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2004.12137
Abolhassan Mohammadi
Abolhassan Mohammadi, Tayeb Golanbari, Salah Nasri, Khaled Saaidi
Brane Constant-roll Inflation
20 pages, 6 figures; Typos fixed; references added, accepted for publication in PRD
Phys. Rev. D 101, 123537 (2020)
10.1103/PhysRevD.101.123537
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The scenario of constant-roll inflation in the frame of the RSII brane gravity model is considered. Based on the scenario, the smallness of the second slow-roll parameter is released and it is assumed as a constant which could be of the order of unity. Applying the Hamilton-Jacobi formalism, the constancy of the para...
[ { "created": "Sat, 25 Apr 2020 13:14:09 GMT", "version": "v1" }, { "created": "Wed, 17 Jun 2020 21:06:18 GMT", "version": "v2" }, { "created": "Wed, 1 Jul 2020 10:32:56 GMT", "version": "v3" } ]
2020-07-08
[ [ "Mohammadi", "Abolhassan", "" ], [ "Golanbari", "Tayeb", "" ], [ "Nasri", "Salah", "" ], [ "Saaidi", "Khaled", "" ] ]
The scenario of constant-roll inflation in the frame of the RSII brane gravity model is considered. Based on the scenario, the smallness of the second slow-roll parameter is released and it is assumed as a constant which could be of the order of unity. Applying the Hamilton-Jacobi formalism, the constancy of the parame...
2207.00878
Genly Le\'on
Miguel A. Garc\'ia-Aspeitia, Guillermo Fernandez-Anaya, A. Hern\'andez-Almada, Genly Leon (Catolica del Norte U. and DUT, Durban) and Juan Maga\~na
Cosmology under the fractional calculus approach
15 pages, 8 figures. Moderate revision. Matches the version accepted for publication in MNRAS
null
10.1093/mnras/stac3006
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fractional cosmology modifies the standard derivative to Caputo's fractional derivative of order $\mu$, generating changes in General Relativity. Friedmann equations are modified, and the evolution of the species densities depends on $\mu$ and the age of the Universe $t_U$. We estimate stringent constraints on $\mu$ ...
[ { "created": "Sat, 2 Jul 2022 16:48:06 GMT", "version": "v1" }, { "created": "Fri, 8 Jul 2022 15:11:45 GMT", "version": "v2" }, { "created": "Mon, 17 Oct 2022 14:10:31 GMT", "version": "v3" } ]
2022-10-26
[ [ "García-Aspeitia", "Miguel A.", "", "Catolica del Norte U. and DUT, Durban" ], [ "Fernandez-Anaya", "Guillermo", "", "Catolica del Norte U. and DUT, Durban" ], [ "Hernández-Almada", "A.", "", "Catolica del Norte U. and DUT, Durban" ], [ "Leon", "...
Fractional cosmology modifies the standard derivative to Caputo's fractional derivative of order $\mu$, generating changes in General Relativity. Friedmann equations are modified, and the evolution of the species densities depends on $\mu$ and the age of the Universe $t_U$. We estimate stringent constraints on $\mu$ us...
2001.05716
Diego Pavon
Diego Pavon
On the degrees of freedom of a black hole
8 pages, no figures. Key words: gravity, black holes, statistical mechanics, equipartition theorem. Comments appreciated
null
null
523 UAB
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By examining whether black holes fulfill the theorem of equipartition of energy we find that the notion of degrees of freedom, previously introduced for cosmic horizons, is meaningful in the case of Schwarzschild and Kerr black holes. However, for Reissner-N\"{o}rdstrom and Kerr-Newman black holes this notion fails.
[ { "created": "Thu, 16 Jan 2020 09:45:03 GMT", "version": "v1" } ]
2020-01-24
[ [ "Pavon", "Diego", "" ] ]
By examining whether black holes fulfill the theorem of equipartition of energy we find that the notion of degrees of freedom, previously introduced for cosmic horizons, is meaningful in the case of Schwarzschild and Kerr black holes. However, for Reissner-N\"{o}rdstrom and Kerr-Newman black holes this notion fails.
0807.1689
Joao Magueijo
Joao Magueijo
Bimetric varying speed of light theories and primordial fluctuations
null
Phys.Rev.D79:043525,2009
10.1103/PhysRevD.79.043525
null
gr-qc astro-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We exhibit a varying speed of light (VSL) theory that implements the recently proposed decaying speed of sound mechanism for generating density fluctuations. We avail ourselves of bimetric VSL theories, where the speed of gravity differs from that of light. We first show that a Dirac-Born-Infeld (DBI) type of $K$-ess...
[ { "created": "Thu, 10 Jul 2008 16:01:12 GMT", "version": "v1" }, { "created": "Fri, 29 Jan 2010 17:41:28 GMT", "version": "v2" } ]
2010-01-29
[ [ "Magueijo", "Joao", "" ] ]
We exhibit a varying speed of light (VSL) theory that implements the recently proposed decaying speed of sound mechanism for generating density fluctuations. We avail ourselves of bimetric VSL theories, where the speed of gravity differs from that of light. We first show that a Dirac-Born-Infeld (DBI) type of $K$-essen...
gr-qc/9508005
Charles Torre
C. G. Torre (Utah State Univ.)
Spinors, Jets, and the Einstein Equations
to appear in the proceedings of the Sixth Canadian Conference on General Relativity and Relativistic Astrophysics, 13 pages, uses AMSTeX and AMSppt.sty
null
null
null
gr-qc
null
Many important features of a field theory, {\it e.g.}, conserved currents, symplectic structures, energy-momentum tensors, {\it etc.}, arise as tensors locally constructed from the fields and their derivatives. Such tensors are naturally defined as geometric objects on the jet space of solutions to the field equation...
[ { "created": "Thu, 3 Aug 1995 16:35:48 GMT", "version": "v1" } ]
2007-05-23
[ [ "Torre", "C. G.", "", "Utah State Univ." ] ]
Many important features of a field theory, {\it e.g.}, conserved currents, symplectic structures, energy-momentum tensors, {\it etc.}, arise as tensors locally constructed from the fields and their derivatives. Such tensors are naturally defined as geometric objects on the jet space of solutions to the field equations....
2104.14031
Jiri Horak
Marek Abramowicz, Ji\v{r}\'i Hor\'ak and Kate\v{r}ina Klimovi\v{c}ov\'a
Wave-fronts of gravitational waves partially trapped in ultra-compact stars
4 pages, 3 figures, to appear in proceedings of "Recontres de Moriond on Gravitation 2021" conference
null
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We dedicate this work to Dr Omer Blaes, professor of physics at UCSB, on the occasion of his sixtieth birthday. We have been collaborating now and then with Dr. Blaes on problems involving oscillations, waves and stability. Happy birthday, Omer. Enjoy the analytic treatment of damping of the gravitational waves trapp...
[ { "created": "Wed, 28 Apr 2021 21:42:08 GMT", "version": "v1" } ]
2021-04-30
[ [ "Abramowicz", "Marek", "" ], [ "Horák", "Jiří", "" ], [ "Klimovičová", "Kateřina", "" ] ]
We dedicate this work to Dr Omer Blaes, professor of physics at UCSB, on the occasion of his sixtieth birthday. We have been collaborating now and then with Dr. Blaes on problems involving oscillations, waves and stability. Happy birthday, Omer. Enjoy the analytic treatment of damping of the gravitational waves trapped...
gr-qc/0405067
Norichika Sago
Norichika Sago, Kunihito Ioka, Takashi Nakamura, Ryo Yamazaki
Gravitational Wave Memory of Gamma-Ray Burst Jets
Revtex4, 10 pages, 6 figures, Fig.2 and Fig.3 replaced, minor changes to text in Sec.I and Sec.V, typos corrected, some reference added, Version to be published in PRD
Phys.Rev.D70:104012,2004
10.1103/PhysRevD.70.104012
OU-TAP-230, IGPC-04/5-2,KUNS-1916
gr-qc astro-ph
null
Gamma-Ray Bursts (GRBs) are now considered as relativistic jets. We analyze the gravitational waves from the acceleration stage of the GRB jets. We show that (i) the point mass approximation is not appropriate if the opening half-angle of the jet is larger than the inverse of the Lorentz factor of the jet, (ii) the g...
[ { "created": "Thu, 13 May 2004 05:03:32 GMT", "version": "v1" }, { "created": "Tue, 16 Nov 2004 10:00:10 GMT", "version": "v2" } ]
2014-11-17
[ [ "Sago", "Norichika", "" ], [ "Ioka", "Kunihito", "" ], [ "Nakamura", "Takashi", "" ], [ "Yamazaki", "Ryo", "" ] ]
Gamma-Ray Bursts (GRBs) are now considered as relativistic jets. We analyze the gravitational waves from the acceleration stage of the GRB jets. We show that (i) the point mass approximation is not appropriate if the opening half-angle of the jet is larger than the inverse of the Lorentz factor of the jet, (ii) the gra...
0712.4333
Anil Zengino\u{g}lu C
An{\i}l Zengino\u{g}lu
Hyperboloidal foliations and scri-fixing
14 pages, 14 figures. Published version
Class.Quant.Grav.25:145002,2008
10.1088/0264-9381/25/14/145002
AEI-2007-177
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a gauge choice which allows us to avoid the introduction of artificial timelike outer boundaries in numerical studies of test fields based on a 3+1 decomposition of asymptotically flat background spacetimes. The main idea is to include null infinity in the computational domain by conformally compactifying ...
[ { "created": "Fri, 28 Dec 2007 14:03:57 GMT", "version": "v1" }, { "created": "Tue, 24 Jun 2008 17:31:59 GMT", "version": "v2" } ]
2008-11-26
[ [ "Zenginoğlu", "Anıl", "" ] ]
We discuss a gauge choice which allows us to avoid the introduction of artificial timelike outer boundaries in numerical studies of test fields based on a 3+1 decomposition of asymptotically flat background spacetimes. The main idea is to include null infinity in the computational domain by conformally compactifying th...
2007.11584
Carlos A. R. Herdeiro
Nicolas Sanchis-Gual, Miguel Zilh\~ao, Carlos Herdeiro, Fabrizio Di Giovanni, Jos\'e A. Font, Eugen Radu
Synchronised gravitational atoms from mergers of bosonic stars
6 pages, 7 figures
Phys. Rev. D 102, 101504 (2020)
10.1103/PhysRevD.102.101504
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If ultralight bosonic fields exist in Nature as dark matter, superradiance spins down rotating black holes (BHs), dynamically endowing them with equilibrium bosonic clouds, here dubbed synchronised gravitational atoms (SGAs). The self-gravity of these same fields, on the other hand, can lump them into (scalar or vect...
[ { "created": "Wed, 22 Jul 2020 18:00:00 GMT", "version": "v1" } ]
2020-11-25
[ [ "Sanchis-Gual", "Nicolas", "" ], [ "Zilhão", "Miguel", "" ], [ "Herdeiro", "Carlos", "" ], [ "Di Giovanni", "Fabrizio", "" ], [ "Font", "José A.", "" ], [ "Radu", "Eugen", "" ] ]
If ultralight bosonic fields exist in Nature as dark matter, superradiance spins down rotating black holes (BHs), dynamically endowing them with equilibrium bosonic clouds, here dubbed synchronised gravitational atoms (SGAs). The self-gravity of these same fields, on the other hand, can lump them into (scalar or vector...
1505.07014
Caio Macedo
Caio F. B. Macedo, Ednilton S. de Oliveira, Lu\'is C. B. Crispino
Scattering by regular black holes: Planar massless scalar waves impinging upon a Bardeen black hole
8 pages, 7 figures. Version to be published in PRD
null
10.1103/PhysRevD.92.024012
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Singularities are common features of general relativity black holes. However, within general relativity, one can construct black holes that present no singularities. These regular black hole solutions can be achieved by, for instance, relaxing one of the energy conditions on the stress energy tensor sourcing the blac...
[ { "created": "Tue, 26 May 2015 15:36:20 GMT", "version": "v1" }, { "created": "Fri, 26 Jun 2015 21:24:52 GMT", "version": "v2" } ]
2016-03-08
[ [ "Macedo", "Caio F. B.", "" ], [ "de Oliveira", "Ednilton S.", "" ], [ "Crispino", "Luís C. B.", "" ] ]
Singularities are common features of general relativity black holes. However, within general relativity, one can construct black holes that present no singularities. These regular black hole solutions can be achieved by, for instance, relaxing one of the energy conditions on the stress energy tensor sourcing the black ...
1204.1483
Hrvoje Stefancic
Silvije Domazet, Hrvoje Stefancic
Renormalization group scale-setting from the action - a road to modified gravity theories
v1: 15 pages; v2: shortened to 10 pages, main results unchanged, published in Class. Quant. Grav
null
10.1088/0264-9381/29/23/235005
null
gr-qc astro-ph.CO hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The renormalization group (RG) corrected gravitational action in Einstein-Hilbert and other truncations is considered. The running scale of the renormalization group is treated as a scalar field at the level of the action and determined in a scale-setting procedure recently introduced by Koch and Ramirez for the Eins...
[ { "created": "Fri, 6 Apr 2012 14:23:38 GMT", "version": "v1" }, { "created": "Tue, 6 Nov 2012 11:02:59 GMT", "version": "v2" } ]
2015-06-04
[ [ "Domazet", "Silvije", "" ], [ "Stefancic", "Hrvoje", "" ] ]
The renormalization group (RG) corrected gravitational action in Einstein-Hilbert and other truncations is considered. The running scale of the renormalization group is treated as a scalar field at the level of the action and determined in a scale-setting procedure recently introduced by Koch and Ramirez for the Einste...
2206.04836
Shin'ichi Nojiri
G.G.L. Nashed and S. Nojiri
Black Holes with Electric and Magnetic Charges in $F(R)$ Gravity
LaTeX 20 pages, 9 figures, to appear in Fortschritte der Physik - Progress of Physics
null
10.1002/prop.202200091
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct spherically symmetric and static solutions in $F(R)$ gravity coupled with electromagnetic fields. The solutions include new types of black holes with electric and magnetic charges. We show that the higher-derivative terms make the curvature singularity much softer than that in the charged black holes in ...
