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1708.03929
Mariusz Dabrowski P.
Mariusz P. Dabrowski
Singularities and Cyclic Universes
4 pages, no figures
Acta Phys. Pol. (Proc. Suppl.) B10, 415 (2017)
10.5506/APhysPolBSupp.10.415
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The models of cyclic universes and cyclic multiverses based on the alternative gravity theories of varying constants are considered.
[ { "created": "Sun, 13 Aug 2017 16:37:53 GMT", "version": "v1" } ]
2017-08-18
[ [ "Dabrowski", "Mariusz P.", "" ] ]
The models of cyclic universes and cyclic multiverses based on the alternative gravity theories of varying constants are considered.
gr-qc/9705041
Chung-I. Kuo
Chung-I Kuo(Soochow University)
Quantum Fluctuations of Scalar Field in Conical Space
8 pages, RevTeX file, no figure, to appear in Phys. Lett. B
Phys.Lett. B405 (1997) 236-242
10.1016/S0370-2693(97)00594-7
null
gr-qc
null
We consider vacuum polarization effect of a conformally coupled massless scalar field in the background produced by an idealized straight cosmic string. Using previous criterion we show the calculation of back reaction of the field to the metric in the context of semiclassical gravity theory is not valid , in some re...
[ { "created": "Wed, 14 May 1997 15:25:32 GMT", "version": "v1" } ]
2009-10-30
[ [ "Kuo", "Chung-I", "", "Soochow University" ] ]
We consider vacuum polarization effect of a conformally coupled massless scalar field in the background produced by an idealized straight cosmic string. Using previous criterion we show the calculation of back reaction of the field to the metric in the context of semiclassical gravity theory is not valid , in some regi...
gr-qc/0301124
Andrew Makarenko
A.N. Makarenko, V.V. Obukhov, K.E. Osetrin
Kantowski-Sachs Brane Cosmology
3 pages, other comments
null
null
null
gr-qc
null
We consider brane Kantowski-Sachs Universe when bulk space is five-dimensional Anti-deSitter space. The corresponding cosmological equations with perfect fluid are written. For several specific choices of relation between energy and pressure it is found the behavior of scale factors at early time. In particulary, for...
[ { "created": "Fri, 31 Jan 2003 07:18:12 GMT", "version": "v1" } ]
2007-05-23
[ [ "Makarenko", "A. N.", "" ], [ "Obukhov", "V. V.", "" ], [ "Osetrin", "K. E.", "" ] ]
We consider brane Kantowski-Sachs Universe when bulk space is five-dimensional Anti-deSitter space. The corresponding cosmological equations with perfect fluid are written. For several specific choices of relation between energy and pressure it is found the behavior of scale factors at early time. In particulary, for $...
1811.06927
Daniel Hartley
Daniel Hartley and Christian K\"ading and Richard Howl and Ivette Fuentes
Quantum simulation of dark energy candidates
26 pages, 3 figures
Phys. Rev. D 99, 105002 (2019)
10.1103/PhysRevD.99.105002
null
gr-qc astro-ph.CO cond-mat.quant-gas quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Additional scalar fields from scalar-tensor, modified gravity or higher dimensional theories beyond general relativity may account for dark energy and the accelerating expansion of the Universe. These theories have lead to proposed models of screening mechanisms, such as chameleon and symmetron fields, to account for...
[ { "created": "Fri, 16 Nov 2018 17:20:57 GMT", "version": "v1" }, { "created": "Mon, 13 May 2019 12:20:33 GMT", "version": "v2" } ]
2019-05-14
[ [ "Hartley", "Daniel", "" ], [ "Käding", "Christian", "" ], [ "Howl", "Richard", "" ], [ "Fuentes", "Ivette", "" ] ]
Additional scalar fields from scalar-tensor, modified gravity or higher dimensional theories beyond general relativity may account for dark energy and the accelerating expansion of the Universe. These theories have lead to proposed models of screening mechanisms, such as chameleon and symmetron fields, to account for t...
1711.02723
Stelios Karydas Mr
B. C. Georgalas, Stelios Karydas, Eleftherios Papantonopoulos
Reconstruction of Cosmological Evolution in the Presence of Extra Dimensions
15 pages, 11 figures, version accepted for publication in JCAP, includes a number of minor clarifications throughout, and a lengthier discussion of needed/used constraints in Section 4
null
10.1088/1475-7516/2018/08/005
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The model of Physics resulting from a Kaluza-Klein dimensional reduction procedure offers very good dark matter candidates in the form of Light Kaluza-Klein Particles, and thus becomes relevant to Cosmology. In this work we recover a late-time cosmological picture, similar to that of the $\Lambda$CDM, in a multidimen...
[ { "created": "Tue, 7 Nov 2017 20:53:56 GMT", "version": "v1" }, { "created": "Thu, 23 Nov 2017 08:58:44 GMT", "version": "v2" }, { "created": "Sat, 24 Mar 2018 11:13:26 GMT", "version": "v3" }, { "created": "Mon, 30 Jul 2018 09:09:27 GMT", "version": "v4" } ]
2018-08-15
[ [ "Georgalas", "B. C.", "" ], [ "Karydas", "Stelios", "" ], [ "Papantonopoulos", "Eleftherios", "" ] ]
The model of Physics resulting from a Kaluza-Klein dimensional reduction procedure offers very good dark matter candidates in the form of Light Kaluza-Klein Particles, and thus becomes relevant to Cosmology. In this work we recover a late-time cosmological picture, similar to that of the $\Lambda$CDM, in a multidimensi...
1206.1420
Subenoy Chakraborty
Subenoy Chakraborty
Is thermodynamics of the universe bounded by the event horizon a Bekenstein system?
4 pages; accepted for publication in Phys. Lett. B
null
10.1016/j.physletb.2012.11.021
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this brief communication, we have studied the validity of the first law of thermodynamics for the universe bounded by event horizon with two examples. The key point is the appropriate choice of the temperature on the event horizon. Finally, we have concluded that universe bounded by the event horizon may be a Beke...
[ { "created": "Thu, 7 Jun 2012 08:07:27 GMT", "version": "v1" }, { "created": "Mon, 12 Nov 2012 08:08:02 GMT", "version": "v2" } ]
2015-06-05
[ [ "Chakraborty", "Subenoy", "" ] ]
In this brief communication, we have studied the validity of the first law of thermodynamics for the universe bounded by event horizon with two examples. The key point is the appropriate choice of the temperature on the event horizon. Finally, we have concluded that universe bounded by the event horizon may be a Bekens...
gr-qc/0508070
Domenico Giulini
Domenico Giulini and Gustav Holzegel
Corvino's construction using Brill waves
14 pages, 2 figures
null
null
Freiburg THEP 05/09
gr-qc
null
For two-black-hole time-symmetric initial data we consider the Corvino construction of gluing an exact Schwarzschild end. We propose to do this by using Brill waves. We address the question of whether this method can be used to reduce the overall energy, which seems to relate to the question of whether it can reduce ...
[ { "created": "Wed, 17 Aug 2005 13:57:53 GMT", "version": "v1" } ]
2007-05-23
[ [ "Giulini", "Domenico", "" ], [ "Holzegel", "Gustav", "" ] ]
For two-black-hole time-symmetric initial data we consider the Corvino construction of gluing an exact Schwarzschild end. We propose to do this by using Brill waves. We address the question of whether this method can be used to reduce the overall energy, which seems to relate to the question of whether it can reduce th...
gr-qc/0103031
Hisaaki Shinkai
Hisa-aki Shinkai and Gen Yoneda
Will hyperbolic formulations help numerical relativity? - Experiments using Ashtekar's connection variables
9 pages, LaTeX, 4 eps figures, for the proceedings of 10th JGRG, Osaka, Japan, Sept. 11 - 14, 2000
null
null
CGPG-00/11-3
gr-qc
null
In order to perform accurate and stable long-term numerical integration of the Einstein equations, several hyperbolic systems have been proposed. We here report our numerical comparisons between weakly hyperbolic, strongly hyperbolic, and symmetric hyperbolic systems based on Ashtekar's connection variables. The prim...
[ { "created": "Fri, 9 Mar 2001 19:58:01 GMT", "version": "v1" } ]
2007-05-23
[ [ "Shinkai", "Hisa-aki", "" ], [ "Yoneda", "Gen", "" ] ]
In order to perform accurate and stable long-term numerical integration of the Einstein equations, several hyperbolic systems have been proposed. We here report our numerical comparisons between weakly hyperbolic, strongly hyperbolic, and symmetric hyperbolic systems based on Ashtekar's connection variables. The primar...
gr-qc/0106003
David Waite
David Waite
Inertia Manipulation through Metric Patching
6 pages
null
null
null
gr-qc
null
This paper will present the exact solution for the stress-energy tensor of a spherical matter shell of finite thickness that will patch together different metrics at the boundaries of the shell. The choice of vacuum field solutions for the shell exterior and hollow interior that we make will allow us to manipulate th...
[ { "created": "Sat, 2 Jun 2001 10:26:56 GMT", "version": "v1" } ]
2007-05-23
[ [ "Waite", "David", "" ] ]
This paper will present the exact solution for the stress-energy tensor of a spherical matter shell of finite thickness that will patch together different metrics at the boundaries of the shell. The choice of vacuum field solutions for the shell exterior and hollow interior that we make will allow us to manipulate the ...
2306.06168
Jonathan Nay
Jonathan Nay, Kimberly K. Boddy, Tristan L. Smith, Chiara M. F. Mingarelli
Harmonic Analysis for Pulsar Timing Arrays
17 pages, 11 figures
null
null
null
gr-qc astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the use of harmonic analysis techniques to perform measurements of the angular power spectrum on mock pulsar timing data for an isotropic stochastic gravitational-wave background (SGWB) with a dimensionless strain amplitude $A_{\text{gw}}=2 \times 10^{-15}$ and spectral index $\gamma_{\text{gw}}=13/3$....
[ { "created": "Fri, 9 Jun 2023 18:00:02 GMT", "version": "v1" } ]
2023-06-13
[ [ "Nay", "Jonathan", "" ], [ "Boddy", "Kimberly K.", "" ], [ "Smith", "Tristan L.", "" ], [ "Mingarelli", "Chiara M. F.", "" ] ]
We investigate the use of harmonic analysis techniques to perform measurements of the angular power spectrum on mock pulsar timing data for an isotropic stochastic gravitational-wave background (SGWB) with a dimensionless strain amplitude $A_{\text{gw}}=2 \times 10^{-15}$ and spectral index $\gamma_{\text{gw}}=13/3$. W...
gr-qc/0106046
Manoelito M. de Souza
Manoelito M. de Souza
Discrete fields and the Pioneer anomalous acceleration
8 pages
null
null
null
gr-qc astro-ph hep-th
null
The dominant contributions from a discrete gravitational interaction produce the standard potential as an effective continuous field. The sub-dominant contributions are, in a first approximation, linear on n, the accumulated number of (discrete) interaction events along the test-body trajectory. For a nearly radial t...
[ { "created": "Thu, 14 Jun 2001 14:57:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "de Souza", "Manoelito M.", "" ] ]
The dominant contributions from a discrete gravitational interaction produce the standard potential as an effective continuous field. The sub-dominant contributions are, in a first approximation, linear on n, the accumulated number of (discrete) interaction events along the test-body trajectory. For a nearly radial tra...
gr-qc/0201014
Angelo Tartaglia
A. Tartaglia
Space time and rotations
RevTex, 15 pages
null
null
null
gr-qc
null
The paper considers the problem of finding the metric of space time around a rotating, weakly gravitating body. Both external and internal metric tensors are consistently found, together with an appropriate source tensor. All tensors are calculated at the lowest meaningful approximation in a power series. The two phy...
[ { "created": "Fri, 4 Jan 2002 13:18:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Tartaglia", "A.", "" ] ]
The paper considers the problem of finding the metric of space time around a rotating, weakly gravitating body. Both external and internal metric tensors are consistently found, together with an appropriate source tensor. All tensors are calculated at the lowest meaningful approximation in a power series. The two physi...
gr-qc/0505161
Fu-Wen Shu
Fu-Wen Shu, You-Gen Shen
Quasinormal modes of Rarita-Schwinger field in Reissner-Nordstr\"{o}m black hole spacetimes
9 pages, 2 figures
Phys.Lett.B614:195-200,2005
10.1016/j.physletb.2005.03.076
null
gr-qc
null
The Newman-Penrose formalism is used to deal with the quasinormal modes(QNM's) of Rarita-Schwinger perturbations outside a Reissner-Nordstr\"{o}m black hole. We obtain four kinds of possible expressions of effective potentials, which are proved to be of the same spectra of quasinormal mode frequencies. The quasinorma...
[ { "created": "Tue, 31 May 2005 15:22:41 GMT", "version": "v1" } ]
2008-11-26
[ [ "Shu", "Fu-Wen", "" ], [ "Shen", "You-Gen", "" ] ]
The Newman-Penrose formalism is used to deal with the quasinormal modes(QNM's) of Rarita-Schwinger perturbations outside a Reissner-Nordstr\"{o}m black hole. We obtain four kinds of possible expressions of effective potentials, which are proved to be of the same spectra of quasinormal mode frequencies. The quasinormal ...
2107.05723
Valerio Bozza
F. Aratore, V. Bozza
Decoding a black hole metric from the interferometric pattern of the relativistic images of a compact source
20 pages, 8 figures
null
10.1088/1475-7516/2021/10/054
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Photons emitted by light sources in the neighbourhood of a black hole can wind several times around it before fleeing towards the observer. For spherically symmetric black holes, two infinite sequences of images are created for any given source, asymptotically approaching the shadow border with decreasing magnitude. ...
