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1909.02862
Muhammad Sharif
M. Sharif and Qanitah Ama-Tul-Mughani
Greybody Factor for a Rotating Bardeen Black Hole
18 pages, 4 figures, to appear in EPJP
Eur. Phys. J. Plus 134(2019)616
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we formulate an analytical expression of greybody factor in the context of rotating Bardeen black hole which is valid in low energy and low angular momentum region. Primarily, we analyze the profile of effective potential which originates the absorption probability. We then derive two asymptotic soluti...
[ { "created": "Thu, 5 Sep 2019 03:44:58 GMT", "version": "v1" } ]
2019-12-09
[ [ "Sharif", "M.", "" ], [ "Ama-Tul-Mughani", "Qanitah", "" ] ]
In this paper, we formulate an analytical expression of greybody factor in the context of rotating Bardeen black hole which is valid in low energy and low angular momentum region. Primarily, we analyze the profile of effective potential which originates the absorption probability. We then derive two asymptotic solution...
1706.07657
Ghulam Abbas
G. Abbas, M.S. Khan, Zahid Ahmad and M. Zubair
Higher Dimensional Inhomogeneous Perfect Fluid Collapse in \emph{f(R)} Gravity
17 Pages, to appear in European Physical Journal C
null
10.1140/epjc/s10052-017-5003-6
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper is about the $n+2$-dimensional gravitational contraction of inhomogeneous fluid without heat flux in the framework of $f(R)$ metric theory of gravity. Matching conditions for two regions of a star has been derived by using the Darmois junction conditions. For the analytic solution of equations of motion in...
[ { "created": "Wed, 21 Jun 2017 05:13:56 GMT", "version": "v1" } ]
2017-08-02
[ [ "Abbas", "G.", "" ], [ "Khan", "M. S.", "" ], [ "Ahmad", "Zahid", "" ], [ "Zubair", "M.", "" ] ]
This paper is about the $n+2$-dimensional gravitational contraction of inhomogeneous fluid without heat flux in the framework of $f(R)$ metric theory of gravity. Matching conditions for two regions of a star has been derived by using the Darmois junction conditions. For the analytic solution of equations of motion in m...
0901.3926
Francisco Lobo
Tiberiu Harko, Zolt\'an Kov\'acs, Francisco S. N. Lobo
Thin accretion disks in stationary axisymmetric wormhole spacetimes
12 pages, 26 figures. V2: minor corrections and references added; to appear in Physical Review D. V3: typos corrected, matches published version
Phys.Rev.D79:064001,2009
10.1103/PhysRevD.79.064001
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study the physical properties and the equilibrium thermal radiation emission characteristics of matter forming thin accretion disks in stationary axially symmetric wormhole spacetimes. The thin disk models are constructed by taking different values of the wormhole's angular velocity, and the time av...
[ { "created": "Sun, 25 Jan 2009 22:26:45 GMT", "version": "v1" }, { "created": "Mon, 9 Feb 2009 22:07:48 GMT", "version": "v2" }, { "created": "Mon, 2 Mar 2009 21:47:06 GMT", "version": "v3" } ]
2009-03-02
[ [ "Harko", "Tiberiu", "" ], [ "Kovács", "Zoltán", "" ], [ "Lobo", "Francisco S. N.", "" ] ]
In this paper, we study the physical properties and the equilibrium thermal radiation emission characteristics of matter forming thin accretion disks in stationary axially symmetric wormhole spacetimes. The thin disk models are constructed by taking different values of the wormhole's angular velocity, and the time aver...
2011.04120
Ren Tsuda
Ren Tsuda, Takanori Fujiwara
Oscillating 4-Polytopal Universe in Regge Calculus
24 pages, 9 figures. arXiv admin note: text overlap with arXiv:1612.06536
Prog. Theor. Exp. Phys. 2021, 083E01
10.1093/ptep/ptab079
null
gr-qc hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The discretized closed Friedmann-Lema\^itre-Robertson-Walker (FLRW) universe with positive cosmological constant is investigated by Regge calculus. According to the Collins-Williams formalism, a hyperspherical Cauchy surface is replaced with regular 4-polytopes. Numerical solutions to the Regge equations approximate ...
[ { "created": "Mon, 9 Nov 2020 00:34:21 GMT", "version": "v1" }, { "created": "Sun, 17 Oct 2021 13:33:12 GMT", "version": "v2" } ]
2021-10-25
[ [ "Tsuda", "Ren", "" ], [ "Fujiwara", "Takanori", "" ] ]
The discretized closed Friedmann-Lema\^itre-Robertson-Walker (FLRW) universe with positive cosmological constant is investigated by Regge calculus. According to the Collins-Williams formalism, a hyperspherical Cauchy surface is replaced with regular 4-polytopes. Numerical solutions to the Regge equations approximate we...
gr-qc/0703036
Mamdouh Wanas
M.I.Wanas
On the Relation between Mass and Charge: A Pure Geometric Approach
15 pages, LaTeX file
Int.J.Geom.Meth.Mod.Phys.4:373-388,2007
10.1142/S0219887807002144
null
gr-qc
null
A new solution of the field equations of the generalized field theory, constructed by Mikhail and Wanas in 1977, has been obtained. The geometric structure used, in the present application, is an absolute parallelism (AP)-space with spherical symmetry (type FIGI). The solution obtained represents a generalized fiel...
[ { "created": "Tue, 6 Mar 2007 13:48:43 GMT", "version": "v1" } ]
2008-11-26
[ [ "Wanas", "M. I.", "" ] ]
A new solution of the field equations of the generalized field theory, constructed by Mikhail and Wanas in 1977, has been obtained. The geometric structure used, in the present application, is an absolute parallelism (AP)-space with spherical symmetry (type FIGI). The solution obtained represents a generalized field ou...
1010.1578
Manasse R. Mbonye
Manasse R. Mbonye, Nicholas Battista and Benjamin Farr
Time evolution of a non-singular primordial black hole
To appear in Int. J. Mod. Phys. D
null
10.1142/S0218271812500277
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
There is growing notion that black holes may not contain curvature singularities (and that indeed nature in general may abhor such spacetime defects). This notion could have implications on our understanding of the evolution of primordial black holes (PBHs) and possibly on their contribution to cosmic energy. This pa...
[ { "created": "Fri, 8 Oct 2010 01:22:07 GMT", "version": "v1" } ]
2015-05-20
[ [ "Mbonye", "Manasse R.", "" ], [ "Battista", "Nicholas", "" ], [ "Farr", "Benjamin", "" ] ]
There is growing notion that black holes may not contain curvature singularities (and that indeed nature in general may abhor such spacetime defects). This notion could have implications on our understanding of the evolution of primordial black holes (PBHs) and possibly on their contribution to cosmic energy. This pape...
1907.07490
Yen Chin Ong
Yen Chin Ong, Yuan Yao
Charged Particle Production Rate from Cosmic Censorship in Dilaton Black Hole Spacetimes
13 pages, 6 figures, Fig.1 improved, typos fixed; published version
JHEP 10 (2019) 129
10.1007/JHEP10(2019)129
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hiscock and Weems showed that under Hawking evaporation, an isolated asymptotically flat Reissner-Nordstrom (RN) black hole evolves in a surprising manner: if it starts with a relatively small value of charge-to-mass ratio Q/M, then said value will temporarily increase along its evolutionary path, before finally decr...
[ { "created": "Wed, 17 Jul 2019 13:11:05 GMT", "version": "v1" }, { "created": "Wed, 23 Oct 2019 12:47:11 GMT", "version": "v2" } ]
2019-10-24
[ [ "Ong", "Yen Chin", "" ], [ "Yao", "Yuan", "" ] ]
Hiscock and Weems showed that under Hawking evaporation, an isolated asymptotically flat Reissner-Nordstrom (RN) black hole evolves in a surprising manner: if it starts with a relatively small value of charge-to-mass ratio Q/M, then said value will temporarily increase along its evolutionary path, before finally decrea...
gr-qc/9207005
null
Ted Jacobson and Joseph D. Romano
Degenerate Extensions of General Relativity
9 pages
Class.Quant.Grav.9:L119-L124,1992
10.1088/0264-9381/9/9/003
UMDGR-92-154
gr-qc
null
General relativity has previously been extended to incorporate degenerate metrics using Ashtekar's hamiltonian formulation of the theory. In this letter, we show that a natural alternative choice for the form of the hamiltonian constraints leads to a theory which agrees with GR for non-degenerate metrics, but differs...
[ { "created": "Thu, 23 Jul 1992 15:51:00 GMT", "version": "v1" } ]
2010-04-06
[ [ "Jacobson", "Ted", "" ], [ "Romano", "Joseph D.", "" ] ]
General relativity has previously been extended to incorporate degenerate metrics using Ashtekar's hamiltonian formulation of the theory. In this letter, we show that a natural alternative choice for the form of the hamiltonian constraints leads to a theory which agrees with GR for non-degenerate metrics, but differs i...
1905.06702
Kubantai Ernazarov
K. K. Ernazarov
Stable exponential cosmological solutions with three factor spaces in $(1+ 3 + 3 +k)$-dimensional Einstein-Gauss-Bonnet model with a $\Lambda$-term
17 pages, Latex, no figures
null
10.1142/S0217732319501116
IGC-PFUR/2019/03-02
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a $(7 + k)$-dimensional Einstein-Gauss-Bonnet model with the cosmological $\Lambda$-term. A cosmological model with three factor spaces of dimensions $3$, $3$ and $k$, $k > 2$ is considered. Exact stable solutions with three (non-coinciding) Hubble-like parameters in this model are obtained. Some examples...