[ { "created": "Fri, 10 Jun 2022 01:44:46 GMT", "version": "v1" }, { "created": "Thu, 24 Nov 2022 23:01:21 GMT", "version": "v2" } ]
2023-03-22
[ [ "Nashed", "G. G. L.", "" ], [ "Nojiri", "S.", "" ] ]
We construct spherically symmetric and static solutions in $F(R)$ gravity coupled with electromagnetic fields. The solutions include new types of black holes with electric and magnetic charges. We show that the higher-derivative terms make the curvature singularity much softer than that in the charged black holes in Ei...
2003.09719
Wan Cong Ms
Wan Cong, Jiri Bicak, David Kubiznak and Robert B. Mann
Quantum Distinction of Inertial Frames: Local vs. Global
6 pages, 4 figures
null
10.1103/PhysRevD.101.104060
null
gr-qc quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the response function of Unruh-deWitt detectors placed in a flat spacetime inside a thin matter shell. We show that the response function distinguishes between the local and global (Minkowski) inertial frames and picks up the presence of the shell even when the detector is switched on for a finite time inter...
[ { "created": "Sat, 21 Mar 2020 18:31:15 GMT", "version": "v1" }, { "created": "Tue, 12 May 2020 01:27:36 GMT", "version": "v2" } ]
2020-06-10
[ [ "Cong", "Wan", "" ], [ "Bicak", "Jiri", "" ], [ "Kubiznak", "David", "" ], [ "Mann", "Robert B.", "" ] ]
We study the response function of Unruh-deWitt detectors placed in a flat spacetime inside a thin matter shell. We show that the response function distinguishes between the local and global (Minkowski) inertial frames and picks up the presence of the shell even when the detector is switched on for a finite time interva...
2108.12930
Naoki Seto
Naoki Seto
Correlation of Gravitational Wave Background Noises and Statistical Loss for Angular Averaged Sensitivity Curves
11 pages, 10 figures
null
10.1103/PhysRevD.104.063025
null
gr-qc astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Gravitational wave backgrounds generate correlated noises to separated detectors. This correlation can induce statistical losses to actual detector networks, compared with idealized noise-independent networks. Assuming that the backgrounds are isotropic, we examine the statistical losses specifically for the angular ...
[ { "created": "Sun, 29 Aug 2021 22:40:49 GMT", "version": "v1" } ]
2021-09-29
[ [ "Seto", "Naoki", "" ] ]
Gravitational wave backgrounds generate correlated noises to separated detectors. This correlation can induce statistical losses to actual detector networks, compared with idealized noise-independent networks. Assuming that the backgrounds are isotropic, we examine the statistical losses specifically for the angular av...
gr-qc/0008019
Keith H. Lockitch
Keith H. Lockitch, Nils Andersson, John L. Friedman
The rotational modes of relativistic stars: Analytic results
36 pages revtex v3.1, 2 eps figures
Phys.Rev. D63 (2001) 024019
10.1103/PhysRevD.63.024019
CGPG-99/12-2
gr-qc astro-ph
null
We study the r-modes and rotational ``hybrid'' modes of relativistic stars. As in Newtonian gravity, the spectrum of low-frequency rotational modes is highly sensitive to the stellar equation of state. If the star and its perturbations obey the same one-parameter equation of state (as with isentropic stars), there ex...
[ { "created": "Tue, 8 Aug 2000 21:59:22 GMT", "version": "v1" } ]
2009-10-31
[ [ "Lockitch", "Keith H.", "" ], [ "Andersson", "Nils", "" ], [ "Friedman", "John L.", "" ] ]
We study the r-modes and rotational ``hybrid'' modes of relativistic stars. As in Newtonian gravity, the spectrum of low-frequency rotational modes is highly sensitive to the stellar equation of state. If the star and its perturbations obey the same one-parameter equation of state (as with isentropic stars), there exis...
1402.5921
Ronald Adler
Ronald J. Adler
A quantum theory of distance along a curve
27 pages, 3 figures; includes added reference and acknowledgements, corrected typos and phrases, results unchanged
null
null
null
gr-qc math-ph math.MP quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a quantum theory of distances along a curve, based on a linear line element that is equal to the operator square root of the quadratic metric of Riemannian geometry. Since the linear line element is an operator, we treat it according to the rules of quantum mechanics and interpret its eigenvalues as physic...
[ { "created": "Thu, 13 Feb 2014 23:57:15 GMT", "version": "v1" }, { "created": "Wed, 16 Apr 2014 17:34:04 GMT", "version": "v2" } ]
2014-05-06
[ [ "Adler", "Ronald J.", "" ] ]
We present a quantum theory of distances along a curve, based on a linear line element that is equal to the operator square root of the quadratic metric of Riemannian geometry. Since the linear line element is an operator, we treat it according to the rules of quantum mechanics and interpret its eigenvalues as physical...
1911.09902
Huaifan Li
Xiong-Ying Guo, Huai-Fan Li, Li-Chun Zhang, Ren Zhao
Continuous phase transition and microstructure of charged AdS black hole with quintessence
25 pages,4 figures,added refs. arXiv admin note: text overlap with arXiv:1901.04703
Eur. Phys. J. C (2020) 80:168
10.1140/epjc/s10052-019-7601-y
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Previously, the Maxwell equal-area law has been used to discuss the conditions satisfied by the phase transition of charged AdS black holes with cloud of string and quintessence, and it was concluded that black holes have phase transition similar to that of vdW system. The phase transition depends on the electric pot...
[ { "created": "Fri, 22 Nov 2019 07:38:55 GMT", "version": "v1" }, { "created": "Tue, 26 Nov 2019 10:57:36 GMT", "version": "v2" }, { "created": "Fri, 28 Feb 2020 09:49:51 GMT", "version": "v3" } ]
2020-03-02
[ [ "Guo", "Xiong-Ying", "" ], [ "Li", "Huai-Fan", "" ], [ "Zhang", "Li-Chun", "" ], [ "Zhao", "Ren", "" ] ]
Previously, the Maxwell equal-area law has been used to discuss the conditions satisfied by the phase transition of charged AdS black holes with cloud of string and quintessence, and it was concluded that black holes have phase transition similar to that of vdW system. The phase transition depends on the electric poten...
2312.08392
Peter K.F. Kuhfittig
Peter K.F. Kuhfittig
Supporting traversable wormholes: the case for noncommutative geometry
9 pages, no figures. arXiv admin note: substantial text overlap with arXiv:2312.05266
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While wormholes may be just as good a prediction of Einstein's theory as black holes, they are subject to severe restrictions from quantum field theory. In particular, a wormhole can only be held open by violating the null energy condition, calling for the existence of "exotic matter," a condition that many researche...
[ { "created": "Tue, 12 Dec 2023 16:32:05 GMT", "version": "v1" }, { "created": "Sun, 21 Jan 2024 21:13:05 GMT", "version": "v2" }, { "created": "Sun, 5 May 2024 21:34:01 GMT", "version": "v3" } ]
2024-05-07
[ [ "Kuhfittig", "Peter K. F.", "" ] ]
While wormholes may be just as good a prediction of Einstein's theory as black holes, they are subject to severe restrictions from quantum field theory. In particular, a wormhole can only be held open by violating the null energy condition, calling for the existence of "exotic matter," a condition that many researchers...
gr-qc/0611020
Janne Hogdahl
Kari Enqvist, Janne Hogdahl, Sami Nurmi, Filippo Vernizzi
Covariant generalization of cosmological perturbation theory
Minor changes to match the version published in PRD. RevTex, 22 pages, 1 figure
Phys.Rev.D75:023515,2007
10.1103/PhysRevD.75.023515
HIP-2006-48/TH
gr-qc astro-ph
null
We present an approach to cosmological perturbations based on a covariant perturbative expansion between two worldlines in the real inhomogeneous universe. As an application, at an arbitrary order we define an exact scalar quantity which describes the inhomogeneities in the number of e-folds on uniform density hypers...
[ { "created": "Fri, 3 Nov 2006 15:18:53 GMT", "version": "v1" }, { "created": "Mon, 15 Jan 2007 14:14:20 GMT", "version": "v2" } ]
2008-11-26
[ [ "Enqvist", "Kari", "" ], [ "Hogdahl", "Janne", "" ], [ "Nurmi", "Sami", "" ], [ "Vernizzi", "Filippo", "" ] ]
We present an approach to cosmological perturbations based on a covariant perturbative expansion between two worldlines in the real inhomogeneous universe. As an application, at an arbitrary order we define an exact scalar quantity which describes the inhomogeneities in the number of e-folds on uniform density hypersur...
0711.0576
Sergey Paston
S.A. Paston, V.A. Franke
Canonical formulation of the embedded theory of gravity equivalent to Einstein's General Relativity
LaTeX, 17 pages
Theor.Math.Phys.153:1581-1595,2007; Teor.Mat.Fiz.153:271-288,2007
10.1007/s11232-007-0134-9
null
gr-qc hep-th
null
We study the approach in which independent variables describing gravity are functions of the space-time embedding into a flat space of higher dimension. We formulate a canonical formalism for such a theory in a form, which requires imposing additional constraints, which are a part of Einstein's equations. As a result...
[ { "created": "Mon, 5 Nov 2007 08:59:42 GMT", "version": "v1" } ]
2010-03-09
[ [ "Paston", "S. A.", "" ], [ "Franke", "V. A.", "" ] ]
We study the approach in which independent variables describing gravity are functions of the space-time embedding into a flat space of higher dimension. We formulate a canonical formalism for such a theory in a form, which requires imposing additional constraints, which are a part of Einstein's equations. As a result, ...
gr-qc/0101101
Vladimir V. Dyadichev
D.V. Gal'tsov and V.V. Dyadichev
Solitons in Non-Abelian Born-Infeld Theory
2pges, LaTeX, Contribution to the 9th Marcel Grossmann meeting (MG9), Rome, July 2000
null
10.1142/9789812777386_0181
DTP-MSU-0020
gr-qc
null
Born-Infeld generalization of the Yang-Mills action suggested by the superstring theory gives rise to modification of previously known as well as to some new classical soliton solutions. Earlier it was shown that within the model with the usual trace over the group generators classical glueballs exist which form an i...
[ { "created": "Fri, 26 Jan 2001 12:21:14 GMT", "version": "v1" } ]
2017-08-23
[ [ "Gal'tsov", "D. V.", "" ], [ "Dyadichev", "V. V.", "" ] ]
Born-Infeld generalization of the Yang-Mills action suggested by the superstring theory gives rise to modification of previously known as well as to some new classical soliton solutions. Earlier it was shown that within the model with the usual trace over the group generators classical glueballs exist which form an inf...
1207.3715
Eugen Radu
Eugen Radu and Bintoro Subagyo
Spinning scalar solitons in anti-de Sitter spacetime
12 pages, 4 figures
null
10.1016/j.physletb.2012.09.050
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present spinning Q-balls and boson stars in four dimensional anti-de Sitter spacetime. These are smooth, horizonless solutions for gravity coupled to a massive complex scalar field with a harmonic dependence on time and the azimuthal angle. Similar to the flat spacetime configurations, the angular momentum is quan...
[ { "created": "Mon, 16 Jul 2012 16:01:13 GMT", "version": "v1" } ]
2015-06-05
[ [ "Radu", "Eugen", "" ], [ "Subagyo", "Bintoro", "" ] ]
We present spinning Q-balls and boson stars in four dimensional anti-de Sitter spacetime. These are smooth, horizonless solutions for gravity coupled to a massive complex scalar field with a harmonic dependence on time and the azimuthal angle. Similar to the flat spacetime configurations, the angular momentum is quanti...
gr-qc/9708061
M. B. Paranjape
A. Edery M. B. Paranjape
Cosmological sector for localized mass and spin in 2+1 dimensional topologically massive gravity
8 pages, no figures
Phys.Lett.B415:344-348,1997
10.1016/S0370-2693(97)01221-5
UdeM-GPP-TH-97-45
gr-qc
null
The cosmological sector to the full non-linear topologically massive gravity (TMG) is obtained for localized sources of mass $m$ and spin $\sigma$ besides the asymptotically spinning conical flat sector previously obtained. In a small region near but outside the sources, the metric resembles the spinning conical flat...
[ { "created": "Mon, 25 Aug 1997 19:44:42 GMT", "version": "v1" } ]
2008-12-30
[ [ "Paranjape", "A. Edery M. B.", "" ] ]
The cosmological sector to the full non-linear topologically massive gravity (TMG) is obtained for localized sources of mass $m$ and spin $\sigma$ besides the asymptotically spinning conical flat sector previously obtained. In a small region near but outside the sources, the metric resembles the spinning conical flat m...
1412.6467
Matthew Robbins
Saurya Das, Matthew P. G. Robbins, Mark A. Walton
Generalized Uncertainty Principle Corrections to the Simple Harmonic Oscillator in Phase Space
minor revisions; included journal reference
Canadian Journal of Physics, 2016, 94(1): 139-146
10.1139/cjp-2015-0456
null
gr-qc hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute Wigner functions for the harmonic oscillator including corrections from generalized uncertainty principles (GUPs), and study the corresponding marginal probability densities and other properties. We show that the GUP corrections to the Wigner functions can be significant, and comment on their potential mea...
[ { "created": "Fri, 19 Dec 2014 18:07:15 GMT", "version": "v1" }, { "created": "Wed, 8 Jul 2015 17:26:18 GMT", "version": "v2" }, { "created": "Tue, 26 Jan 2016 21:16:25 GMT", "version": "v3" } ]
2016-01-28
[ [ "Das", "Saurya", "" ], [ "Robbins", "Matthew P. G.", "" ], [ "Walton", "Mark A.", "" ] ]
We compute Wigner functions for the harmonic oscillator including corrections from generalized uncertainty principles (GUPs), and study the corresponding marginal probability densities and other properties. We show that the GUP corrections to the Wigner functions can be significant, and comment on their potential measu...
gr-qc/0610006
Jose Luis Jaramillo
J.L. Jaramillo, M. Ansorg, F. Limousin
Numerical implementation of isolated horizon boundary conditions
11 pages, 5 figures, references added and corrected
Phys.Rev.D75:024019,2007
10.1103/PhysRevD.75.024019
null
gr-qc
null
We study the numerical implementation of a set of boundary conditions derived from the isolated horizon formalism, and which characterize a black hole whose horizon is in quasi-equilibrium. More precisely, we enforce these geometrical prescriptions as inner boundary conditions on an excised sphere, in the numerical r...