[ { "created": "Mon, 12 Jul 2021 20:29:17 GMT", "version": "v1" }, { "created": "Tue, 28 Sep 2021 07:16:10 GMT", "version": "v2" } ]
2021-10-27
[ [ "Aratore", "F.", "" ], [ "Bozza", "V.", "" ] ]
Photons emitted by light sources in the neighbourhood of a black hole can wind several times around it before fleeing towards the observer. For spherically symmetric black holes, two infinite sequences of images are created for any given source, asymptotically approaching the shadow border with decreasing magnitude. Th...
gr-qc/0205035
Ilja Schmelzer
I. Schmelzer
A generalization of the Lorentz ether to gravity with general-relativistic limit
Some changes in the presentation
Advances in Applied Clifford Algebras 22, 1 (2012), p. 203-242
10.1007/s00006-011-0303-7
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Does relativistic gravity provide arguments against the existence of a preferred frame? Our answer is negative. We define a viable theory of gravity with preferred frame. In this theory, the EEP holds exactly, and the Einstein equations of GR limit are obtained in a natural limit. Despite some remarkable differences ...
[ { "created": "Wed, 8 May 2002 21:24:54 GMT", "version": "v1" }, { "created": "Tue, 19 Nov 2002 16:52:18 GMT", "version": "v2" }, { "created": "Fri, 11 Feb 2011 15:25:59 GMT", "version": "v3" }, { "created": "Sat, 20 Oct 2012 17:35:09 GMT", "version": "v4" } ]
2012-10-23
[ [ "Schmelzer", "I.", "" ] ]
Does relativistic gravity provide arguments against the existence of a preferred frame? Our answer is negative. We define a viable theory of gravity with preferred frame. In this theory, the EEP holds exactly, and the Einstein equations of GR limit are obtained in a natural limit. Despite some remarkable differences (s...
1810.05527
Abdul Jawad
Abdul Jawad, Shamaila Rani and Salman Rafique
Thermodynamics of Various Entropies in Specific Modified Gravity with Particle Creation
32 pages, 12 figures, AHEP accepted. arXiv admin note: text overlap with arXiv:1801.09999; text overlap with arXiv:1604.00899, arXiv:0811.4477 by other authors
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the particle creation scenario in the dynamical Chern-Simons modified gravity in the presence of perfect fluid equation of state $p=(\gamma-1)\rho$. By assuming various modified entropies (Bekenstein, logarithmic, power law correction and Reyni), we investigate the first law of thermodynamics and generali...
[ { "created": "Wed, 10 Oct 2018 06:33:10 GMT", "version": "v1" } ]
2018-10-15
[ [ "Jawad", "Abdul", "" ], [ "Rani", "Shamaila", "" ], [ "Rafique", "Salman", "" ] ]
We consider the particle creation scenario in the dynamical Chern-Simons modified gravity in the presence of perfect fluid equation of state $p=(\gamma-1)\rho$. By assuming various modified entropies (Bekenstein, logarithmic, power law correction and Reyni), we investigate the first law of thermodynamics and generalize...
1603.01461
Naser Sadeghnezhad
N. Sadeghnezhad
A Note on Coherent States with Quantum Gravity Effects
14 pages, 2 figures
null
10.1016/j.cjph.2016.06.009
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Existence of a minimal measurable length and an upper bound for the momentum fluctuations are the casting reasons for generalization of uncertainty principle and then reformulation of Hilbert space representation of quantum mechanics. In this paper, we study the consequences of the Generalized Uncertainty Principle (...
[ { "created": "Fri, 26 Feb 2016 22:46:37 GMT", "version": "v1" } ]
2016-11-29
[ [ "Sadeghnezhad", "N.", "" ] ]
Existence of a minimal measurable length and an upper bound for the momentum fluctuations are the casting reasons for generalization of uncertainty principle and then reformulation of Hilbert space representation of quantum mechanics. In this paper, we study the consequences of the Generalized Uncertainty Principle (GU...
1106.5066
Eugen Radu
Eugen Radu, Ya. Shnir and D. H. Tchrakian
Scalar hairy black holes and solitons in a gravitating Goldstone model
17 pages, 5 figures
Phys.Lett.B703:386-393,2011
10.1016/j.physletb.2011.08.032
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study black hole solutions of Einstein gravity coupled to a specific global symmetry breaking Goldstone model described by an O(3) isovector scalar field in four spacetime dimensions. Our configurations are static and spherically symmetric, approaching at infinity a Minkowski spacetime background. A set of globall...
[ { "created": "Fri, 24 Jun 2011 20:47:38 GMT", "version": "v1" }, { "created": "Thu, 14 Jul 2011 12:08:37 GMT", "version": "v2" } ]
2011-09-07
[ [ "Radu", "Eugen", "" ], [ "Shnir", "Ya.", "" ], [ "Tchrakian", "D. H.", "" ] ]
We study black hole solutions of Einstein gravity coupled to a specific global symmetry breaking Goldstone model described by an O(3) isovector scalar field in four spacetime dimensions. Our configurations are static and spherically symmetric, approaching at infinity a Minkowski spacetime background. A set of globally ...
0906.3088
Michael Gabler
Michael Gabler, Ulrich Sperhake and Nils Andersson
Nonlinear radial oscillations of neutron stars
15 pages, 10 figures, 9 tables; To match published version in Phys.Rev.D; discussion about interpretation of the expression "mode coupling" and one figure added
Phys.Rev.D80:064012,2009
10.1103/PhysRevD.80.064012
null
gr-qc astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The effects of nonlinear oscillations in compact stars are attracting considerable current interest. In order to study such phenomena in the framework of fully nonlinear general relativity, highly accurate numerical studies are required. We present a numerical scheme specifically tailored for studies, based on formul...
[ { "created": "Wed, 17 Jun 2009 08:48:14 GMT", "version": "v1" }, { "created": "Wed, 23 Sep 2009 06:12:12 GMT", "version": "v2" } ]
2009-09-24
[ [ "Gabler", "Michael", "" ], [ "Sperhake", "Ulrich", "" ], [ "Andersson", "Nils", "" ] ]
The effects of nonlinear oscillations in compact stars are attracting considerable current interest. In order to study such phenomena in the framework of fully nonlinear general relativity, highly accurate numerical studies are required. We present a numerical scheme specifically tailored for studies, based on formulat...
2405.08563
Soma Heydari
Soma Heydari and Kayoomars Karami
Primordial black holes generated by fast-roll mechanism in non-canonical natural inflation
29 pages, 6 figures, 5 tables
null
null
null
gr-qc astro-ph.CO hep-th
http://creativecommons.org/licenses/by-nc-sa/4.0/
In this work, a new fast-roll (FR) mechanism to generate primordial black holes (PBHs) and their coeval gravitational waves (GWs) in generalized non-canonical natural inflation is introduced. In this model, choosing a suitable function for non-canonical mass scale parameter $M(\phi)$ gives rise to produce a cliff-lik...
[ { "created": "Tue, 14 May 2024 12:51:40 GMT", "version": "v1" } ]
2024-05-15
[ [ "Heydari", "Soma", "" ], [ "Karami", "Kayoomars", "" ] ]
In this work, a new fast-roll (FR) mechanism to generate primordial black holes (PBHs) and their coeval gravitational waves (GWs) in generalized non-canonical natural inflation is introduced. In this model, choosing a suitable function for non-canonical mass scale parameter $M(\phi)$ gives rise to produce a cliff-like ...
0803.0786
S. K. Sahay
S.K. Sahay
On the independent points in the sky for the search of periodic gravitational wave
10 Pages, 2 figures
Rom.Rep.Phys.61:191-201,2009
null
null
gr-qc astro-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the independent points in the sky require to search the periodic gravitational wave, assuming the noise power spectral density to be flat. We have made an analysis with different initial azimuth of the Earth for a week data set. The analysis shows significant difference in the independent points in the...
[ { "created": "Thu, 6 Mar 2008 04:15:09 GMT", "version": "v1" } ]
2010-02-05
[ [ "Sahay", "S. K.", "" ] ]
We investigate the independent points in the sky require to search the periodic gravitational wave, assuming the noise power spectral density to be flat. We have made an analysis with different initial azimuth of the Earth for a week data set. The analysis shows significant difference in the independent points in the s...
1807.06105
David Garfinkle
David Garfinkle
Matters of Gravity, The Newsletter of the Division of Gravitational Physics of the American Physical Society, Volume 51, June 2018
null
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
DGRAV News: We hear that.... DGRAV Student Travel Grants Town Hall Meeting GRG Society Research Briefs: What's new in LIGO Conference Reports: Christodoulou Conference Obituaries: Stephen Hawking (1942-2018) Joseph Polchinski (1954-2018)
[ { "created": "Mon, 16 Jul 2018 20:54:51 GMT", "version": "v1" } ]
2018-07-18
[ [ "Garfinkle", "David", "" ] ]
DGRAV News: We hear that.... DGRAV Student Travel Grants Town Hall Meeting GRG Society Research Briefs: What's new in LIGO Conference Reports: Christodoulou Conference Obituaries: Stephen Hawking (1942-2018) Joseph Polchinski (1954-2018)
0808.3120
L. C. Garcia de Andrade
Garcia de Andrade
Acoustic black hole evaporation as plasma diffusion phenomena
Dept fisica teorica-UERJ-Brasil
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Acoustic analogues of Kerr black hole in plasmas are considered, by taking for granted the existence of acoustic ion waves in plasmas. An effective black holes (BH) in curved Riemannian spacetime in a random walk plasmas is endowed with a naked singularity, when plasmas are in the lowest diffusion mode. The plasma pa...
[ { "created": "Fri, 22 Aug 2008 18:23:25 GMT", "version": "v1" } ]
2008-08-25
[ [ "de Andrade", "Garcia", "" ] ]
Acoustic analogues of Kerr black hole in plasmas are considered, by taking for granted the existence of acoustic ion waves in plasmas. An effective black holes (BH) in curved Riemannian spacetime in a random walk plasmas is endowed with a naked singularity, when plasmas are in the lowest diffusion mode. The plasma part...
gr-qc/0004003
Shahar Hod
Shahar Hod
Evidence for a null entropy of extremal black holes
11 pages
Phys.Rev. D61 (2000) 084018
10.1103/PhysRevD.61.084018
null
gr-qc hep-th
null
We present some arguments in support of a {\it zero} entropy for {\it extremal} black holes. These rely on a combination of both quantum, thermodynamic, and statistical physics arguments. This result may shed some light on the nature of these extreme objects. In addition, we show that within a {\it quantum} framework...
[ { "created": "Sat, 1 Apr 2000 06:38:19 GMT", "version": "v1" }, { "created": "Wed, 5 Apr 2000 10:15:34 GMT", "version": "v2" } ]
2009-10-31
[ [ "Hod", "Shahar", "" ] ]
We present some arguments in support of a {\it zero} entropy for {\it extremal} black holes. These rely on a combination of both quantum, thermodynamic, and statistical physics arguments. This result may shed some light on the nature of these extreme objects. In addition, we show that within a {\it quantum} framework t...
0705.1346
Alexey Toporensky
A. Toporensky, P. Tretyakov
Power-law anisotropic cosmological solution in 5+1 dimensional Gauss-Bonnet gravity
10 pages, one statement corrected, references added
Grav.Cosmol.13:207-210,2007
null
null
gr-qc
null
We write down an anisotropic solution for a flat 5+1 dimensional Universe in Gauss-Bonnet gravity. In the model under investigation this solution replaces the generalized Kasner solution near a cosmological singularity.
[ { "created": "Wed, 9 May 2007 19:21:52 GMT", "version": "v1" }, { "created": "Tue, 22 May 2007 19:34:23 GMT", "version": "v2" }, { "created": "Fri, 3 Aug 2007 17:39:08 GMT", "version": "v3" } ]
2008-11-26
[ [ "Toporensky", "A.", "" ], [ "Tretyakov", "P.", "" ] ]
We write down an anisotropic solution for a flat 5+1 dimensional Universe in Gauss-Bonnet gravity. In the model under investigation this solution replaces the generalized Kasner solution near a cosmological singularity.
1507.06123
Ivan de Martino
Ivan de Martino, Mariafelicia De Laurentis, Salvatore Capozziello
Constraining $f(R)$ gravity by the Large Scale Structure
37 pages, 3 Tables, 6 Figures. Invited Review belonging "Special Issue Modified Gravity Cosmology: From Inflation to Dark Energy". The manuscript matches the accepted version. References updated
Universe 2015, 1(2), 123-157
10.3390/universe1020123
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Over the past decades, General Relativity and the concordance $\Lambda$CDM model have been successfully tested using several different astrophysical and cosmological probes based on large datasets ({\it precision cosmology}). Despite their successes, some shortcomings emerge due to the fact that General Relativity sh...
[ { "created": "Wed, 22 Jul 2015 10:53:38 GMT", "version": "v1" }, { "created": "Mon, 27 Jul 2015 21:53:06 GMT", "version": "v2" } ]
2015-08-07
[ [ "de Martino", "Ivan", "" ], [ "De Laurentis", "Mariafelicia", "" ], [ "Capozziello", "Salvatore", "" ] ]
Over the past decades, General Relativity and the concordance $\Lambda$CDM model have been successfully tested using several different astrophysical and cosmological probes based on large datasets ({\it precision cosmology}). Despite their successes, some shortcomings emerge due to the fact that General Relativity shou...
1808.04412
Jose Luis Flores
L. Ak\'e Hau, Jos\'e L. Flores, Miguel S\'anchez
Structure of globally hyperbolic spacetimes with timelike boundary
Added Appendix B and four references, several improvements in section 2.4 and other minor modifications. To appear in Rev. Mat. Iberoamericana
Rev. Matem. Iberoamericana, Volume 37, Issue 1 (2021) pp. 45-94
10.4171/rmi/1201
null
gr-qc math.DG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Globally hyperbolic spacetimes with timelike boundary $(\overline{M} = M \cup \partial M, g)$ are the natural class of spacetimes where regular boundary conditions (eventually asymptotic, if $\overline{M}$ is obtained by means of a conformal embedding) can be posed. $\partial M$ represents the naked singularities and...
[ { "created": "Mon, 13 Aug 2018 19:31:11 GMT", "version": "v1" }, { "created": "Mon, 3 Sep 2018 06:51:11 GMT", "version": "v2" }, { "created": "Wed, 21 Nov 2018 23:06:47 GMT", "version": "v3" }, { "created": "Wed, 14 Aug 2019 08:59:21 GMT", "version": "v4" } ]
2021-04-23
[ [ "Hau", "L. Aké", "" ], [ "Flores", "José L.", "" ], [ "Sánchez", "Miguel", "" ] ]
Globally hyperbolic spacetimes with timelike boundary $(\overline{M} = M \cup \partial M, g)$ are the natural class of spacetimes where regular boundary conditions (eventually asymptotic, if $\overline{M}$ is obtained by means of a conformal embedding) can be posed. $\partial M$ represents the naked singularities and c...
