paper establishes a mathematical proof of the blue-shift instability at the sub-extremal Kerr Cauchy horizon for the linearised vacuum Einstein equations. More precisely, we exhibit conditions on the $s=+2$ Teukolsky field, consisting of suitable integrated upper and lower bounds on the decay along the event horiz...
1903.10879
Peter Hess O
Peter O. Hess
Review on the pseudo-complex General Relativity and dark energy
24 pages10 figures, contribution to "Dark Matter and Dark Energy in General Relativity and Modified Theories of Gravity", Advances in High Energy Physics, Hindawi
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A review will be presented on the algebraic extension of the standard Theory of Relativity (GR) to the pseudo-complex formulation (pc-GR). The pc-GR predicts the existence of a dark energy outside and inside the mass distribution, corresponding to a modification of the GR- metric. The structure of the emission profil...
[ { "created": "Mon, 25 Mar 2019 16:49:08 GMT", "version": "v1" } ]
2019-03-27
[ [ "Hess", "Peter O.", "" ] ]
A review will be presented on the algebraic extension of the standard Theory of Relativity (GR) to the pseudo-complex formulation (pc-GR). The pc-GR predicts the existence of a dark energy outside and inside the mass distribution, corresponding to a modification of the GR- metric. The structure of the emission profile ...
2212.13311
Chen-Kai Qiao
Chen-Kai Qiao, Mi Zhou
Gravitational Lensing of Schwarzschild and Charged Black Holes Immersed in Perfect Fluid Dark Matter Halo
31 pages, 10 figures; V2 minor revision; V3 major revision (some errors removed)
JCAP 12 (2023) 005
10.1088/1475-7516/2023/12/005
null
gr-qc astro-ph.GA
http://creativecommons.org/licenses/by-nc-nd/4.0/
Dark matter and dark energy dominate the behavior of our universe. The dark matter usually forms halo structures in large number of galaxies. Properties of dark matter halo can be revealed and understood from the gravitational lensing observations. In this work, a comprehensive study on the gravitational lensing of b...
[ { "created": "Mon, 26 Dec 2022 22:26:38 GMT", "version": "v1" }, { "created": "Thu, 2 Feb 2023 17:04:19 GMT", "version": "v2" }, { "created": "Mon, 23 Oct 2023 21:02:45 GMT", "version": "v3" } ]
2024-03-12
[ [ "Qiao", "Chen-Kai", "" ], [ "Zhou", "Mi", "" ] ]
Dark matter and dark energy dominate the behavior of our universe. The dark matter usually forms halo structures in large number of galaxies. Properties of dark matter halo can be revealed and understood from the gravitational lensing observations. In this work, a comprehensive study on the gravitational lensing of bla...
2210.00295
Kun Meng
Kun Meng and Shao-Jun Zhang
Gravito-Electromagnetic Perturbations and QNMs of Regular Black Holes
21 pages, 2 figures, 3 tables, references added
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of Einstein's gravity coupled to nonlinear electromagnetic fields, we study gravito-electromagnetic perturbations of magnetic regular black holes. The master equations of perturbations are obtained through Chandrasekhar's procedure, in which gravitational perturbations with odd-parity are coupled to ...
[ { "created": "Sat, 1 Oct 2022 14:58:13 GMT", "version": "v1" }, { "created": "Sat, 8 Oct 2022 14:44:21 GMT", "version": "v2" } ]
2022-10-11
[ [ "Meng", "Kun", "" ], [ "Zhang", "Shao-Jun", "" ] ]
In the framework of Einstein's gravity coupled to nonlinear electromagnetic fields, we study gravito-electromagnetic perturbations of magnetic regular black holes. The master equations of perturbations are obtained through Chandrasekhar's procedure, in which gravitational perturbations with odd-parity are coupled to th...
gr-qc/0111035
Gian Paolo Vacca
F. Finelli, G. Marozzi, G. P. Vacca and G. Venturi
Energy-Momentum Tensor of Field Fluctuations in Massive Chaotic Inflation
revtex style, 24 pages, 6 eps figures Numerical checks added and moduli section improved
Phys.Rev.D65:103521,2002
10.1103/PhysRevD.65.103521
null
gr-qc astro-ph hep-ph hep-th
null
We study the renormalized energy-momentum tensor (EMT) of the inflaton fluctuations in rigid space-times during the slow-rollover regime for chaotic inflation with a mass term. We use dimensional regularization with adiabatic subtraction and introduce a novel analytic approximation for the inflaton fluctuations which...
[ { "created": "Tue, 13 Nov 2001 14:19:41 GMT", "version": "v1" }, { "created": "Tue, 27 Nov 2001 12:39:11 GMT", "version": "v2" } ]
2008-11-26
[ [ "Finelli", "F.", "" ], [ "Marozzi", "G.", "" ], [ "Vacca", "G. P.", "" ], [ "Venturi", "G.", "" ] ]
We study the renormalized energy-momentum tensor (EMT) of the inflaton fluctuations in rigid space-times during the slow-rollover regime for chaotic inflation with a mass term. We use dimensional regularization with adiabatic subtraction and introduce a novel analytic approximation for the inflaton fluctuations which i...
1712.08444
A. Yu. Petrov
J. R. Nascimento, A. Yu. Petrov, P. J. Porfirio
Traversable wormholes in Chern-Simons modified gravity
18 pages, 2 figures, revised version
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we examine the existence of traversable wormhole solutions within the Chern-Simons modified gravity. We find a non-trivial solution in the theory with dynamical Chern-Simons coefficient in the absence of matter sources. This result displays a situation opposite to GR where the matter sources violating ...
[ { "created": "Fri, 22 Dec 2017 13:53:55 GMT", "version": "v1" }, { "created": "Tue, 9 Jan 2018 13:52:13 GMT", "version": "v2" } ]
2018-01-10
[ [ "Nascimento", "J. R.", "" ], [ "Petrov", "A. Yu.", "" ], [ "Porfirio", "P. J.", "" ] ]
In this paper, we examine the existence of traversable wormhole solutions within the Chern-Simons modified gravity. We find a non-trivial solution in the theory with dynamical Chern-Simons coefficient in the absence of matter sources. This result displays a situation opposite to GR where the matter sources violating th...