[ { "created": "Thu, 16 May 2019 12:51:12 GMT", "version": "v1" } ]
2019-05-22
[ [ "Ernazarov", "K. K.", "" ] ]
We consider a $(7 + k)$-dimensional Einstein-Gauss-Bonnet model with the cosmological $\Lambda$-term. A cosmological model with three factor spaces of dimensions $3$, $3$ and $k$, $k > 2$ is considered. Exact stable solutions with three (non-coinciding) Hubble-like parameters in this model are obtained. Some examples o...
1209.4501
Alexander Zhuk
Maxim Eingorn, Seyed Hossein Fakhr and Alexander Zhuk
Kaluza-Klein models with spherical compactification: observational constraints and possible examples
18 pages. Combined (with arXiv:1207.4339) version accepted by CQG
Class.Quant.Grav. 30 (2013) 115004
10.1088/0264-9381/30/11/115004
null
gr-qc astro-ph.HE hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider Kaluza-Klein models with background matter in the form of a multicomponent perfect fluid. This matter provides spherical compactification of the internal space with an arbitrary number of dimensions. The gravitating source has the dust-like equation of state in the external/our space and an arbitrary equa...
[ { "created": "Thu, 20 Sep 2012 11:52:27 GMT", "version": "v1" }, { "created": "Mon, 22 Apr 2013 19:44:59 GMT", "version": "v2" } ]
2013-05-08
[ [ "Eingorn", "Maxim", "" ], [ "Fakhr", "Seyed Hossein", "" ], [ "Zhuk", "Alexander", "" ] ]
We consider Kaluza-Klein models with background matter in the form of a multicomponent perfect fluid. This matter provides spherical compactification of the internal space with an arbitrary number of dimensions. The gravitating source has the dust-like equation of state in the external/our space and an arbitrary equati...
2209.09781
Vasilis Oikonomou
V.K. Oikonomou
Amplification of the Primordial Gravitational Waves Energy Spectrum by a Kinetic Scalar in $F(R)$ Gravity
Astroparticle Physics in press
null
10.1016/j.astropartphys.2022.102777
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we consider a combined theoretical framework comprised by $F(R)$ gravity and a kinetic scalar field. The kinetic energy of the scalar field dominates over its potential for all cosmic times, and the kinetic scalar potential is chosen to be small and non-trivial. In this case, we show that the primordial ...
[ { "created": "Tue, 20 Sep 2022 15:05:58 GMT", "version": "v1" } ]
2022-10-12
[ [ "Oikonomou", "V. K.", "" ] ]
In this work we consider a combined theoretical framework comprised by $F(R)$ gravity and a kinetic scalar field. The kinetic energy of the scalar field dominates over its potential for all cosmic times, and the kinetic scalar potential is chosen to be small and non-trivial. In this case, we show that the primordial gr...
gr-qc/9311016
Jack Gegenberg
H. Zaidi, J. Gegenberg
Quantum Bubble Dynamics in 2+1 Dimensional Gravity I: Geometrodynamic Approach
14 pages, Latex (\cite typos corrected)
Phys.Lett.B328:22-27,1994
10.1016/0370-2693(94)90422-7
null
gr-qc hep-th
null
The Dirac quantization of a 2+1 dimensional bubble is performed. The bubble consists of a string forming a boundary between two regions of space-time with distinct geometries. The ADM constraints are solved and the coupling to the string is introduced through the boundary conditions. The wave functional is obtained a...
[ { "created": "Tue, 9 Nov 1993 18:49:37 GMT", "version": "v1" }, { "created": "Wed, 10 Nov 1993 13:53:58 GMT", "version": "v2" } ]
2010-11-01
[ [ "Zaidi", "H.", "" ], [ "Gegenberg", "J.", "" ] ]
The Dirac quantization of a 2+1 dimensional bubble is performed. The bubble consists of a string forming a boundary between two regions of space-time with distinct geometries. The ADM constraints are solved and the coupling to the string is introduced through the boundary conditions. The wave functional is obtained and...
1712.05149
Soumya Chakrabarti
Soumya Chakrabarti
Collapsing spherical star in Scalar-Einstein-Gauss-Bonnet gravity with a quadratic coupling
To Appear in EPJC
null
10.1140/epjc/s10052-018-5798-9
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the evolution of a self interacting scalar field in Einstein-Gauss-Bonnet theory in four dimension where the scalar field couples non minimally with the Gauss-Bonnet term. Considering a polynomial coupling of the scalar field with the Gauss-Bonnet term, a self-interaction potential and an additional perfect ...
[ { "created": "Thu, 14 Dec 2017 10:19:15 GMT", "version": "v1" }, { "created": "Tue, 10 Apr 2018 17:36:11 GMT", "version": "v2" } ]
2018-05-09
[ [ "Chakrabarti", "Soumya", "" ] ]
We study the evolution of a self interacting scalar field in Einstein-Gauss-Bonnet theory in four dimension where the scalar field couples non minimally with the Gauss-Bonnet term. Considering a polynomial coupling of the scalar field with the Gauss-Bonnet term, a self-interaction potential and an additional perfect fl...
gr-qc/0304013
Ralf Lehnert
Ralf Lehnert
Threshold analyses and Lorentz violation
9 pages
Phys.Rev.D68:085003,2003
10.1103/PhysRevD.68.085003
null
gr-qc
null
In the context of threshold investigations of Lorentz violation, we discuss the fundamental principle of coordinate invariance, the role of an effective dynamical framework, and the conditions of positivity and causality. Our analysis excludes a variety of previously considered Lorentz-breaking parameters and opens a...
[ { "created": "Wed, 2 Apr 2003 14:52:55 GMT", "version": "v1" } ]
2008-11-26
[ [ "Lehnert", "Ralf", "" ] ]
In the context of threshold investigations of Lorentz violation, we discuss the fundamental principle of coordinate invariance, the role of an effective dynamical framework, and the conditions of positivity and causality. Our analysis excludes a variety of previously considered Lorentz-breaking parameters and opens an ...
1307.0594
Sergey Kozyrev
Sergey N. Andrianov, Rinat A. Daishev, Sergey M. Kozyrev
Klein-Gordon equation for a particles in brane model
8 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Brane model of universe is considered for a free particle. Conservation laws on the brane are obtained using the symmetry properties of the brane. Equation of motion is derived for a particle using variation principle from these conservation laws. This equation has a form of Klein-Gordon equation. Comparison of squar...
[ { "created": "Tue, 2 Jul 2013 06:13:11 GMT", "version": "v1" } ]
2013-07-03
[ [ "Andrianov", "Sergey N.", "" ], [ "Daishev", "Rinat A.", "" ], [ "Kozyrev", "Sergey M.", "" ] ]
Brane model of universe is considered for a free particle. Conservation laws on the brane are obtained using the symmetry properties of the brane. Equation of motion is derived for a particle using variation principle from these conservation laws. This equation has a form of Klein-Gordon equation. Comparison of squared...
2204.13161
Alberto Escalante
Alberto Escalante and J. Aldair Pantoja-Gonzalez (Puebla U., Inst. Fis.)
Canonical analysis for Chern-Simons modification of general relativity
null
null
10.1016/j.aop.2023.169246
null
gr-qc math-ph math.MP
http://creativecommons.org/publicdomain/zero/1.0/
By using the Gitman-Lyakhovich-Tyutin canonical analysis for higher-order theories a four-dimensional Chern-Simons modification of general relativity is analyzed. The counting of physical degrees of freedom, the symmetries, and the fundamental Dirac brackets are reported. Additionally, we report the complete structur...
[ { "created": "Wed, 27 Apr 2022 19:53:53 GMT", "version": "v1" }, { "created": "Wed, 19 Oct 2022 00:50:09 GMT", "version": "v2" }, { "created": "Thu, 26 Jan 2023 00:44:04 GMT", "version": "v3" } ]
2023-03-22
[ [ "Escalante", "Alberto", "", "Puebla U., Inst.\n Fis." ], [ "Pantoja-Gonzalez", "J. Aldair", "", "Puebla U., Inst.\n Fis." ] ]
By using the Gitman-Lyakhovich-Tyutin canonical analysis for higher-order theories a four-dimensional Chern-Simons modification of general relativity is analyzed. The counting of physical degrees of freedom, the symmetries, and the fundamental Dirac brackets are reported. Additionally, we report the complete structure ...
1404.3144
Everton Murilo Carvalho Abreu
Everton M. C. Abreu and N\'elio Sasaki
Rotating traversable wormholes in a noncommutative space and the energy conditions
10 pages. Pre-print format. arXiv admin note: substantial text overlap with arXiv:1207.7130
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is a very well known fact that the energy conditions concerning traversable wormhole (WH) solutions of Einstein equations are violated. Consequently, attempts to avoid the violation of the energy conditions constitutes one of the main areas of research in WH physics. On the other hand, the current literature shows...
[ { "created": "Wed, 9 Apr 2014 20:29:09 GMT", "version": "v1" } ]
2014-04-14
[ [ "Abreu", "Everton M. C.", "" ], [ "Sasaki", "Nélio", "" ] ]
It is a very well known fact that the energy conditions concerning traversable wormhole (WH) solutions of Einstein equations are violated. Consequently, attempts to avoid the violation of the energy conditions constitutes one of the main areas of research in WH physics. On the other hand, the current literature shows u...
gr-qc/0006015
Garcia
L.C.Garcia de Andrade
Extended Thermodynamics to Einstein-Cartan Cosmology
Latex file
null
null
null
gr-qc
null
The thermodynamics is extented to spacetimes with spin-torsion density.Impplications to Einstein-Cartan-de Sitter inflationary phases are discussed.A relation between the spin-torsion density,entropy and temperature is presented.A lower limit for the radius of the Universe may be obtained from the spin-torsion densit...