1411.7878
Georgios Doulis
Georgios Doulis and Oliver Rinne
Numerical construction of initial data for Einstein's equations with static extension to space-like infinity
20 pages, 13 figures. Agrees with the published version
Class. Quantum Grav. 33, 075014 (2016)
10.1088/0264-9381/33/7/075014
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe a numerical method to construct Cauchy data extending to space-like infinity based on Corvino's (2000) gluing method. Adopting the setting of Giulini and Holzegel (2005), we restrict ourselves here to vacuum axisymmetric spacetimes and glue a Schwarzschildean end to Brill-Lindquist data describing two non...
[ { "created": "Fri, 28 Nov 2014 14:30:13 GMT", "version": "v1" }, { "created": "Wed, 25 Nov 2015 12:54:39 GMT", "version": "v2" }, { "created": "Thu, 29 Dec 2016 10:41:48 GMT", "version": "v3" } ]
2016-12-30
[ [ "Doulis", "Georgios", "" ], [ "Rinne", "Oliver", "" ] ]
We describe a numerical method to construct Cauchy data extending to space-like infinity based on Corvino's (2000) gluing method. Adopting the setting of Giulini and Holzegel (2005), we restrict ourselves here to vacuum axisymmetric spacetimes and glue a Schwarzschildean end to Brill-Lindquist data describing two non-r...
1111.4586
J. Brian Pitts
J. Brian Pitts
The Nontriviality of Trivial General Covariance: How Electrons Restrict 'Time' Coordinates, Spinors (Almost) Fit into Tensor Calculus, and 7/16 of a Tetrad Is Surplus Structure
Forthcoming in \textit{Studies in History and Philosophy of Modern Physics}
Studies in History and Philosophy of Modern Physics 43 (2012) 1-24
10.1016/j.shpsb.2011.11.001
null
gr-qc hep-th math-ph math.MP physics.hist-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is a commonplace that any theory can be written in any coordinates via tensor calculus. But it is claimed that spinors as such cannot be represented in coordinates in a curved space-time. What general covariance means for theories with fermions is thus unclear. In fact both commonplaces are wrong. Though it is not...
[ { "created": "Sat, 19 Nov 2011 21:39:44 GMT", "version": "v1" } ]
2016-03-21
[ [ "Pitts", "J. Brian", "" ] ]
It is a commonplace that any theory can be written in any coordinates via tensor calculus. But it is claimed that spinors as such cannot be represented in coordinates in a curved space-time. What general covariance means for theories with fermions is thus unclear. In fact both commonplaces are wrong. Though it is not w...
1302.5560
Burkhard Kleihaus
Efstathios Charalampidis, Theodora Ioannidou, Burkhard Kleihaus and Jutta Kunz
Wormholes Threaded by Chiral Fields
14 pages, 9 figures
null
10.1103/PhysRevD.87.084069
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider Lorentzian wormholes with a phantom field and chiral matter fields. The chiral fields are described by the non-linear sigma model with or without a Skyrme term. When the gravitational coupling of the chiral fields is increased, the wormhole geometry changes. The single throat is replaced by a double throa...
[ { "created": "Fri, 22 Feb 2013 11:43:55 GMT", "version": "v1" } ]
2013-05-08
[ [ "Charalampidis", "Efstathios", "" ], [ "Ioannidou", "Theodora", "" ], [ "Kleihaus", "Burkhard", "" ], [ "Kunz", "Jutta", "" ] ]
We consider Lorentzian wormholes with a phantom field and chiral matter fields. The chiral fields are described by the non-linear sigma model with or without a Skyrme term. When the gravitational coupling of the chiral fields is increased, the wormhole geometry changes. The single throat is replaced by a double throat ...
1509.04243
Gabor Kunstatter
Gabor Kunstatter, Hideki Maeda, and Tim Taves
Designer black holes from new 2D gravity
11 pages
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a family of extensions of spherically symmetric Einstein-Lanczos-Lovelock gravity. The field equations are second order and obey a generalized Birkhoff's theorem. The Hamiltonian constraint can be written in terms of a generalized Misner-Sharp mass function that determines the form of the vacuum solution. ...
[ { "created": "Mon, 14 Sep 2015 19:04:50 GMT", "version": "v1" } ]
2015-09-16
[ [ "Kunstatter", "Gabor", "" ], [ "Maeda", "Hideki", "" ], [ "Taves", "Tim", "" ] ]
We present a family of extensions of spherically symmetric Einstein-Lanczos-Lovelock gravity. The field equations are second order and obey a generalized Birkhoff's theorem. The Hamiltonian constraint can be written in terms of a generalized Misner-Sharp mass function that determines the form of the vacuum solution. Th...
1505.02188
Hooman Moradpour Hooman
H. Moradpour, N. Riazi
Spherically symmetric solutions in a FRW background
null
Mod. Phys. Lett. A 8, (2015) 1550042
10.1142/S021773231550042X
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We impose perfect fluid concept along with slow expansion approximation to derive new solutions which, considering non-static spherically symmetric metrics, can be treated as Black Holes (BHs). We will refer to these solutions as Quasi BHs. Mathematical and physical features such as Killing vectors, singularities, an...
[ { "created": "Mon, 4 May 2015 14:58:47 GMT", "version": "v1" } ]
2015-05-12
[ [ "Moradpour", "H.", "" ], [ "Riazi", "N.", "" ] ]
We impose perfect fluid concept along with slow expansion approximation to derive new solutions which, considering non-static spherically symmetric metrics, can be treated as Black Holes (BHs). We will refer to these solutions as Quasi BHs. Mathematical and physical features such as Killing vectors, singularities, and ...
1602.05594
Vladimir Ivashchuk
A.A. Kobtsev, V.D. Ivashchuk and K.K. Ernazarov
On multidimensional solutions in the Einstein-Gauss-Bonnet model with a cosmological term
7 pages, Latex, no figures. To be published in: Proceedings of the XII International Conference on Gravitation, Cosmology and Astrophysics, (ICGAC-12, June 28-July 5, 2015, Moscow, PFUR), Eds. J.P. Hsu and V.N. Melnikov, World Scientific Publ., Singapore, 2016
null
10.1142/9789814759816_0074
PFUR-IGC-2016-02/01
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A D-dimensional gravitational model with Gauss-Bonnet and cosmological term is considered. When ansatz with diagonal cosmological metrics is adopted, we overview recent solutions for zero cosmological term and find new examples of solutions for non-zero cosmological term and D = 8 with exponential dependence of scale...
[ { "created": "Wed, 17 Feb 2016 21:06:17 GMT", "version": "v1" } ]
2016-03-16
[ [ "Kobtsev", "A. A.", "" ], [ "Ivashchuk", "V. D.", "" ], [ "Ernazarov", "K. K.", "" ] ]
A D-dimensional gravitational model with Gauss-Bonnet and cosmological term is considered. When ansatz with diagonal cosmological metrics is adopted, we overview recent solutions for zero cosmological term and find new examples of solutions for non-zero cosmological term and D = 8 with exponential dependence of scale f...
1809.01403
Dieter L\"ust
Dieter Lust, Ward Vleeshouwers
Black Hole Information and Thermodynamics
Revised version with typos corrected
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This SpringerBrief is based on a masters course on black hole thermodynamics and the black hole information problem taught by Dieter L\"ust during the summer term 2017 at the Ludwig-Maximilians-Universit\"at in Munich; it was written by Ward Vleeshouwers. It provides a short introduction to general relativity, which ...
[ { "created": "Wed, 5 Sep 2018 09:32:05 GMT", "version": "v1" }, { "created": "Mon, 26 Nov 2018 16:26:21 GMT", "version": "v2" } ]
2018-11-27
[ [ "Lust", "Dieter", "" ], [ "Vleeshouwers", "Ward", "" ] ]
This SpringerBrief is based on a masters course on black hole thermodynamics and the black hole information problem taught by Dieter L\"ust during the summer term 2017 at the Ludwig-Maximilians-Universit\"at in Munich; it was written by Ward Vleeshouwers. It provides a short introduction to general relativity, which de...
1801.05942
Shilpa Kastha
Shilpa Kastha, M. Saleem and K G Arun
Imprints of the redshift evolution of double neutron star merger rate on the signal to noise ratio distribution
9 pages, 4 figures
Monthly Notices of the Royal Astronomical Society, staa1077, 22 April 2020
10.1093/mnras/staa1077
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Proposed third generation gravitational wave (GW) interferometers such as Cosmic Explorer will have the sensitivity to observe double neutron star (DNS) mergers up to a redshift of $\sim 5$ with good signal to noise ratios. We argue that the comoving spatial distribution of DNS mergers leaves a unique imprint on the ...
[ { "created": "Thu, 18 Jan 2018 05:32:14 GMT", "version": "v1" }, { "created": "Fri, 12 Jul 2019 11:15:23 GMT", "version": "v2" }, { "created": "Mon, 27 Apr 2020 17:50:58 GMT", "version": "v3" } ]
2020-06-16
[ [ "Kastha", "Shilpa", "" ], [ "Saleem", "M.", "" ], [ "Arun", "K G", "" ] ]
Proposed third generation gravitational wave (GW) interferometers such as Cosmic Explorer will have the sensitivity to observe double neutron star (DNS) mergers up to a redshift of $\sim 5$ with good signal to noise ratios. We argue that the comoving spatial distribution of DNS mergers leaves a unique imprint on the st...
1810.11486
Seramika Ariwahjoedi
S. Ariwahjoedi, I. Husin, I. Sebastian, F. P. Zen
Hermiticity of the Volume Operators in Loop Quantum Gravity
15 pages, no figure
Gen. Rel. Grav. 51, 58 (2019)
10.1007/s10714-019-2541-2
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The aim of this article is to provide a rigorous-but-simple steps to prove the hermiticity of the volume operator of Rovelli-Smolin and Ashtekar-Lewandowski using the angular momentum approach, as well as pointing out some subleties which have not been given a lot of attention previously. Besides of being hermitian, ...
[ { "created": "Fri, 26 Oct 2018 18:26:53 GMT", "version": "v1" }, { "created": "Tue, 6 Nov 2018 15:32:15 GMT", "version": "v2" } ]
2021-03-30
[ [ "Ariwahjoedi", "S.", "" ], [ "Husin", "I.", "" ], [ "Sebastian", "I.", "" ], [ "Zen", "F. P.", "" ] ]
The aim of this article is to provide a rigorous-but-simple steps to prove the hermiticity of the volume operator of Rovelli-Smolin and Ashtekar-Lewandowski using the angular momentum approach, as well as pointing out some subleties which have not been given a lot of attention previously. Besides of being hermitian, we...
2009.14582
Jackson Levi Said
Rebecca Briffa, Salvatore Capozziello, Jackson Levi Said, Jurgen Mifsud and Emmanuel N. Saridakis
Constraining Teleparallel Gravity through Gaussian Processes
36 pages, 16 figures
null
10.1088/1361-6382/abd4f5
null
gr-qc astro-ph.CO hep-th physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply Gaussian processes (GP) in order to impose constraints on teleparallel gravity and its $f(T)$ extensions. We use available $H(z)$ observations from (i) cosmic chronometers data (CC); (ii) Supernova Type Ia (SN) data from the compressed Pantheon release together with the CANDELS and CLASH Multi-Cycle Treasury...
[ { "created": "Tue, 29 Sep 2020 10:02:07 GMT", "version": "v1" } ]
2021-02-03
[ [ "Briffa", "Rebecca", "" ], [ "Capozziello", "Salvatore", "" ], [ "Said", "Jackson Levi", "" ], [ "Mifsud", "Jurgen", "" ], [ "Saridakis", "Emmanuel N.", "" ] ]
We apply Gaussian processes (GP) in order to impose constraints on teleparallel gravity and its $f(T)$ extensions. We use available $H(z)$ observations from (i) cosmic chronometers data (CC); (ii) Supernova Type Ia (SN) data from the compressed Pantheon release together with the CANDELS and CLASH Multi-Cycle Treasury p...
0807.4559
Kristin Schleich
K. Schleich and D. M. Witt
Designer de Sitter Spacetimes
6 pages, no figure, correction of sign in eq. 4
Can. J. Phys. 86, 591-595 (2008)
10.1139/P07-191
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent observations in cosmology indicate an accelerating expansion of the universe postulated to arise from some form of dark energy, the paradigm being positive cosmological constant. De Sitter spacetime is the well-known isotropic solution to the Einstein equations with cosmological constant. However, as discussed...
[ { "created": "Mon, 28 Jul 2008 23:39:41 GMT", "version": "v1" }, { "created": "Sat, 13 Sep 2008 22:26:40 GMT", "version": "v2" } ]
2009-11-13
[ [ "Schleich", "K.", "" ], [ "Witt", "D. M.", "" ] ]
Recent observations in cosmology indicate an accelerating expansion of the universe postulated to arise from some form of dark energy, the paradigm being positive cosmological constant. De Sitter spacetime is the well-known isotropic solution to the Einstein equations with cosmological constant. However, as discussed h...
2210.11959
Cosimo Bambi
Cosimo Bambi
Search for Variations of Fundamental Constants
15 pages, no figures. Chapter for the book "Recent Progress on Gravity Tests" (Eds. C. Bambi and A. C\'ardenas-Avenda\~no, Springer Singapore, expected in 2023)
null
10.1007/978-981-97-2871-8_10
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The possibility of variations of the values of fundamental constants is a phenomenon predicted by a number of scenarios beyond General Relativity. This can happen if ``our'' fundamental constants are not the actual constants of the fundamental theory and their value is instead determined, for example, by the backgrou...