1212.3699
Shan Bai
Shan Bai, Niall \'O Murchadha
Scaling up the extrinsic curvature in asymptotically flat gravitational initial data: Generating trapped surfaces
10 pages, accepted for publication in CQG
null
10.1088/0264-9381/30/2/025013
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The existence of the initial value constraints means that specifying initial data for the Einstein equations is non-trivial. The standard method of constructing initial data in the asymptotically flat case is to choose an asymptotically flat 3-metric and a transverse-tracefree (TT) tensor on it. One can find a confor...
[ { "created": "Sat, 15 Dec 2012 16:23:42 GMT", "version": "v1" } ]
2015-06-12
[ [ "Bai", "Shan", "" ], [ "Murchadha", "Niall Ó", "" ] ]
The existence of the initial value constraints means that specifying initial data for the Einstein equations is non-trivial. The standard method of constructing initial data in the asymptotically flat case is to choose an asymptotically flat 3-metric and a transverse-tracefree (TT) tensor on it. One can find a conforma...
2402.11348
Ayan Banerjee
Ayan Banerjee, Sudan Hansraj, Anirudh Pradhan and Abdelghani Errehymy
Is dark energy necessary for the sustainability of traversable wormholes?
18 pages, 10 figures, updated discussion, added references
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the standard approach to studying wormhole geometry, the presence of dark energy is unavoidable to ensure traversability. The dark energy provides the negative gravity effect to keep the throat open. The question we analyse is whether the same can be achieved without dark energy. It turns out that if we couple the...
[ { "created": "Sat, 17 Feb 2024 17:51:03 GMT", "version": "v1" }, { "created": "Thu, 25 Apr 2024 09:17:06 GMT", "version": "v2" } ]
2024-04-26
[ [ "Banerjee", "Ayan", "" ], [ "Hansraj", "Sudan", "" ], [ "Pradhan", "Anirudh", "" ], [ "Errehymy", "Abdelghani", "" ] ]
In the standard approach to studying wormhole geometry, the presence of dark energy is unavoidable to ensure traversability. The dark energy provides the negative gravity effect to keep the throat open. The question we analyse is whether the same can be achieved without dark energy. It turns out that if we couple the t...
gr-qc/9505041
James H. Horne
Douglas M. Eardley, Eric W. Hirschmann, James H. Horne
S-Duality at the Black Hole Threshold in Gravitational Collapse
8 pages of LaTeX, uses style "revtex"; 1 figure, available in archive, or at ftp://ftp.itp.ucsb.edu/figures/nsf-itp-95-15.eps
Phys.Rev.D52:5397-5401,1995
10.1103/PhysRevD.52.R5397
NSF-ITP-95-15 DAMTP-R95/27
gr-qc hep-th
null
We study gravitational collapse of the axion/dilaton field in classical low energy string theory, at the threshold for black hole formation. A new critical solution is derived that is spherically symmetric and continuously self-similar. The universal scaling and echoing behavior discovered by Choptuik in gravitationa...
[ { "created": "Mon, 22 May 1995 18:17:38 GMT", "version": "v1" } ]
2010-01-06
[ [ "Eardley", "Douglas M.", "" ], [ "Hirschmann", "Eric W.", "" ], [ "Horne", "James H.", "" ] ]
We study gravitational collapse of the axion/dilaton field in classical low energy string theory, at the threshold for black hole formation. A new critical solution is derived that is spherically symmetric and continuously self-similar. The universal scaling and echoing behavior discovered by Choptuik in gravitational ...
0907.3816
Mustapha Azreg-A\"inou
M Azreg-A\"inou
Comment on `The Newtonian force experienced by a point mass near a finite cylindrical source'
2 pages, LaTeX
Class.Quant.Grav.26:158001,2009
10.1088/0264-9381/26/15/158001
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compare the computation times and precisions of three expansions for the gravitational potential. The evaluation of the series by Selvaggi et al (2008 \textit{Class. Quantum Grav.} \textbf{25} 015013) is time-consuming to be applied to the gravitational constant ($G$) or STEP experiments.
[ { "created": "Wed, 22 Jul 2009 11:20:01 GMT", "version": "v1" } ]
2009-10-02
[ [ "Azreg-Aïnou", "M", "" ] ]
We compare the computation times and precisions of three expansions for the gravitational potential. The evaluation of the series by Selvaggi et al (2008 \textit{Class. Quantum Grav.} \textbf{25} 015013) is time-consuming to be applied to the gravitational constant ($G$) or STEP experiments.
1603.00112
Ichiro Oda
Ichiro Oda
Topological Induced Gravity
16 pages. arXiv admin note: text overlap with arXiv:1602.03478
null
10.1142/S0218271817500237
DPUR/TH/48
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a topological model of induced gravity (pregeometry) where both Newton's coupling constant and the cosmological constant appear as integration constants in solving field equations. The matter sector of a scalar field is also considered, and by solving field equations it is shown that various types of cosmo...
[ { "created": "Tue, 1 Mar 2016 02:00:08 GMT", "version": "v1" } ]
2017-02-15
[ [ "Oda", "Ichiro", "" ] ]
We propose a topological model of induced gravity (pregeometry) where both Newton's coupling constant and the cosmological constant appear as integration constants in solving field equations. The matter sector of a scalar field is also considered, and by solving field equations it is shown that various types of cosmolo...
gr-qc/0207051
Marcelo S. Berman
Marcelo Samuel Berman and Luis A. Trevisan
Inflationary Lambda-Universe with Time Varying Fundamental Constants
8 pages including front cover
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Barrow, and Barrow and collaborators, have put forward theoretical models with variable fundamental constants including JBD theories. The experimental evidence for an accelerating Universe points out to a deceleration parameter approximately equal to -- 1. On the other hand, there is evidence for a time varying fine ...
[ { "created": "Fri, 12 Jul 2002 14:54:57 GMT", "version": "v1" }, { "created": "Mon, 15 Jul 2002 20:42:22 GMT", "version": "v2" }, { "created": "Sat, 25 Jul 2009 23:58:08 GMT", "version": "v3" }, { "created": "Mon, 27 Jul 2009 23:17:48 GMT", "version": "v4" }, { "c...
2009-09-23
[ [ "Berman", "Marcelo Samuel", "" ], [ "Trevisan", "Luis A.", "" ] ]
Barrow, and Barrow and collaborators, have put forward theoretical models with variable fundamental constants including JBD theories. The experimental evidence for an accelerating Universe points out to a deceleration parameter approximately equal to -- 1. On the other hand, there is evidence for a time varying fine st...