[ { "created": "Mon, 2 Oct 2006 10:11:13 GMT", "version": "v1" }, { "created": "Fri, 6 Oct 2006 10:17:44 GMT", "version": "v2" } ]
2008-11-26
[ [ "Jaramillo", "J. L.", "" ], [ "Ansorg", "M.", "" ], [ "Limousin", "F.", "" ] ]
We study the numerical implementation of a set of boundary conditions derived from the isolated horizon formalism, and which characterize a black hole whose horizon is in quasi-equilibrium. More precisely, we enforce these geometrical prescriptions as inner boundary conditions on an excised sphere, in the numerical res...
gr-qc/0201097
Dag Østvang
Dag {\O}stvang
Spherically Symmetric, Metrically Static, Isolated Systems in Quasi-Metric Gravity
34 pages; v2: connection changed; v3: extended and local conservation laws changed; v4: major revision; v5: accepted for publication in G&C, v6: must have non-universal gravitational coupling; v7: fully coupled theory implemented; v8: fully coupled theory abandoned; v11: inconsistent equation replaced (oh well)...
Grav.Cosmol.13:1-15,2007
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The gravitational field exterior respectively interior to a spherically symmetric, isolated body made of perfect fluid is examined within the quasi-metric framework (QMF). It is required that the gravitational field is "metrically static", meaning that it is static except for the effects of the global cosmic expansio...
[ { "created": "Thu, 31 Jan 2002 16:59:13 GMT", "version": "v1" }, { "created": "Fri, 3 Feb 2023 15:01:35 GMT", "version": "v10" }, { "created": "Wed, 20 Mar 2024 15:28:38 GMT", "version": "v11" }, { "created": "Sat, 4 May 2002 17:29:54 GMT", "version": "v2" }, { "c...
2024-03-21
[ [ "Østvang", "Dag", "" ] ]
The gravitational field exterior respectively interior to a spherically symmetric, isolated body made of perfect fluid is examined within the quasi-metric framework (QMF). It is required that the gravitational field is "metrically static", meaning that it is static except for the effects of the global cosmic expansion ...
1007.2790
John F. Donoghue
Thibault Damour and John F. Donoghue
Phenomenology of the Equivalence Principle with Light Scalars
5 pages
Class.Quant.Grav.27:202001,2010
10.1088/0264-9381/27/20/202001
null
gr-qc hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Light scalar particles with couplings of sub-gravitational strength, which can generically be called 'dilatons', can produce violations of the equivalence principle. However, in order to understand experimental sensitivities one must know the coupling of these scalars to atomic systems. We report here on a study of t...
[ { "created": "Fri, 16 Jul 2010 15:11:17 GMT", "version": "v1" }, { "created": "Mon, 19 Jul 2010 00:12:33 GMT", "version": "v2" } ]
2011-03-28
[ [ "Damour", "Thibault", "" ], [ "Donoghue", "John F.", "" ] ]
Light scalar particles with couplings of sub-gravitational strength, which can generically be called 'dilatons', can produce violations of the equivalence principle. However, in order to understand experimental sensitivities one must know the coupling of these scalars to atomic systems. We report here on a study of the...
1212.2204
Martin Bojowald
Stephon Alexander, Martin Bojowald, Antonino Marciano, David Simpson
Electric Time in Quantum Cosmology
19 pages, 5 figures
Class. Quantum Grav. 30 (2013) 155024
10.1088/0264-9381/30/15/155024
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Effective quantum cosmology is formulated with a realistic global internal time given by the electric vector potential. New possibilities for the quantum behavior of space-time are found, and the high-density regime is shown to be very sensitive to the specific form of state realized.
[ { "created": "Mon, 10 Dec 2012 20:59:45 GMT", "version": "v1" } ]
2015-06-12
[ [ "Alexander", "Stephon", "" ], [ "Bojowald", "Martin", "" ], [ "Marciano", "Antonino", "" ], [ "Simpson", "David", "" ] ]
Effective quantum cosmology is formulated with a realistic global internal time given by the electric vector potential. New possibilities for the quantum behavior of space-time are found, and the high-density regime is shown to be very sensitive to the specific form of state realized.
1402.6613
Brajesh Gupt
Peter Diener, Brajesh Gupt, Parampreet Singh
Numerical simulations of a loop quantum cosmos: robustness of the quantum bounce and the validity of effective dynamics
47 pages, 26 figures; References updated. Minor changes to match the version published in CQG
Class. Quantum Grav. 31 105015 (2014)
10.1088/0264-9381/31/10/105015
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A key result of isotropic loop quantum cosmology is the existence of a quantum bounce which occurs when the energy density of the matter field approaches a universal maximum close to the Planck density. Though the bounce has been exhibited in various matter models, due to severe computational challenges some importan...
[ { "created": "Wed, 26 Feb 2014 17:07:10 GMT", "version": "v1" }, { "created": "Fri, 16 May 2014 16:41:36 GMT", "version": "v2" } ]
2015-06-18
[ [ "Diener", "Peter", "" ], [ "Gupt", "Brajesh", "" ], [ "Singh", "Parampreet", "" ] ]
A key result of isotropic loop quantum cosmology is the existence of a quantum bounce which occurs when the energy density of the matter field approaches a universal maximum close to the Planck density. Though the bounce has been exhibited in various matter models, due to severe computational challenges some important ...
gr-qc/0401107
Miguel Lorente
P. Kramer, M. Lorente
Surface embedding, topology and dualization for spin networks
LaTeX 17 pages, 6 eps figures (late submission to arxiv.org)
J.Phys.A35:8563-8574,2002
10.1088/0305-4470/35/40/314
null
gr-qc
null
Spin networks are graphs derived from 3nj symbols of angular momentum. The surface embedding, the topology and dualization of these networks are considered. Embeddings into compact surfaces include the orientable sphere S^2 and the torus T, and the not orientable projective space P^2 and Klein's bottle K. Two familie...
[ { "created": "Tue, 27 Jan 2004 18:11:58 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kramer", "P.", "" ], [ "Lorente", "M.", "" ] ]
Spin networks are graphs derived from 3nj symbols of angular momentum. The surface embedding, the topology and dualization of these networks are considered. Embeddings into compact surfaces include the orientable sphere S^2 and the torus T, and the not orientable projective space P^2 and Klein's bottle K. Two families ...
gr-qc/0505050
Badiali Jean Pierre
J.P. Badiali
Entropy: From Black Holes to Ordinary Systems
null
J.Phys. A39 (2006) 7175-7186
10.1088/0305-4470/39/23/001
null
gr-qc
null
Several results of black holes thermodynamics can be considered as firmly founded and formulated in a very general manner. From this starting point we analyse in which way these results may give us the opportunity to gain a better understanding in the thermodynamics of ordinary systems for which a pre-relativistic de...
[ { "created": "Wed, 11 May 2005 15:56:58 GMT", "version": "v1" } ]
2009-11-11
[ [ "Badiali", "J. P.", "" ] ]
Several results of black holes thermodynamics can be considered as firmly founded and formulated in a very general manner. From this starting point we analyse in which way these results may give us the opportunity to gain a better understanding in the thermodynamics of ordinary systems for which a pre-relativistic desc...
1603.00637
Yi Xie
Shan-Shan Zhao and Yi Xie
Strong field gravitational lensing by a charged Galileon black hole
null
JCAP07(2016)007
10.1088/1475-7516/2016/07/007
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Strong field gravitational lensings are dramatically disparate from those in the weak field by representing relativistic images due to light winds one to infinity loops around a lens before escaping. We study such a lensing caused by a charged Galileon black hole, which is expected to have possibility to evade no-hai...
[ { "created": "Wed, 2 Mar 2016 09:54:52 GMT", "version": "v1" }, { "created": "Mon, 20 Jun 2016 14:01:17 GMT", "version": "v2" } ]
2016-07-11
[ [ "Zhao", "Shan-Shan", "" ], [ "Xie", "Yi", "" ] ]
Strong field gravitational lensings are dramatically disparate from those in the weak field by representing relativistic images due to light winds one to infinity loops around a lens before escaping. We study such a lensing caused by a charged Galileon black hole, which is expected to have possibility to evade no-hair ...
2012.09888
Ammar Kasem
Ammar Kasem and Shaaban Khalil
Quantum Cosmology with vector torsion
null
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend the treatment of quantum cosmology to a manifold with torsion. We adopt a model of Einstein-Cartan-Sciama-Kibble compatible with the cosmological principle. The universe wavefunction will be subject to a $\mathcal{PT}$-symmetric Hamiltonian. With a vanishing energy-momentum tensor, the universe evolution in...
[ { "created": "Thu, 17 Dec 2020 19:12:31 GMT", "version": "v1" } ]
2020-12-22
[ [ "Kasem", "Ammar", "" ], [ "Khalil", "Shaaban", "" ] ]
We extend the treatment of quantum cosmology to a manifold with torsion. We adopt a model of Einstein-Cartan-Sciama-Kibble compatible with the cosmological principle. The universe wavefunction will be subject to a $\mathcal{PT}$-symmetric Hamiltonian. With a vanishing energy-momentum tensor, the universe evolution in t...
2406.08501
\'Alvaro Mozota Frauca
\'Alvaro Mozota Frauca
Foundational Issues in Group Field Theory
null
Found Phys 54, 33 (2024)
10.1007/s10701-024-00763-9
null
gr-qc physics.hist-ph
http://creativecommons.org/licenses/by/4.0/
In this paper I offer an introduction to group field theory (GFT) and to some of the issues affecting the foundations of this approach to quantum gravity. I first introduce covariant GFT as the theory that one obtains by interpreting the amplitudes of certain spin foam models as Feynman amplitudes in a perturbative e...
[ { "created": "Wed, 22 May 2024 08:10:55 GMT", "version": "v1" } ]
2024-06-14
[ [ "Frauca", "Álvaro Mozota", "" ] ]
In this paper I offer an introduction to group field theory (GFT) and to some of the issues affecting the foundations of this approach to quantum gravity. I first introduce covariant GFT as the theory that one obtains by interpreting the amplitudes of certain spin foam models as Feynman amplitudes in a perturbative exp...
gr-qc/0212087
Gilad Gour
Gilad Gour
Extensive Entropy Bounds
8 pages, revtex, To appear in Phys. Rev. D
Phys.Rev. D67 (2003) 127501
10.1103/PhysRevD.67.127501
null
gr-qc cond-mat.stat-mech hep-th quant-ph
null
It is shown that, for systems in which the entropy is an extensive function of the energy and volume, the Bekenstein and the holographic entropy bounds predict new results. More explicitly, the Bekenstein entropy bound leads to the entropy of thermal radiation (the Unruh-Wald bound) and the spherical entropy bound im...
[ { "created": "Fri, 20 Dec 2002 20:47:30 GMT", "version": "v1" }, { "created": "Mon, 28 Apr 2003 21:03:29 GMT", "version": "v2" } ]
2009-11-07
[ [ "Gour", "Gilad", "" ] ]
It is shown that, for systems in which the entropy is an extensive function of the energy and volume, the Bekenstein and the holographic entropy bounds predict new results. More explicitly, the Bekenstein entropy bound leads to the entropy of thermal radiation (the Unruh-Wald bound) and the spherical entropy bound impl...
gr-qc/0307084
Cosimo Stornaiolo
V.I. Manko, G. Marmo, C. Stornaiolo
Radon transform of Wheeler-De Witt equation and tomography of quantum states of the universe
22 pages LaTeX, some minor corrections, new references added, submitted to General Relativity and Gravitation
Gen.Rel.Grav. 37 (2005) 99-114
10.1007/s10714-005-0005-3
null
gr-qc
null
The notion of standard positive probability distribution function (tomogram) which describes the quantum state of universe alternatively to wave function or to density matrix is introduced. Connection of the tomographic probability distribution with the Wigner function of the universe and with the star-product (defor...
[ { "created": "Thu, 17 Jul 2003 15:46:03 GMT", "version": "v1" }, { "created": "Wed, 21 Apr 2004 09:57:01 GMT", "version": "v2" } ]
2009-11-10
[ [ "Manko", "V. I.", "" ], [ "Marmo", "G.", "" ], [ "Stornaiolo", "C.", "" ] ]
The notion of standard positive probability distribution function (tomogram) which describes the quantum state of universe alternatively to wave function or to density matrix is introduced. Connection of the tomographic probability distribution with the Wigner function of the universe and with the star-product (deforma...
2405.19282
Edward Kurianovich
E. A. Kurianovich, A.I. Mikhailov, I. V. Volovich
On the theory of relativistic Brownian motion
null
p-Adic Numbers, Ultrametric Analysis and Applications 16 (2024) 2
null
null
gr-qc math.PR
http://creativecommons.org/licenses/by/4.0/
The approach to the theory of a relativistic random process is considered by the path integral method as Brownian motion taking into account the boundedness of speed. An attempt was made to build a relativistic analogue of the Wiener measure as a weak limit of finite-difference approximations. A formula has been prop...
[ { "created": "Wed, 29 May 2024 17:14:34 GMT", "version": "v1" } ]
2024-05-30
[ [ "Kurianovich", "E. A.", "" ], [ "Mikhailov", "A. I.", "" ], [ "Volovich", "I. V.", "" ] ]
The approach to the theory of a relativistic random process is considered by the path integral method as Brownian motion taking into account the boundedness of speed. An attempt was made to build a relativistic analogue of the Wiener measure as a weak limit of finite-difference approximations. A formula has been propos...
2206.12671
Carlos A. S. Almeida
F. C. E. Lima, A. R. P. Moreira, and C. A. S. Almeida
Properties of black hole vortex in Einstein's gravity
22 pages, 7 captioned figures. Enhanced version to appear in European Physical Journal Plus
null
null
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We investigate the influence of the matter field and the gauge field on the metric functions of the AdS$_3$ spacetime of the Maxwell-Higgs model. By considering a matter field with a solitonic profile with the ability to adjust the field variable from kink to compact-like configurations, the appearance of black hole ...