[ { "created": "Sun, 4 Jun 2000 01:02:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "de Andrade", "L. C. Garcia", "" ] ]
The thermodynamics is extented to spacetimes with spin-torsion density.Impplications to Einstein-Cartan-de Sitter inflationary phases are discussed.A relation between the spin-torsion density,entropy and temperature is presented.A lower limit for the radius of the Universe may be obtained from the spin-torsion density ...
gr-qc/0304067
Roy Maartens
Burin Gumjudpai, Roy Maartens (Portsmouth), Christopher Gordon (Cambridge)
Density perturbations in a brane-world universe with dark radiation
10 pages, 4 figures
Class.Quant.Grav. 20 (2003) 3295
10.1088/0264-9381/20/15/302
null
gr-qc astro-ph hep-th
null
We investigate the effects on cosmological density perturbations of dark radiation in a Randall-Sundrum 2 type brane-world. Dark radiation in the background is limited by observational constraints to be a small fraction of the radiation energy density, but it has an interesting qualitative effect in the radiation era...
[ { "created": "Sat, 19 Apr 2003 11:23:52 GMT", "version": "v1" } ]
2009-11-10
[ [ "Gumjudpai", "Burin", "", "Portsmouth" ], [ "Maartens", "Roy", "", "Portsmouth" ], [ "Gordon", "Christopher", "", "Cambridge" ] ]
We investigate the effects on cosmological density perturbations of dark radiation in a Randall-Sundrum 2 type brane-world. Dark radiation in the background is limited by observational constraints to be a small fraction of the radiation energy density, but it has an interesting qualitative effect in the radiation era. ...
2111.13882
Zhi-Chao Zhao
Zhi-Chao Zhao, Xiaolin Liu, Zhoujian Cao, and Xiaokai He
Gravitational wave memory of the binary black hole events in GWTC-2
10 pages, 11 figures
null
10.1103/PhysRevD.104.064056
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
Gravitational wave (GW) memory is an important prediction of general relativity. Existing works on the GW memory detection focus on the waveform analysis. It is hard for waveform analysis method to detect the GW memory due to its quasi-direct current behavior and weakness. We implement a completely different scheme i...
[ { "created": "Sat, 27 Nov 2021 12:38:51 GMT", "version": "v1" } ]
2021-11-30
[ [ "Zhao", "Zhi-Chao", "" ], [ "Liu", "Xiaolin", "" ], [ "Cao", "Zhoujian", "" ], [ "He", "Xiaokai", "" ] ]
Gravitational wave (GW) memory is an important prediction of general relativity. Existing works on the GW memory detection focus on the waveform analysis. It is hard for waveform analysis method to detect the GW memory due to its quasi-direct current behavior and weakness. We implement a completely different scheme in ...
2005.02225
Alexander Zhidenko
R. A. Konoplya and A. Zhidenko
4D Einstein-Lovelock black holes: Hierarchy of orders in curvature
8 pages, 1 ancillary Mathematica(R) notebook
Phys. Lett. B807 (2020) 135607
10.1016/j.physletb.2020.135607
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Einstein-Lovelock theory contains an infinite series of corrections to the Einstein term with an increasing power of the curvature. It is well-known that for large black holes the lowest (Gauss-Bonnet) term is the dominant one, while for smaller black holes higher curvature corrections become important. We will s...
[ { "created": "Sun, 3 May 2020 14:34:11 GMT", "version": "v1" }, { "created": "Fri, 10 Jul 2020 15:45:26 GMT", "version": "v2" } ]
2020-07-13
[ [ "Konoplya", "R. A.", "" ], [ "Zhidenko", "A.", "" ] ]
The Einstein-Lovelock theory contains an infinite series of corrections to the Einstein term with an increasing power of the curvature. It is well-known that for large black holes the lowest (Gauss-Bonnet) term is the dominant one, while for smaller black holes higher curvature corrections become important. We will sho...
2310.09464
Emanuel Costa
Emanuel Wallison de Oliveira Costa, Raheleh Jalalzadeh, Pedro Felix da Silva J\'unior, Seyed Meraj Mousavi Rasouli, and Shahram Jalalzadeh
Estimated Age of the Universe in Fractional Cosmology
24 pages, 9 figures
Fractal Fract. 7 (2023) 854
10.3390/fractalfract7120854
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
Our proposed cosmological framework, which is based on fractional quantum cosmology, aims to address the issue of synchronicity in the age of the universe. To achieve this, we have developed a new fractional $\Lambda$CDM cosmological model. We obtained the necessary formalism by obtaining the fractional Hamiltonian c...
[ { "created": "Sat, 14 Oct 2023 01:30:15 GMT", "version": "v1" }, { "created": "Thu, 30 Nov 2023 16:58:07 GMT", "version": "v2" }, { "created": "Mon, 5 Aug 2024 18:05:01 GMT", "version": "v3" } ]
2024-08-07
[ [ "Costa", "Emanuel Wallison de Oliveira", "" ], [ "Jalalzadeh", "Raheleh", "" ], [ "Júnior", "Pedro Felix da Silva", "" ], [ "Rasouli", "Seyed Meraj Mousavi", "" ], [ "Jalalzadeh", "Shahram", "" ] ]
Our proposed cosmological framework, which is based on fractional quantum cosmology, aims to address the issue of synchronicity in the age of the universe. To achieve this, we have developed a new fractional $\Lambda$CDM cosmological model. We obtained the necessary formalism by obtaining the fractional Hamiltonian con...
1911.05311
Mandar Patil
Harsha Miriam Reji, Mandar Patil
Gravitational lensing signature of matter distribution around Schwarzschild black hole
42 pages, 7 figures, published in PRD
Phys. Rev. D 101, 064051 (2020)
10.1103/PhysRevD.101.064051
null
gr-qc astro-ph.GA hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we focus on the situation where a significant amount of matter could be located close to the event horizon of the central black hole and how it affects the gravitational lensing signal. We consider a simple toy model where the matter is concentrated in the rather small region between the inner photon sp...
[ { "created": "Wed, 13 Nov 2019 06:11:00 GMT", "version": "v1" }, { "created": "Sat, 16 Nov 2019 05:01:39 GMT", "version": "v2" }, { "created": "Wed, 26 Feb 2020 09:06:45 GMT", "version": "v3" }, { "created": "Mon, 27 Apr 2020 15:21:43 GMT", "version": "v4" } ]
2020-04-28
[ [ "Reji", "Harsha Miriam", "" ], [ "Patil", "Mandar", "" ] ]
In this work, we focus on the situation where a significant amount of matter could be located close to the event horizon of the central black hole and how it affects the gravitational lensing signal. We consider a simple toy model where the matter is concentrated in the rather small region between the inner photon sphe...
2006.10614
Gabriele Barca
Eleonora Giovannetti, Gabriele Barca, Federico Mandini, Giovanni Montani
Polymer dynamics of isotropic universe in Ashtekar and in volume variables
16 pages, 6 figures
null
10.3390/universe8060302
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We analyze the semiclassical and quantum polymer dynamics of the isotropic Universe in terms of both the standard Ashtekar-Barbero-Immirzi connection and its conjugate momentum and also of the new generalized coordinate conjugate to the Universe volume. We study the properties of the resulting bouncing cosmology that...
[ { "created": "Thu, 18 Jun 2020 15:35:20 GMT", "version": "v1" }, { "created": "Mon, 10 Aug 2020 12:16:10 GMT", "version": "v2" }, { "created": "Tue, 16 Mar 2021 13:03:01 GMT", "version": "v3" }, { "created": "Tue, 22 Jun 2021 13:14:11 GMT", "version": "v4" }, { "c...
2022-06-01
[ [ "Giovannetti", "Eleonora", "" ], [ "Barca", "Gabriele", "" ], [ "Mandini", "Federico", "" ], [ "Montani", "Giovanni", "" ] ]
We analyze the semiclassical and quantum polymer dynamics of the isotropic Universe in terms of both the standard Ashtekar-Barbero-Immirzi connection and its conjugate momentum and also of the new generalized coordinate conjugate to the Universe volume. We study the properties of the resulting bouncing cosmology that e...
gr-qc/0504087
Elizabeth Winstanley
Anne-Marie Barlow, Daniel Doherty and Elizabeth Winstanley
Thermodynamics of de Sitter black holes with a conformally coupled scalar field
9 pages, 2 figures, REVTEX. Minor changes, accepted for publication in Phys. Rev. D
Phys.Rev.D72:024008,2005
10.1103/PhysRevD.72.024008
null
gr-qc hep-th
null
We study the thermodynamics of de Sitter black holes with a conformally coupled scalar field. The geometry is that of the ``lukewarm'' Reissner-Nordstrom-de Sitter black holes, with the event and cosmological horizons at the same temperature. This means that the region between the event and cosmological horizons can ...
[ { "created": "Tue, 19 Apr 2005 18:31:41 GMT", "version": "v1" }, { "created": "Wed, 29 Jun 2005 09:43:36 GMT", "version": "v2" } ]
2011-07-19
[ [ "Barlow", "Anne-Marie", "" ], [ "Doherty", "Daniel", "" ], [ "Winstanley", "Elizabeth", "" ] ]
We study the thermodynamics of de Sitter black holes with a conformally coupled scalar field. The geometry is that of the ``lukewarm'' Reissner-Nordstrom-de Sitter black holes, with the event and cosmological horizons at the same temperature. This means that the region between the event and cosmological horizons can fo...
2302.03846
Xi-Long Fan
Yang Jiang, Xi-Long Fan and Qing-Guo Huang
Search for stochastic gravitational-wave background from string cosmology with Advanced LIGO and Virgo's O1$\sim$O3 data
Accepted by Journal of Cosmology and Astroparticle Physics
null
10.1088/1475-7516/2023/04/024
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
String cosmology models predict a relic background of gravitational-wave (GW) radiation in the early universe. The GW energy spectrum of radiated power increases rapidly with the frequency, and therefore it becomes a potential and meaningful observation object for high-frequency GW detector. We focus on the stochasti...