1108.4519
Kourosh Nozari
Kourosh Nozari and Faeze Kiani
On the cosmological viability of the Hu-Sawicki type modified induced gravity
17 pages, 2 figures, accepted for publication in Phys. Lett. B
Phys.Lett.B703:395-401,2011
10.1016/j.physletb.2011.08.020
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been shown recently that the normal branch of a DGP braneworld scenario self-accelerates if the induced gravity on the brane is modified in the spirit of $f(R)$ modified gravity. Within this viewpoint, we investigate cosmological viability of the Hu-Sawicki type modified induced gravity. Firstly, we present a ...
[ { "created": "Tue, 23 Aug 2011 07:55:09 GMT", "version": "v1" } ]
2011-09-27
[ [ "Nozari", "Kourosh", "" ], [ "Kiani", "Faeze", "" ] ]
It has been shown recently that the normal branch of a DGP braneworld scenario self-accelerates if the induced gravity on the brane is modified in the spirit of $f(R)$ modified gravity. Within this viewpoint, we investigate cosmological viability of the Hu-Sawicki type modified induced gravity. Firstly, we present a dy...
2312.03811
Matthew J. Lake Dr
Matthew J. Lake and Marek Miller
Quantum reference frames, revisited
95 pages, including 13 pages of references. 13 figures. Comments welcome
null
null
null
gr-qc hep-ph quant-ph
http://creativecommons.org/licenses/by/4.0/
The topic of quantum reference frames (QRFs) has attracted a great deal of attention in the recent literature. Potentially, the correct description of such frames is important for both the technological applications of quantum mechanics and for its foundations, including the search for a future theory of quantum grav...
[ { "created": "Wed, 6 Dec 2023 18:15:52 GMT", "version": "v1" } ]
2023-12-08
[ [ "Lake", "Matthew J.", "" ], [ "Miller", "Marek", "" ] ]
The topic of quantum reference frames (QRFs) has attracted a great deal of attention in the recent literature. Potentially, the correct description of such frames is important for both the technological applications of quantum mechanics and for its foundations, including the search for a future theory of quantum gravit...
gr-qc/0012001
Spiros Cotsakis
Spiros Cotsakis and John Miritzis
Algebraic integrability of FRW-scalar cosmologies
Research announcement, 2 pages, submitted for publication in the MG9 Proceedings
null
null
null
gr-qc
null
For dynamical systems of dimension three or more the question of integrability or nonintegrability is extended by the possibility of chaotic behaviour in the general solution. We determine the integrability of isotropic cosmological models in general relativity and string theory with a variety of matter terms, by a p...
[ { "created": "Fri, 1 Dec 2000 11:29:02 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cotsakis", "Spiros", "" ], [ "Miritzis", "John", "" ] ]
For dynamical systems of dimension three or more the question of integrability or nonintegrability is extended by the possibility of chaotic behaviour in the general solution. We determine the integrability of isotropic cosmological models in general relativity and string theory with a variety of matter terms, by a per...
gr-qc/0702056
Calvin Smith
Christopher J. Fewster and Calvin J. Smith
Absolute quantum energy inequalities in curved spacetime
31 pages. Corrections and clarifications added. Final version to appear in Ann. H. Poincare
AnnalesHenriPoincare9:425-455,2008
10.1007/s00023-008-0361-0
null
gr-qc
null
Quantum Energy Inequalities (QEIs) are results which limit the extent to which the smeared renormalised energy density of the quantum field can be negative, when averaged along a timelike curve or over a more general timelike submanifold in spacetime. On globally hyperbolic spacetimes the minimally-coupled massive qu...
[ { "created": "Fri, 9 Feb 2007 12:43:33 GMT", "version": "v1" }, { "created": "Thu, 22 Feb 2007 17:00:01 GMT", "version": "v2" }, { "created": "Thu, 20 Dec 2007 09:42:54 GMT", "version": "v3" } ]
2008-11-26
[ [ "Fewster", "Christopher J.", "" ], [ "Smith", "Calvin J.", "" ] ]
Quantum Energy Inequalities (QEIs) are results which limit the extent to which the smeared renormalised energy density of the quantum field can be negative, when averaged along a timelike curve or over a more general timelike submanifold in spacetime. On globally hyperbolic spacetimes the minimally-coupled massive quan...
2209.14484
Stephen Adler
Stephen L. Adler
Equation of state, and atomic electron effective potential, for a Weyl scaling invariant dark energy
10 pages. Sec. I Introduction expanded. Sec. II on w and the figures are new. Secs. III and IV are the original 2208.14484 with minor edits. This posting will be submitted for publication
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A key attribute of dark energy is the equation of state parameter $w={\rm pressure}/{\rm energy~density}$, and this has been recently measured observationally, giving values close to $-1$. In this paper we calculate the $w$ parameter characterizing the novel Weyl scaling invariant dark energy that we have analyzed in...
[ { "created": "Thu, 29 Sep 2022 00:30:11 GMT", "version": "v1" }, { "created": "Wed, 21 Feb 2024 20:02:40 GMT", "version": "v2" }, { "created": "Sat, 15 Jun 2024 02:40:30 GMT", "version": "v3" } ]
2024-06-18
[ [ "Adler", "Stephen L.", "" ] ]
A key attribute of dark energy is the equation of state parameter $w={\rm pressure}/{\rm energy~density}$, and this has been recently measured observationally, giving values close to $-1$. In this paper we calculate the $w$ parameter characterizing the novel Weyl scaling invariant dark energy that we have analyzed in a...
1802.09073
Mariafelicia De Laurentis Professor
Mariafelicia De Laurentis
Noether's stars in $f(\cal {R})$ gravity
7 pages, 4 figures, accepted for publication in Physics Letter B
null
10.1016/j.physletb.2018.03.001
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Noether Symmetry Approach can be used to construct spherically symmetric solutions in $f({\cal R})$ gravity. Specifically, the Noether conserved quantity is related to the gravitational mass and a gravitational radius that reduces to the Schwarzschild radius in the limit $f({\cal R})\rightarrow {\cal R}$. We show...