[ { "created": "Sat, 25 Jun 2022 15:27:31 GMT", "version": "v1" }, { "created": "Sun, 30 Apr 2023 18:39:01 GMT", "version": "v2" } ]
2023-05-02
[ [ "Lima", "F. C. E.", "" ], [ "Moreira", "A. R. P.", "" ], [ "Almeida", "C. A. S.", "" ] ]
We investigate the influence of the matter field and the gauge field on the metric functions of the AdS$_3$ spacetime of the Maxwell-Higgs model. By considering a matter field with a solitonic profile with the ability to adjust the field variable from kink to compact-like configurations, the appearance of black hole so...
2004.00336
Carlos A. R. Herdeiro
Carlos A. R. Herdeiro and Eugen Radu
Spherical electro-vacuum black holes with resonant, scalar $Q$-hair
18 pages, 5 figures; v2. typos corrected, matches published version
null
10.1140/epjc/s10052-020-7976-9
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The asymptotically flat, spherical, electro-vacuum black holes (BHs) are shown to support static, spherical configurations of a gauged, self-interacting, scalar field, minimally coupled to the geometry. Considering a $Q$-ball type potential for the scalar field, we dub these configurations $Q$-clouds, in the test fie...
[ { "created": "Wed, 1 Apr 2020 10:56:04 GMT", "version": "v1" }, { "created": "Mon, 11 May 2020 13:42:28 GMT", "version": "v2" } ]
2020-06-24
[ [ "Herdeiro", "Carlos A. R.", "" ], [ "Radu", "Eugen", "" ] ]
The asymptotically flat, spherical, electro-vacuum black holes (BHs) are shown to support static, spherical configurations of a gauged, self-interacting, scalar field, minimally coupled to the geometry. Considering a $Q$-ball type potential for the scalar field, we dub these configurations $Q$-clouds, in the test field...
1003.1680
Sergei Winitzki
Sergei Winitzki
Observability of the total inflationary expansion
11 pages, RevTeX, no figures
null
null
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I consider the question of possible observability of the total number of e-folds accumulated during the epoch of inflation. The total number of observable e-folds has been previously constrained by the de Sitter entropy after inflation, assuming that the null energy condition (NEC) holds. The NEC is violated by upwar...
[ { "created": "Mon, 8 Mar 2010 17:16:42 GMT", "version": "v1" } ]
2010-03-09
[ [ "Winitzki", "Sergei", "" ] ]
I consider the question of possible observability of the total number of e-folds accumulated during the epoch of inflation. The total number of observable e-folds has been previously constrained by the de Sitter entropy after inflation, assuming that the null energy condition (NEC) holds. The NEC is violated by upward ...
gr-qc/9912007
Mamdouh Wanas
M.I. Wanas and M.E. Kahil
Quantum Features of Non-Symmetric Geometries
Eight pages Latex file, published in GRG, vol.31, 1921, (1999)
Gen.Rel.Grav. 31 (1999) 1921
10.1023/A:1026743007086
null
gr-qc
null
Paths in an appropriate geometry are usually used as trajectories of test particles in geometric theories of gravity. It is shown that non-symmetric geometries possess some interesting quantum features. Without carrying out any quantization schemes, paths in such geometries are naturally quantized. Two different non-...
[ { "created": "Thu, 2 Dec 1999 12:57:12 GMT", "version": "v1" } ]
2015-06-25
[ [ "Wanas", "M. I.", "" ], [ "Kahil", "M. E.", "" ] ]
Paths in an appropriate geometry are usually used as trajectories of test particles in geometric theories of gravity. It is shown that non-symmetric geometries possess some interesting quantum features. Without carrying out any quantization schemes, paths in such geometries are naturally quantized. Two different non-sy...
1704.02747
Ken-Ichi Nakao
Yumi Akai and Ken-ichi Nakao
Non-linear stability of a brane wormhole
32 pages, 10 figure. arXiv admin note: substantial text overlap with arXiv:1306.6917
Phys. Rev. D 96, 024033 (2017)
10.1103/PhysRevD.96.024033
OCU-PHYS-461, AP-GR-136
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analytically study the non-linear stability of a spherically symmetric wormhole supported by an infinitesimally thin brane of negative tension, which has been devised by Barcelo and Visser. We consider a situation in which a thin spherical shell composed of dust falls into an initially static wormhole; The dust sh...
[ { "created": "Mon, 10 Apr 2017 08:06:55 GMT", "version": "v1" }, { "created": "Thu, 27 Apr 2017 07:56:14 GMT", "version": "v2" } ]
2017-07-26
[ [ "Akai", "Yumi", "" ], [ "Nakao", "Ken-ichi", "" ] ]
We analytically study the non-linear stability of a spherically symmetric wormhole supported by an infinitesimally thin brane of negative tension, which has been devised by Barcelo and Visser. We consider a situation in which a thin spherical shell composed of dust falls into an initially static wormhole; The dust shel...
2210.09823
Jean-David Pailleron
Jean-David Pailleron
A class of solutions to the conformal constraint equations on compact manifolds with apparent horizon boundary conditions
42 pages
null
null
null
gr-qc math.AP math.DG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This article is dedicated to solving the Einstein constraint equations with apparent horizon boundaries and freely specified mean curvature. The main novelty is that we study the conformal constraint equations assuming only low regularity.
[ { "created": "Tue, 18 Oct 2022 13:04:32 GMT", "version": "v1" } ]
2022-10-19
[ [ "Pailleron", "Jean-David", "" ] ]
This article is dedicated to solving the Einstein constraint equations with apparent horizon boundaries and freely specified mean curvature. The main novelty is that we study the conformal constraint equations assuming only low regularity.
2307.04873
Francisco X. Linares Cede\~no
Francisco X. Linares Cede\~no and Ulises Nucamendi
Gauge fixing in cosmological perturbations of Unimodular Gravity
32 pages, new text and references added. Version accepted for publication in JCAP
null
null
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With focus on the cosmological evolution of linear perturbations of matter and geometry, we calculate the equivalent expressions to that of the Newtonian and Synchronous gauges within the framework of Unimodular Gravity, being these two gauges commonly used and implemented in Boltzmann codes. An important aspect of o...
[ { "created": "Mon, 10 Jul 2023 19:50:36 GMT", "version": "v1" }, { "created": "Mon, 17 Jul 2023 18:55:31 GMT", "version": "v2" }, { "created": "Tue, 3 Oct 2023 16:54:36 GMT", "version": "v3" } ]
2023-10-04
[ [ "Cedeño", "Francisco X. Linares", "" ], [ "Nucamendi", "Ulises", "" ] ]
With focus on the cosmological evolution of linear perturbations of matter and geometry, we calculate the equivalent expressions to that of the Newtonian and Synchronous gauges within the framework of Unimodular Gravity, being these two gauges commonly used and implemented in Boltzmann codes. An important aspect of our...
2312.00706
Vojtech Pravda
Marcello Ortaggio, Vojtech Pravda, Alena Pravdova
Kerr-Schild double copy for Kundt spacetimes of any dimension
26 pages, minor changes, new references added, matches version to appear in JHEP
J. High Energy Phys. 2024, 69 (2024)
10.1007/JHEP02(2024)069
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that vacuum type N Kundt spacetimes in an arbitrary dimension admit a Kerr-Schild (KS) double copy. This is mostly done in a coordinate-independent way using the higher-dimensional Newman-Penrose formalism. We also discuss two kinds of non-uniqueness of an electromagnetic field corresponding to a given KS met...
[ { "created": "Fri, 1 Dec 2023 16:42:01 GMT", "version": "v1" }, { "created": "Fri, 9 Feb 2024 16:39:53 GMT", "version": "v2" } ]
2024-02-15
[ [ "Ortaggio", "Marcello", "" ], [ "Pravda", "Vojtech", "" ], [ "Pravdova", "Alena", "" ] ]
We show that vacuum type N Kundt spacetimes in an arbitrary dimension admit a Kerr-Schild (KS) double copy. This is mostly done in a coordinate-independent way using the higher-dimensional Newman-Penrose formalism. We also discuss two kinds of non-uniqueness of an electromagnetic field corresponding to a given KS metri...
1604.04734
Joao Paulo Morais Graca
J. P. Morais Gra\c{c}a, Godonou I. Salako and V. B. Bezerra
Quasinormal modes of a black hole with a cloud of strings in Einstein-Gauss-Bonnet gravity
15 pages, 7 figures; To appear in IJMPD
null
10.1142/S0218271817501139
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The quasinormal modes for a scalar field in the background spacetime corresponding to a black hole, with a cloud of strings, in Einstein-Gauss-Bonnet gravity, and the tensor quasinormal modes corresponding to perturbations in such spacetime, were both calculated using the WKB approximation. In the obtained results we...
[ { "created": "Sat, 16 Apr 2016 12:07:03 GMT", "version": "v1" }, { "created": "Sun, 9 Apr 2017 23:46:56 GMT", "version": "v2" } ]
2023-02-22
[ [ "Graça", "J. P. Morais", "" ], [ "Salako", "Godonou I.", "" ], [ "Bezerra", "V. B.", "" ] ]
The quasinormal modes for a scalar field in the background spacetime corresponding to a black hole, with a cloud of strings, in Einstein-Gauss-Bonnet gravity, and the tensor quasinormal modes corresponding to perturbations in such spacetime, were both calculated using the WKB approximation. In the obtained results we e...
2311.17198
Akshay Ghalsasi
Akshay Ghalsasi
Amplifying the Chirp: Using Deep Learning (U-Nets) to filter signal from noise in LIGO data
20 pages, 9 figures, comments welcome
null
null
PITT-PACC-2322
gr-qc astro-ph.CO astro-ph.IM hep-ph
http://creativecommons.org/licenses/by/4.0/
The direct detection of gravitational waves by LIGO has heralded a new era for astronomy and physics. Typically the gravitational waves observed by LIGO are dominated by noise. In this work we use Deep Convolutional Neural Networks (specifically U-Nets) to filter a clean signal from noisy data. We present two realiza...
[ { "created": "Tue, 28 Nov 2023 20:04:27 GMT", "version": "v1" } ]
2023-11-30
[ [ "Ghalsasi", "Akshay", "" ] ]
The direct detection of gravitational waves by LIGO has heralded a new era for astronomy and physics. Typically the gravitational waves observed by LIGO are dominated by noise. In this work we use Deep Convolutional Neural Networks (specifically U-Nets) to filter a clean signal from noisy data. We present two realizati...
1502.00811
Danylo Yerokhin
Yu.L. Bolotin, V.A. Cherkaskiy, O.A. Lemets, D.A. Yerokhin and L.G. Zazunov
Cosmology In Terms Of The Deceleration Parameter. Part I
67 pages, 6 figures. arXiv admin note: text overlap with arXiv:1104.4458, arXiv:1409.3352, arXiv:0708.3414, arXiv:gr-qc/0508052, arXiv:astro-ph/0402278, arXiv:astro-ph/0104349, arXiv:0807.0207 by other authors
null
null
null
gr-qc astro-ph.CO hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the early seventies, Alan Sandage defined cosmology as the search for two numbers: Hubble parameter ${{H}_{0}}$ and deceleration parameter ${{q}_{0}}$. The first of the two basic cosmological parameters (the Hubble parameter) describes the linear part of the time dependence of the scale factor. Treating the Univer...
[ { "created": "Tue, 3 Feb 2015 11:11:11 GMT", "version": "v1" } ]
2015-02-04
[ [ "Bolotin", "Yu. L.", "" ], [ "Cherkaskiy", "V. A.", "" ], [ "Lemets", "O. A.", "" ], [ "Yerokhin", "D. A.", "" ], [ "Zazunov", "L. G.", "" ] ]
In the early seventies, Alan Sandage defined cosmology as the search for two numbers: Hubble parameter ${{H}_{0}}$ and deceleration parameter ${{q}_{0}}$. The first of the two basic cosmological parameters (the Hubble parameter) describes the linear part of the time dependence of the scale factor. Treating the Universe...
1512.08623
Patrick Das Gupta
Patrick Das Gupta and Eklavya Thareja
Supermassive Black Holes from self-gravitating Bose-Einstein Condensates comprised of Ultra-light Bosonic Dark Matter
Presented the paper in ICGC 2015, IISER, Mohali, India, as well as in GR21, July 2016, Columbia University, USA
Classical and Quantum Gravity, Volume 34, Number 3 (2017)
10.1088/1361-6382/aa51fc
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Observed active galactic nuclei at redshifts $\gtrsim 6$ suggest that supermassive black holes (SMBHs) had formed early on. Accretion of matter onto remnants of Population III stars leading to SMBHs is a very slow process, and therefore, such models encounter difficulties in explaining quasars detected at $ z \gtrsim...
[ { "created": "Tue, 29 Dec 2015 08:53:20 GMT", "version": "v1" }, { "created": "Thu, 21 Apr 2016 15:09:31 GMT", "version": "v2" }, { "created": "Wed, 16 Nov 2016 06:02:20 GMT", "version": "v3" } ]
2018-12-27
[ [ "Gupta", "Patrick Das", "" ], [ "Thareja", "Eklavya", "" ] ]
Observed active galactic nuclei at redshifts $\gtrsim 6$ suggest that supermassive black holes (SMBHs) had formed early on. Accretion of matter onto remnants of Population III stars leading to SMBHs is a very slow process, and therefore, such models encounter difficulties in explaining quasars detected at $ z \gtrsim 6...
2103.15906
Christian Boehmer
Christian G. Boehmer, Erik Jensko
Modified gravity: a unified approach
34 pages, 2 figures; v2 minor changes, references added; v3 final changes, published version
Phys. Rev. D 104, 024010 (2021)
10.1103/PhysRevD.104.024010
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Starting from the original Einstein action, sometimes called the Gamma squared action, we propose a new setup to formulate modified theories of gravity. This can yield a theory with second order field equations similar to those found in other popular modified gravity models. Using a more general setting the theory gi...
[ { "created": "Mon, 29 Mar 2021 19:37:06 GMT", "version": "v1" }, { "created": "Thu, 15 Apr 2021 14:54:39 GMT", "version": "v2" }, { "created": "Thu, 8 Jul 2021 11:55:34 GMT", "version": "v3" } ]
2021-07-14
[ [ "Boehmer", "Christian G.", "" ], [ "Jensko", "Erik", "" ] ]
Starting from the original Einstein action, sometimes called the Gamma squared action, we propose a new setup to formulate modified theories of gravity. This can yield a theory with second order field equations similar to those found in other popular modified gravity models. Using a more general setting the theory give...