[ { "created": "Wed, 8 Feb 2023 02:41:31 GMT", "version": "v1" }, { "created": "Tue, 4 Apr 2023 05:39:34 GMT", "version": "v2" } ]
2023-04-19
[ [ "Jiang", "Yang", "" ], [ "Fan", "Xi-Long", "" ], [ "Huang", "Qing-Guo", "" ] ]
String cosmology models predict a relic background of gravitational-wave (GW) radiation in the early universe. The GW energy spectrum of radiated power increases rapidly with the frequency, and therefore it becomes a potential and meaningful observation object for high-frequency GW detector. We focus on the stochastic ...
gr-qc/0605041
James Lindesay
James Lindesay
Thermal Evolution of a Dual Scale Cosmology
8 pages
null
null
null
gr-qc
null
Previous work developed a space-time metric with two cosmological scales; one that conveniently describes the classical evolution of the dynamics, and the other describing a scale associated with macroscopic quantum aspects like vacuum energy. The present work expands upon the dynamics of these scales to demonstrate ...
[ { "created": "Sun, 7 May 2006 20:33:41 GMT", "version": "v1" }, { "created": "Tue, 9 May 2006 02:31:30 GMT", "version": "v2" } ]
2007-05-23
[ [ "Lindesay", "James", "" ] ]
Previous work developed a space-time metric with two cosmological scales; one that conveniently describes the classical evolution of the dynamics, and the other describing a scale associated with macroscopic quantum aspects like vacuum energy. The present work expands upon the dynamics of these scales to demonstrate th...
2408.00832
James Alvey
James Alvey, Uddipta Bhardwaj, Valerie Domcke, Mauro Pieroni and Christoph Weniger
Leveraging Time-Dependent Instrumental Noise for LISA SGWB Analysis
12 pages, 5 figures. saqqara available at https://github.com/peregrine-gw/saqqara, GW_response available at https://github.com/Mauropieroni/GW_response
null
null
CERN-TH-2024-127
gr-qc astro-ph.CO astro-ph.IM hep-ph
http://creativecommons.org/licenses/by/4.0/
Variations in the instrumental noise of the Laser Interferometer Space Antenna (LISA) over time are expected as a result of e.g. scheduled satellite operations or unscheduled glitches. We demonstrate that these fluctuations can be leveraged to improve the sensitivity to stochastic gravitational wave backgrounds (SGWB...
[ { "created": "Thu, 1 Aug 2024 18:00:01 GMT", "version": "v1" } ]
2024-08-05
[ [ "Alvey", "James", "" ], [ "Bhardwaj", "Uddipta", "" ], [ "Domcke", "Valerie", "" ], [ "Pieroni", "Mauro", "" ], [ "Weniger", "Christoph", "" ] ]
Variations in the instrumental noise of the Laser Interferometer Space Antenna (LISA) over time are expected as a result of e.g. scheduled satellite operations or unscheduled glitches. We demonstrate that these fluctuations can be leveraged to improve the sensitivity to stochastic gravitational wave backgrounds (SGWBs)...
1109.5837
Naiereh Elyasi
Naiereh Elyasi and Nasser Boroojerdian
Application of Lie algebroid structures to unification of Einstein and yang-mills field equations
null
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Yang-mills field equations describe new forces in the context of Lie groups and principle bundles. It is of interest to know if the new forces and gravitation can be described in the context of algebroids. This work was intended as an attempt to answer last question. The basic idea is to construct Einstein field equa...
[ { "created": "Tue, 27 Sep 2011 11:10:42 GMT", "version": "v1" }, { "created": "Tue, 4 Oct 2011 07:00:04 GMT", "version": "v2" } ]
2011-10-05
[ [ "Elyasi", "Naiereh", "" ], [ "Boroojerdian", "Nasser", "" ] ]
Yang-mills field equations describe new forces in the context of Lie groups and principle bundles. It is of interest to know if the new forces and gravitation can be described in the context of algebroids. This work was intended as an attempt to answer last question. The basic idea is to construct Einstein field equati...
1208.3731
Valerio Faraoni
Valerio Faraoni and Andres F. Zambrano Moreno (Bishop's University)
Interpreting the conformal cousin of the Husain-Martinez-Nunez solution
7 pages, 2 figures. Removed a subsection which referred to an empty subclass of solutions, added discussion, a special (static) case, and references
null
10.1103/PhysRevD.86.084044
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A 2-parameter inhomogeneous cosmology in Brans-Dicke theory, obtained by conformally transforming the Husain-Martinez-Nunez (HMN) scalar field solution of the Einstein equations is studied and interpreted physically. According to the values of the parameters it describes a wormhole, a naked singularity, or else a spa...
[ { "created": "Sat, 18 Aug 2012 08:49:48 GMT", "version": "v1" }, { "created": "Wed, 3 Oct 2012 22:51:47 GMT", "version": "v2" } ]
2013-05-30
[ [ "Faraoni", "Valerio", "", "Bishop's University" ], [ "Moreno", "Andres F. Zambrano", "", "Bishop's University" ] ]
A 2-parameter inhomogeneous cosmology in Brans-Dicke theory, obtained by conformally transforming the Husain-Martinez-Nunez (HMN) scalar field solution of the Einstein equations is studied and interpreted physically. According to the values of the parameters it describes a wormhole, a naked singularity, or else a space...
1305.5512
Farkhat Zaripov Shaukatovich
Farkhat Zaripov
Modified equations in the theory of induced gravity. Solution to the cosmological constant problem
21 pages, 13 Postscript figures
Astrophysics and Space Science : Volume 352, Issue 1 (2014), Page 289-305
10.1007/s10509-014-1909-8
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This research is an extension of the author's article \cite{zar}, in which conformally invariant generalization of string theory was suggested to higher-dimensional objects. Special cases of the proposed theory are Einstein's theory of gravity and string theory. This work is devoted to the formation of self-consisten...
[ { "created": "Thu, 23 May 2013 18:36:58 GMT", "version": "v1" }, { "created": "Fri, 10 Oct 2014 15:30:00 GMT", "version": "v2" } ]
2014-10-13
[ [ "Zaripov", "Farkhat", "" ] ]
This research is an extension of the author's article \cite{zar}, in which conformally invariant generalization of string theory was suggested to higher-dimensional objects. Special cases of the proposed theory are Einstein's theory of gravity and string theory. This work is devoted to the formation of self-consistent ...
2401.09818
Lang Liu
Zu-Cheng Chen, Jun Li, Lang Liu and Zhu Yi
Probing the speed of scalar-induced gravitational waves with pulsar timing arrays
8 pages, 2 figures
Phys. Rev. D 109, L101302 (2024)
10.1103/PhysRevD.109.L101302
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, several regional pulsar timing array collaborations, including CPTA, EPTA, PPTA, and NANOGrav, have individually reported compelling evidence for a stochastic signal at nanohertz frequencies. This signal originates potentially from scalar-induced gravitational waves associated with significant primordial cu...
[ { "created": "Thu, 18 Jan 2024 09:19:53 GMT", "version": "v1" }, { "created": "Fri, 10 May 2024 15:14:41 GMT", "version": "v2" } ]
2024-05-13
[ [ "Chen", "Zu-Cheng", "" ], [ "Li", "Jun", "" ], [ "Liu", "Lang", "" ], [ "Yi", "Zhu", "" ] ]
Recently, several regional pulsar timing array collaborations, including CPTA, EPTA, PPTA, and NANOGrav, have individually reported compelling evidence for a stochastic signal at nanohertz frequencies. This signal originates potentially from scalar-induced gravitational waves associated with significant primordial curv...
gr-qc/9404010
Lee Smolin
Lee Smolin
Fermions and Topology
LATEX, 17 pages, no figures, CGPG-93/9-4
null
null
null
gr-qc
null
The canonical theory of quantum gravity in the loop representation can be extended to incorporate topology change, in the simple case that this refers to the creation or annihilation of "minimalist wormholes" in which two points of the spatial manifold are identified. Furthermore, if the states of the wormholes threa...
[ { "created": "Thu, 7 Apr 1994 22:23:40 GMT", "version": "v1" } ]
2007-05-23
[ [ "Smolin", "Lee", "" ] ]
The canonical theory of quantum gravity in the loop representation can be extended to incorporate topology change, in the simple case that this refers to the creation or annihilation of "minimalist wormholes" in which two points of the spatial manifold are identified. Furthermore, if the states of the wormholes threade...
2011.06792
Jun-Qi Guo
Jun-Qi Guo, Lin Zhang, Yuewen Chen, Pankaj S. Joshi, Hongsheng Zhang
Strength of the naked singularity in critical collapse
5 pages, 3 figures
Eur. Phys. J. C 80, 924 (2020)
10.1140/epjc/s10052-020-08486-7
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
The critical collapse of a scalar field is a threshold solution of black hole formation, in which a naked singularity arises. We study here the curvature strength of this singularity using a numerical ansatz. The behavior of the Jacobi volume forms is examined along a non-spacelike geodesic in the limit of approach t...
[ { "created": "Fri, 13 Nov 2020 07:17:02 GMT", "version": "v1" } ]
2020-11-16
[ [ "Guo", "Jun-Qi", "" ], [ "Zhang", "Lin", "" ], [ "Chen", "Yuewen", "" ], [ "Joshi", "Pankaj S.", "" ], [ "Zhang", "Hongsheng", "" ] ]
The critical collapse of a scalar field is a threshold solution of black hole formation, in which a naked singularity arises. We study here the curvature strength of this singularity using a numerical ansatz. The behavior of the Jacobi volume forms is examined along a non-spacelike geodesic in the limit of approach to ...
0807.4874
Martin Bojowald
Martin Bojowald
Canonical Relativity and the Dimensionality of the World
17 pages, 2 figures; Chapter in: Relativity and the Dimensionality of the World, Ed. V. Petkov (Springer, 2007), pp. 137-152
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Different aspects of relativity, mainly in a canonical formulation, relevant for the question "Is spacetime nothing more than a mathematical space (which describes the evolution in time of the ordinary three-dimensional world) or is it a mathematical model of a real four-dimensional world with time entirely given as ...