[ { "created": "Sun, 25 Feb 2018 20:37:07 GMT", "version": "v1" } ]
2018-04-04
[ [ "De Laurentis", "Mariafelicia", "" ] ]
The Noether Symmetry Approach can be used to construct spherically symmetric solutions in $f({\cal R})$ gravity. Specifically, the Noether conserved quantity is related to the gravitational mass and a gravitational radius that reduces to the Schwarzschild radius in the limit $f({\cal R})\rightarrow {\cal R}$. We show t...
gr-qc/9408033
Jorma Louko
Jorma Louko
Chern-Simons functional and the no-boundary proposal in Bianchi IX quantum cosmology
9 pages, REVTeX v3.0. (One reference added.)
Phys.Rev.D51:586-590,1995
10.1103/PhysRevD.51.586
WISC-MILW-94-TH-20
gr-qc hep-th
null
The Chern-Simons functional $S_{\rm CS}$ is an exact solution to the Ashtekar-Hamilton-Jacobi equation of general relativity with a nonzero cosmological constant. In this paper we consider $S_{\rm CS}$ in Bianchi type IX cosmology with $S^3$ spatial surfaces. We show that among the classical solutions generated by~$S...
[ { "created": "Fri, 26 Aug 1994 03:22:18 GMT", "version": "v1" }, { "created": "Wed, 15 Feb 1995 01:27:42 GMT", "version": "v2" } ]
2010-11-01
[ [ "Louko", "Jorma", "" ] ]
The Chern-Simons functional $S_{\rm CS}$ is an exact solution to the Ashtekar-Hamilton-Jacobi equation of general relativity with a nonzero cosmological constant. In this paper we consider $S_{\rm CS}$ in Bianchi type IX cosmology with $S^3$ spatial surfaces. We show that among the classical solutions generated by~$S_{...
gr-qc/0702133
Yosef Zlochower
Manuela Campanelli, Carlos O. Lousto, Yosef Zlochower, David Merritt
Maximum gravitational recoil
4 pages, 4 figs, revtex4
Phys.Rev.Lett.98:231102,2007
10.1103/PhysRevLett.98.231102
null
gr-qc astro-ph
null
Recent calculations of gravitational radiation recoil generated during black-hole binary mergers have reopened the possibility that a merged binary can be ejected even from the nucleus of a massive host galaxy. Here we report the first systematic study of gravitational recoil of equal-mass binaries with equal, but an...
[ { "created": "Sun, 25 Feb 2007 20:48:58 GMT", "version": "v1" }, { "created": "Tue, 27 Feb 2007 23:52:41 GMT", "version": "v2" } ]
2010-04-06
[ [ "Campanelli", "Manuela", "" ], [ "Lousto", "Carlos O.", "" ], [ "Zlochower", "Yosef", "" ], [ "Merritt", "David", "" ] ]
Recent calculations of gravitational radiation recoil generated during black-hole binary mergers have reopened the possibility that a merged binary can be ejected even from the nucleus of a massive host galaxy. Here we report the first systematic study of gravitational recoil of equal-mass binaries with equal, but anti...
gr-qc/0402040
Yuichirou Sekiguchi
Masaru Shibata and Yu-ichirou Sekiguchi
Gravitational waves from axisymmetric rotating stellar core collapse to a neutron star in full general relativity
Phys. Rev. D in press
Phys.Rev.D69:084024,2004
10.1103/PhysRevD.69.084024
null
gr-qc astro-ph
null
Axisymmetric numerical simulations of rotating stellar core collapse to a neutron star are performed in the framework of full general relativity. The so-called Cartoon method, in which the Einstein field equations are solved in the Cartesian coordinates and the axisymmetric condition is imposed around the $y=0$ plane...
[ { "created": "Sun, 8 Feb 2004 12:23:13 GMT", "version": "v1" } ]
2011-07-18
[ [ "Shibata", "Masaru", "" ], [ "Sekiguchi", "Yu-ichirou", "" ] ]
Axisymmetric numerical simulations of rotating stellar core collapse to a neutron star are performed in the framework of full general relativity. The so-called Cartoon method, in which the Einstein field equations are solved in the Cartesian coordinates and the axisymmetric condition is imposed around the $y=0$ plane, ...
2311.03315
Indranil Chakraborty
Soumya Bhattacharya, Debanjan Bose, Indranil Chakraborty, Arpan Hait, and Subhendra Mohanty
Gravitational memory signal from neutrino self-interactions in supernova
12 pages, 3 figures, comments are welcome
null
null
null
gr-qc astro-ph.HE hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrinos with large self-interactions, arising from exchange of light scalars or vectors with mass $M_\phi\simeq 10{\rm MeV}$, can play a useful role in cosmology for structure formation and solving the Hubble tension. It has been proposed that large self-interactions of neutrinos may change the observed properties ...
[ { "created": "Mon, 6 Nov 2023 18:08:19 GMT", "version": "v1" } ]
2023-11-07
[ [ "Bhattacharya", "Soumya", "" ], [ "Bose", "Debanjan", "" ], [ "Chakraborty", "Indranil", "" ], [ "Hait", "Arpan", "" ], [ "Mohanty", "Subhendra", "" ] ]
Neutrinos with large self-interactions, arising from exchange of light scalars or vectors with mass $M_\phi\simeq 10{\rm MeV}$, can play a useful role in cosmology for structure formation and solving the Hubble tension. It has been proposed that large self-interactions of neutrinos may change the observed properties of...
2210.09254
Jamie Bamber
Jamie Bamber, Josu C. Aurrekoetxea, Katy Clough, Pedro G. Ferreira
Black hole merger simulations in wave dark matter environments
9 pages, 5 figures, 1 appendix, 2 movies: https://youtube.com/playlist?list=PLSkfizpQDrcb8Zd7C9yEfnMpnKQk7I9ts Comments welcome!
null
10.1103/PhysRevD.107.024035
null
gr-qc astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
The interaction of binary black hole mergers with their environments can be studied using numerical relativity simulations. These start only a short finite time before merger, at which point appropriate initial conditions must be imposed. A key task is therefore to identify the configuration that is appropriate for t...