1112.6381
A Khodam-Mohammadi
Antonio Pasqua, A. Khodam-Mohammadi, Mubasher Jamil, R. Myrzakulov
Interacting Ricci Dark Energy with Logarithmic Correction
24 pages, accepted for publication in 'Astrophysics and Space Science, DOI:10.1007/s10509-012-1031-8'
Astrophysics and Space Science: Volume 340, 199-208, (2012)
10.1007/s10509-012-1031-8
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the holographic principle, it has been suggested that the dark energy density may be inversely proportional to the area $A$ of the event horizon of the universe. However, such a model would have a causality problem. In this work, we consider the entropy-corrected version of the holographic dark energy mo...
[ { "created": "Thu, 29 Dec 2011 19:05:21 GMT", "version": "v1" }, { "created": "Thu, 23 Feb 2012 07:02:40 GMT", "version": "v2" }, { "created": "Thu, 1 Mar 2012 09:19:49 GMT", "version": "v3" }, { "created": "Sat, 3 Mar 2012 20:10:57 GMT", "version": "v4" } ]
2012-06-06
[ [ "Pasqua", "Antonio", "" ], [ "Khodam-Mohammadi", "A.", "" ], [ "Jamil", "Mubasher", "" ], [ "Myrzakulov", "R.", "" ] ]
Motivated by the holographic principle, it has been suggested that the dark energy density may be inversely proportional to the area $A$ of the event horizon of the universe. However, such a model would have a causality problem. In this work, we consider the entropy-corrected version of the holographic dark energy mode...
2407.14954
Erick Ivan Duque Gonzalez
Erick I. Duque
Emergent electromagnetism
66 pages
null
null
null
gr-qc hep-ph
http://creativecommons.org/licenses/by/4.0/
We introduce the concept of emergent electric field. This is distinguished from the fundamental one in that the emergent electric field directly appears in observations through the Lorentz force, while the latter enters the phase space as the canonical momentum of the electromagnetic field. In Hamiltonian classical e...
[ { "created": "Sat, 20 Jul 2024 18:14:37 GMT", "version": "v1" } ]
2024-07-23
[ [ "Duque", "Erick I.", "" ] ]
We introduce the concept of emergent electric field. This is distinguished from the fundamental one in that the emergent electric field directly appears in observations through the Lorentz force, while the latter enters the phase space as the canonical momentum of the electromagnetic field. In Hamiltonian classical ele...
gr-qc/0604013
Parampreet Singh
Abhay Ashtekar, Tomasz Pawlowski, Parampreet Singh
Quantum Nature of the Big Bang: An Analytical and Numerical Investigation
Revised version to appear in Physical Review D. References added and typos corrected
Phys.Rev.D73:124038,2006
10.1103/PhysRevD.73.124038
IGPG-06/03-2
gr-qc hep-th
null
Analytical and numerical methods are developed to analyze the quantum nature of the big bang in the setting of loop quantum cosmology. They enable one to explore the effects of quantum geometry both on the gravitational and matter sectors and significantly extend the known results on the resolution of the big bang si...
[ { "created": "Tue, 4 Apr 2006 19:03:37 GMT", "version": "v1" }, { "created": "Thu, 13 Apr 2006 18:29:12 GMT", "version": "v2" }, { "created": "Mon, 19 Jun 2006 17:54:59 GMT", "version": "v3" } ]
2008-11-26
[ [ "Ashtekar", "Abhay", "" ], [ "Pawlowski", "Tomasz", "" ], [ "Singh", "Parampreet", "" ] ]
Analytical and numerical methods are developed to analyze the quantum nature of the big bang in the setting of loop quantum cosmology. They enable one to explore the effects of quantum geometry both on the gravitational and matter sectors and significantly extend the known results on the resolution of the big bang sing...
2105.11690
Jafar Khodagholizadeh
Jafar Khodagholizadeh, Amir H. Abbassi, Ali Vahedi and Komeil Babaei
Gravitational Waves in a Closed Spacetime via Deviation Equation
22 pages, 11 figures
Results in Physics, Volume 26, July 2021, 104347
10.1016/j.rinp.2021.104347
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the closed universe, we obtain the amplitude and frequency of gravitational waves in the terms of discrete wave numbers, wave propagation time, and cosmological constant using the deviation equation in the first-order perturbed metric. We demonstrate that the cosmological constant effect on GWs is only seen in...
[ { "created": "Tue, 25 May 2021 06:15:05 GMT", "version": "v1" } ]
2021-05-27
[ [ "Khodagholizadeh", "Jafar", "" ], [ "Abbassi", "Amir H.", "" ], [ "Vahedi", "Ali", "" ], [ "Babaei", "Komeil", "" ] ]
Within the closed universe, we obtain the amplitude and frequency of gravitational waves in the terms of discrete wave numbers, wave propagation time, and cosmological constant using the deviation equation in the first-order perturbed metric. We demonstrate that the cosmological constant effect on GWs is only seen in t...
2101.07147
Vladimir Khatsymovsky
V.M. Khatsymovsky
On the Kerr metric in a synchronous reference frame
9 pages, 1 figure
Int. J. Mod. Phys. D, Volume No. 30, Issue No. 10, Article No. 2150071, Year 2021
10.1142/S0218271821500711
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Kerr metric is considered in a synchronous frame of reference obtained by using proper time and initial conditions for particles that freely move along a certain set of trajectories as coordinates. Modifying these coordinates in a certain way (keeping their interpretation as initial values at large distances), we...
[ { "created": "Mon, 18 Jan 2021 16:28:23 GMT", "version": "v1" } ]
2021-08-26
[ [ "Khatsymovsky", "V. M.", "" ] ]
The Kerr metric is considered in a synchronous frame of reference obtained by using proper time and initial conditions for particles that freely move along a certain set of trajectories as coordinates. Modifying these coordinates in a certain way (keeping their interpretation as initial values at large distances), we s...
0804.0153
Selcuk Bayin
Selcuk S. Bayin
Friedmann Thermodynamics and the Geometry of the Universe
Key note speech delivered in the International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS'95 and ASME
Proceedings of ECOS' 95 and ASME, Y.A. Gogus, Y.A. Ozturk, G. Tsatsaronis (eds.) Vol.1, pg. 3, 1995
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a recent article we have introduced Friedmann thermodynamics, where certain geometric parameters in Friedmann models are treated like their thermodynamic counterparts (temperature, entropy, Gibbs potential etc.). This model has the advantage of allowing us to determine the geometry of the universe by thermodynamic...
[ { "created": "Tue, 1 Apr 2008 12:12:36 GMT", "version": "v1" } ]
2008-04-02
[ [ "Bayin", "Selcuk S.", "" ] ]
In a recent article we have introduced Friedmann thermodynamics, where certain geometric parameters in Friedmann models are treated like their thermodynamic counterparts (temperature, entropy, Gibbs potential etc.). This model has the advantage of allowing us to determine the geometry of the universe by thermodynamic s...
1010.5837
Bei Lok Hu
B. L. Hu
Gravity and Nonequilibrium Thermodynamics of Classical Matter
25 pages essay. Invited Talk at Mariofest, March 2010, Rosario, Argentina. Festschrift to appear as an issue of IJMPD
Int.J.Mod.Phys.D20:697-716,2011
10.1142/S0218271811019049
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Renewed interest in deriving gravity (more precisely, the Einstein equations) from thermodynamics considerations [1, 2] is stirred up by a recent proposal that 'gravity is an entropic force' [3] (see also [4]). Even though I find the arguments justifying such a claim in this latest proposal rather ad hoc and simplist...
[ { "created": "Thu, 28 Oct 2010 01:36:56 GMT", "version": "v1" } ]
2011-05-25
[ [ "Hu", "B. L.", "" ] ]
Renewed interest in deriving gravity (more precisely, the Einstein equations) from thermodynamics considerations [1, 2] is stirred up by a recent proposal that 'gravity is an entropic force' [3] (see also [4]). Even though I find the arguments justifying such a claim in this latest proposal rather ad hoc and simplistic...
gr-qc/9503067
Carlo Rovelli
Carlo Rovelli
OUTLINE OF A GENERALLY COVARIANT QUANTUM FIELD THEORY AND A QUANTUM THEORY OF GRAVITY
Latex file, 33 pages
J.Math.Phys.36:6529-6547,1995
10.1063/1.531255
null
gr-qc
null
We study a tentative generally covariant quantum field theory, denoted the T-Theory, as a tool to investigate the consistency of quantum general relativity. The theory describes the gravitational field and a minimally coupled scalar field; it is based on the loop representation, and on a certain number of quantizatio...
[ { "created": "Sat, 1 Apr 1995 14:45:13 GMT", "version": "v1" } ]
2010-11-01
[ [ "Rovelli", "Carlo", "" ] ]
We study a tentative generally covariant quantum field theory, denoted the T-Theory, as a tool to investigate the consistency of quantum general relativity. The theory describes the gravitational field and a minimally coupled scalar field; it is based on the loop representation, and on a certain number of quantization ...
2210.14049
Naritaka Oshita
Naritaka Oshita and Daichi Tsuna
Slowly Decaying Ringdown of a Rapidly Spinning Black Hole: Probing the No-Hair Theorem by Small Mass-Ratio Mergers with LISA
8 pages, 8 figures, version accepted for publication in PRD
Phys. Rev. D 108, 104031 (2023)
10.1103/PhysRevD.108.104031
RIKEN-iTHEMS-Report-22, RESCEU-19/22, YITP-23-155
gr-qc astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
The measurability of multiple quasinormal (QN) modes, including overtones and higher harmonics, with the Laser Interferometer Space Antenna is investigated by computing the gravitational wave (GW) signal induced by an intermediate or extreme mass ratio merger involving a supermassive black hole (SMBH). We confirm tha...
[ { "created": "Tue, 25 Oct 2022 14:28:48 GMT", "version": "v1" }, { "created": "Thu, 30 Nov 2023 06:23:46 GMT", "version": "v2" } ]
2023-12-01
[ [ "Oshita", "Naritaka", "" ], [ "Tsuna", "Daichi", "" ] ]
The measurability of multiple quasinormal (QN) modes, including overtones and higher harmonics, with the Laser Interferometer Space Antenna is investigated by computing the gravitational wave (GW) signal induced by an intermediate or extreme mass ratio merger involving a supermassive black hole (SMBH). We confirm that ...
gr-qc/0605067
Tatyana P. Shestakova
T. P. Shestakova
Cosmological solutions for the Universe filled with matter in various states and gauge invariance
8 pages, talk presented at the International Conference on Gravitation, Cosmology and Astrophysics dedicated to 90th anniversary of K. P. Staniukovich, Moscow, March 2006
Grav.Cosmol. 12 (2006) 223-226
null
null
gr-qc
null
We explore at phenomenological level a model of the Universe filled with various kinds of matter characterized by different equations of state. We show that introducing of each kind of matter is equivalent to a certain choice of a gauge condition, the gauge condition describing a medium with a given equation of state...
[ { "created": "Thu, 11 May 2006 11:57:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Shestakova", "T. P.", "" ] ]
We explore at phenomenological level a model of the Universe filled with various kinds of matter characterized by different equations of state. We show that introducing of each kind of matter is equivalent to a certain choice of a gauge condition, the gauge condition describing a medium with a given equation of state. ...
1811.04327
Javier Olmedo
Javier Olmedo and Emanuele Alesci
Power spectrum of primordial perturbations for an emergent universe in quantum reduced loop gravity
28 pages, 8 figures
null
10.1088/1475-7516/2019/04/030
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the dynamics and predictions of a new emergent-universe model recently derived within Quantum Reduced Loop Gravity and based on the so-called statistical regularization scheme. These effective geometries show a dynamical transition from a stationary spacetime, with nearly constant scale factor at very early ...
[ { "created": "Sun, 11 Nov 2018 00:20:20 GMT", "version": "v1" } ]
2019-04-24
[ [ "Olmedo", "Javier", "" ], [ "Alesci", "Emanuele", "" ] ]
We study the dynamics and predictions of a new emergent-universe model recently derived within Quantum Reduced Loop Gravity and based on the so-called statistical regularization scheme. These effective geometries show a dynamical transition from a stationary spacetime, with nearly constant scale factor at very early ti...
gr-qc/0408088
Daniel Hofmann
D. Hofmann and W. Kummer
Effective Action and Hawking Flux from Covariant Perturbation Theory
26 pages
Eur.Phys.J. C40 (2005) 275-286
10.1140/epjc/s2005-02129-9
TUW-04-20
gr-qc
null
The computation of the radiation flux related to the Hawking temperature of a Schwarzschild Black Hole or another geometric background is still well-known to be fraught with a number of delicate problems. In spherical reduction, as shown by one of the present authors (W. K.) with D.V. Vassilevich, the correct black b...
[ { "created": "Thu, 26 Aug 2004 21:46:06 GMT", "version": "v1" } ]
2009-11-10
[ [ "Hofmann", "D.", "" ], [ "Kummer", "W.", "" ] ]
The computation of the radiation flux related to the Hawking temperature of a Schwarzschild Black Hole or another geometric background is still well-known to be fraught with a number of delicate problems. In spherical reduction, as shown by one of the present authors (W. K.) with D.V. Vassilevich, the correct black bod...
2002.08048
Huiquan Li
Huiquan Li and Jiancheng Wang
Towards the merger of Hawking radiating black holes
17 pages, no figure
null
10.1142/S0218271821500607
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the merger process of binary black holes with Hawking radiation taken into account. Besides the redshifted radiation to infinity, binary black holes can exchange radiation between themselves, which is first redshifted and then blueshifted when it propagates from one hole to the other. The exchange rate sho...
[ { "created": "Wed, 19 Feb 2020 08:23:44 GMT", "version": "v1" }, { "created": "Mon, 11 May 2020 15:46:57 GMT", "version": "v2" }, { "created": "Thu, 3 Jun 2021 13:59:37 GMT", "version": "v3" } ]
2021-07-21
[ [ "Li", "Huiquan", "" ], [ "Wang", "Jiancheng", "" ] ]
We discuss the merger process of binary black holes with Hawking radiation taken into account. Besides the redshifted radiation to infinity, binary black holes can exchange radiation between themselves, which is first redshifted and then blueshifted when it propagates from one hole to the other. The exchange rate shoul...