[ { "created": "Fri, 21 Oct 2022 13:33:56 GMT", "version": "v1" } ]
2024-07-12
[ [ "Bambi", "Cosimo", "" ] ]
The possibility of variations of the values of fundamental constants is a phenomenon predicted by a number of scenarios beyond General Relativity. This can happen if ``our'' fundamental constants are not the actual constants of the fundamental theory and their value is instead determined, for example, by the background...
gr-qc/0001034
Kazuya Koyama
Kazuya Koyama, Kayoko Maeda and Jiro Soda
Creation of an Open Universe from Valley Bounce
LaTeX, 8 pages, 2 figure, Presented at 9th Workshop on General Relativity and Gravitation, Hiroshima, Japan, Nov 3-6, 1999, For details see hep-ph/9910556
null
null
null
gr-qc
null
It appears difficult to construct a simple model for an open universe based on the one bubble inflationary scenario. The reason is that one needs a large mass to avoid the tunneling via the Hawking Moss solution and a small mass for successful slow-rolling. However, Rubakov and Sibiryakov suggest that the Hawking Mos...
[ { "created": "Wed, 12 Jan 2000 09:09:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Koyama", "Kazuya", "" ], [ "Maeda", "Kayoko", "" ], [ "Soda", "Jiro", "" ] ]
It appears difficult to construct a simple model for an open universe based on the one bubble inflationary scenario. The reason is that one needs a large mass to avoid the tunneling via the Hawking Moss solution and a small mass for successful slow-rolling. However, Rubakov and Sibiryakov suggest that the Hawking Moss ...
2205.09758
Subhayan Maity
Subhayan Maity
Non-equilibrium thermodynamics in the non-canonical scalar field perturbed space-time : Stability analysis
null
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The space-time of the Universe has been perturbed under a scalar field $\phi$ considering the minimum coupling between {\phi} and the background metric. The solutions of Einstein field equations have been obtained under perturbed geometry and the corresponding conservation equation shows the non-equilibrium thermodyn...
[ { "created": "Thu, 19 May 2022 07:29:02 GMT", "version": "v1" }, { "created": "Tue, 31 May 2022 13:06:20 GMT", "version": "v2" }, { "created": "Fri, 3 Jun 2022 18:56:22 GMT", "version": "v3" }, { "created": "Sun, 16 Oct 2022 14:31:15 GMT", "version": "v4" } ]
2022-10-18
[ [ "Maity", "Subhayan", "" ] ]
The space-time of the Universe has been perturbed under a scalar field $\phi$ considering the minimum coupling between {\phi} and the background metric. The solutions of Einstein field equations have been obtained under perturbed geometry and the corresponding conservation equation shows the non-equilibrium thermodynam...
2104.00594
Gr\'egory Baltus
Gregory Baltus, Justin Janquart, Melissa Lopez, Amit Reza, Sarah Caudill, Jean-Rene Cudell
Convolutional neural networks for the detection of the early inspiral of a gravitational-wave signal
12 pages, 14 figures
Phys. Rev. D 103, 102003 (2021)
10.1103/PhysRevD.103.102003
LIGO DCC number LIGO-P2100087
gr-qc
http://creativecommons.org/licenses/by/4.0/
GW170817 has led to the first example of multi-messenger astronomy with observations from gravitational wave interferometers and electromagnetic telescopes combined to characterise the source. However, detections of the early inspiral phase by the gravitational wave detectors would allow the observation of the earlie...
[ { "created": "Thu, 1 Apr 2021 16:22:09 GMT", "version": "v1" } ]
2021-05-26
[ [ "Baltus", "Gregory", "" ], [ "Janquart", "Justin", "" ], [ "Lopez", "Melissa", "" ], [ "Reza", "Amit", "" ], [ "Caudill", "Sarah", "" ], [ "Cudell", "Jean-Rene", "" ] ]
GW170817 has led to the first example of multi-messenger astronomy with observations from gravitational wave interferometers and electromagnetic telescopes combined to characterise the source. However, detections of the early inspiral phase by the gravitational wave detectors would allow the observation of the earlier ...
0906.0990
Guillermo A. Gonzalez
Guillermo A. Gonz\'alez, Antonio C. Guti\'errez-Pi\~neres, Viviana M. Vi\~na-Cervantes
Exact Static Axially Symmetric Thin Annular Dust Disks
Physics and Mathematics of Gravitation: Proceedings of the Spanish Relativity Meeting 2008
AIP Conf.Proc.1122:284-287,2009
10.1063/1.3141294
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new family of exact solutions of the Einstein field equations for static and axially simmetric spacetimes is presented. All the metric functions of the solutions are explicitly computed and the obtained expressions are simply written in terms of oblate spheroidal coordinates. The solutions describe an infinite fami...
[ { "created": "Thu, 4 Jun 2009 20:19:15 GMT", "version": "v1" } ]
2010-11-22
[ [ "González", "Guillermo A.", "" ], [ "Gutiérrez-Piñeres", "Antonio C.", "" ], [ "Viña-Cervantes", "Viviana M.", "" ] ]
A new family of exact solutions of the Einstein field equations for static and axially simmetric spacetimes is presented. All the metric functions of the solutions are explicitly computed and the obtained expressions are simply written in terms of oblate spheroidal coordinates. The solutions describe an infinite family...
1009.0647
Angus Prain
Angus Prain, Serena Fagnocchi and Stefano Liberati
Analogue Cosmological Particle Creation: Quantum Correlations in Expanding Bose Einstein Condensates
Reference added
Phys.Rev.D82:105018,2010
10.1103/PhysRevD.82.105018
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the structure of quantum correlations in an expanding Bose Einstein Condensate (BEC) through the analogue gravity framework. We consider both a 3+1 isotropically expanding BEC as well as the experimentally relevant case of an elongated, effectively 1+1 dimensional, expanding condensate. In this case we...
[ { "created": "Fri, 3 Sep 2010 12:51:50 GMT", "version": "v1" }, { "created": "Wed, 15 Sep 2010 13:30:34 GMT", "version": "v2" } ]
2010-12-09
[ [ "Prain", "Angus", "" ], [ "Fagnocchi", "Serena", "" ], [ "Liberati", "Stefano", "" ] ]
We investigate the structure of quantum correlations in an expanding Bose Einstein Condensate (BEC) through the analogue gravity framework. We consider both a 3+1 isotropically expanding BEC as well as the experimentally relevant case of an elongated, effectively 1+1 dimensional, expanding condensate. In this case we i...
2208.03170
Justin Vines
M. V. S. Saketh and Justin Vines
Scattering of gravitational waves off spinning compact objects with an effective worldline theory
v2: minor corrections and additional discussion; two-column format; submitted to PRD
null
10.1103/PhysRevD.106.124026
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the process, within classical general relativity, in which an incident gravitational plane wave, of weak amplitude and long wavelength, scatters off a massive spinning compact object, such as a black hole or neutron star. The amplitude of the asymptotic scattered wave, considered here at linear order in Newt...
[ { "created": "Fri, 5 Aug 2022 13:56:28 GMT", "version": "v1" }, { "created": "Tue, 30 Aug 2022 10:43:15 GMT", "version": "v2" } ]
2023-01-04
[ [ "Saketh", "M. V. S.", "" ], [ "Vines", "Justin", "" ] ]
We study the process, within classical general relativity, in which an incident gravitational plane wave, of weak amplitude and long wavelength, scatters off a massive spinning compact object, such as a black hole or neutron star. The amplitude of the asymptotic scattered wave, considered here at linear order in Newton...
gr-qc/9711004
Pierre Savaria
Pierre Savaria
Anisotropic Homogeneous Cosmology in the Nonsymmetric Theory of Gravitation
13 pages, TeX, no figure
null
null
UTPT-97-22
gr-qc
null
Solutions to the field equations of the Nonsymmetric Gravitational Theory with $g_[i0] = 0$ are obtained for the homogeneous, plane-symmetric, time-dependent case, both in vacuum and in the presence of a perfect fluid. Cosmological consequences include a dependence of the speed of light on its polarisation, as in a b...
[ { "created": "Mon, 3 Nov 1997 18:58:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Savaria", "Pierre", "" ] ]
Solutions to the field equations of the Nonsymmetric Gravitational Theory with $g_[i0] = 0$ are obtained for the homogeneous, plane-symmetric, time-dependent case, both in vacuum and in the presence of a perfect fluid. Cosmological consequences include a dependence of the speed of light on its polarisation, as in a bir...
2203.14595
Athanasios Bakopoulos
Athanasios Bakopoulos, Christos Charmousis, Panagiota Kanti, Nicolas Lecoeur
Compact objects of spherical symmetry in beyond Horndeski theories
References updated, typos corrected, matches published version
JHEP 08 (2022) 055
10.1007/JHEP08(2022)055
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We analyse in all generality beyond Horndeski theories of shift symmetry in a static and spherically symmetric spacetime. By introducing four auxiliary functions, we write the field equations in a particularly compact form. We show that assuming additionally parity symmetry renders the system directly integrable givi...
[ { "created": "Mon, 28 Mar 2022 09:15:15 GMT", "version": "v1" }, { "created": "Wed, 10 Aug 2022 16:44:50 GMT", "version": "v2" } ]
2022-08-11
[ [ "Bakopoulos", "Athanasios", "" ], [ "Charmousis", "Christos", "" ], [ "Kanti", "Panagiota", "" ], [ "Lecoeur", "Nicolas", "" ] ]
We analyse in all generality beyond Horndeski theories of shift symmetry in a static and spherically symmetric spacetime. By introducing four auxiliary functions, we write the field equations in a particularly compact form. We show that assuming additionally parity symmetry renders the system directly integrable giving...
1204.1199
Laszlo Arpad Gergely
Zolt\'an Keresztes, L\'aszl\'o \'A. Gergely, Alexander Yu. Kamenshchik
The paradox of soft singularity crossing and its resolution by distributional cosmological quantitities
12 pages; to be published in Phys.Rev.D
Phys.Rev.D86:063522,2012
10.1103/PhysRevD.86.063522
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A cosmological model of a flat Friedmann universe filled with a mixture of anti-Chaplygin gas and dust-like matter exhibits a future soft singularity, where the pressure of the anti-Chaplygin gas diverges (while its energy density is finite). Despite infinite tidal forces the geodesics pass through the singularity. D...
[ { "created": "Thu, 5 Apr 2012 12:28:15 GMT", "version": "v1" }, { "created": "Sat, 1 Sep 2012 09:19:51 GMT", "version": "v2" } ]
2015-06-04
[ [ "Keresztes", "Zoltán", "" ], [ "Gergely", "László Á.", "" ], [ "Kamenshchik", "Alexander Yu.", "" ] ]
A cosmological model of a flat Friedmann universe filled with a mixture of anti-Chaplygin gas and dust-like matter exhibits a future soft singularity, where the pressure of the anti-Chaplygin gas diverges (while its energy density is finite). Despite infinite tidal forces the geodesics pass through the singularity. Due...
gr-qc/9805102
Daniel Kennefick
Daniel Kennefick
Stability under radiation reaction of circular equatorial orbits around Kerr black holes
Revtex, 20 pages including three figures
Phys.Rev. D58 (1998) 064012
10.1103/PhysRevD.58.064012
null
gr-qc
null
We examine the evolution, under gravitational radiation reaction, of slightly eccentric equatorial orbits of point particles around Kerr black holes. Our method involves numerical integration of the Sasaki-Nakamura equation. It is discovered that such orbits decrease in eccentricity throughout most of the inspiral, u...
[ { "created": "Fri, 29 May 1998 14:42:53 GMT", "version": "v1" } ]
2009-10-31
[ [ "Kennefick", "Daniel", "" ] ]
We examine the evolution, under gravitational radiation reaction, of slightly eccentric equatorial orbits of point particles around Kerr black holes. Our method involves numerical integration of the Sasaki-Nakamura equation. It is discovered that such orbits decrease in eccentricity throughout most of the inspiral, unt...
1808.05703
Dimitry Ayzenberg
Harrison Gott, Dimitry Ayzenberg, Nicolas Yunes, Anne Lohfink
Observing the Shadows of Stellar-Mass Black Holes with Binary Companions
24 pages, 5 Figures, 2 Tables. Videos included in supplemental material. Submitted to CQG
null
10.1088/1361-6382/ab01b0
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The observation of the shadows cast by the event horizon of black holes on the light emitted in its neighborhood is the target of current very-long-baseline-interferometric observations. When considering supermassive black holes, the light source is the black hole's accretion disk, and therefore, the observation of t...
[ { "created": "Thu, 16 Aug 2018 23:19:14 GMT", "version": "v1" } ]
2019-02-20
[ [ "Gott", "Harrison", "" ], [ "Ayzenberg", "Dimitry", "" ], [ "Yunes", "Nicolas", "" ], [ "Lohfink", "Anne", "" ] ]
The observation of the shadows cast by the event horizon of black holes on the light emitted in its neighborhood is the target of current very-long-baseline-interferometric observations. When considering supermassive black holes, the light source is the black hole's accretion disk, and therefore, the observation of the...
0901.4828
Lau Loi So
Lau Loi So
An alternative non-negative gravitational energy tensor to the Bel-Robinson tensor
7 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Bel-Robinson tensor $B_{\alpha\beta\mu\nu}$ gives a positive definite gravitational energy in the small sphere limit approximation. However, there is an alternative tensor $V_{\alpha\beta\mu\nu}$ which was proposed recently that offers the same positivity as $B_{\alpha\beta\mu\nu}$ does. These two tensors are a b...
[ { "created": "Fri, 30 Jan 2009 06:23:42 GMT", "version": "v1" } ]
2009-02-02
[ [ "So", "Lau Loi", "" ] ]
The Bel-Robinson tensor $B_{\alpha\beta\mu\nu}$ gives a positive definite gravitational energy in the small sphere limit approximation. However, there is an alternative tensor $V_{\alpha\beta\mu\nu}$ which was proposed recently that offers the same positivity as $B_{\alpha\beta\mu\nu}$ does. These two tensors are a bas...
1905.07340
Adrien Kuntz
Adrien Kuntz
The two-body potential of Vainshtein screened theories
15 pages, 8 figures
Phys. Rev. D 100, 024024 (2019)
10.1103/PhysRevD.100.024024
null
gr-qc astro-ph.CO hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Adding a light scalar degree of freedom to General Relativity often induces a fifth force whose magnitude is strongly constrained by laboratory experiments and solar system tests. The Vainshtein screening mechanism ensures that the effects of this supplementary force are suppressed in dense environments. However, the...