[ { "created": "Mon, 17 Oct 2022 16:51:13 GMT", "version": "v1" } ]
2023-02-08
[ [ "Bamber", "Jamie", "" ], [ "Aurrekoetxea", "Josu C.", "" ], [ "Clough", "Katy", "" ], [ "Ferreira", "Pedro G.", "" ] ]
The interaction of binary black hole mergers with their environments can be studied using numerical relativity simulations. These start only a short finite time before merger, at which point appropriate initial conditions must be imposed. A key task is therefore to identify the configuration that is appropriate for the...
gr-qc/0501106
Victor Varela
V. Varela
Neutral perfect fluids of Majumdar-type in general relativity
9 pages
Gen.Rel.Grav. 37 (2005) 1769-1777
10.1007/s10714-005-0157-1
null
gr-qc
null
We consider the extension of the Majumdar-type class of static solutions for the Einstein-Maxwell equations, proposed by Ida to include charged perfect fluid sources. We impose the equation of state $\rho+3p=0$ and discuss spherically symmetric solutions for the linear potential equation satisfied by the metric. In t...
[ { "created": "Mon, 31 Jan 2005 20:07:44 GMT", "version": "v1" } ]
2009-11-11
[ [ "Varela", "V.", "" ] ]
We consider the extension of the Majumdar-type class of static solutions for the Einstein-Maxwell equations, proposed by Ida to include charged perfect fluid sources. We impose the equation of state $\rho+3p=0$ and discuss spherically symmetric solutions for the linear potential equation satisfied by the metric. In thi...
2112.02654
Pierre-Henri Chavanis
Pierre-Henri Chavanis
The self-gravitating Fermi gas in Newtonian gravity and general relativity
null
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the history of the self-gravitating Fermi gas in Newtonian gravity and general relativity. We mention applications to white dwarfs, neutron stars and dark matter halos. We describe the nature of instabilities and phase transitions in the self-gravitating Fermi gas as energy (microcanonical ensemble) or temp...
[ { "created": "Sun, 5 Dec 2021 19:05:04 GMT", "version": "v1" } ]
2021-12-07
[ [ "Chavanis", "Pierre-Henri", "" ] ]
We review the history of the self-gravitating Fermi gas in Newtonian gravity and general relativity. We mention applications to white dwarfs, neutron stars and dark matter halos. We describe the nature of instabilities and phase transitions in the self-gravitating Fermi gas as energy (microcanonical ensemble) or temper...
1606.08183
Li-E Qiang
Li-E Qiang
Secular Gravity Gradients in Non-Dynamical Chern-Simons Modified Gravity for Satellite Gradiometry Measurements
11 pages, 1 figure
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With continuous advances in related technologies, relativistic gravitational experiments with orbiting gradiometers becomes feasible, which could naturally be incorporated into future satellite gravity missions. Tests of Chern-Simons modified gravity are meaningful since such a modification gives us insights into (po...
[ { "created": "Mon, 27 Jun 2016 09:59:44 GMT", "version": "v1" }, { "created": "Wed, 29 Jun 2016 03:46:58 GMT", "version": "v2" } ]
2016-06-30
[ [ "Qiang", "Li-E", "" ] ]
With continuous advances in related technologies, relativistic gravitational experiments with orbiting gradiometers becomes feasible, which could naturally be incorporated into future satellite gravity missions. Tests of Chern-Simons modified gravity are meaningful since such a modification gives us insights into (poss...
0709.1400
Orchidea Maria Lecian
O. M. Lecian, G. Montani
Dark Energy as a Relic of the Vacuum-Energy Cancellation?
24 pages, 2 figures, to appear on IJMPD
Int.J.Mod.Phys.D17:111-133,2008
10.1142/S0218271808011900
null
gr-qc
null
We analyze the dynamical implications of an exponential Lagrangian density for the gravitational field, as referred to an isotropic FRW Universe. Then, we discuss the features of the generalized deSitter phase, predicted by the new Friedmann equation. The existence of a consistent deSitter solution arises only if the...
[ { "created": "Mon, 10 Sep 2007 14:01:45 GMT", "version": "v1" } ]
2008-11-26
[ [ "Lecian", "O. M.", "" ], [ "Montani", "G.", "" ] ]
We analyze the dynamical implications of an exponential Lagrangian density for the gravitational field, as referred to an isotropic FRW Universe. Then, we discuss the features of the generalized deSitter phase, predicted by the new Friedmann equation. The existence of a consistent deSitter solution arises only if the r...
1306.0374
Domenico Giulini J.W.
Domenico Giulini
Does cosmological expansion affect local physics?
39 pages, 6 figures. Based on a talk delivered at the conference on "Philosophical Aspects of Modern Cosmology", held in Granada, 22-23 September 2011. In version 2 references were added and updated. Also, a new final subsection on "black-hole cosmology" was added
Studies in History and Philosophy of Modern Physics Volume 46, Part A, May 2014, Pages 24-37
10.1016/j.shpsb.2013.09.009
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this contribution I wish to address the question whether, and how, the global cosmological expansion influences local physics. I argue that a pseudo Newtonian picture can be quite accurate if "expansion" is taken to be an attribute of the inertial structure rather than of "space" in some substantivalist sense. Thi...
[ { "created": "Mon, 3 Jun 2013 12:11:27 GMT", "version": "v1" }, { "created": "Thu, 3 Oct 2013 13:00:23 GMT", "version": "v2" } ]
2014-09-10
[ [ "Giulini", "Domenico", "" ] ]
In this contribution I wish to address the question whether, and how, the global cosmological expansion influences local physics. I argue that a pseudo Newtonian picture can be quite accurate if "expansion" is taken to be an attribute of the inertial structure rather than of "space" in some substantivalist sense. This ...
0907.4146
Theodore A. Jacobson
Ted Jacobson and Thomas P. Sotiriou
Over-spinning a black hole with a test body
4 pages; v2: reference added, incorporates the missed case of an oblate test body, which appears with the published version only as an erratum, other minor edits (with respect to v1)
Phys. Rev. Lett. 103, 141101 (2009); 103, 209903(E) (2009)
10.1103/PhysRevLett.103.141101
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has long been known that a maximally spinning black hole can not be over-spun by tossing in a test body. Here we show that if instead the black hole starts out with below maximal spin, then indeed over-spinning can be achieved when adding either orbital or spin angular momentum. We find that requirements on the si...