2006.15622
She-Sheng Xue
She-Sheng Xue
Massive particle pair production and oscillation in Friedman Universe: reheating energy and entropy, and cold dark matter
The final version to appear in the European Physical Journal C. 41 pages and 11 captioned figures. Secs 2-3, holographic and massive pair plasma state; Sec. 5 cosmological model; Sec. 6-10 reheating
null
null
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
Suppose that the early Universe starts with a cosmological $\Lambda$-term originating from quantum spacetime at the Planck scale. Dark energy drives inflation and reheating by reducing its value for massive particle-antiparticle pairs production and oscillation, resulting in a holographic and massive pair plasma stat...
[ { "created": "Sun, 28 Jun 2020 14:36:58 GMT", "version": "v1" }, { "created": "Mon, 3 May 2021 08:59:43 GMT", "version": "v2" }, { "created": "Tue, 17 Jan 2023 17:54:26 GMT", "version": "v3" }, { "created": "Mon, 17 Apr 2023 09:03:31 GMT", "version": "v4" } ]
2023-04-18
[ [ "Xue", "She-Sheng", "" ] ]
Suppose that the early Universe starts with a cosmological $\Lambda$-term originating from quantum spacetime at the Planck scale. Dark energy drives inflation and reheating by reducing its value for massive particle-antiparticle pairs production and oscillation, resulting in a holographic and massive pair plasma state....
1906.03790
Marcony Silva Cunha
C.R. Muniz, H.R. Christiansen, M.S. Cunha, H.S. Vieira
Exact solutions of the Wheeler-DeWitt equation with ordering term in a dark energy scenario
16 pages, improved figures, some new relevant conclusions, references added
Physics of the Dark Universe, v28, 100547 (2020)
10.1016/j.dark.2020.100547
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the quantum evolution of the universe in the presence of two types of dark energies. First, we consider the phantom class ($\omega<-1$) which would be responsible for a super-accelerated cosmic expansion, and then we apply the procedure to an ordinary $\Lambda>0$ vacuum ($\omega=-1$). This is done by a...
[ { "created": "Mon, 10 Jun 2019 04:24:08 GMT", "version": "v1" }, { "created": "Fri, 11 Oct 2019 23:10:22 GMT", "version": "v2" }, { "created": "Fri, 20 Mar 2020 17:20:39 GMT", "version": "v3" } ]
2022-04-11
[ [ "Muniz", "C. R.", "" ], [ "Christiansen", "H. R.", "" ], [ "Cunha", "M. S.", "" ], [ "Vieira", "H. S.", "" ] ]
We investigate the quantum evolution of the universe in the presence of two types of dark energies. First, we consider the phantom class ($\omega<-1$) which would be responsible for a super-accelerated cosmic expansion, and then we apply the procedure to an ordinary $\Lambda>0$ vacuum ($\omega=-1$). This is done by ana...
1211.2913
Guido Pizzella
R. de Sangro, G. Finocchiaro, P.Patteri, M. Piccolo, G. Pizzella
Measuring Propagation Speed of Coulomb Fields
23 pages, 15 figures
null
null
null
gr-qc physics.acc-ph physics.gen-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The problem of gravity propagation has been subject of discussion for quite a long time: Newton, Laplace and, in relatively more modern times, Eddington pointed out that, if gravity propagated with finite velocity, planets motion around the sun would become unstable due to a torque originating from time lag of the gr...
[ { "created": "Tue, 13 Nov 2012 08:35:20 GMT", "version": "v1" }, { "created": "Mon, 10 Nov 2014 09:23:07 GMT", "version": "v2" } ]
2014-11-11
[ [ "de Sangro", "R.", "" ], [ "Finocchiaro", "G.", "" ], [ "Patteri", "P.", "" ], [ "Piccolo", "M.", "" ], [ "Pizzella", "G.", "" ] ]
The problem of gravity propagation has been subject of discussion for quite a long time: Newton, Laplace and, in relatively more modern times, Eddington pointed out that, if gravity propagated with finite velocity, planets motion around the sun would become unstable due to a torque originating from time lag of the grav...
2403.17278
Julio Cesar Fabris
J\'ulio C. Fabris and Richard Kerner
A unimodular Kaluza-Klein theory
Latex file, 19 pages, 2 figures
null
null
null
gr-qc astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
Unimodular gravity became an object of increasing interest in the late $80$-ties and was recently used in primordial Universe modeling with cosmological constant, in the context of the Brans-Dicke gravity including scalar field. In the present article we investigate the possibility of imposing the unimodular conditio...
[ { "created": "Mon, 25 Mar 2024 23:48:19 GMT", "version": "v1" } ]
2024-03-27
[ [ "Fabris", "Júlio C.", "" ], [ "Kerner", "Richard", "" ] ]
Unimodular gravity became an object of increasing interest in the late $80$-ties and was recently used in primordial Universe modeling with cosmological constant, in the context of the Brans-Dicke gravity including scalar field. In the present article we investigate the possibility of imposing the unimodular condition ...
gr-qc/0602099
Yaneer Bar-Yam
Yaneer Bar-Yam
ZM theory I: Introduction and Lorentz covariance
15 pages, 2 figures
null
null
NECSI Report 2006-02-01
gr-qc
null
We consider defining time as a function of a cyclical field, an abstraction of a clock. The definition of time corresponds to a novel interpretation of the relationship between space-time coordinates of observers at different locations in space. As a first test of the utility of this definition, we show that it leads...
[ { "created": "Fri, 24 Feb 2006 17:29:32 GMT", "version": "v1" } ]
2009-09-29
[ [ "Bar-Yam", "Yaneer", "" ] ]
We consider defining time as a function of a cyclical field, an abstraction of a clock. The definition of time corresponds to a novel interpretation of the relationship between space-time coordinates of observers at different locations in space. As a first test of the utility of this definition, we show that it leads t...
1905.04814
Artymowski Michal
Vahid Kamali, Micha{\l} Artymowski and Mohammad Reza Setare
Constant roll warm inflation in high dissipative regime
17 pages, 2 figures, published version
null
10.1088/1475-7516/2020/07/002
JCAP07(2020)002
gr-qc hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Constant-roll warm inflation is introduced in this work. A novel approach to finding an exact solution for Friedman equations coupled to scalar field equation of motion is presented for cold inflation and is extended to warm inflation with the constant dissipative parameter $Q=\frac{\Gamma}{3H}$. The evolution of the...
[ { "created": "Mon, 13 May 2019 00:11:13 GMT", "version": "v1" }, { "created": "Thu, 16 Jul 2020 07:01:55 GMT", "version": "v2" } ]
2020-07-17
[ [ "Kamali", "Vahid", "" ], [ "Artymowski", "Michał", "" ], [ "Setare", "Mohammad Reza", "" ] ]
Constant-roll warm inflation is introduced in this work. A novel approach to finding an exact solution for Friedman equations coupled to scalar field equation of motion is presented for cold inflation and is extended to warm inflation with the constant dissipative parameter $Q=\frac{\Gamma}{3H}$. The evolution of the p...
0905.2442
Alan Coley
A.A. Coley
Cosmological Observations: Averaging on the Null Cone
null
null
null
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The universe is not isotropic or spatially homogeneous on local scales. The averaging of local inhomogeneities in general relativity can lead to significant dynamical effects on the evolution of the universe and on the interpretation of cosmological data. In particular, all deductions about cosmology are based on lig...
[ { "created": "Thu, 14 May 2009 23:05:35 GMT", "version": "v1" } ]
2009-05-19
[ [ "Coley", "A. A.", "" ] ]
The universe is not isotropic or spatially homogeneous on local scales. The averaging of local inhomogeneities in general relativity can lead to significant dynamical effects on the evolution of the universe and on the interpretation of cosmological data. In particular, all deductions about cosmology are based on light...
1712.02210
Vilson T. Zanchin
Jos\'e D. V. Arba\~nil, Vilson T. Zanchin
Relativistic polytropic spheres with electric charge: Compact stars, compactness and mass bounds, and quasiblack hole configurations
15 pages, 15 figures
Phys. Rev. D 97, 104045 (2018)
10.1103/PhysRevD.97.104045
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the static stellar equilibrium configurations ofuncharged and charged spheres composed by a relativistic polytropic fluid, and compare with those of spheres composed by a non-relativistic polytropic fluid, the later case already being studied in a previous work [J. D. Arba\~nil, P. S. Lemos, V. T. Zanchin, P...
[ { "created": "Wed, 6 Dec 2017 14:49:29 GMT", "version": "v1" } ]
2018-05-30
[ [ "Arbañil", "José D. V.", "" ], [ "Zanchin", "Vilson T.", "" ] ]
We study the static stellar equilibrium configurations ofuncharged and charged spheres composed by a relativistic polytropic fluid, and compare with those of spheres composed by a non-relativistic polytropic fluid, the later case already being studied in a previous work [J. D. Arba\~nil, P. S. Lemos, V. T. Zanchin, Phy...
1003.5357
Robert C. Myers
Robert C. Myers and Brandon Robinson
Black Holes in Quasi-topological Gravity
33 pages, 4 figures; two references added
JHEP 1008:067,2010
10.1007/JHEP08(2010)067
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct a new gravitational action which includes cubic curvature interactions and which provides a useful toy model for the holographic study of a three parameter family of four- and higher-dimensional CFT's. We also investigate the black hole solutions of this new gravity theory. Further we examine the equatio...
[ { "created": "Sun, 28 Mar 2010 10:39:15 GMT", "version": "v1" }, { "created": "Wed, 9 Jun 2010 14:07:25 GMT", "version": "v2" } ]
2014-11-20
[ [ "Myers", "Robert C.", "" ], [ "Robinson", "Brandon", "" ] ]
We construct a new gravitational action which includes cubic curvature interactions and which provides a useful toy model for the holographic study of a three parameter family of four- and higher-dimensional CFT's. We also investigate the black hole solutions of this new gravity theory. Further we examine the equations...
2308.00917
Tayyab Naseer
M. Sharif, Tayyab Naseer
Cosmological Solutions through Gravitational Decoupling in $f(\mathcal{R},\mathcal{T},\mathcal{R}_{\mathrm{a}\mathrm{b}}\mathcal{T}^{\mathrm{a}\mathrm{b}})$ Gravity
30 pages, 10 figures
Gen. Relativ. Gravit. 55(2023)87
10.1007/s10714-023-03135-2
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we adopt minimal gravitational decoupling scheme to extend a non-static spherically symmetric isotropic composition to anisotropic interior in $f(\mathcal{R},\mathcal{T},\mathcal{R}_{\mathrm{a}\mathrm{b}}\mathcal{T}^{\mathrm{a}\mathrm{b}})$ theory. A geometric deformation is applied only on $g_{rr}$ me...
[ { "created": "Wed, 2 Aug 2023 03:14:52 GMT", "version": "v1" } ]
2023-08-03
[ [ "Sharif", "M.", "" ], [ "Naseer", "Tayyab", "" ] ]
In this paper, we adopt minimal gravitational decoupling scheme to extend a non-static spherically symmetric isotropic composition to anisotropic interior in $f(\mathcal{R},\mathcal{T},\mathcal{R}_{\mathrm{a}\mathrm{b}}\mathcal{T}^{\mathrm{a}\mathrm{b}})$ theory. A geometric deformation is applied only on $g_{rr}$ metr...
gr-qc/0611131
Shailesh Kulkarni
Rabin Banerjee, Subir Ghosh and Shailesh Kulkarni
Remarks on the Generalized Chaplygin Gas
References addeded
Phys.Rev.D75:025008,2007
10.1103/PhysRevD.75.025008
null
gr-qc hep-th
null
We have developed an action formulation for the Generalized Chaplygin Gas (GCG). The most general form for the nonrelativistic GCG action is derived consistent with the equation of state. We have also discussed a relativistic formulation for GCG by providing a detailed analysis of the Poincare algebra.
[ { "created": "Fri, 24 Nov 2006 10:55:37 GMT", "version": "v1" }, { "created": "Thu, 30 Nov 2006 05:35:54 GMT", "version": "v2" } ]
2016-08-31
[ [ "Banerjee", "Rabin", "" ], [ "Ghosh", "Subir", "" ], [ "Kulkarni", "Shailesh", "" ] ]
We have developed an action formulation for the Generalized Chaplygin Gas (GCG). The most general form for the nonrelativistic GCG action is derived consistent with the equation of state. We have also discussed a relativistic formulation for GCG by providing a detailed analysis of the Poincare algebra.
gr-qc/0208084
Janusz Garecki
Janusz Garecki (Institute of Physics, U. of Szczecin)
Einsteinian Strengths and Dynamical Degrees of Freedom for Alternative Gravity Theories
19 pages, no figures, LaTeX + RevTeX, Talk delivered at the International Conference: "Ideas of Albert Abraham Michelson in Mathematical Physics", Stefan Banach International Mathematical Center, August 4 - 11, 2002, Bedlevo, Poland
null
null
null
gr-qc
null
In this paper we present the results of our calculations of the Einsteinian strengths S_E(d) and numbers dynamical degrees of freedom N_{DF}(d) for alternative gravity theories in d >= 4 dimensions. In the first part we consider the numbers S_E(d) and N_{DF}(d) for metric-compatible and quadratic in curvature (or qua...
[ { "created": "Tue, 27 Aug 2002 14:47:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Garecki", "Janusz", "", "Institute of Physics, U. of Szczecin" ] ]
In this paper we present the results of our calculations of the Einsteinian strengths S_E(d) and numbers dynamical degrees of freedom N_{DF}(d) for alternative gravity theories in d >= 4 dimensions. In the first part we consider the numbers S_E(d) and N_{DF}(d) for metric-compatible and quadratic in curvature (or quadr...
1810.07356
Ernesto Contreras
Ernesto Contreras, \'Angel Rinc\'on and J. M. Ram\'irez-Velasquez
Relativistic dust accretion onto a scale--dependent polytropic black hole
5 pages, 2 figures
Eur. Phys. J. C (2019) 79:53
10.1140/epjc/s10052-019-6601-2
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we study steady and spherical relativistic dust accretion onto a static and spherically symmetric scale--dependent black hole. In particular we consider a polytropic scale--dependent black hole as a central object and obtain that the radial velocity profile and the energy density are affected when scale-...