[ { "created": "Wed, 30 Jul 2008 14:44:19 GMT", "version": "v1" } ]
2008-07-31
[ [ "Bojowald", "Martin", "" ] ]
Different aspects of relativity, mainly in a canonical formulation, relevant for the question "Is spacetime nothing more than a mathematical space (which describes the evolution in time of the ordinary three-dimensional world) or is it a mathematical model of a real four-dimensional world with time entirely given as th...
1902.06748
Nuno M. Santos
Carlos A. R. Herdeiro, Nuno M. Santos
Exotic compact object behavior in black hole analogues
12 pages, 6 figures. Accepted for publication as a Regular Article in Physical Review D
Phys. Rev. D 99, 084029 (2019)
10.1103/PhysRevD.99.084029
null
gr-qc astro-ph.HE hep-ph hep-th physics.flu-dyn
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Classical phenomenological aspects of acoustic perturbations on a draining bathtub geometry where a surface with reflectivity $\mathcal{R}$ is set at a small distance from the would-be acoustic horizon, which is excised, are addressed. Like most exotic compact objects featuring an ergoregion but not a horizon, this m...
[ { "created": "Mon, 18 Feb 2019 19:00:01 GMT", "version": "v1" }, { "created": "Mon, 1 Apr 2019 21:42:09 GMT", "version": "v2" } ]
2019-04-17
[ [ "Herdeiro", "Carlos A. R.", "" ], [ "Santos", "Nuno M.", "" ] ]
Classical phenomenological aspects of acoustic perturbations on a draining bathtub geometry where a surface with reflectivity $\mathcal{R}$ is set at a small distance from the would-be acoustic horizon, which is excised, are addressed. Like most exotic compact objects featuring an ergoregion but not a horizon, this mod...
gr-qc/0011088
Victor K. Shchigolev
V.K.Shchigolev, M.V.Shchigolev
Cosmological Models with Nonlinearity of Scalar Field Induced by Yang-Mills Field
9 pages, LaTeX
Grav.Cosmol. 7 (2001) 219-222
null
null
gr-qc
null
The exact solutions of Einstein - Yang - Mills and interacting with SO (3) - Yang-Mills field nonlinear scalar field equations in a class of spatially homogeneous cosmological Friedmann models are obtained.
[ { "created": "Fri, 24 Nov 2000 14:58:31 GMT", "version": "v1" } ]
2007-05-23
[ [ "Shchigolev", "V. K.", "" ], [ "Shchigolev", "M. V.", "" ] ]
The exact solutions of Einstein - Yang - Mills and interacting with SO (3) - Yang-Mills field nonlinear scalar field equations in a class of spatially homogeneous cosmological Friedmann models are obtained.
1801.07195
Alexander Zhidenko
R. A. Konoplya, Z. Stuchl\'ik, A. Zhidenko
Axisymmetric black holes allowing for separation of variables in the Klein-Gordon and Hamilton-Jacobi equation
14 pages
Phys. Rev. D 97, 084044 (2018)
10.1103/PhysRevD.97.084044
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine the class of axisymmetric and asymptotically flat black-hole spacetimes for which the test Klein-Gordon and Hamilton-Jacobi equations allow for the separation of variables. The known Kerr, Kerr-Newman, Kerr-Sen and some other black-hole metrics in various theories of gravity are within the class of space...
[ { "created": "Mon, 22 Jan 2018 17:05:34 GMT", "version": "v1" }, { "created": "Tue, 23 Jan 2018 20:54:30 GMT", "version": "v2" }, { "created": "Mon, 16 Apr 2018 23:59:07 GMT", "version": "v3" } ]
2018-04-27
[ [ "Konoplya", "R. A.", "" ], [ "Stuchlík", "Z.", "" ], [ "Zhidenko", "A.", "" ] ]
We determine the class of axisymmetric and asymptotically flat black-hole spacetimes for which the test Klein-Gordon and Hamilton-Jacobi equations allow for the separation of variables. The known Kerr, Kerr-Newman, Kerr-Sen and some other black-hole metrics in various theories of gravity are within the class of spaceti...
2210.02669
Tomohiro Ishikawa
Tomohiro Ishikawa, Shoki Iwaguchi, Bin Wu, Izumi Watanabe, Yuki Kawasaki, Ryuma Shimizu, Yutaro Enomoto, Yuta Michimura, Akira Furusawa, Seiji Kawamura
Can the phase of radiation pressure fluctuations be flipped in a single path for laser interferometric gravitational wave detectors?
14 pages, 8 figures
null
10.1016/j.physleta.2022.128485
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
Radiation pressure (RP) noise, one component of quantum noise, can limit the sensitivity of laser interferometric gravitational wave (GW) detectors at lower frequencies. We conceived a possible RP noise cancellation method, using phase flipped ponderomotive-squeezed light (FPSL) incident on free-mass mirrors in inter...
[ { "created": "Thu, 6 Oct 2022 04:17:06 GMT", "version": "v1" } ]
2022-10-19
[ [ "Ishikawa", "Tomohiro", "" ], [ "Iwaguchi", "Shoki", "" ], [ "Wu", "Bin", "" ], [ "Watanabe", "Izumi", "" ], [ "Kawasaki", "Yuki", "" ], [ "Shimizu", "Ryuma", "" ], [ "Enomoto", "Yutaro", "" ], [ "M...
Radiation pressure (RP) noise, one component of quantum noise, can limit the sensitivity of laser interferometric gravitational wave (GW) detectors at lower frequencies. We conceived a possible RP noise cancellation method, using phase flipped ponderomotive-squeezed light (FPSL) incident on free-mass mirrors in interfe...
1604.06217
Pavel Bushev
Pavel Bushev, Jared H. Cole, Dmitry Sholokhov, Nadezhda Kukharchyk and Magdalena Zych
Single electron relativistic clock interferometer
9 pages, 4 figures
New J. Phys. 18, 093050 (2016)
10.1088/1367-2630/18/9/093050
null
gr-qc quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Although time is one of the fundamental notions in physics, it does not have a unique description. In quantum theory time is a parameter ordering the succession of the probability amplitudes of a quantum system, while according to relativity theory each system experiences in general a different proper time, depending...
[ { "created": "Thu, 21 Apr 2016 08:58:14 GMT", "version": "v1" }, { "created": "Mon, 3 Oct 2016 17:20:55 GMT", "version": "v2" } ]
2016-10-04
[ [ "Bushev", "Pavel", "" ], [ "Cole", "Jared H.", "" ], [ "Sholokhov", "Dmitry", "" ], [ "Kukharchyk", "Nadezhda", "" ], [ "Zych", "Magdalena", "" ] ]
Although time is one of the fundamental notions in physics, it does not have a unique description. In quantum theory time is a parameter ordering the succession of the probability amplitudes of a quantum system, while according to relativity theory each system experiences in general a different proper time, depending o...
1310.7632
Roberto A. Sussman
Roberto A Sussman and Julien Larena
Gravitational entropies in LTB dust models
Version accepted for publication in Classical and Quantum Gravity. 39 pages, 6 figures
Classical and Quantum Gravity, vol 31, page 075021, (2014)
10.1088/0264-9381/31/7/075021
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider generic Lemaitre-Tolman-Bondi (LTB) dust models to probe the gravitational entropy proposals of Clifton, Ellis and Tavakol (CET) and of Hosoya and Buchert (HB). We also consider a variant of the HB proposal based on a suitable quasi-local scalar weighted average. We show that the conditions for entropy gr...
[ { "created": "Mon, 28 Oct 2013 21:53:28 GMT", "version": "v1" }, { "created": "Tue, 4 Mar 2014 04:51:15 GMT", "version": "v2" } ]
2015-06-17
[ [ "Sussman", "Roberto A", "" ], [ "Larena", "Julien", "" ] ]
We consider generic Lemaitre-Tolman-Bondi (LTB) dust models to probe the gravitational entropy proposals of Clifton, Ellis and Tavakol (CET) and of Hosoya and Buchert (HB). We also consider a variant of the HB proposal based on a suitable quasi-local scalar weighted average. We show that the conditions for entropy grow...
gr-qc/9307020
David Garfinkle
David Garfinkle and G. Comer Duncan
Collapse of a Circular Loop of Cosmic String
15 pages
Phys.Rev. D49 (1994) 2752-2758
10.1103/PhysRevD.49.2752
null
gr-qc
null
We study the collapse of a circular loop of cosmic string. The gravitational field of the string is treated using the weak field approximation. The gravitational radiation from the loop is evaluated numerically. The memtric of the loop near the point of collapse is found analytically.
[ { "created": "Wed, 14 Jul 1993 23:23:55 GMT", "version": "v1" } ]
2009-10-22
[ [ "Garfinkle", "David", "" ], [ "Duncan", "G. Comer", "" ] ]
We study the collapse of a circular loop of cosmic string. The gravitational field of the string is treated using the weak field approximation. The gravitational radiation from the loop is evaluated numerically. The memtric of the loop near the point of collapse is found analytically.
2206.15145
Yi Zhong
Yi Zhong, Ke Yang, and Yu-Xiao Liu
Thick brane in Rastall gravity
13 pages, 7 figures
JHEP 09 (2022) 128
10.1007/JHEP09(2022)128
null
gr-qc
http://creativecommons.org/publicdomain/zero/1.0/
In this work, thick branes in Rastall gravity are investigated. Three types of maximally symmetric thick brane models are constructed and the linear tensor perturbation is analyzed. In the flat brane model, the tensor modes of the perturbation are either unstable or nonlocalizable for a nonvanishing Rastall parameter...