[ { "created": "Thu, 23 Jul 2009 19:56:39 GMT", "version": "v1" }, { "created": "Tue, 1 Dec 2009 22:58:20 GMT", "version": "v2" } ]
2009-12-02
[ [ "Jacobson", "Ted", "" ], [ "Sotiriou", "Thomas P.", "" ] ]
It has long been known that a maximally spinning black hole can not be over-spun by tossing in a test body. Here we show that if instead the black hole starts out with below maximal spin, then indeed over-spinning can be achieved when adding either orbital or spin angular momentum. We find that requirements on the size...
gr-qc/9610050
null
Cristian Martinez, Jorge Zanelli
Back-reaction of a conformal field on a three-dimensional black hole
12 pages, RevTeX, no figures
Phys.Rev. D55 (1997) 3642-3646
10.1103/PhysRevD.55.3642
null
gr-qc
null
The first order corrections to the geometry of the (2+1)-dimensional black hole due to back-reaction of a massless conformal scalar field are computed. The renormalized stress energy tensor used as the source of Einstein equations is computed with the Green function for the black-hole background with transparent boun...
[ { "created": "Tue, 22 Oct 1996 22:12:00 GMT", "version": "v1" } ]
2009-10-28
[ [ "Martinez", "Cristian", "" ], [ "Zanelli", "Jorge", "" ] ]
The first order corrections to the geometry of the (2+1)-dimensional black hole due to back-reaction of a massless conformal scalar field are computed. The renormalized stress energy tensor used as the source of Einstein equations is computed with the Green function for the black-hole background with transparent bounda...
gr-qc/0205070
Victor Hugo Cardenas
Victor H. Cardenas
Protecting the Holographic Principle: Inflation
10 pages, 2 figures. To appear in Physics Letter B
null
null
UCV-IF 02/03
gr-qc astro-ph
null
A scenario where inflation emerges as a response to protect the holographic principle is described. A two fluid model in a closed universe inflation picture is assumed, and a possible explanation for secondary exponential expansion phases as those currently observed is given.
[ { "created": "Thu, 16 May 2002 13:32:17 GMT", "version": "v1" }, { "created": "Wed, 9 Apr 2003 19:17:13 GMT", "version": "v2" } ]
2007-05-23
[ [ "Cardenas", "Victor H.", "" ] ]
A scenario where inflation emerges as a response to protect the holographic principle is described. A two fluid model in a closed universe inflation picture is assumed, and a possible explanation for secondary exponential expansion phases as those currently observed is given.
gr-qc/9608022
Hideo Kodama
Hideo Kodama(Yukawa Institute) and Takashi Hamazaki(Dept. of Phys., Kyoto University)
Evolution of cosmological perturbations in a stage dominated by an oscillatory scalar field
Revised version, 23 pages, no figure, plain LaTeX, minor errors in some equations are corrected, no change in the main results and the conclusion
Prog.Theor.Phys. 96 (1996) 949-970
10.1143/PTP.96.949
YITP-96-28, KUNS 1406
gr-qc
null
In the investigation of the evolution of cosmological perturbations in inflationary universe models the behavior of perturbations during the reheating stage is the most unclear point. In particular in the early reheating phase in which a rapidly oscillating scalar field dominates the energy density, the behavior of p...
[ { "created": "Fri, 9 Aug 1996 07:56:40 GMT", "version": "v1" }, { "created": "Fri, 27 Sep 1996 07:11:49 GMT", "version": "v2" } ]
2009-10-28
[ [ "Kodama", "Hideo", "", "Yukawa Institute" ], [ "Hamazaki", "Takashi", "", "Dept. of Phys.,\n Kyoto University" ] ]
In the investigation of the evolution of cosmological perturbations in inflationary universe models the behavior of perturbations during the reheating stage is the most unclear point. In particular in the early reheating phase in which a rapidly oscillating scalar field dominates the energy density, the behavior of per...
2007.00026
Ufuk Aydemir
Ufuk Aydemir
Primordial Black-Hole Mimicker in Quadratic Gravity as Dark Matter
24 pages, 3 figures. Invited talk at Corfu Summer Institute 2019 "School and Workshops on Elementary Particle Physics and Gravity" (CORFU2019), 31 August - 25 September 2019, Corfu, Greece. Based mainly on arXiv:2003.10682; slightly different presentation and some complementary remarks
null
null
null
gr-qc astro-ph.CO astro-ph.HE hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the astrophysical and cosmological implications of having primordial thermal 2-2-hole remnants as dark matter. Thermal 2-2-holes emanate in quadratic gravity as horizonless classical solutions for ultracompact distributions of relativistic thermal gas. In contrast to a large 2-2-hole that imitates the ther...
[ { "created": "Tue, 30 Jun 2020 18:01:15 GMT", "version": "v1" } ]
2020-07-02
[ [ "Aydemir", "Ufuk", "" ] ]
We discuss the astrophysical and cosmological implications of having primordial thermal 2-2-hole remnants as dark matter. Thermal 2-2-holes emanate in quadratic gravity as horizonless classical solutions for ultracompact distributions of relativistic thermal gas. In contrast to a large 2-2-hole that imitates the thermo...
1312.2279
Viktor G. Czinner
Viktor G. Czinner
Thick Dirac-Nambu-Goto branes on black hole backgrounds
4 pages, 2 figures, Proceedings of the Spanish Relativity Meeting in Portugal ERE2012
Progress in Mathematical Relativity, Gravitation and Cosmology, Springer Proceedings in Mathematics & Statistics Volume 60, 2014, pp 223-226
10.1007/978-3-642-40157-2_28
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Thickness corrections to static, axisymmetric Dirac-Nambu-Goto branes embedded into spherically symmetric black hole spacetimes with arbitrary number of dimensions are studied. First, by applying a perturbative approximation, it is found that the thick solutions deviate significantly in their analytic properties from...
[ { "created": "Sun, 8 Dec 2013 23:26:01 GMT", "version": "v1" } ]
2013-12-13
[ [ "Czinner", "Viktor G.", "" ] ]
Thickness corrections to static, axisymmetric Dirac-Nambu-Goto branes embedded into spherically symmetric black hole spacetimes with arbitrary number of dimensions are studied. First, by applying a perturbative approximation, it is found that the thick solutions deviate significantly in their analytic properties from t...
gr-qc/9812024
Don Marolf
Domenico Giulini and Donald Marolf
On the Generality of Refined Algebraic Quantization
12 pages, no figures, ReVTeX, some changes in presentation, some references added
Class.Quant.Grav.16:2479-2488,1999
10.1088/0264-9381/16/7/321
ZU-TH-98/20
gr-qc
null
The Dirac quantization `procedure' for constrained systems is well known to have many subtleties and ambiguities. Within this ill-defined framework, we explore the generality of a particular interpretation of the Dirac procedure known as refined algebraic quantization. We find technical conditions under which refined...