[ { "created": "Wed, 17 Oct 2018 02:23:37 GMT", "version": "v1" }, { "created": "Thu, 18 Oct 2018 00:36:55 GMT", "version": "v2" } ]
2019-04-01
[ [ "Contreras", "Ernesto", "" ], [ "Rincón", "Ángel", "" ], [ "Ramírez-Velasquez", "J. M.", "" ] ]
In this work we study steady and spherical relativistic dust accretion onto a static and spherically symmetric scale--dependent black hole. In particular we consider a polytropic scale--dependent black hole as a central object and obtain that the radial velocity profile and the energy density are affected when scale--d...
1710.04181
Jos\'e Andr\'e Louren\c{c}o
Jos\'e A. Louren\c{c}o, Jos\'e A. Helay\"el Neto, Wesley Spalenza
Topological Gravity on $(D,N)-$Shift Superspace Formulation
null
Adv. High Energy Phys. 2018 (2018) 2786081
10.1155/2018/2786081
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this contribution, we re-assess the subject of topological gravity by following the Shift Supersymmetry formalism. The gauge-fixing of the theory goes under the Batallin-Vilkovisky (BV) prescription based on a diagram that contains both ghost and anti-ghost superfields, associated to the super-vielbein and the sup...
[ { "created": "Wed, 11 Oct 2017 17:23:20 GMT", "version": "v1" }, { "created": "Tue, 8 May 2018 22:47:22 GMT", "version": "v2" }, { "created": "Thu, 28 Jun 2018 18:20:10 GMT", "version": "v3" } ]
2018-08-09
[ [ "Lourenço", "José A.", "" ], [ "Neto", "José A. Helayël", "" ], [ "Spalenza", "Wesley", "" ] ]
In this contribution, we re-assess the subject of topological gravity by following the Shift Supersymmetry formalism. The gauge-fixing of the theory goes under the Batallin-Vilkovisky (BV) prescription based on a diagram that contains both ghost and anti-ghost superfields, associated to the super-vielbein and the super...
gr-qc/9509007
null
Giampiero Esposito
Hamiltonian Structure of a Friedmann-Robertson-Walker Universe with Torsion
16 pages, plain-tex, published in Nuovo Cimento B, Volume 104, pages 199-212, year 1989
NuovoCim.B104:199-212,1989; Erratum-ibid.B106:1315,1991
10.1007/BF02906317
DAMTP R 89/9
gr-qc
null
We study a $R^{2}$ model of gravity with torsion in a closed Friedmann-Robertson-Walker universe. The model is cast in Hamiltonian form subtracting from the original Lagrangian the total time derivative of $f_{K}f_{R}$, where $f_{K}$ is proportional to the trace of the extrinsic curvature tensor, and $f_{R}$ is obtai...
[ { "created": "Wed, 6 Sep 1995 06:04:21 GMT", "version": "v1" } ]
2008-11-26
[ [ "Esposito", "Giampiero", "" ] ]
We study a $R^{2}$ model of gravity with torsion in a closed Friedmann-Robertson-Walker universe. The model is cast in Hamiltonian form subtracting from the original Lagrangian the total time derivative of $f_{K}f_{R}$, where $f_{K}$ is proportional to the trace of the extrinsic curvature tensor, and $f_{R}$ is obtaine...
2403.00916
Maarten Grothus
Maarten Grothus, V. Vilasini
Characterizing Signalling: Connections between Causal Inference and Space-time Geometry
24 + 24 pages, 10 figures. This work includes significantly improved versions of initial results presented in MG's master's thesis arXiv:2211.03593. Comments welcome!
null
null
null
gr-qc math-ph math.MP math.ST quant-ph stat.TH
http://creativecommons.org/licenses/by/4.0/
Causality is pivotal to our understanding of the world, presenting itself in different forms: information-theoretic and relativistic, the former linked to the flow of information, the latter to the structure of space-time. Leveraging a framework introduced in PRA, 106, 032204 (2022), which formally connects these two...
[ { "created": "Fri, 1 Mar 2024 19:00:45 GMT", "version": "v1" } ]
2024-03-05
[ [ "Grothus", "Maarten", "" ], [ "Vilasini", "V.", "" ] ]
Causality is pivotal to our understanding of the world, presenting itself in different forms: information-theoretic and relativistic, the former linked to the flow of information, the latter to the structure of space-time. Leveraging a framework introduced in PRA, 106, 032204 (2022), which formally connects these two n...
gr-qc/0105117
Matthew F. Parry
Matthew Parry and Richard Easther
Inhomogeneity and Nonlinear Preheating
Talk given at Marcel Grossmann Meeting IX. 3 pages, 1 figure
null
10.1142/9789812777386_0451
null
gr-qc astro-ph hep-ph
null
We investigated the possibility that nonlinear gravitational effects influence the preheating era after inflation, using numerical solutions of the inhomogeneous Einstein field equations. We compared our results to perturbative calculations and to solutions of the nonlinear field equations in a rigid (unperturbed) sp...
[ { "created": "Wed, 30 May 2001 18:57:53 GMT", "version": "v1" } ]
2017-08-23
[ [ "Parry", "Matthew", "" ], [ "Easther", "Richard", "" ] ]
We investigated the possibility that nonlinear gravitational effects influence the preheating era after inflation, using numerical solutions of the inhomogeneous Einstein field equations. We compared our results to perturbative calculations and to solutions of the nonlinear field equations in a rigid (unperturbed) spac...
1910.13094
Tsuyoshi Houri
Tsuyoshi Houri, Norihiro Tanahashi, Yukinori Yasui
Hidden symmetry and the separability of the Maxwell equation on the Wahlquist spacetime
13 pages, 2 figures, v2: typos corrected
null
10.1088/1361-6382/ab6e8a
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine hidden symmetry and its relation to the separability of the Maxwell equation on the Wahlquist spacetime. After seeing that the Wahlquist spacetime is a type-D spacetime whose repeated principal null directions are shear-free and geodesic, we show that the spacetime admits three gauged conformal Killing-Yan...
[ { "created": "Tue, 29 Oct 2019 05:46:20 GMT", "version": "v1" }, { "created": "Fri, 1 Nov 2019 09:07:58 GMT", "version": "v2" } ]
2020-04-08
[ [ "Houri", "Tsuyoshi", "" ], [ "Tanahashi", "Norihiro", "" ], [ "Yasui", "Yukinori", "" ] ]
We examine hidden symmetry and its relation to the separability of the Maxwell equation on the Wahlquist spacetime. After seeing that the Wahlquist spacetime is a type-D spacetime whose repeated principal null directions are shear-free and geodesic, we show that the spacetime admits three gauged conformal Killing-Yano ...
gr-qc/9312030
Jim McCarthy
T. Damour, S. Deser and J. McCarthy
Nonsymmetric Gravity has Unacceptable Global Asymptotics
10 pages, ADP-93-221/M20
null
null
null
gr-qc
null
We analyze the radiative aspects of nonsymmetric gravity theory to show that, in contrast to General Relativity, its nonstationary solutions cannot simultaneously exhibit acceptable asymptotic behavior at both future and past null infinity: good behavior at future null infinity is only possible through the use of adv...
[ { "created": "Mon, 20 Dec 1993 04:42:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Damour", "T.", "" ], [ "Deser", "S.", "" ], [ "McCarthy", "J.", "" ] ]
We analyze the radiative aspects of nonsymmetric gravity theory to show that, in contrast to General Relativity, its nonstationary solutions cannot simultaneously exhibit acceptable asymptotic behavior at both future and past null infinity: good behavior at future null infinity is only possible through the use of advan...
1708.04761
Dao-Jun Liu
Yang Huang, Dao-Jun Liu, Xiang-hua Zhai and Xin-zhou Li
Massive charged Dirac fields around Reissner-Nordstr\"om black holes: quasibound states and long-lived modes
9 pages, 5 figures, accepted for publication in PRD
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The behavior of a massive charged test Dirac field in the background of a Reissner-Nordstr\"om black hole is investigated. Especially, we obtain the frequencies of quasibound states by solving the Dirac equation numerically both in time and frequency domain. Our results suggest that although the absence of superradia...
[ { "created": "Wed, 16 Aug 2017 03:38:57 GMT", "version": "v1" } ]
2017-08-17
[ [ "Huang", "Yang", "" ], [ "Liu", "Dao-Jun", "" ], [ "Zhai", "Xiang-hua", "" ], [ "Li", "Xin-zhou", "" ] ]
The behavior of a massive charged test Dirac field in the background of a Reissner-Nordstr\"om black hole is investigated. Especially, we obtain the frequencies of quasibound states by solving the Dirac equation numerically both in time and frequency domain. Our results suggest that although the absence of superradianc...
1403.1984
Genly Le\'on
Genly Leon
Phase Space of Anisotropic $R^n$ Cosmologies
Prepared for the First Caribbean Symposium on Nuclear and Astroparticle Physics - STARS2011
Int. J. Mod. Phys. E, 20, 19 (2011)
10.1142/S0218301311040037
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct general anisotropic cosmological scenarios governed by an $f(R)=R^n$ gravitational sector. Focusing then on some specific geometries, and modelling the matter content as a perfect fluid, we perform a phase-space analysis. We analyze the possibility of accelerating expansion at late times, and additionall...
[ { "created": "Sat, 8 Mar 2014 16:28:28 GMT", "version": "v1" } ]
2014-03-11
[ [ "Leon", "Genly", "" ] ]
We construct general anisotropic cosmological scenarios governed by an $f(R)=R^n$ gravitational sector. Focusing then on some specific geometries, and modelling the matter content as a perfect fluid, we perform a phase-space analysis. We analyze the possibility of accelerating expansion at late times, and additionally,...
1702.05716
Sung-Jin Oh
Jonathan Luk, Sung-Jin Oh
Strong cosmic censorship in spherical symmetry for two-ended asymptotically flat initial data II. The exterior of the black hole region
132 pages, 10 figures; minor revisions; version accepted for publication
null
null
null
gr-qc math-ph math.AP math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is the second and last paper of a two-part series in which we prove the $C^2$-formulation of the strong cosmic censorship conjecture for the Einstein-Maxwell-(real)-scalar-field system in spherical symmetry for two-ended asymptotically flat data. In the first paper (arXiv:1702.05715), we showed that the maximal ...
[ { "created": "Sun, 19 Feb 2017 08:20:17 GMT", "version": "v1" }, { "created": "Fri, 22 Feb 2019 03:51:25 GMT", "version": "v2" } ]
2019-02-25
[ [ "Luk", "Jonathan", "" ], [ "Oh", "Sung-Jin", "" ] ]
This is the second and last paper of a two-part series in which we prove the $C^2$-formulation of the strong cosmic censorship conjecture for the Einstein-Maxwell-(real)-scalar-field system in spherical symmetry for two-ended asymptotically flat data. In the first paper (arXiv:1702.05715), we showed that the maximal gl...
0908.1693
Mohammad Sami
I. Thongkool, M. Sami, S. Rai Choudhury
How delicate are the $f(R)$ gravity models with disappearing cosmological constant?
5 pages and no figures, minor clarification added, final version to appear in PRD
Phys.Rev.D80:127501,2009
10.1103/PhysRevD.80.127501
null
gr-qc astro-ph.CO hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider stability of spherically symmetric solutions in $f(R)$ gravity model proposed by Starobinsky. We find that the model suffers from a severe fine tuning problem when applied to compact objects like neutron stars. The problem can be remedied by introducing a cut off on the mass of the scalar degree of freedo...
[ { "created": "Wed, 12 Aug 2009 12:45:47 GMT", "version": "v1" }, { "created": "Wed, 25 Nov 2009 04:50:20 GMT", "version": "v2" } ]
2010-03-25
[ [ "Thongkool", "I.", "" ], [ "Sami", "M.", "" ], [ "Choudhury", "S. Rai", "" ] ]
We consider stability of spherically symmetric solutions in $f(R)$ gravity model proposed by Starobinsky. We find that the model suffers from a severe fine tuning problem when applied to compact objects like neutron stars. The problem can be remedied by introducing a cut off on the mass of the scalar degree of freedom ...
2402.06114
Lehel Csillag
Lehel Csillag, Tiberiu Harko
Semi-Symmetric Metric Gravity: from the Friedmann-Schouten geometry with torsion to dynamical dark energy models
17 pages, 10 figures, major revision; new Section and references added
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the present paper we introduce a geometric generalization of standard general relativity, based on a geometry initially introduced by Friedmann and Schouten in 1924, through the notion of a semi-symmetric connection. The semi-symmetric connection is a particular connection that extends the Levi-Civita one, by allo...
[ { "created": "Fri, 9 Feb 2024 00:37:28 GMT", "version": "v1" }, { "created": "Tue, 13 Feb 2024 20:41:04 GMT", "version": "v2" }, { "created": "Thu, 4 Apr 2024 13:44:22 GMT", "version": "v3" } ]
2024-04-05
[ [ "Csillag", "Lehel", "" ], [ "Harko", "Tiberiu", "" ] ]
In the present paper we introduce a geometric generalization of standard general relativity, based on a geometry initially introduced by Friedmann and Schouten in 1924, through the notion of a semi-symmetric connection. The semi-symmetric connection is a particular connection that extends the Levi-Civita one, by allowi...
1101.2634
Lorenzo Iorio
Lorenzo Iorio
Constraints on the location of a putative distant massive body in the Solar System from recent planetary data
LaTex2e, 21 pages. 1 figure, 1 table. Uncited references deleted. Expired link removed and replaced with published references. At press in Celestial Mechanics and Dynamical Astronomy
Celest.Mech.Dyn.Astron.112:117-130,2012
10.1007/s10569-011-9386-7
null
gr-qc astro-ph.EP physics.space-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analytically work out the long-term variations caused on the motion of a planet orbiting a star by a very distant, pointlike massive object X. Apart from the semi-major axis a, all the other Keplerian osculating orbital elements experience long-term variations which are complicated functions of the orbital configu...
[ { "created": "Thu, 13 Jan 2011 19:07:43 GMT", "version": "v1" }, { "created": "Fri, 14 Jan 2011 15:46:13 GMT", "version": "v2" }, { "created": "Wed, 19 Jan 2011 19:30:13 GMT", "version": "v3" }, { "created": "Fri, 19 Aug 2011 18:47:19 GMT", "version": "v4" }, { "c...