[ { "created": "Thu, 30 Jun 2022 09:26:37 GMT", "version": "v1" }, { "created": "Sat, 2 Jul 2022 05:11:11 GMT", "version": "v2" } ]
2022-09-27
[ [ "Zhong", "Yi", "" ], [ "Yang", "Ke", "" ], [ "Liu", "Yu-Xiao", "" ] ]
In this work, thick branes in Rastall gravity are investigated. Three types of maximally symmetric thick brane models are constructed and the linear tensor perturbation is analyzed. In the flat brane model, the tensor modes of the perturbation are either unstable or nonlocalizable for a nonvanishing Rastall parameter. ...
2106.00392
Suvodip Mukherjee
Suvodip Mukherjee, Tom Broadhurst, Jose M. Diego, Joseph Silk, George F. Smoot
Impact of astrophysical binary coalescence timescales on the rate of lensed gravitational wave events
10 pages, 6 figures. Accepted for publication in MNRAS
null
10.1093/mnras/stab1980
null
gr-qc astro-ph.CO astro-ph.GA astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The expected event rate of lensed gravitational wave sources scales with the merger rate at redshift $z\geq 1$, where the optical depth for lensing is high. It is commonly assumed that the merger rate of the astrophysical compact objects is closely connected with the star formation rate, which peaks around redshift $...
[ { "created": "Tue, 1 Jun 2021 11:02:09 GMT", "version": "v1" }, { "created": "Thu, 8 Jul 2021 11:51:00 GMT", "version": "v2" } ]
2021-07-21
[ [ "Mukherjee", "Suvodip", "" ], [ "Broadhurst", "Tom", "" ], [ "Diego", "Jose M.", "" ], [ "Silk", "Joseph", "" ], [ "Smoot", "George F.", "" ] ]
The expected event rate of lensed gravitational wave sources scales with the merger rate at redshift $z\geq 1$, where the optical depth for lensing is high. It is commonly assumed that the merger rate of the astrophysical compact objects is closely connected with the star formation rate, which peaks around redshift $z\...
2205.14742
Maria Babiuc
Dillon Buskirk and Maria C. Babiuc Hamilton
Merging Black Holes: Assessing the Performance of Two Analytic Gravitational Waves Models
28 pages, 8 figures
Journal of Cosmology and Astroparticle Physics (2023) 005
10.1088/1475-7516/2023/03/005
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
Merging black holes produce the loudest signal in the detectors. However, this is the most difficult signal to accurately predict with analytical techniques. Only computer simulations can account for the nonlinear physics during the collision, but they are inherently complex, costly, and affected by numerical errors....
[ { "created": "Sun, 29 May 2022 19:29:52 GMT", "version": "v1" }, { "created": "Thu, 15 Sep 2022 14:37:13 GMT", "version": "v2" }, { "created": "Thu, 22 Dec 2022 21:01:32 GMT", "version": "v3" }, { "created": "Wed, 1 Mar 2023 22:20:29 GMT", "version": "v4" } ]
2023-03-08
[ [ "Buskirk", "Dillon", "" ], [ "Hamilton", "Maria C. Babiuc", "" ] ]
Merging black holes produce the loudest signal in the detectors. However, this is the most difficult signal to accurately predict with analytical techniques. Only computer simulations can account for the nonlinear physics during the collision, but they are inherently complex, costly, and affected by numerical errors. I...
gr-qc/0407051
Jerzy Lewandowski
Marcin Domagala and Jerzy Lewandowski (Uniwersytet Warszawski)
Black hole entropy from Quantum Geometry
a new section ``The spin probability distribution'' added
Class.Quant.Grav. 21 (2004) 5233-5244
10.1088/0264-9381/21/22/014
null
gr-qc hep-th
null
Quantum Geometry (the modern Loop Quantum Gravity using graphs and spin-networks instead of the loops) provides microscopic degrees of freedom that account for the black-hole entropy. However, the procedure for state counting used in the literature contains an error and the number of the relevant horizon states is un...
[ { "created": "Wed, 14 Jul 2004 18:52:16 GMT", "version": "v1" }, { "created": "Mon, 23 Aug 2004 08:08:23 GMT", "version": "v2" } ]
2009-11-10
[ [ "Domagala", "Marcin", "", "Uniwersytet Warszawski" ], [ "Lewandowski", "Jerzy", "", "Uniwersytet Warszawski" ] ]
Quantum Geometry (the modern Loop Quantum Gravity using graphs and spin-networks instead of the loops) provides microscopic degrees of freedom that account for the black-hole entropy. However, the procedure for state counting used in the literature contains an error and the number of the relevant horizon states is unde...
gr-qc/0506137
Herbert Hamber
Herbert W. Hamber and Ruth M. Williams
Nonlocal Effective Field Equations for Quantum Cosmology
9 pages
Mod.Phys.Lett. A21 (2006) 735-742
10.1142/S0217732306019979
DAMTP-2005-58
gr-qc
null
The possibility that the strength of gravitational interactions might slowly increase with distance, is explored by formulating a set of effective field equations, which incorporate the gravitational, vacuum-polarization induced, running of Newton's constant $G$. The resulting long distance (or large time) behaviour ...
[ { "created": "Wed, 29 Jun 2005 18:33:36 GMT", "version": "v1" } ]
2009-11-11
[ [ "Hamber", "Herbert W.", "" ], [ "Williams", "Ruth M.", "" ] ]
The possibility that the strength of gravitational interactions might slowly increase with distance, is explored by formulating a set of effective field equations, which incorporate the gravitational, vacuum-polarization induced, running of Newton's constant $G$. The resulting long distance (or large time) behaviour de...
2302.08900
Marco Brito MSc
Marco Brito, Carlos Herdeiro, Eugen Radu, Nicolas Sanchis-Gual and Miguel Zilh\~ao
Stability and physical properties of spherical excited scalar boson stars
16 pages, 16 figures, updated with an appendix to match published version
Phys. Rev. D 107, 084022 (2023)
10.1103/PhysRevD.107.084022
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the time evolution of spherical, excited -- with $n$ radial nodes -- scalar boson stars in General Relativity minimally coupled to a complex massive scalar field with quartic self-interactions. We report that these stars, with up to $n=10$, can be made dynamically stable, up to timescales of $t\sim\frac{10^{...
[ { "created": "Fri, 17 Feb 2023 14:28:36 GMT", "version": "v1" }, { "created": "Fri, 14 Apr 2023 13:47:19 GMT", "version": "v2" } ]
2023-04-17
[ [ "Brito", "Marco", "" ], [ "Herdeiro", "Carlos", "" ], [ "Radu", "Eugen", "" ], [ "Sanchis-Gual", "Nicolas", "" ], [ "Zilhão", "Miguel", "" ] ]
We study the time evolution of spherical, excited -- with $n$ radial nodes -- scalar boson stars in General Relativity minimally coupled to a complex massive scalar field with quartic self-interactions. We report that these stars, with up to $n=10$, can be made dynamically stable, up to timescales of $t\sim\frac{10^{4}...
1902.09531
Wenbin Lin
Bo Yang and Chunhua Jiang and Wenbin Lin
Post-Minkowskian solution for the small-deflection motion of test particles in Kerr-Newman spacetime
Submitted to Class. Quantum Grav
null
10.1088/1361-6382/ab0ec9
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the second-order post-Minkowskian solution for the small-deflection motion of test particles in the external field of the Kerr-Newman black hole via an iterative method. The analytical results are exhibited in the coordinate system constituted by the particles' initial velocity unit vector, impact vector, a...
[ { "created": "Sun, 24 Feb 2019 14:02:43 GMT", "version": "v1" } ]
2019-05-22
[ [ "Yang", "Bo", "" ], [ "Jiang", "Chunhua", "" ], [ "Lin", "Wenbin", "" ] ]
We derive the second-order post-Minkowskian solution for the small-deflection motion of test particles in the external field of the Kerr-Newman black hole via an iterative method. The analytical results are exhibited in the coordinate system constituted by the particles' initial velocity unit vector, impact vector, and...
gr-qc/9709044
Carlo Baccigalupi
Carlo Baccigalupi, Luca Amendola, Pierluigi Fortini, Franco Occhionero
Stochastic gravitational background from inflationary phase transitions
12 pages, 3 figures. Phys.Rev.D in press
Phys.Rev.D56:4610-4617,1997
10.1103/PhysRevD.56.4610
null
gr-qc
null
We consider true vacuum bubbles generated in a first order phase transition occurring during the slow rolling era of a two field inflation: it is known that gravitational waves are produced by the collision of such bubbles. We find that the epoch of the phase transition strongly affects the characteristic peak freque...
[ { "created": "Tue, 16 Sep 1997 15:17:07 GMT", "version": "v1" } ]
2011-09-09
[ [ "Baccigalupi", "Carlo", "" ], [ "Amendola", "Luca", "" ], [ "Fortini", "Pierluigi", "" ], [ "Occhionero", "Franco", "" ] ]
We consider true vacuum bubbles generated in a first order phase transition occurring during the slow rolling era of a two field inflation: it is known that gravitational waves are produced by the collision of such bubbles. We find that the epoch of the phase transition strongly affects the characteristic peak frequenc...
gr-qc/0312109
Masato Minamitsuji
Masato Minamitsuji and Misao Sasaki
Local conservation law and dark radiation in cosmological braneworld
21 pages, discussions on naked singularity formation and references added
Phys.Rev.D70:044021,2004
10.1103/PhysRevD.70.044021
YITP-03-81
gr-qc astro-ph hep-th
null
In the context of the Randall-Sundrum (RS) single-brane scenario, we discuss the bulk geometry and dynamics of a cosmological brane in terms of the local energy conservation law which exists for the bulk that allows slicing with a maximally symmetric 3-space. This conservation law enables us to define a local mass in...