[ { "created": "Mon, 7 Dec 1998 14:17:44 GMT", "version": "v1" }, { "created": "Mon, 31 May 1999 20:13:22 GMT", "version": "v2" } ]
2008-11-26
[ [ "Giulini", "Domenico", "" ], [ "Marolf", "Donald", "" ] ]
The Dirac quantization `procedure' for constrained systems is well known to have many subtleties and ambiguities. Within this ill-defined framework, we explore the generality of a particular interpretation of the Dirac procedure known as refined algebraic quantization. We find technical conditions under which refined a...
2302.00229
Zu-Cheng Chen
Yu-Mei Wu, Zu-Cheng Chen, Qing-Guo Huang
Search for Stochastic Gravitational-Wave Background from Massive Gravity in the NANOGrav 12.5-Year Data Set
7 pages, 2 figures, 1 table; accepted for publication in Phys. Rev. D
null
10.1103/PhysRevD.107.042003
null
gr-qc astro-ph.CO astro-ph.GA astro-ph.HE hep-ph
http://creativecommons.org/licenses/by/4.0/
Gravitational waves offer a new window to probe the nature of gravity, including answering if the mediating particle, graviton, has a non-zero mass or not. Pulsar timing arrays measure stochastic gravitational wave background (SGWB) at $\sim1-100$~nanohertz. Recently, the North American Nanohertz Observatory for Grav...
[ { "created": "Wed, 1 Feb 2023 04:19:54 GMT", "version": "v1" } ]
2023-03-01
[ [ "Wu", "Yu-Mei", "" ], [ "Chen", "Zu-Cheng", "" ], [ "Huang", "Qing-Guo", "" ] ]
Gravitational waves offer a new window to probe the nature of gravity, including answering if the mediating particle, graviton, has a non-zero mass or not. Pulsar timing arrays measure stochastic gravitational wave background (SGWB) at $\sim1-100$~nanohertz. Recently, the North American Nanohertz Observatory for Gravit...
1306.5974
P. A. Gonzalez
Ramon Becar, P. A. Gonzalez and Y. Vasquez
Dirac quasinormal modes of Chern-Simons and BTZ black holes with torsion
Version accepted for publication in PRD
Phys. Rev. D 89, 023001 (2014)
10.1103/PhysRevD.89.023001
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study Chern-Simons black holes in d-dimensions and we calculate analytically the quasinormal modes of fermionic perturbations. Also, we consider as background the five-dimensional Chern-Simons black hole with torsion and the BTZ black hole with torsion. We have found that the quasinormal modes depend on the highes...
[ { "created": "Tue, 25 Jun 2013 14:14:58 GMT", "version": "v1" }, { "created": "Sun, 21 Jul 2013 01:35:36 GMT", "version": "v2" }, { "created": "Sun, 8 Dec 2013 15:01:32 GMT", "version": "v3" } ]
2014-01-15
[ [ "Becar", "Ramon", "" ], [ "Gonzalez", "P. A.", "" ], [ "Vasquez", "Y.", "" ] ]
We study Chern-Simons black holes in d-dimensions and we calculate analytically the quasinormal modes of fermionic perturbations. Also, we consider as background the five-dimensional Chern-Simons black hole with torsion and the BTZ black hole with torsion. We have found that the quasinormal modes depend on the highest ...
gr-qc/0309098
Diego Pavon
German Izquierdo and Diego Pavon
Mini Black Holes and the Relic Gravitational Waves Spectrum
19 pages, 2 figures. To be published in section D of the Physical Review
Phys.Rev. D68 (2003) 124005
10.1103/PhysRevD.68.124005
null
gr-qc astro-ph hep-ph
null
In this paper we explore the impact of an era -right after reheating- dominated by mini black holes and radiation on the spectrum of the relic gravitational waves. This era may lower the spectrum several orders of magnitude.
[ { "created": "Fri, 19 Sep 2003 13:45:07 GMT", "version": "v1" } ]
2009-11-10
[ [ "Izquierdo", "German", "" ], [ "Pavon", "Diego", "" ] ]
In this paper we explore the impact of an era -right after reheating- dominated by mini black holes and radiation on the spectrum of the relic gravitational waves. This era may lower the spectrum several orders of magnitude.
gr-qc/9404038
Hans-Juergen Schmidt
Hans - Juergen Schmidt
Stability and Hamiltonian formulation of higher derivative theories
38 pages, LaTeX, no figures, Phys. Rev. D 49 (1994) 6354; the Erratum Phys. Rev. D 54 (1996) 7906 clarifies that a spatially flat Friedmann model need not be geodesically complete even if the scale factor a(t) is positive and smooth for all real values of the synchronized time t
Phys.Rev.D49:6354,1994; Erratum-ibid.D54:7906,1996; Phys.Rev.D54:7906,1996
10.1103/PhysRevD.49.6354 10.1103/PhysRevD.54.7906
null
gr-qc
null
We analyze the presumptions which lead to instabilities in theories of order higher than second. That type of fourth order gravity which leads to an inflationary (quasi de Sitter) period of cosmic evolution by inclusion of one curvature squared term (i.e. the Starobinsky model) is used as an example. The correspondin...
[ { "created": "Tue, 19 Apr 1994 16:30:25 GMT", "version": "v1" }, { "created": "Mon, 3 Mar 1997 13:51:02 GMT", "version": "v2" } ]
2014-11-17
[ [ "Schmidt", "Hans - Juergen", "" ] ]
We analyze the presumptions which lead to instabilities in theories of order higher than second. That type of fourth order gravity which leads to an inflationary (quasi de Sitter) period of cosmic evolution by inclusion of one curvature squared term (i.e. the Starobinsky model) is used as an example. The corresponding ...
gr-qc/0304031
Huguet Eric
T. Garidi, E. Huguet, J. Renaud
De Sitter Waves and the Zero Curvature Limit
9 pages, latex no figure, to appear in Phys. Rev. D
Phys.Rev. D67 (2003) 124028
10.1103/PhysRevD.67.124028
null
gr-qc
null
We show that a particular set of global modes for the massive de Sitter scalar field (the de Sitter waves) allows to manage the group representations and the Fourier transform in the flat (Minkowskian) limit. This is in opposition to the usual acceptance based on a previous result, suggesting the appearance of negati...