2015-03-17
[ [ "Iorio", "Lorenzo", "" ] ]
We analytically work out the long-term variations caused on the motion of a planet orbiting a star by a very distant, pointlike massive object X. Apart from the semi-major axis a, all the other Keplerian osculating orbital elements experience long-term variations which are complicated functions of the orbital configura...
2112.05651
Philip Lynch
Philip Lynch, Maarten van de Meent and Niels Warburton
Eccentric self-forced inspirals into a rotating black hole
46 pages, 12 figures
Class. Quantum Grav. 39:145004 (2022)
10.1088/1361-6382/ac7507
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We develop the first model for extreme mass-ratio inspirals (EMRIs) into a rotating massive black hole driven by the gravitational self-force. Our model is based on an action angle formulation of the method of osculating geodesics for eccentric, equatorial (i.e., spin-aligned) motion in Kerr spacetime. The forcing te...
[ { "created": "Fri, 10 Dec 2021 16:28:02 GMT", "version": "v1" }, { "created": "Wed, 3 Aug 2022 16:09:03 GMT", "version": "v2" } ]
2022-08-04
[ [ "Lynch", "Philip", "" ], [ "van de Meent", "Maarten", "" ], [ "Warburton", "Niels", "" ] ]
We develop the first model for extreme mass-ratio inspirals (EMRIs) into a rotating massive black hole driven by the gravitational self-force. Our model is based on an action angle formulation of the method of osculating geodesics for eccentric, equatorial (i.e., spin-aligned) motion in Kerr spacetime. The forcing term...
0705.2987
Helge Mueller-Ebhardt
Henning Rehbein, Helge Mueller-Ebhardt, Kentaro Somiya, Chao Li, Roman Schnabel, Karsten Danzmann, Yanbei Chen
Local readout enhancement for detuned signal-recycling interferometers
null
Phys.Rev.D76:062002,2007
10.1103/PhysRevD.76.062002
null
gr-qc
null
Motivated by the optical-bar scheme of Braginsky, Gorodetsky and Khalili, we propose to add to a high power detuned signal-recycling interferometer a local readout scheme which measures the motion of the arm-cavity front mirror. At low frequencies this mirror moves together with the arm-cavity end mirror, under the i...
[ { "created": "Mon, 21 May 2007 14:33:59 GMT", "version": "v1" }, { "created": "Mon, 4 Jun 2007 12:56:49 GMT", "version": "v2" }, { "created": "Wed, 22 Aug 2007 15:32:48 GMT", "version": "v3" } ]
2008-11-26
[ [ "Rehbein", "Henning", "" ], [ "Mueller-Ebhardt", "Helge", "" ], [ "Somiya", "Kentaro", "" ], [ "Li", "Chao", "" ], [ "Schnabel", "Roman", "" ], [ "Danzmann", "Karsten", "" ], [ "Chen", "Yanbei", "" ] ]
Motivated by the optical-bar scheme of Braginsky, Gorodetsky and Khalili, we propose to add to a high power detuned signal-recycling interferometer a local readout scheme which measures the motion of the arm-cavity front mirror. At low frequencies this mirror moves together with the arm-cavity end mirror, under the inf...
gr-qc/0310116
Scott Noble
Scott C. Noble (University of Illinois at Urbana-Champaign)
A Numerical Study of Relativistic Fluid Collapse
228 pages, 66 Postscript figures, Ph.D. Thesis, the University of Texa s at Austin, uses utdiss2.sty v5
null
null
null
gr-qc astro-ph
null
We investigate the dynamics of self-gravitating, spherically-symmetric distributions of fluid through numerical means. In particular, systems involving neutron star models driven far from equilibrium in the strong-field regime of general relativity are studied. Hydrostatic solutions of Einstein's equations using a st...
[ { "created": "Tue, 28 Oct 2003 00:53:36 GMT", "version": "v1" } ]
2007-05-23
[ [ "Noble", "Scott C.", "", "University of Illinois at Urbana-Champaign" ] ]
We investigate the dynamics of self-gravitating, spherically-symmetric distributions of fluid through numerical means. In particular, systems involving neutron star models driven far from equilibrium in the strong-field regime of general relativity are studied. Hydrostatic solutions of Einstein's equations using a stif...
0804.0357
Patricio S. Letelier
Valeria M. Rosa and Patricio S. Letelier
A Comment on Bonnor-Steadman Closed Timelike Curves
2 pages, RevTex, minor corrections
Gen.Rel.Grav.41:571-573,2009
10.1007/s10714-008-0687-4
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The existence and stability closed timelike curves in a Bonnor-Ward spacetime without torsion line singularities is shown by exhibiting particular examples.
[ { "created": "Wed, 2 Apr 2008 14:13:58 GMT", "version": "v1" }, { "created": "Thu, 3 Apr 2008 13:35:51 GMT", "version": "v2" } ]
2009-03-12
[ [ "Rosa", "Valeria M.", "" ], [ "Letelier", "Patricio S.", "" ] ]
The existence and stability closed timelike curves in a Bonnor-Ward spacetime without torsion line singularities is shown by exhibiting particular examples.
gr-qc/9906107
Ruth A. W. Gregory
Caroline Santos and Ruth Gregory
Vortices and black holes in dilatonic gravity
16 pages revtex, published version
Phys. Rev. D 61, 024006 (1999)
10.1103/PhysRevD.61.024006
DTP/99/49
gr-qc hep-ph hep-th
null
We study analytically black holes pierced by a thin vortex in dilatonic gravity for an arbitrary coupling of the vortex to the dilaton in an arbitrary frame. We show that the horizon of the charged black hole supports the long-range fields of the Nielsen-Olesen vortex that can be considered as black hole hair for bot...
[ { "created": "Fri, 25 Jun 1999 19:12:56 GMT", "version": "v1" }, { "created": "Tue, 11 Apr 2000 14:08:33 GMT", "version": "v2" } ]
2016-08-25
[ [ "Santos", "Caroline", "" ], [ "Gregory", "Ruth", "" ] ]
We study analytically black holes pierced by a thin vortex in dilatonic gravity for an arbitrary coupling of the vortex to the dilaton in an arbitrary frame. We show that the horizon of the charged black hole supports the long-range fields of the Nielsen-Olesen vortex that can be considered as black hole hair for both ...
0905.0661
Aharon Davidson
Aharon Davidson and Shimon Rubin
Zero Cosmological Constant from Normalized General Relativity
5 PRD pages;
Class.Quant.Grav.26:235019,2009
10.1088/0264-9381/26/23/235019
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Normalizing the Einstein-Hilbert action by the volume functional makes the theory invariant under constant shifts in the Lagrangian. The associated field equations then resemble unimodular gravity whose otherwise arbitrary cosmological constant is now determined as a Machian universal average. We prove that an empty ...
[ { "created": "Tue, 5 May 2009 18:08:30 GMT", "version": "v1" }, { "created": "Tue, 21 Jul 2009 12:45:18 GMT", "version": "v2" }, { "created": "Wed, 14 Oct 2009 08:42:56 GMT", "version": "v3" } ]
2017-04-06
[ [ "Davidson", "Aharon", "" ], [ "Rubin", "Shimon", "" ] ]
Normalizing the Einstein-Hilbert action by the volume functional makes the theory invariant under constant shifts in the Lagrangian. The associated field equations then resemble unimodular gravity whose otherwise arbitrary cosmological constant is now determined as a Machian universal average. We prove that an empty sp...
0911.1890
Xin Li
X. Li and Z. Chang
Kinematics in Randers-Finsler geometry and secular increase of the astronomical unit
10 pages, 2 tables
null
10.1088/1674-1137/35/10/005
null
gr-qc
http://creativecommons.org/licenses/by-nc-sa/3.0/
Kinematics in Finsler space is investigated. It is showed that the result based on the kinematics with a special Finsler structure is in good agreement with the reported value of secular trend in the astronomical unit, $d{\rm AU}/dt=15\pm4[{\rm m/century}]$. The space deformation parameter $\lambda$ in this special s...
[ { "created": "Tue, 10 Nov 2009 11:52:38 GMT", "version": "v1" } ]
2015-05-14
[ [ "Li", "X.", "" ], [ "Chang", "Z.", "" ] ]
Kinematics in Finsler space is investigated. It is showed that the result based on the kinematics with a special Finsler structure is in good agreement with the reported value of secular trend in the astronomical unit, $d{\rm AU}/dt=15\pm4[{\rm m/century}]$. The space deformation parameter $\lambda$ in this special str...
gr-qc/9701014
Ruth A. W. Gregory
Ruth Gregory and Caroline Santos
Cosmic strings in dilaton gravity
24 pages plain TEX, 4 figures -- references amended, some additional comments added, version to appear in journal
Phys.Rev.D56:1194-1203,1997
10.1103/PhysRevD.56.1194
DTP/97/1
gr-qc astro-ph hep-th
null
We examine the metric of an isolated self-gravitating abelian-Higgs vortex in dilatonic gravity for arbitrary coupling of the vortex fields to the dilaton. We look for solutions in both massless and massive dilaton gravity. We compare our results to existing metrics for strings in Einstein and Jordan-Brans-Dicke theo...
[ { "created": "Thu, 9 Jan 1997 17:39:20 GMT", "version": "v1" }, { "created": "Fri, 6 Jun 1997 13:17:12 GMT", "version": "v2" } ]
2011-09-09
[ [ "Gregory", "Ruth", "" ], [ "Santos", "Caroline", "" ] ]
We examine the metric of an isolated self-gravitating abelian-Higgs vortex in dilatonic gravity for arbitrary coupling of the vortex fields to the dilaton. We look for solutions in both massless and massive dilaton gravity. We compare our results to existing metrics for strings in Einstein and Jordan-Brans-Dicke theory...
gr-qc/9711088
Kostas Kokkotas
Nils Andersson (Washington University) and Kostas D. Kokkotas (Aristotle University of Thessaloniki)
Towards gravitational-wave asteroseismology
11 pages, 8 figures, mn.sty
Mon.Not.Roy.Astron.Soc.299:1059-1068,1998
10.1046/j.1365-8711.1998.01840.x
AUTH-GRAV-97-03
gr-qc astro-ph
null
We present new results for pulsating neutron stars. We have calculated the eigenfrequencies of the modes that one would expect to be the most important gravitational-wave sources: the fundamental fluid f-mode, the first pressure p-mode and the first gravitational-wave w-mode, for twelve realistic equations of state. ...
[ { "created": "Fri, 28 Nov 1997 15:45:02 GMT", "version": "v1" } ]
2009-10-30
[ [ "Andersson", "Nils", "", "Washington University" ], [ "Kokkotas", "Kostas D.", "", "Aristotle University of Thessaloniki" ] ]
We present new results for pulsating neutron stars. We have calculated the eigenfrequencies of the modes that one would expect to be the most important gravitational-wave sources: the fundamental fluid f-mode, the first pressure p-mode and the first gravitational-wave w-mode, for twelve realistic equations of state. Fr...
2404.00867
Paul Steinhardt
Anna Ijjas, Paul J. Steinhardt, David Garfinkle and William G. Cook
Smoothing and flattening the universe through slow contraction versus inflation
18 pages, 6 figures, 1 table
null
null
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a systematic study, we use an equivalent pair of improved numerical relativity codes based on a tetrad-formulation of the classical Einstein-scalar field equations to examine whether slow contraction or inflation (or both) can resolve the homogeneity, isotropy and flatness problems. Our finding, based on a set of ...
[ { "created": "Mon, 1 Apr 2024 02:26:28 GMT", "version": "v1" }, { "created": "Tue, 2 Apr 2024 11:14:36 GMT", "version": "v2" } ]
2024-04-03
[ [ "Ijjas", "Anna", "" ], [ "Steinhardt", "Paul J.", "" ], [ "Garfinkle", "David", "" ], [ "Cook", "William G.", "" ] ]
In a systematic study, we use an equivalent pair of improved numerical relativity codes based on a tetrad-formulation of the classical Einstein-scalar field equations to examine whether slow contraction or inflation (or both) can resolve the homogeneity, isotropy and flatness problems. Our finding, based on a set of ga...
1904.00260
Daniele Vernieri
In\^es Terrucha, Daniele Vernieri, Jos\'e P. S. Lemos
Covariant action for bouncing cosmologies in modified Gauss-Bonnet gravity
8 pages
Annals of Physics 404 (2019) 39
10.1016/j.aop.2019.02.010
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cyclic universes with bouncing solutions are candidates for solving the big bang initial singularity problem. Here we seek bouncing solutions in a modified Gauss-Bonnet gravity theory, of the type $R+f(G)$, where $R$ is the Ricci scalar, $G$ is the Gauss-Bonnet term, and $f$ some function of it. In finding such a bou...
[ { "created": "Sat, 30 Mar 2019 17:37:06 GMT", "version": "v1" } ]
2019-04-02
[ [ "Terrucha", "Inês", "" ], [ "Vernieri", "Daniele", "" ], [ "Lemos", "José P. S.", "" ] ]
Cyclic universes with bouncing solutions are candidates for solving the big bang initial singularity problem. Here we seek bouncing solutions in a modified Gauss-Bonnet gravity theory, of the type $R+f(G)$, where $R$ is the Ricci scalar, $G$ is the Gauss-Bonnet term, and $f$ some function of it. In finding such a bounc...
2008.08704
Tao Zhu
Tao Zhu and Anzhong Wang
Observational tests of the self-dual spacetime in loop quantum gravity
9 pages, 1 table; version to appear in Phys. Rev. D
Phys. Rev. D 102, 124042 (2020)
10.1103/PhysRevD.102.124042
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The self-dual spacetime was derived from the mini-superspace approach, based on the polymerization quantization procedure in loop quantum gravity (LQG). Its deviation from the Schwarzschild spacetime is characterized by the polymeric function $P$, purely due to the geometric quantum effects from LQG. In this paper, w...
[ { "created": "Wed, 19 Aug 2020 23:37:15 GMT", "version": "v1" }, { "created": "Fri, 25 Dec 2020 02:38:29 GMT", "version": "v2" } ]
2021-01-04
[ [ "Zhu", "Tao", "" ], [ "Wang", "Anzhong", "" ] ]
The self-dual spacetime was derived from the mini-superspace approach, based on the polymerization quantization procedure in loop quantum gravity (LQG). Its deviation from the Schwarzschild spacetime is characterized by the polymeric function $P$, purely due to the geometric quantum effects from LQG. In this paper, we ...