[ { "created": "Thu, 25 Dec 2003 05:05:32 GMT", "version": "v1" }, { "created": "Sun, 11 Jan 2004 11:25:29 GMT", "version": "v2" }, { "created": "Mon, 26 Jan 2004 09:24:50 GMT", "version": "v3" } ]
2009-10-09
[ [ "Minamitsuji", "Masato", "" ], [ "Sasaki", "Misao", "" ] ]
In the context of the Randall-Sundrum (RS) single-brane scenario, we discuss the bulk geometry and dynamics of a cosmological brane in terms of the local energy conservation law which exists for the bulk that allows slicing with a maximally symmetric 3-space. This conservation law enables us to define a local mass in t...
gr-qc/0409022
Spiros Cotsakis
Spiros Cotsakis and Ifigeneia Klaoudatou
Future Singularities of Isotropic Cosmologies
v2: 16 pages, references added, clarrifications throughout, version to appear in the J.Geom.Phys
J.Geom.Phys. 55 (2005) 306-315
10.1016/j.geomphys.2004.12.012
null
gr-qc
null
We show that globally and regularly hyperbolic future geodesically incomplete isotropic universes, except for the standard all-encompassing `big crunch', can accommodate singularities of only one kind, namely, those having a non-integrable Hubble parameter, $H$. We analyze several examples from recent literature whic...
[ { "created": "Sun, 5 Sep 2004 17:52:00 GMT", "version": "v1" }, { "created": "Mon, 20 Dec 2004 09:59:16 GMT", "version": "v2" } ]
2009-11-10
[ [ "Cotsakis", "Spiros", "" ], [ "Klaoudatou", "Ifigeneia", "" ] ]
We show that globally and regularly hyperbolic future geodesically incomplete isotropic universes, except for the standard all-encompassing `big crunch', can accommodate singularities of only one kind, namely, those having a non-integrable Hubble parameter, $H$. We analyze several examples from recent literature which ...
1511.03655
Abdul Jawad
Abdul Jawad, Davood Momeni, Shamaila Rani and Ratbay Myrzakulov
Dynamical Instability of Cylindrically Symmetric Collapsing Star in Generalized Teleparallel Gravity
20 pages; Accepted for publication in Astrophysics and Space Sceince
Astrophys. Space Sci. 361 (2016)
10.1007/s10509-016-2721-4
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper is devoted to analyze the dynamical instability of a self-gravitating object undergoes to collapse process. We take the framework of generalized teleparallel gravity with cylindrically symmetric gravitating object. The matter distribution is represented by locally anisotropic energy-momentum tensor. We dev...
[ { "created": "Wed, 11 Nov 2015 11:00:16 GMT", "version": "v1" }, { "created": "Tue, 15 Mar 2016 09:46:46 GMT", "version": "v2" } ]
2016-10-31
[ [ "Jawad", "Abdul", "" ], [ "Momeni", "Davood", "" ], [ "Rani", "Shamaila", "" ], [ "Myrzakulov", "Ratbay", "" ] ]
This paper is devoted to analyze the dynamical instability of a self-gravitating object undergoes to collapse process. We take the framework of generalized teleparallel gravity with cylindrically symmetric gravitating object. The matter distribution is represented by locally anisotropic energy-momentum tensor. We devel...
1501.07161
Ayan Banerjee
Piyali Bhar and Ayan Banerjee
Stability of Thin-Shell Wormholes from Noncommutative BTZ Black Hole
13 pages, 16 figures, accepted in Int.J.Mod.Phys. D. arXiv admin note: text overlap with arXiv:0806.4459, arXiv:0909.1071 by other authors
International Journal of Modern Physics D, Vol. 24, No. 5 (2015) 1550034
10.1142/S0218271815500340
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we construct thin-shell wormholes in (2+1)-dimensions from noncommutative BTZ black hole by applying the cut-and-paste procedure implemented by Visser. We calculate the surface stresses localized at the wormhole throat by using the Darmois-Israel formalism, and we find that the wormholes are supported ...
[ { "created": "Tue, 27 Jan 2015 18:02:39 GMT", "version": "v1" } ]
2016-10-31
[ [ "Bhar", "Piyali", "" ], [ "Banerjee", "Ayan", "" ] ]
In this paper, we construct thin-shell wormholes in (2+1)-dimensions from noncommutative BTZ black hole by applying the cut-and-paste procedure implemented by Visser. We calculate the surface stresses localized at the wormhole throat by using the Darmois-Israel formalism, and we find that the wormholes are supported by...
1611.06935
Guido Pizzella
R. de Sangro, G. Finocchiaro, P. Patteri, M. Piccolo, G. Pizzella
Why the interpretation of "Measuring propagation speed of Coulomb fields" stands
3 pages
null
10.1140/epjc/s10052-017-4650-y
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The experimental findings reported in our original paper [1] (arXiv:1211.2913) have been criticized in ref.[2] (arXiv:1606.00710). We believe that the arguments brought in ref. [2] are not correct and we show evidence for this.
[ { "created": "Fri, 18 Nov 2016 10:25:59 GMT", "version": "v1" } ]
2017-03-08
[ [ "de Sangro", "R.", "" ], [ "Finocchiaro", "G.", "" ], [ "Patteri", "P.", "" ], [ "Piccolo", "M.", "" ], [ "Pizzella", "G.", "" ] ]
The experimental findings reported in our original paper [1] (arXiv:1211.2913) have been criticized in ref.[2] (arXiv:1606.00710). We believe that the arguments brought in ref. [2] are not correct and we show evidence for this.
0704.3102
Hernando Quevedo
Hernando Quevedo
Geometrothermodynamics of black holes
Revised version, to be published in Gen.Rel.Grav.(Mashhoon's Festschrift)
Gen.Rel.Grav.40:971-984,2008
10.1007/s10714-007-0586-0
null
gr-qc
null
The thermodynamics of black holes is reformulated within the context of the recently developed formalism of geometrothermodynamics. This reformulation is shown to be invariant with respect to Legendre transformations, and to allow several equivalent representations. Legendre invariance allows us to explain a series o...
[ { "created": "Tue, 24 Apr 2007 01:37:35 GMT", "version": "v1" }, { "created": "Mon, 2 Jul 2007 18:33:21 GMT", "version": "v2" } ]
2008-11-26
[ [ "Quevedo", "Hernando", "" ] ]
The thermodynamics of black holes is reformulated within the context of the recently developed formalism of geometrothermodynamics. This reformulation is shown to be invariant with respect to Legendre transformations, and to allow several equivalent representations. Legendre invariance allows us to explain a series of ...
1111.2647
Peter Komorowski
N. Kiriushcheva, P. G. Komorowski and S. V. Kuzmin
Comment on "Arnowitt--Deser--Misner representation and Hamiltonian analysis of covariant renormalizable gravity" by M. Chaichian, M. Oksanen, A. Tureanu
10 Pages. We found a mistake in our first version -- the Horava-type models of EPJC 71, 1657 (2011) do have a spatial diffeomorphism gauge symmetry, but the partial Hamiltonian analysis of the action presented in the EPJC paper has been confirmed to be incorrect. The true algebra of constraints is different fro...
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The partial Hamiltonian analysis of the actions presented in the paper by M. Chaichian, M. Oksanen, A. Tureanu (Eur. Phys. J. C 71, 1657 (2011)) is incorrect; the true algebra of constraints differs from what they claim for their choice of momentum constraint. Our blind acceptance of the correctness of their constrai...
[ { "created": "Fri, 11 Nov 2011 02:36:50 GMT", "version": "v1" }, { "created": "Tue, 15 Nov 2011 23:41:06 GMT", "version": "v2" }, { "created": "Sun, 20 Nov 2011 21:55:10 GMT", "version": "v3" } ]
2011-11-22
[ [ "Kiriushcheva", "N.", "" ], [ "Komorowski", "P. G.", "" ], [ "Kuzmin", "S. V.", "" ] ]
The partial Hamiltonian analysis of the actions presented in the paper by M. Chaichian, M. Oksanen, A. Tureanu (Eur. Phys. J. C 71, 1657 (2011)) is incorrect; the true algebra of constraints differs from what they claim for their choice of momentum constraint. Our blind acceptance of the correctness of their constraint...
gr-qc/9905106
Martin Rainer
Martin Rainer
Cones and causal structures on topological and differentiable manifolds
v3: 12 pages, latex+amssymb; compatibility conditions (2.5) and (3.2) with misprints corrected and improved argument
J.Math.Phys. 40 (1999) 6589-6597; Erratum-ibid. 41 (2000) 3303
10.1063/1.533108
null
gr-qc
null
General definitions for causal structures on manifolds of dimension d+1>2 are presented for the topological category and for any differentiable one. Locally, these are given as cone structures via local (pointwise) homeomorphic or diffeomorphic abstraction from the standard null cone variety in R^{d+1}. Weak and st...
[ { "created": "Mon, 31 May 1999 21:43:01 GMT", "version": "v1" }, { "created": "Tue, 19 Oct 1999 10:43:45 GMT", "version": "v2" }, { "created": "Wed, 5 Jan 2000 17:30:17 GMT", "version": "v3" } ]
2015-06-25
[ [ "Rainer", "Martin", "" ] ]
General definitions for causal structures on manifolds of dimension d+1>2 are presented for the topological category and for any differentiable one. Locally, these are given as cone structures via local (pointwise) homeomorphic or diffeomorphic abstraction from the standard null cone variety in R^{d+1}. Weak and strong...
2307.04678
Frans Klinkhamer
Frans R. Klinkhamer
New Type of Traversable Wormhole
Invited paper at Bahamas Advanced Study Institute & Conferences (BASIC), February 8-14, 2023, Stella Maris, Long Island, Bahamas. v2: final version to appear in Bulg. J. Phys
null
null
KA-TP-13-2023
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review a new traversable-wormhole solution of the gravitational field equation of general relativity without exotic matter. Instead of having exotic matter to keep the wormhole throat open, the solution relies on a 3-dimensional "spacetime defect," which is characterized by a locally vanishing metric determinant. ...