[ { "created": "Fri, 17 May 2019 15:55:18 GMT", "version": "v1" } ]
2019-07-24
[ [ "Kuntz", "Adrien", "" ] ]
Adding a light scalar degree of freedom to General Relativity often induces a fifth force whose magnitude is strongly constrained by laboratory experiments and solar system tests. The Vainshtein screening mechanism ensures that the effects of this supplementary force are suppressed in dense environments. However, the f...
gr-qc/9712066
WU Zhong Chao
Wu Zhong Chao (ICRA)
Quantum Fields in Schwarzschild-de Sitter Space
24 pages
Int.J.Mod.Phys. D7 (1998) 887-907
null
ICRA-97-101
gr-qc hep-th
null
In the No-Boundary Universe a primordial black hole is created from a constrained gravitational instanton. The black hole created is immersed in the de Sitter background with a positive cosmological constant. The constrained instanton is characterized not only by the external parameters, the mass parameter, charge an...
[ { "created": "Mon, 15 Dec 1997 20:56:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Chao", "Wu Zhong", "", "ICRA" ] ]
In the No-Boundary Universe a primordial black hole is created from a constrained gravitational instanton. The black hole created is immersed in the de Sitter background with a positive cosmological constant. The constrained instanton is characterized not only by the external parameters, the mass parameter, charge and ...
1108.3550
Thomas W. Baumgarte
Thomas W. Baumgarte
Puncture black hole initial data in the conformal thin-sandwich formalism
17 pages, 4 figures
null
10.1088/0264-9381/28/21/215003
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the construction of puncture black hole initial data in the conformal thin-sandwich decomposition of Einstein's constraint equations. It has been shown previously that this approach cannot yield quasiequilibrium wormhole data, which connect two asymptotically flat spatial infinities. This argument does not...
[ { "created": "Wed, 17 Aug 2011 18:59:01 GMT", "version": "v1" } ]
2015-05-30
[ [ "Baumgarte", "Thomas W.", "" ] ]
We revisit the construction of puncture black hole initial data in the conformal thin-sandwich decomposition of Einstein's constraint equations. It has been shown previously that this approach cannot yield quasiequilibrium wormhole data, which connect two asymptotically flat spatial infinities. This argument does not a...
2003.09486
Roberto Percacci
Roberto Percacci
Towards Metric-Affine Quantum Gravity
Talk given at PAFT2019, Vietri sul Mare, Italy; to appear in International Journal of Geometric Methods in Modern Physics
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I review here some motivations to consider a theory of gravity based on independent metric and connection, and its status as a quantum theory.
[ { "created": "Fri, 20 Mar 2020 20:19:15 GMT", "version": "v1" } ]
2020-03-24
[ [ "Percacci", "Roberto", "" ] ]
I review here some motivations to consider a theory of gravity based on independent metric and connection, and its status as a quantum theory.
gr-qc/9406012
Haret Rosu
H.C. Rosu
Hawking-like effects and Unruh-like effects: toward experiments ?
31 pages, revised, a few references updated
Grav.Cosmol. 7 (2001) 1-17
null
null
gr-qc
null
The Hawking effect and the Unruh effect are two of the most important predictions in the theoretical physics of the last quarter of the 20th century. In parallel to the theoretical investigations there is great interest in the possibility of revealing effects of this type in some sort of experiments. I present a gene...
[ { "created": "Mon, 6 Jun 1994 23:40:00 GMT", "version": "v1" }, { "created": "Fri, 26 Apr 1996 01:49:00 GMT", "version": "v2" }, { "created": "Tue, 30 Dec 1997 23:57:24 GMT", "version": "v3" }, { "created": "Wed, 31 Dec 1997 03:20:16 GMT", "version": "v4" }, { "cr...
2008-02-03
[ [ "Rosu", "H. C.", "" ] ]
The Hawking effect and the Unruh effect are two of the most important predictions in the theoretical physics of the last quarter of the 20th century. In parallel to the theoretical investigations there is great interest in the possibility of revealing effects of this type in some sort of experiments. I present a genera...
1801.08208
Lionel London
L. London
Modeling ringdown II: non-precessing binary black holes
null
Phys. Rev. D 102, 084052 (2020)
10.1103/PhysRevD.102.084052
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The aftermath of binary black hole coalescence is a perturbed remnant whose gravitational radiation rings down, encoding information about the new black hole's recent history and current state.It is expected that this ringdown radiation will be composed primarily of Kerr quasinormal modes, and thereby enable tests of...
[ { "created": "Wed, 24 Jan 2018 21:37:28 GMT", "version": "v1" }, { "created": "Thu, 15 Oct 2020 00:44:31 GMT", "version": "v2" } ]
2020-10-28
[ [ "London", "L.", "" ] ]
The aftermath of binary black hole coalescence is a perturbed remnant whose gravitational radiation rings down, encoding information about the new black hole's recent history and current state.It is expected that this ringdown radiation will be composed primarily of Kerr quasinormal modes, and thereby enable tests of g...
2108.13361
Daine Danielson
Daine L. Danielson, Gautam Satishchandran, Robert M. Wald, Robert J. Weinbaum
Bl\'azquez-Salcedo-Knoll-Radu Wormholes Are Not Solutions to the Einstein-Dirac-Maxwell Equations
12 pages, no figures
Phys. Rev. D 104, 124055 (2021)
10.1103/PhysRevD.104.124055
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
Recently, Bl\'azquez-Salcedo, Knoll, and Radu (BSKR) have given a class of static, spherically symmetric, traversable wormhole spacetimes with Dirac and Maxwell fields. The BSKR wormholes are obtained by joining a classical solution to the Einstein-Dirac-Maxwell (EDM) equations on the "up" side of the wormhole ($r \g...
[ { "created": "Mon, 30 Aug 2021 16:33:46 GMT", "version": "v1" }, { "created": "Fri, 17 Dec 2021 21:18:53 GMT", "version": "v2" } ]
2021-12-21
[ [ "Danielson", "Daine L.", "" ], [ "Satishchandran", "Gautam", "" ], [ "Wald", "Robert M.", "" ], [ "Weinbaum", "Robert J.", "" ] ]
Recently, Bl\'azquez-Salcedo, Knoll, and Radu (BSKR) have given a class of static, spherically symmetric, traversable wormhole spacetimes with Dirac and Maxwell fields. The BSKR wormholes are obtained by joining a classical solution to the Einstein-Dirac-Maxwell (EDM) equations on the "up" side of the wormhole ($r \geq...
1501.04003
Surajit Chattopadhyay
Ines G. Salako, Abdul Jawad, Surajit Chattopadhyay
Holographic dark energy reconstruction of $f(T,\mathcal{T})$ gravity
14 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The present paper reports a holographic reconstruction scheme for $f(T,\mathcal T)$ gravity proposed in Harko et al. $\emph{JCAP}\; 12(2014)021$ where $T$ is the torsion scalar and $\mathcal{T}$ is the trace of the energy-momentum tensor considering future event horizon as the enveloping horizon of the universe. We h...
[ { "created": "Tue, 6 Jan 2015 09:56:30 GMT", "version": "v1" }, { "created": "Fri, 20 Feb 2015 07:24:06 GMT", "version": "v2" } ]
2015-02-23
[ [ "Salako", "Ines G.", "" ], [ "Jawad", "Abdul", "" ], [ "Chattopadhyay", "Surajit", "" ] ]
The present paper reports a holographic reconstruction scheme for $f(T,\mathcal T)$ gravity proposed in Harko et al. $\emph{JCAP}\; 12(2014)021$ where $T$ is the torsion scalar and $\mathcal{T}$ is the trace of the energy-momentum tensor considering future event horizon as the enveloping horizon of the universe. We hav...
1410.6678
Anzhong Wang
Kai Lin, O. Goldoni, M.F. da Silva, and Anzhong Wang
New look at black holes: Existence of universal horizons
revtex4, 17 figures. Version appeared in Phys. Rev. D91, 024047 (2015)
Phys. Rev. D 91, 024047 (2015)
10.1103/PhysRevD.91.024047
null
gr-qc hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study the existence of universal horizons in a given static spacetime, and find that the test khronon field can be solved explicitly when its velocity becomes infinitely large, at which point the universal horizon coincides with the sound horizon of the khronon. Choosing the timelike coordinate alig...
[ { "created": "Thu, 23 Oct 2014 16:21:29 GMT", "version": "v1" }, { "created": "Wed, 14 Jan 2015 03:10:17 GMT", "version": "v2" }, { "created": "Wed, 4 Feb 2015 14:20:44 GMT", "version": "v3" } ]
2015-03-05
[ [ "Lin", "Kai", "" ], [ "Goldoni", "O.", "" ], [ "da Silva", "M. F.", "" ], [ "Wang", "Anzhong", "" ] ]
In this paper, we study the existence of universal horizons in a given static spacetime, and find that the test khronon field can be solved explicitly when its velocity becomes infinitely large, at which point the universal horizon coincides with the sound horizon of the khronon. Choosing the timelike coordinate aligne...
1908.05442
Michalis Agathos
Michalis Agathos, Francesco Zappa, Sebastiano Bernuzzi, Albino Perego, Matteo Breschi and David Radice
Inferring prompt black-hole formation in neutron star mergers from gravitational-wave data
14 pages, 14 figures
Phys. Rev. D 101, 044006 (2020)
10.1103/PhysRevD.101.044006
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The gravitational-wave GW170817 is associated to the inspiral phase of a binary neutron star coalescence event. The LIGO-Virgo detectors sensitivity at high frequencies was not sufficient to detect the signal corresponding to the merger and post-merger phases. Hence, the question whether the merger outcome was a prom...
[ { "created": "Thu, 15 Aug 2019 07:00:45 GMT", "version": "v1" } ]
2020-02-12
[ [ "Agathos", "Michalis", "" ], [ "Zappa", "Francesco", "" ], [ "Bernuzzi", "Sebastiano", "" ], [ "Perego", "Albino", "" ], [ "Breschi", "Matteo", "" ], [ "Radice", "David", "" ] ]
The gravitational-wave GW170817 is associated to the inspiral phase of a binary neutron star coalescence event. The LIGO-Virgo detectors sensitivity at high frequencies was not sufficient to detect the signal corresponding to the merger and post-merger phases. Hence, the question whether the merger outcome was a prompt...
2212.09407
Vishwa Vijay Singh
Vishwa Vijay Singh and J\"urgen M\"uller and Liliane Biskupek and Eva Hackmann and Claus L\"ammerzahl
Equivalence of Active and Passive Gravitational Mass Tested with Lunar Laser Ranging
4 pages, 1 figure
null
10.1103/PhysRevLett.131.021401
null
gr-qc astro-ph.EP physics.space-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
LLR measures the distance between observatories on Earth and retro-reflectors on Moon since 1969. In this paper, we study the possible violation of the equality of passive and active gravitational mass ($m_{a}/m_{p}$), for Aluminium (Al) and Iron (Fe), using LLR data. Our new limit of $3.9\cdot10^{-14}$ is about 100 ...
[ { "created": "Mon, 19 Dec 2022 12:37:40 GMT", "version": "v1" } ]
2023-07-17
[ [ "Singh", "Vishwa Vijay", "" ], [ "Müller", "Jürgen", "" ], [ "Biskupek", "Liliane", "" ], [ "Hackmann", "Eva", "" ], [ "Lämmerzahl", "Claus", "" ] ]
LLR measures the distance between observatories on Earth and retro-reflectors on Moon since 1969. In this paper, we study the possible violation of the equality of passive and active gravitational mass ($m_{a}/m_{p}$), for Aluminium (Al) and Iron (Fe), using LLR data. Our new limit of $3.9\cdot10^{-14}$ is about 100 ti...
2111.07207
Michael Efroimsky
Pini Gurfil and Michael Efroimsky
Analysis of the PPN Two-Body Problem Using Non-Osculating Orbital Elements
null
null
10.1016/j.asr.2021.09.009
null
gr-qc astro-ph.EP math.DS
http://creativecommons.org/licenses/by-sa/4.0/
The parameterised post-Newtonian (PPN) formalism is a weak-field slow-motion approximation for both GR and some of its generalisations. It permits various parameterisations of the motion, among which are the Lagrange-type and Gauss-type orbital equations. Often, these equations are developed under the Lagrange constr...
[ { "created": "Sat, 13 Nov 2021 23:16:48 GMT", "version": "v1" } ]
2021-11-16
[ [ "Gurfil", "Pini", "" ], [ "Efroimsky", "Michael", "" ] ]
The parameterised post-Newtonian (PPN) formalism is a weak-field slow-motion approximation for both GR and some of its generalisations. It permits various parameterisations of the motion, among which are the Lagrange-type and Gauss-type orbital equations. Often, these equations are developed under the Lagrange constrai...
1510.04010
Puxun Wu
Yize Fan, Puxun Wu and Hongwei Yu
Spherical collapse in the extended quintessence cosmological models
17 pages, 4 figures. References added
Physical Review D 92, 083529 (2015)
10.1103/PhysRevD.92.083529
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use the spherical collapse method to investigate the non-linear density perturbations of pressureless matter in the cosmological models with the extended quintessence as dark energy in the metric and Palatini formalisms. We find that for both formalisms, when the coupling constant is negative, the deviation from t...
[ { "created": "Wed, 14 Oct 2015 09:02:05 GMT", "version": "v1" }, { "created": "Fri, 6 Nov 2015 15:15:20 GMT", "version": "v2" } ]
2015-11-09
[ [ "Fan", "Yize", "" ], [ "Wu", "Puxun", "" ], [ "Yu", "Hongwei", "" ] ]
We use the spherical collapse method to investigate the non-linear density perturbations of pressureless matter in the cosmological models with the extended quintessence as dark energy in the metric and Palatini formalisms. We find that for both formalisms, when the coupling constant is negative, the deviation from the...
2112.04065
Erik Jimenez
Erik Jim\'enez-V\'azquez, Miguel Alcubierre
Critical gravitational collapse of a non-minimally coupled scalar field
null
null
10.1103/PhysRevD.105.064071
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the critical gravitational collapse of a massless scalar field non-minimally coupled to gravity, using a quadratic coupling function with a strength parameter $\xi$. We concentrate on critical phenomena of type II, and determine with an accuracy of at least $10^{-12}$ the value of the critical amplitude for ...