[ { "created": "Mon, 7 Apr 2003 10:51:08 GMT", "version": "v1" } ]
2009-11-10
[ [ "Garidi", "T.", "" ], [ "Huguet", "E.", "" ], [ "Renaud", "J.", "" ] ]
We show that a particular set of global modes for the massive de Sitter scalar field (the de Sitter waves) allows to manage the group representations and the Fourier transform in the flat (Minkowskian) limit. This is in opposition to the usual acceptance based on a previous result, suggesting the appearance of negative...
2010.07059
Marc Geiller
Marc Geiller, Etera R. Livine, Francesco Sartini
Symmetries of the Black Hole Interior and Singularity Regularization
46 pages, 6 figures
SciPost Phys. 10, 022 (2021)
10.21468/SciPostPhys.10.1.022
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We reveal an $\mathfrak{iso}(2,1)$ Poincar\'e algebra of conserved charges associated with the dynamics of the interior of black holes. The action of these Noether charges integrates to a symmetry of the gravitational system under the Poincar\'e group ISO$(2,1)$, which allows to describe the evolution of the geometry...
[ { "created": "Wed, 14 Oct 2020 13:07:14 GMT", "version": "v1" }, { "created": "Fri, 15 Jan 2021 13:56:04 GMT", "version": "v2" } ]
2021-02-01
[ [ "Geiller", "Marc", "" ], [ "Livine", "Etera R.", "" ], [ "Sartini", "Francesco", "" ] ]
We reveal an $\mathfrak{iso}(2,1)$ Poincar\'e algebra of conserved charges associated with the dynamics of the interior of black holes. The action of these Noether charges integrates to a symmetry of the gravitational system under the Poincar\'e group ISO$(2,1)$, which allows to describe the evolution of the geometry i...
gr-qc/0703038
Sigbjorn Hervik
S Hervik, R J van den Hoogen, W C Lim and A A Coley
Late-time behaviour of the tilted Bianchi type VIh models
35 pages, 14 figures; v2:added more comments and refs, typos corrected
Class.Quant.Grav.24:3859-3896,2007
10.1088/0264-9381/24/15/007
null
gr-qc astro-ph hep-th
null
We study tilted perfect fluid cosmological models with a constant equation of state parameter in spatially homogeneous models of Bianchi type VI_h using dynamical systems methods and numerical experimentation, with an emphasis on their future asymptotic evolution. We determine all of the equilibrium points of the typ...
[ { "created": "Tue, 6 Mar 2007 13:55:33 GMT", "version": "v1" }, { "created": "Wed, 18 Jul 2007 14:04:49 GMT", "version": "v2" } ]
2008-11-26
[ [ "Hervik", "S", "" ], [ "Hoogen", "R J van den", "" ], [ "Lim", "W C", "" ], [ "Coley", "A A", "" ] ]
We study tilted perfect fluid cosmological models with a constant equation of state parameter in spatially homogeneous models of Bianchi type VI_h using dynamical systems methods and numerical experimentation, with an emphasis on their future asymptotic evolution. We determine all of the equilibrium points of the type ...
1004.1973
Arturo Stabile
A. Stabile
The Post-Newtonian Limit of f(R)-gravity in the Harmonic Gauge
16 pages, 10 figures
Phys.Rev.D82:064021,2010
10.1103/PhysRevD.82.064021
null
gr-qc astro-ph.EP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A general analytic procedure is developed for the post-Newtonian limit of $f(R)$-gravity with metric approach in the Jordan frame by using the harmonic gauge condition. In a pure perturbative framework and by using the Green function method a general scheme of solutions up to $(v/c)^4$ order is shown. Considering the...
[ { "created": "Mon, 12 Apr 2010 14:34:20 GMT", "version": "v1" }, { "created": "Tue, 1 Jun 2010 20:16:12 GMT", "version": "v2" } ]
2014-11-20
[ [ "Stabile", "A.", "" ] ]
A general analytic procedure is developed for the post-Newtonian limit of $f(R)$-gravity with metric approach in the Jordan frame by using the harmonic gauge condition. In a pure perturbative framework and by using the Green function method a general scheme of solutions up to $(v/c)^4$ order is shown. Considering the T...
gr-qc/0606100
Xiao-Gang Wen
Zheng-Cheng Gu and Xiao-Gang Wen
A lattice bosonic model as a quantum theory of gravity
4 pages. RevTeX4. Homepage http://dao.mit.edu/~wen
null
null
null
gr-qc cond-mat.str-el hep-th
null
A local quantum bosonic model on a lattice is constructed whose low energy excitations are gravitons described by linearized Einstein action. Thus the bosonic model is a quantum theory of gravity, at least at the linear level. We find that the compactification and the discretization of metric tenor are crucial in obt...
[ { "created": "Fri, 23 Jun 2006 00:15:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gu", "Zheng-Cheng", "" ], [ "Wen", "Xiao-Gang", "" ] ]
A local quantum bosonic model on a lattice is constructed whose low energy excitations are gravitons described by linearized Einstein action. Thus the bosonic model is a quantum theory of gravity, at least at the linear level. We find that the compactification and the discretization of metric tenor are crucial in obtai...
1508.01402
Raul Vera
Borja Reina and Ra\"ul Vera
On the mass of rotating stars in Newtonian gravity and GR
11 pages, uses iopart style and a custom bibtex style
null
10.1088/0264-9381/33/1/017001
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show how the correction to the calculation of the mass in the original relativistic model of a rotating star by Hartle [6], found recently [10], appears in the Newtonian limit, and that the correcting term is indeed present, albeit hidden, in the original Newtonian approach by Chandrasekhar [2].
[ { "created": "Thu, 6 Aug 2015 13:55:12 GMT", "version": "v1" } ]
2015-12-16
[ [ "Reina", "Borja", "" ], [ "Vera", "Raül", "" ] ]
We show how the correction to the calculation of the mass in the original relativistic model of a rotating star by Hartle [6], found recently [10], appears in the Newtonian limit, and that the correcting term is indeed present, albeit hidden, in the original Newtonian approach by Chandrasekhar [2].