[ { "created": "Wed, 8 Dec 2021 01:07:45 GMT", "version": "v1" } ]
2022-04-13
[ [ "Jiménez-Vázquez", "Erik", "" ], [ "Alcubierre", "Miguel", "" ] ]
We study the critical gravitational collapse of a massless scalar field non-minimally coupled to gravity, using a quadratic coupling function with a strength parameter $\xi$. We concentrate on critical phenomena of type II, and determine with an accuracy of at least $10^{-12}$ the value of the critical amplitude for co...
1006.2609
Ujjal Debnath
Samarpita Bhattacharya and Ujjal Debnath
Brans-Dicke Theory and Thermodynamical Laws on Apparent and Event Horizons
6 pages, 2 figures
null
10.1139/p11-072
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we have described the Brans-Dicke theory of gravity and given a particular solution by choosing a power law form of scalar field $\phi$ and constant $\omega$. If we assume first law and entropy formula on apparent horizon then we recover Friedmann equations. Next, assuming first law of thermodynamics, t...
[ { "created": "Mon, 14 Jun 2010 06:58:47 GMT", "version": "v1" } ]
2015-05-19
[ [ "Bhattacharya", "Samarpita", "" ], [ "Debnath", "Ujjal", "" ] ]
In this work, we have described the Brans-Dicke theory of gravity and given a particular solution by choosing a power law form of scalar field $\phi$ and constant $\omega$. If we assume first law and entropy formula on apparent horizon then we recover Friedmann equations. Next, assuming first law of thermodynamics, the...
1707.09309
Ryuichi Fujita
Ryuichi Fujita, Norichika Sago, Hiroyuki Nakano
Note on Accuracy of the Post-Newtonian Approximation for Extreme-Mass Ratio Inspirals: Retrograde Orbits
10 pages, 3 figures
Class. Quantum Grav. 35 027001 (2018)
10.1088/1361-6382/aa9ad5
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The post-Newtonian approximation is useful to discuss gravitational waveforms for binary inspirals. In this note, for retrograde circular orbits in the equatorial plane, we discuss the region of validity of the post-Newtonian approximation by using the gravitational energy flux derived numerically and analytically in...
[ { "created": "Fri, 28 Jul 2017 16:24:27 GMT", "version": "v1" }, { "created": "Thu, 21 Dec 2017 07:58:05 GMT", "version": "v2" } ]
2017-12-22
[ [ "Fujita", "Ryuichi", "" ], [ "Sago", "Norichika", "" ], [ "Nakano", "Hiroyuki", "" ] ]
The post-Newtonian approximation is useful to discuss gravitational waveforms for binary inspirals. In this note, for retrograde circular orbits in the equatorial plane, we discuss the region of validity of the post-Newtonian approximation by using the gravitational energy flux derived numerically and analytically in t...
gr-qc/9805088
Bozhidar Zakhariev Iliev
Bozhidar Z. Iliev (Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia, Bulgaria)
Normal frames and the validity of the equivalence principle. III. The case along smooth maps with separable points of self-intersection
15 standard LaTeX 2e (11pt, A4) pages. The package amsfonts is required
J.Phys.A31:1287-1296,1998
10.1088/0305-4470/31/4/016
JINR Communication E5-92-543, Dubna, 1992
gr-qc
null
The equivalence principle is treated on a mathematically rigorous base on sufficiently general subsets of a differentiable manifold. This is carried out using the basis of derivations of the tensor algebra over that manifold. Necessary and/or sufficient conditions of existence, uniqueness, and holonomicity of these b...
[ { "created": "Fri, 22 May 1998 15:31:23 GMT", "version": "v1" } ]
2008-11-26
[ [ "Iliev", "Bozhidar Z.", "", "Institute for Nuclear Research and Nuclear Energy,\n Bulgarian Academy of Sciences, Sofia, Bulgaria" ] ]
The equivalence principle is treated on a mathematically rigorous base on sufficiently general subsets of a differentiable manifold. This is carried out using the basis of derivations of the tensor algebra over that manifold. Necessary and/or sufficient conditions of existence, uniqueness, and holonomicity of these bas...
gr-qc/9905062
Maurizio Gasperini
M. Gasperini
Looking back in time beyond the big bang
11 pages, Latex, four figures included using epsfig. Essay written for the 1999 Awards of the Gravity Research Foundation (Wellesley Hills, Ma, 02481-0004), and selected for Honorable Mention. To appear in Mod. Phys. Lett. A
Mod.Phys.Lett. A14 (1999) 1059-1066
10.1142/S0217732399001127
BARI-TH/99-331
gr-qc
null
String theory can (in principle) describe gravity at all curvature scales, and can be applied to cosmology to look back in time beyond the Planck epoch. The duality symmetries of string theory suggest a cosmological picture in which the imprint of a primordial, pre-big bang phase could still be accessible to present ...
[ { "created": "Tue, 18 May 1999 13:35:55 GMT", "version": "v1" } ]
2009-10-31
[ [ "Gasperini", "M.", "" ] ]
String theory can (in principle) describe gravity at all curvature scales, and can be applied to cosmology to look back in time beyond the Planck epoch. The duality symmetries of string theory suggest a cosmological picture in which the imprint of a primordial, pre-big bang phase could still be accessible to present ob...
1302.2646
Paolo Pani
Caio F.B. Macedo, Paolo Pani, Vitor Cardoso, Luis C.B. Crispino
Into the lair: gravitational-wave signatures of dark matter
17 pages, 6 figures. Abstract abridged. v2: Sections 1 and 2 improved. Version to be published in the ApJ
null
10.1088/0004-637X/774/1/48
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The nature and properties of dark matter (DM) are both outstanding issues in physics. Besides clustering in halos, the universal character of gravity implies that self-gravitating compact DM configurations might be spread throughout the universe. The astrophysical signature of these objects may be used to probe funda...
[ { "created": "Mon, 11 Feb 2013 21:15:01 GMT", "version": "v1" }, { "created": "Fri, 24 May 2013 14:52:50 GMT", "version": "v2" } ]
2015-06-15
[ [ "Macedo", "Caio F. B.", "" ], [ "Pani", "Paolo", "" ], [ "Cardoso", "Vitor", "" ], [ "Crispino", "Luis C. B.", "" ] ]
The nature and properties of dark matter (DM) are both outstanding issues in physics. Besides clustering in halos, the universal character of gravity implies that self-gravitating compact DM configurations might be spread throughout the universe. The astrophysical signature of these objects may be used to probe fundame...
2001.09082
Alessandro Nagar
Alessandro Nagar, Gunnar Riemenschneider, Geraint Pratten, Piero Rettegno and Francesco Messina
A multipolar effective one body waveform model for spin-aligned black hole binaries
45 pages, 21 figures, several changes with respect to the earlier version. Matches published version
Phys. Rev. D 102, 024077 (2020)
10.1103/PhysRevD.102.024077
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce \TEOBiResumSM{}, an improved version of the effective-one-body (EOB) waveform model \TEOBResumS{} for spin-aligned, coalescing black hole binaries, that includes subdominant gravitational waveform modes completed through merger and ringdown. Beyond the dominant $(\ell,|m|)=(2,2)$ one, the more robust mul...
[ { "created": "Fri, 24 Jan 2020 16:44:24 GMT", "version": "v1" }, { "created": "Sun, 13 Sep 2020 09:53:17 GMT", "version": "v2" } ]
2020-09-15
[ [ "Nagar", "Alessandro", "" ], [ "Riemenschneider", "Gunnar", "" ], [ "Pratten", "Geraint", "" ], [ "Rettegno", "Piero", "" ], [ "Messina", "Francesco", "" ] ]
We introduce \TEOBiResumSM{}, an improved version of the effective-one-body (EOB) waveform model \TEOBResumS{} for spin-aligned, coalescing black hole binaries, that includes subdominant gravitational waveform modes completed through merger and ringdown. Beyond the dominant $(\ell,|m|)=(2,2)$ one, the more robust multi...
1001.5429
Jose Luis Jaramillo
J.L. Jaramillo, E. Gourgoulhon
Mass and Angular Momentum in General Relativity
41 pages. Notes based on the lecture given at the C.N.R.S. "School on Mass" (June 2008) in Orleans, France. To appear as proceedings in the book "Mass and Motion in General Relativity", eds. L. Blanchet, A. Spallicci and B. Whiting. Some comments and references added.
null
10.1007/978-90-481-3015-3_4
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an introduction to mass and angular momentum in General Relativity. After briefly reviewing energy-momentum for matter fields, first in the flat Minkowski case (Special Relativity) and then in curved spacetimes with or without symmetries, we focus on the discussion of energy-momentum for the gravitational ...
[ { "created": "Fri, 29 Jan 2010 16:26:37 GMT", "version": "v1" }, { "created": "Fri, 30 Apr 2010 08:30:01 GMT", "version": "v2" } ]
2015-05-18
[ [ "Jaramillo", "J. L.", "" ], [ "Gourgoulhon", "E.", "" ] ]
We present an introduction to mass and angular momentum in General Relativity. After briefly reviewing energy-momentum for matter fields, first in the flat Minkowski case (Special Relativity) and then in curved spacetimes with or without symmetries, we focus on the discussion of energy-momentum for the gravitational fi...
2004.05627
Arunima Banerjee Dr.
K. Aditya, Indrani Banerjee, Arunima Banerjee and Soumitra SenGupta
Dynamical modelling of disc vertical structure in superthin galaxy `UGC 7321' in braneworld gravity: An MCMC study
20 pages, 2 figures (Accepted for publication in MNRAS)
null
10.1093/mnras/staa3104
null
gr-qc astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Low surface brightness (LSBs) superthins constitute classic examples of very late-type galaxies, with their disc dynamics strongly regulated by their dark matter halos. In this work we consider a gravitational origin of dark matter in the brane world scenario, where the higher dimensional Weyl stress term projected o...
[ { "created": "Sun, 12 Apr 2020 14:57:01 GMT", "version": "v1" }, { "created": "Sun, 27 Sep 2020 10:55:37 GMT", "version": "v2" } ]
2020-10-21
[ [ "Aditya", "K.", "" ], [ "Banerjee", "Indrani", "" ], [ "Banerjee", "Arunima", "" ], [ "SenGupta", "Soumitra", "" ] ]
Low surface brightness (LSBs) superthins constitute classic examples of very late-type galaxies, with their disc dynamics strongly regulated by their dark matter halos. In this work we consider a gravitational origin of dark matter in the brane world scenario, where the higher dimensional Weyl stress term projected ont...
2001.03228
Davide Fermi
Davide Fermi, Massimo Gengo, Livio Pizzocchero (Univ. di Milano)
Integrable scalar cosmologies with matter and curvature
83 pages, 31 figures. In comparison with version v1, the exposition of the results has been polished and some references have been added
Nucl. Phys. B 957 (2020), 115095
10.1016/j.nuclphysb.2020.115095
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that several integrable (i.e., exactly solvable) scalar cosmologies considered by Fr\'e, Sagnotti and Sorin (Nuclear Physics \textbf{B 877}(3) (2013), 1028--1106) can be generalized to include cases where the spatial curvature is not zero and, besides a scalar field, matter or radiation are present with an eq...
[ { "created": "Thu, 9 Jan 2020 21:34:18 GMT", "version": "v1" }, { "created": "Tue, 18 Feb 2020 16:24:19 GMT", "version": "v2" } ]
2020-07-03
[ [ "Fermi", "Davide", "", "Univ. di Milano" ], [ "Gengo", "Massimo", "", "Univ. di Milano" ], [ "Pizzocchero", "Livio", "", "Univ. di Milano" ] ]
We show that several integrable (i.e., exactly solvable) scalar cosmologies considered by Fr\'e, Sagnotti and Sorin (Nuclear Physics \textbf{B 877}(3) (2013), 1028--1106) can be generalized to include cases where the spatial curvature is not zero and, besides a scalar field, matter or radiation are present with an equa...
0906.0926
Luke Butcher
Luke M. Butcher, Michael Hobson, Anthony Lasenby
Bootstrapping gravity: a consistent approach to energy-momentum self-coupling
18 pages, RevTex; Published version
Phys.Rev.D80:084014,2009
10.1103/PhysRevD.80.084014
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is generally believed that coupling the graviton (a classical Fierz-Pauli massless spin-2 field) to its own energy-momentum tensor successfully recreates the dynamics of the Einstein field equations order by order; however the validity of this idea has recently been brought into doubt [1]. Motivated by this, we pr...
[ { "created": "Thu, 4 Jun 2009 15:01:20 GMT", "version": "v1" }, { "created": "Wed, 14 Oct 2009 11:45:46 GMT", "version": "v2" } ]
2009-10-29
[ [ "Butcher", "Luke M.", "" ], [ "Hobson", "Michael", "" ], [ "Lasenby", "Anthony", "" ] ]
It is generally believed that coupling the graviton (a classical Fierz-Pauli massless spin-2 field) to its own energy-momentum tensor successfully recreates the dynamics of the Einstein field equations order by order; however the validity of this idea has recently been brought into doubt [1]. Motivated by this, we pres...
2010.15202
Ssohrab Borhanian
Ssohrab Borhanian
Gwbench: a novel Fisher information package for gravitational-wave benchmarking
18 pages, 6 figures, 4 tables
Class. Quantum Grav. 38 175014 (2021)
10.1088/1361-6382/ac1618
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We present a new Python package, gwbench, implementing the well-established Fisher information formalism as a fast and straightforward tool for the purpose of gravitational-wave benchmarking, i.e. the estimation of signal-to-noise ratios and measurement errors of gravitational waves observed by a network of detectors...
[ { "created": "Wed, 28 Oct 2020 19:52:19 GMT", "version": "v1" }, { "created": "Mon, 9 Nov 2020 15:54:22 GMT", "version": "v2" }, { "created": "Fri, 13 Aug 2021 16:51:07 GMT", "version": "v3" } ]
2021-08-31
[ [ "Borhanian", "Ssohrab", "" ] ]
We present a new Python package, gwbench, implementing the well-established Fisher information formalism as a fast and straightforward tool for the purpose of gravitational-wave benchmarking, i.e. the estimation of signal-to-noise ratios and measurement errors of gravitational waves observed by a network of detectors. ...
1506.05014
Minas Tsoukalas
Christos Charmousis and Minas Tsoukalas
On Lovelock galileons and black holes
11 pages, minor corrections, references added, version accepted to PRD
Phys. Rev. D 92, 104050 (2015)
10.1103/PhysRevD.92.104050
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a scalar-tensor version of Lovelock theory with a non trivial higher order galileon term involving the coupling of the Lovelock two tensor with derivatives of the scalar galileon field. For a static and spherically symmetric spacetime we extend the Boulware-Deser solution to the presence of a Galileon field....
[ { "created": "Tue, 16 Jun 2015 16:11:14 GMT", "version": "v1" }, { "created": "Tue, 8 Dec 2015 07:52:26 GMT", "version": "v2" } ]
2015-12-09
[ [ "Charmousis", "Christos", "" ], [ "Tsoukalas", "Minas", "" ] ]
We study a scalar-tensor version of Lovelock theory with a non trivial higher order galileon term involving the coupling of the Lovelock two tensor with derivatives of the scalar galileon field. For a static and spherically symmetric spacetime we extend the Boulware-Deser solution to the presence of a Galileon field. T...
0710.4345
Spindel
Robert Brout, Serge Massar, Renaud Parentani, Philippe Spindel
A Primer for Black Hole Quantum Physics
An old review article on black hole evaporation and black hole thermodynamics, put on the archive following popular demand, 178 pages, 21 figures (This text differs in slightly from the published version)
Phys.Rept.260:329-454,1995
10.1016/0370-1573(95)00008-5
null
gr-qc hep-th
null
The mechanisms which give rise to Hawking radiation are revealed by analyzing in detail pair production in the presence of horizons. In preparation for the black hole problem, three preparatory problems are dwelt with at length: pair production in an external electric field, thermalization of a uniformly accelerated ...
[ { "created": "Tue, 23 Oct 2007 21:09:32 GMT", "version": "v1" } ]
2008-11-26
[ [ "Brout", "Robert", "" ], [ "Massar", "Serge", "" ], [ "Parentani", "Renaud", "" ], [ "Spindel", "Philippe", "" ] ]
The mechanisms which give rise to Hawking radiation are revealed by analyzing in detail pair production in the presence of horizons. In preparation for the black hole problem, three preparatory problems are dwelt with at length: pair production in an external electric field, thermalization of a uniformly accelerated de...
1010.4004
Ivan Agullo
I. Agullo, J. Navarro-Salas, G. J. Olmo, and L. Parker
Acceleration radiation, transition probabilities, and trans-Planckian physics
19 pages
New J.Phys.12:095017,2010
10.1088/1367-2630/12/9/095017
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An important question in the derivation of the acceleration radiation, which also arises in Hawking's derivation of black hole radiance, is the need to invoke trans-Planckian physics for the quantum field that originates the created quanta. We point out that this issue can be further clarified by reconsidering the an...
[ { "created": "Tue, 19 Oct 2010 18:46:59 GMT", "version": "v1" } ]
2015-03-12
[ [ "Agullo", "I.", "" ], [ "Navarro-Salas", "J.", "" ], [ "Olmo", "G. J.", "" ], [ "Parker", "L.", "" ] ]
An important question in the derivation of the acceleration radiation, which also arises in Hawking's derivation of black hole radiance, is the need to invoke trans-Planckian physics for the quantum field that originates the created quanta. We point out that this issue can be further clarified by reconsidering the anal...
2105.13896
Qasem Exirifard
Qasem Exirifard, Ebrahim Karimi
Schr\"odinger equation in a general curved space-time geometry
39 pages, 9 figures, Matches the published version
International Journal of Modern Physics D(2022) 225001
10.1142/S0218271822500183
null
gr-qc hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider relativistic quantum field theory in the presence of an external electric potential in a general curved space-time geometry. We utilise Fermi coordinates adapted to the time-like geodesic to describe the low-energy physics in the laboratory and calculate the leading correction due to the curvature of the ...
[ { "created": "Wed, 26 May 2021 18:47:44 GMT", "version": "v1" }, { "created": "Tue, 30 Nov 2021 15:08:39 GMT", "version": "v2" } ]
2022-01-10
[ [ "Exirifard", "Qasem", "" ], [ "Karimi", "Ebrahim", "" ] ]
We consider relativistic quantum field theory in the presence of an external electric potential in a general curved space-time geometry. We utilise Fermi coordinates adapted to the time-like geodesic to describe the low-energy physics in the laboratory and calculate the leading correction due to the curvature of the sp...
1208.5839
Anil Zenginoglu C
An{\i}l Zengino\u{g}lu, Gaurav Khanna, Lior M. Burko
Intermediate behavior of Kerr tails
16 pages
General Relativity and Gravitation 46, 1672 (2014)
10.1007/s10714-014-1672-8
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The numerical investigation of wave propagation in the asymptotic domain of Kerr spacetime has only recently been possible thanks to the construction of suitable hyperboloidal coordinates. The asymptotics revealed an apparent puzzle in the decay rates of scalar fields: the late-time rates seemed to depend on whether ...
[ { "created": "Wed, 29 Aug 2012 04:58:21 GMT", "version": "v1" }, { "created": "Tue, 25 Jun 2013 20:08:42 GMT", "version": "v2" }, { "created": "Mon, 17 Feb 2014 13:33:07 GMT", "version": "v3" } ]
2014-02-18
[ [ "Zenginoğlu", "Anıl", "" ], [ "Khanna", "Gaurav", "" ], [ "Burko", "Lior M.", "" ] ]
The numerical investigation of wave propagation in the asymptotic domain of Kerr spacetime has only recently been possible thanks to the construction of suitable hyperboloidal coordinates. The asymptotics revealed an apparent puzzle in the decay rates of scalar fields: the late-time rates seemed to depend on whether fi...
gr-qc/9906118
Valery M. Koryukin
Valery Koryukin (Mari State Technical University)
Neutrinos of Universe and masses of particles
11 pages, submitted to PANIC'99
null
null
null
gr-qc
null
The detection and the research of the neutrinos background of Universe are the attractive problems. This problems do not seem the unpromising one in the case of the high neutrinos density that is necessary for the explanation of the nucleons-antinucleons asymmetry of Universe. It was offered before to use the low e...
[ { "created": "Tue, 29 Jun 1999 11:46:57 GMT", "version": "v1" } ]
2016-08-31
[ [ "Koryukin", "Valery", "", "Mari State Technical University" ] ]
The detection and the research of the neutrinos background of Universe are the attractive problems. This problems do not seem the unpromising one in the case of the high neutrinos density that is necessary for the explanation of the nucleons-antinucleons asymmetry of Universe. It was offered before to use the low energ...
1602.04459
Josef Schmidt
Ji\v{r}\'i Bi\v{c}\'ak, Josef Schmidt
Energy-momentum tensors in linearized Einstein's theory and massive gravity: The question of uniqueness
13 pages
Phys. Rev. D 93, 024009 (2016)
10.1103/PhysRevD.93.024009
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The question of the uniqueness of energy-momentum tensors in the linearized general relativity and in the linear massive gravity is analyzed without using variational techniques. We start from a natural ansatz for the form of the tensor (for example, that it is a linear combination of the terms quadratic in the first...
[ { "created": "Sun, 14 Feb 2016 14:11:36 GMT", "version": "v1" } ]
2016-02-16
[ [ "Bičák", "Jiří", "" ], [ "Schmidt", "Josef", "" ] ]
The question of the uniqueness of energy-momentum tensors in the linearized general relativity and in the linear massive gravity is analyzed without using variational techniques. We start from a natural ansatz for the form of the tensor (for example, that it is a linear combination of the terms quadratic in the first d...
1203.4801
Michel Miranda
Tonatiuh Matos, L. Arturo Urena-Lopez and Galaxia Miranda
Wormhole Cosmic Censorship
null
Gen. Rel. Grav. 48, (2016), 61
10.1007/s10714-016-2040-7
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the properties of a Kerr-like wormhole supported by phantom matter, which is an exact solution of the Einstein-phantom field equations. It is shown that the solution has a naked ring singularity which is unreachable to null geodesics falling freely from the outside. Similarly to Roger Penrose's cosmic cens...
[ { "created": "Wed, 21 Mar 2012 18:58:16 GMT", "version": "v1" }, { "created": "Sun, 9 Jun 2013 05:57:00 GMT", "version": "v2" }, { "created": "Wed, 1 Jul 2015 02:06:14 GMT", "version": "v3" }, { "created": "Mon, 28 Mar 2016 21:23:32 GMT", "version": "v4" } ]
2021-02-09
[ [ "Matos", "Tonatiuh", "" ], [ "Urena-Lopez", "L. Arturo", "" ], [ "Miranda", "Galaxia", "" ] ]
We analyze the properties of a Kerr-like wormhole supported by phantom matter, which is an exact solution of the Einstein-phantom field equations. It is shown that the solution has a naked ring singularity which is unreachable to null geodesics falling freely from the outside. Similarly to Roger Penrose's cosmic censor...
1804.07740
Mohammad Mehrafarin
Hamideh Balajani and Mohammad Mehrafarin
Berry phase of primordial scalar and tensor perturbations in single-field inflationary models
null
Phys. Lett. A 382 (2018) 1524
null
null
gr-qc quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of the single-field slow-roll inflation, we derive the Hamiltonian of the linear primordial scalar and tensor perturbations in the form of time-dependent harmonic oscillator Hamiltonians. We find the invariant operators of the resulting Hamiltonians and use their eigenstates to calculate the adiabati...
[ { "created": "Fri, 20 Apr 2018 17:35:09 GMT", "version": "v1" } ]
2018-04-24
[ [ "Balajani", "Hamideh", "" ], [ "Mehrafarin", "Mohammad", "" ] ]
In the framework of the single-field slow-roll inflation, we derive the Hamiltonian of the linear primordial scalar and tensor perturbations in the form of time-dependent harmonic oscillator Hamiltonians. We find the invariant operators of the resulting Hamiltonians and use their eigenstates to calculate the adiabatic ...
0904.3541
Carlos O. Lousto
Carlos O. Lousto, Manuela Campanelli, Yosef Zlochower, Hiroyuki Nakano (RIT)
Remnant Masses, Spins and Recoils from the Merger of Generic Black-Hole Binaries
15 pages, 2 figures. Rewritten and added new section.
Class.Quant.Grav.27:114006,2010
10.1088/0264-9381/27/11/114006
null
gr-qc astro-ph.CO astro-ph.GA astro-ph.HE astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We obtain empirical formulae for the final remnant black hole mass, spin, and recoil velocity from merging black-hole binaries with arbitrary mass ratios and spins. Our formulae are based on the mass ratio and spin dependence of the post-Newtonian expressions for the instantaneous radiated energy, linear momentum, an...
[ { "created": "Wed, 22 Apr 2009 20:01:10 GMT", "version": "v1" }, { "created": "Wed, 3 Jun 2009 19:22:23 GMT", "version": "v2" }, { "created": "Mon, 25 Jan 2010 22:25:40 GMT", "version": "v3" }, { "created": "Tue, 20 Apr 2010 21:28:28 GMT", "version": "v4" } ]
2010-05-25
[ [ "Lousto", "Carlos O.", "", "RIT" ], [ "Campanelli", "Manuela", "", "RIT" ], [ "Zlochower", "Yosef", "", "RIT" ], [ "Nakano", "Hiroyuki", "", "RIT" ] ]
We obtain empirical formulae for the final remnant black hole mass, spin, and recoil velocity from merging black-hole binaries with arbitrary mass ratios and spins. Our formulae are based on the mass ratio and spin dependence of the post-Newtonian expressions for the instantaneous radiated energy, linear momentum, and ...
2005.14211
Jose' P. S. Lemos
Jos\'e P. S. Lemos, Diogo L. F. G. Silva
Maximal extension of the Schwarzschild metric: From Painlev\'e-Gullstrand to Kruskal-Szekeres
18 pages, 7 figures
Annals of Physics 430, 168497 (2021)
10.1016/j.aop.2021.168497
null
gr-qc astro-ph.HE hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We find a specific coordinate system that goes from the Painlev\'e-Gullstrand partial extension to the Kruskal-Szekeres maximal extension and thus exhibit the maximal extension of the Schwarzschild metric in a unified picture. We do this by adopting two time coordinates, one being the proper time of a congruence of o...
[ { "created": "Thu, 28 May 2020 18:00:25 GMT", "version": "v1" } ]
2021-11-01
[ [ "Lemos", "José P. S.", "" ], [ "Silva", "Diogo L. F. G.", "" ] ]
We find a specific coordinate system that goes from the Painlev\'e-Gullstrand partial extension to the Kruskal-Szekeres maximal extension and thus exhibit the maximal extension of the Schwarzschild metric in a unified picture. We do this by adopting two time coordinates, one being the proper time of a congruence of out...
0709.0299
Latham Boyle
Latham Boyle, Michael Kesden and Samaya Nissanke
Binary black hole merger: symmetry and the spin expansion
4 pages, 4 figures, matches Phys. Rev. Lett. version
Phys.Rev.Lett.100:151101,2008
10.1103/PhysRevLett.100.151101
null
gr-qc astro-ph hep-ph hep-th
null
We regard binary black hole (BBH) merger as a map from a simple initial state (two Kerr black holes, with dimensionless spins {\bf a} and {\bf b}) to a simple final state (a Kerr black hole with mass m, dimensionless spin {\bf s}, and kick velocity {\bf k}). By expanding this map around {\bf a} = {\bf b} = 0 and appl...
[ { "created": "Tue, 4 Sep 2007 19:02:29 GMT", "version": "v1" }, { "created": "Fri, 9 May 2008 02:52:03 GMT", "version": "v2" } ]
2008-11-26
[ [ "Boyle", "Latham", "" ], [ "Kesden", "Michael", "" ], [ "Nissanke", "Samaya", "" ] ]
We regard binary black hole (BBH) merger as a map from a simple initial state (two Kerr black holes, with dimensionless spins {\bf a} and {\bf b}) to a simple final state (a Kerr black hole with mass m, dimensionless spin {\bf s}, and kick velocity {\bf k}). By expanding this map around {\bf a} = {\bf b} = 0 and applyi...
1210.1449
Abraham Harte
Abraham I. Harte
Strong lensing, plane gravitational waves and transient flashes
32 pages, 8 figures, fixed typos and slightly added to some explanations
null
10.1088/0264-9381/30/7/075011
AEI-2012-106
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Plane-symmetric gravitational waves are considered as gravitational lenses. Numbers of images, frequency shifts, mutual angles, and image distortion parameters are computed exactly in essentially all non-singular plane wave spacetimes. For a fixed observation event in a particular plane wave spacetime, the number of ...
[ { "created": "Thu, 4 Oct 2012 14:10:14 GMT", "version": "v1" }, { "created": "Mon, 22 Oct 2012 16:12:40 GMT", "version": "v2" } ]
2015-06-11
[ [ "Harte", "Abraham I.", "" ] ]
Plane-symmetric gravitational waves are considered as gravitational lenses. Numbers of images, frequency shifts, mutual angles, and image distortion parameters are computed exactly in essentially all non-singular plane wave spacetimes. For a fixed observation event in a particular plane wave spacetime, the number of im...
2308.09826
John Friedman
John L. Friedman
Notes on Gravitational Physics
371 pages. This updated version includes a chapter on cosmology as well as a number of revisions and corrections
null
null
null
gr-qc astro-ph.HE
http://creativecommons.org/licenses/by-nc-sa/4.0/
These notes are self-contained, with the first 7 chapters used in a one-semester course with recommended texts by Wald, by Misner, Thorne and Wheeler, and by Schutz. In its treatment of topics covered in these standard texts, the presentation here typically includes steps skipped in Wald or MTW. Treatments of gravita...
[ { "created": "Fri, 18 Aug 2023 21:31:53 GMT", "version": "v1" }, { "created": "Tue, 21 May 2024 15:56:45 GMT", "version": "v2" } ]
2024-05-22
[ [ "Friedman", "John L.", "" ] ]
These notes are self-contained, with the first 7 chapters used in a one-semester course with recommended texts by Wald, by Misner, Thorne and Wheeler, and by Schutz. In its treatment of topics covered in these standard texts, the presentation here typically includes steps skipped in Wald or MTW. Treatments of gravitati...
1708.07851
Andreas Sch\"arer
Manuel Hohmann, Andreas Sch\"arer
Post-Newtonian parameters $\gamma$ and $\beta$ of scalar-tensor gravity for a homogeneous gravitating sphere
35 pages, 5 figures
Phys. Rev. D 96, 104026 (2017)
10.1103/PhysRevD.96.104026
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the parameters $\gamma$ and $\beta$ in the parametrized post-Newtonian (PPN) formalism for scalar-tensor gravity (STG) with an arbitrary potential, under the assumption that the source matter is given by a non-rotating sphere of constant density, pressure and internal energy. For our calculation we write...
[ { "created": "Fri, 25 Aug 2017 18:15:12 GMT", "version": "v1" }, { "created": "Thu, 7 Sep 2017 15:56:37 GMT", "version": "v2" } ]
2017-11-22
[ [ "Hohmann", "Manuel", "" ], [ "Schärer", "Andreas", "" ] ]
We calculate the parameters $\gamma$ and $\beta$ in the parametrized post-Newtonian (PPN) formalism for scalar-tensor gravity (STG) with an arbitrary potential, under the assumption that the source matter is given by a non-rotating sphere of constant density, pressure and internal energy. For our calculation we write t...
gr-qc/0409023
Sayan Kar
Supratik Pal, Somnath Bharadwaj and Sayan Kar (IIT Kharagpur, India)
Can extra dimensional effects replace dark matter ?
10 pages, no figures, RevTex4
Phys.Lett. B609 (2005) 194-199
10.1016/j.physletb.2005.01.043
null
gr-qc astro-ph hep-th
null
In the braneworld scenario, the four dimensional effective Einstein equation has extra terms which arise from the embedding of the 3-brane in the bulk. We show that in this modified theory of gravity, it is possible to model observations of galaxy rotation curves and the X-ray profiles of clusters of galaxies, withou...
[ { "created": "Mon, 6 Sep 2004 09:51:36 GMT", "version": "v1" } ]
2009-11-10
[ [ "Pal", "Supratik", "", "IIT Kharagpur, India" ], [ "Bharadwaj", "Somnath", "", "IIT Kharagpur, India" ], [ "Kar", "Sayan", "", "IIT Kharagpur, India" ] ]
In the braneworld scenario, the four dimensional effective Einstein equation has extra terms which arise from the embedding of the 3-brane in the bulk. We show that in this modified theory of gravity, it is possible to model observations of galaxy rotation curves and the X-ray profiles of clusters of galaxies, without ...
1407.7742
Taeyoon Moon
Yun Soo Myung and Taeyoon Moon
Cosmological singleton gravity theory and dS/LCFT correspondence
1+18 pages, no figures, published version
JHEP10(2014)137
10.1007/JHEP10(2014)137
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the evolution of cosmological perturbations generated during de Sitter inflation in the singleton gravity theory. This theory is composed of a dipole ghost pair in addition to tensor. We obtain the singleton power spectra which show that the de Sitter/logarithmic conformal field theory (dS/LCFT) corresponden...
[ { "created": "Tue, 29 Jul 2014 14:42:57 GMT", "version": "v1" }, { "created": "Thu, 30 Oct 2014 02:26:24 GMT", "version": "v2" } ]
2015-06-22
[ [ "Myung", "Yun Soo", "" ], [ "Moon", "Taeyoon", "" ] ]
We study the evolution of cosmological perturbations generated during de Sitter inflation in the singleton gravity theory. This theory is composed of a dipole ghost pair in addition to tensor. We obtain the singleton power spectra which show that the de Sitter/logarithmic conformal field theory (dS/LCFT) correspondence...
0811.4316
Oleg Zaslavskii
Naresh Dadhich and Oleg B. Zaslavskii
Focusing versus defocusing properties of truly naked black holes
16 pages. To appear in IJMP D
Int.J.Mod.Phys.D18:1073-1084,2009
10.1142/S0218271809014959
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the properties of the congruence of null geodesics propagating near the so-called truly naked horizons (TNH) - objects having finite Kretschmann scalar but with diverging tidal acceleration for freely falling observers. The expansion of outgoing rays near the future horizon always tends to vanish for the non...
[ { "created": "Wed, 26 Nov 2008 14:06:15 GMT", "version": "v1" } ]
2009-08-25
[ [ "Dadhich", "Naresh", "" ], [ "Zaslavskii", "Oleg B.", "" ] ]
We study the properties of the congruence of null geodesics propagating near the so-called truly naked horizons (TNH) - objects having finite Kretschmann scalar but with diverging tidal acceleration for freely falling observers. The expansion of outgoing rays near the future horizon always tends to vanish for the non-e...
2010.13518
S. Q. Wu
Di Wu, Shuang-Qing Wu, Puxun Wu, Hongwei Yu
Aspects of the dyonic Kerr-Sen-AdS$_4$ black hole and its ultraspinning version
12 pages,2 figures, revtex4-1.cls. Title changed; six references newly-added
Phys. Rev. D 103, 044014 (2021)
10.1103/PhysRevD.103.044014
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We explore some (especially, thermodynamical) properties of the dyonic Kerr-Sen-AdS$_4$ black hole and its ultraspinning counterpart, and check whether or not both black holes satisfy the first law and Bekenstein-Smarr mass formulas. To this end, new Christodoulou-Ruffini-like squared-mass formulae for the usual dyon...
[ { "created": "Fri, 23 Oct 2020 01:42:40 GMT", "version": "v1" }, { "created": "Thu, 31 Dec 2020 05:45:29 GMT", "version": "v2" } ]
2021-02-16
[ [ "Wu", "Di", "" ], [ "Wu", "Shuang-Qing", "" ], [ "Wu", "Puxun", "" ], [ "Yu", "Hongwei", "" ] ]
We explore some (especially, thermodynamical) properties of the dyonic Kerr-Sen-AdS$_4$ black hole and its ultraspinning counterpart, and check whether or not both black holes satisfy the first law and Bekenstein-Smarr mass formulas. To this end, new Christodoulou-Ruffini-like squared-mass formulae for the usual dyonic...
1409.4918
Marcelo Disconzi
Marcelo M. Disconzi, Thomas W. Kephart, Robert J. Scherrer
A New Approach to Cosmological Bulk Viscosity
Text and references expanded. To appear in Physical Review D
Phys. Rev. D 91, 043532 (2015)
10.1103/PhysRevD.91.043532
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the cosmological consequences of an alternative to the standard expression for bulk viscosity, one which was proposed to avoid the propagation of superluminal signals without the necessity of extending the space of variables of the theory. The Friedmann equation is derived for this case, along with an expr...
[ { "created": "Wed, 17 Sep 2014 09:33:53 GMT", "version": "v1" }, { "created": "Fri, 6 Feb 2015 14:34:35 GMT", "version": "v2" } ]
2016-04-08
[ [ "Disconzi", "Marcelo M.", "" ], [ "Kephart", "Thomas W.", "" ], [ "Scherrer", "Robert J.", "" ] ]
We examine the cosmological consequences of an alternative to the standard expression for bulk viscosity, one which was proposed to avoid the propagation of superluminal signals without the necessity of extending the space of variables of the theory. The Friedmann equation is derived for this case, along with an expres...
1801.03382
Shaoqi Hou
Yungui Gong, Shaoqi Hou, Dicong Liang, Eleftherios Papantonopoulos
Gravitational waves in Einstein-{\ae}ther and generalized TeVeS theory after GW170817
33 pages, 7 figures
Phys. Rev. D 97, 084040 (2018)
10.1103/PhysRevD.97.084040
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we discuss the polarization contents of Einstein-\ae ther theory and the generalized tensor-vector-scalar (TeVeS) theory, as both theories have a normalized timelike vector field. We derive the linearized equations of motion around the flat spacetime background using the gauge-invariant variables to eas...
[ { "created": "Wed, 10 Jan 2018 14:08:36 GMT", "version": "v1" }, { "created": "Fri, 23 Mar 2018 12:10:16 GMT", "version": "v2" }, { "created": "Sun, 15 Apr 2018 13:21:49 GMT", "version": "v3" } ]
2018-04-25
[ [ "Gong", "Yungui", "" ], [ "Hou", "Shaoqi", "" ], [ "Liang", "Dicong", "" ], [ "Papantonopoulos", "Eleftherios", "" ] ]
In this work, we discuss the polarization contents of Einstein-\ae ther theory and the generalized tensor-vector-scalar (TeVeS) theory, as both theories have a normalized timelike vector field. We derive the linearized equations of motion around the flat spacetime background using the gauge-invariant variables to easil...
1508.05120
Christian Boehmer
Sebastian Bahamonde, Christian G. Boehmer, Matthew Wright
Modified teleparallel theories of gravity
9 pages, 1 figure; some typos fixed, slightly improved notation
Phys. Rev. D 92, 104042 (2015)
10.1103/PhysRevD.92.104042
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate modified theories of gravity in the context of teleparallel geometries. It is well known that modified gravity models based on the torsion scalar are not invariant under local Lorentz transformations while modifications based on the Ricci scalar are. This motivates the study of a model depending on the...
[ { "created": "Thu, 20 Aug 2015 20:50:36 GMT", "version": "v1" }, { "created": "Thu, 12 Nov 2015 10:29:12 GMT", "version": "v2" } ]
2015-11-30
[ [ "Bahamonde", "Sebastian", "" ], [ "Boehmer", "Christian G.", "" ], [ "Wright", "Matthew", "" ] ]
We investigate modified theories of gravity in the context of teleparallel geometries. It is well known that modified gravity models based on the torsion scalar are not invariant under local Lorentz transformations while modifications based on the Ricci scalar are. This motivates the study of a model depending on the t...
gr-qc/0112077
Christos G. Tsagas
Christos G Tsagas (Univ. of Portsmouth/Univ. of Cape Town)
Geometrical Aspects of Cosmic Magnetic Fields
To appear in proceedings of the 2nd Hellenic Cosmology Workshop, Athens 2001 (Kluwer-ASSL series)
null
10.1007/978-94-010-0622-4_4
null
gr-qc astro-ph
null
We discuss how the vector nature of magnetic fields, and the geometrical interpretation of gravity introduced by general relativity, lead to a special coupling between magnetism and spacetime curvature. This magneto-geometrical interaction effectively transfers the tension properties of the field into the spacetime f...
[ { "created": "Sat, 29 Dec 2001 12:16:06 GMT", "version": "v1" } ]
2017-01-25
[ [ "Tsagas", "Christos G", "", "Univ. of Portsmouth/Univ. of Cape Town" ] ]
We discuss how the vector nature of magnetic fields, and the geometrical interpretation of gravity introduced by general relativity, lead to a special coupling between magnetism and spacetime curvature. This magneto-geometrical interaction effectively transfers the tension properties of the field into the spacetime fab...
2304.12407
Guillermo Palma Prof. Dr.
Norman Cruz, Gabriel Gomez, Esteban Gonzalez, Guillermo Palma and Angel Rincon
Exploring Models of Running Vacuum Energy with Viscous Dark Matter from a Dynamical System Perspective
26 pages and 13 figures
null
null
null
gr-qc astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Running vacuum models and viscous dark matter scenarios beyond perfect fluid idealization are two appealing theoretical strategies that have been separately studied as alternatives to solve some problems rooted in the $\Lambda$CDM cosmological model. In this paper, we combine these two notions in a single cosmologica...
[ { "created": "Mon, 24 Apr 2023 19:38:04 GMT", "version": "v1" } ]
2023-04-26
[ [ "Cruz", "Norman", "" ], [ "Gomez", "Gabriel", "" ], [ "Gonzalez", "Esteban", "" ], [ "Palma", "Guillermo", "" ], [ "Rincon", "Angel", "" ] ]
Running vacuum models and viscous dark matter scenarios beyond perfect fluid idealization are two appealing theoretical strategies that have been separately studied as alternatives to solve some problems rooted in the $\Lambda$CDM cosmological model. In this paper, we combine these two notions in a single cosmological ...