[ { "created": "Thu, 6 Jul 2023 17:40:22 GMT", "version": "v1" }, { "created": "Mon, 24 Jul 2023 13:00:49 GMT", "version": "v2" } ]
2023-07-25
[ [ "Klinkhamer", "Frans R.", "" ] ]
We review a new traversable-wormhole solution of the gravitational field equation of general relativity without exotic matter. Instead of having exotic matter to keep the wormhole throat open, the solution relies on a 3-dimensional "spacetime defect," which is characterized by a locally vanishing metric determinant. We...
2107.05171
Xiao-Mei Kuang
Ru Ling, Hong Guo, Hang Liu, Xiao-Mei Kuang, Bin Wang
Shadow and near-horizon characteristics of the acoustic charged black hole in curved spacetime
Published version
Physical Review D 104, 104003 (2021)
10.1103/PhysRevD.104.104003
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
In this paper, we first analyze the horizon structure of the acoustic charged black hole in curved spacetime, and then study its acoustic shadow as well as the near-horizon characteristics including the quasinormal modes (QNM) frequencies and analogue Hawking radiation. We find that the radius of the acoustic shadow ...
[ { "created": "Mon, 12 Jul 2021 03:05:23 GMT", "version": "v1" }, { "created": "Tue, 2 Nov 2021 04:49:25 GMT", "version": "v2" } ]
2021-11-03
[ [ "Ling", "Ru", "" ], [ "Guo", "Hong", "" ], [ "Liu", "Hang", "" ], [ "Kuang", "Xiao-Mei", "" ], [ "Wang", "Bin", "" ] ]
In this paper, we first analyze the horizon structure of the acoustic charged black hole in curved spacetime, and then study its acoustic shadow as well as the near-horizon characteristics including the quasinormal modes (QNM) frequencies and analogue Hawking radiation. We find that the radius of the acoustic shadow fo...
gr-qc/9407009
Othmar Brodbeck
Othmar Brodbeck and Norbert Straumann
Instability Proof for Einstein-Yang-Mills Solitons with Arbitrary Gauge Groups
18 pages, Latex, ZU-TH 19/94
null
null
null
gr-qc
null
We prove that static, spherically symmetric, asymptotically flat, regular solutions of the Einstein-Yang-Mills equations are unstable for arbitrary gauge groups, at least for the ``generic" case. This conclusion is derived without explicit knowledge of the possible equilibrium solutions.
[ { "created": "Tue, 12 Jul 1994 11:45:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Brodbeck", "Othmar", "" ], [ "Straumann", "Norbert", "" ] ]
We prove that static, spherically symmetric, asymptotically flat, regular solutions of the Einstein-Yang-Mills equations are unstable for arbitrary gauge groups, at least for the ``generic" case. This conclusion is derived without explicit knowledge of the possible equilibrium solutions.
gr-qc/0502015
Valerio Faraoni
Valerio Faraoni (Bishop's University)
Phase space geometry in scalar-tensor cosmology
18 pages, 9 figures, latex, to appear in Ann. Phys. (NY)
Ann.Phys.317:366-382,2005
10.1016/j.aop.2004.11.009
null
gr-qc astro-ph
null
We study the phase space of spatially homogeneous and isotropic cosmology in general scalar-tensor theories. A reduction to a two-dimensional phase space is performed when possible-in these situations the phase space is usually a two-dimensional curved surface embedded in a three-dimensional space and composed of two...
[ { "created": "Thu, 3 Feb 2005 20:54:04 GMT", "version": "v1" } ]
2008-11-26
[ [ "Faraoni", "Valerio", "", "Bishop's University" ] ]
We study the phase space of spatially homogeneous and isotropic cosmology in general scalar-tensor theories. A reduction to a two-dimensional phase space is performed when possible-in these situations the phase space is usually a two-dimensional curved surface embedded in a three-dimensional space and composed of two s...
0803.0416
Jesus Martin-Martin
J. Martin and A. Tiemblo
The role of translational invariance in non linear gauge theories of gravity
17 pages, LaTeX
Int.J.Geom.Meth.Mod.Phys.05:253-264,2008
10.1142/S0219887808002734
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The internal structure of the tetrads in a Poincar\'e non linear gauge theory of gravity is considered. Minkowskian coordinates becomes dynamical degrees of freedom playing the role of Goldstone bosons of the translations. A critical length allowing a covariant expansion similar to the weak field approach is deduced,...
[ { "created": "Tue, 4 Mar 2008 11:34:48 GMT", "version": "v1" } ]
2008-11-26
[ [ "Martin", "J.", "" ], [ "Tiemblo", "A.", "" ] ]
The internal structure of the tetrads in a Poincar\'e non linear gauge theory of gravity is considered. Minkowskian coordinates becomes dynamical degrees of freedom playing the role of Goldstone bosons of the translations. A critical length allowing a covariant expansion similar to the weak field approach is deduced, t...
1409.0527
Hooman Moradpour Hooman
Hooman Moradpour and Nematollah Riazi
Dynamic conformal spherically symmetric solutions in an accelerated background
Accepted by Rom. Rep. Phys
Romanian Reports in Physics, Vol. 68, No. 4, P. 1382--1396 (2016)
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider dynamical spherically symmetric spacetimes, which are conformal to the static spherically symmetric metrics, and find new solutions of Einstein equations by symmetry considerations. Our study help us classify various conformal Black Holes that are embedded within a dynamic background into the one class of...
[ { "created": "Sun, 31 Aug 2014 14:27:22 GMT", "version": "v1" }, { "created": "Wed, 18 Feb 2015 08:04:27 GMT", "version": "v2" }, { "created": "Tue, 23 Jun 2015 10:26:30 GMT", "version": "v3" }, { "created": "Mon, 3 Aug 2015 12:48:44 GMT", "version": "v4" } ]
2016-12-23
[ [ "Moradpour", "Hooman", "" ], [ "Riazi", "Nematollah", "" ] ]
We consider dynamical spherically symmetric spacetimes, which are conformal to the static spherically symmetric metrics, and find new solutions of Einstein equations by symmetry considerations. Our study help us classify various conformal Black Holes that are embedded within a dynamic background into the one class of s...
gr-qc/9912083
Gaetano Lambiase
S. Capozziello, G. Lambiase
Selection Rules in Minisuperspace Quantum Cosmology
LaTex file, 22 pag., no figures, to appear in Gen. Rel. Grav
Gen.Rel.Grav. 32 (2000) 673-696
10.1023/A:1001967102409
null
gr-qc
null
The existence of a Noether symmetry for a given minisuperspace cosmological model is a sort of selection rule to recover classical behaviours in cosmic evolution since oscillatory regimes for the wave function of the universe come out. The so called Hartle criterion to select correlated regions in the configuration s...
[ { "created": "Mon, 20 Dec 1999 18:22:40 GMT", "version": "v1" } ]
2015-06-25
[ [ "Capozziello", "S.", "" ], [ "Lambiase", "G.", "" ] ]
The existence of a Noether symmetry for a given minisuperspace cosmological model is a sort of selection rule to recover classical behaviours in cosmic evolution since oscillatory regimes for the wave function of the universe come out. The so called Hartle criterion to select correlated regions in the configuration spa...
gr-qc/0502037
Oliver Rinne
Oliver Rinne and John M. Stewart
A strongly hyperbolic and regular reduction of Einstein's equations for axisymmetric spacetimes
22 pages, to appear in Class. Quantum Grav. 22
Class. Quantum Grav. 22, 1143-1166 (2005)
10.1088/0264-9381/22/6/015
DAMTP-2005-17
gr-qc
null
This paper is concerned exclusively with axisymmetric spacetimes. We want to develop reductions of Einstein's equations which are suitable for numerical evolutions. We first make a Kaluza-Klein type dimensional reduction followed by an ADM reduction on the Lorentzian 3-space, the (2+1)+1 formalism. We include also th...
[ { "created": "Wed, 9 Feb 2005 15:16:38 GMT", "version": "v1" } ]
2008-11-22
[ [ "Rinne", "Oliver", "" ], [ "Stewart", "John M.", "" ] ]
This paper is concerned exclusively with axisymmetric spacetimes. We want to develop reductions of Einstein's equations which are suitable for numerical evolutions. We first make a Kaluza-Klein type dimensional reduction followed by an ADM reduction on the Lorentzian 3-space, the (2+1)+1 formalism. We include also the ...
1503.05552
Subenoy Chakraborty
Subenoy Chakraborty, Supriya Pan, and Subhajit Saha
A unified cosmic evolution: Inflation to late time acceleration
21 pages, 17 figures, some typos corrected, references updated
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The present work deals with a cosmological model having particle creation mechanism in the framework of irreversible thermodynamics. In the second order non-equilibrium thermodynamical prescription, the particle creation rate is treated as the dissipative effect. The non-equilibrium thermodynamical process is assumed...
[ { "created": "Wed, 18 Mar 2015 18:54:20 GMT", "version": "v1" }, { "created": "Thu, 30 Apr 2015 12:36:50 GMT", "version": "v2" } ]
2015-05-01
[ [ "Chakraborty", "Subenoy", "" ], [ "Pan", "Supriya", "" ], [ "Saha", "Subhajit", "" ] ]
The present work deals with a cosmological model having particle creation mechanism in the framework of irreversible thermodynamics. In the second order non-equilibrium thermodynamical prescription, the particle creation rate is treated as the dissipative effect. The non-equilibrium thermodynamical process is assumed t...
1103.6140
Vyacheslav Ivanovich Dokuchaev
Vyacheslav I. Dokuchaev
Is there life inside black holes?
11 pages, 5 figures; references added
Class. Quantum Grav. 28 (2011) 235015
10.1088/0264-9381/28/23/235015
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Bound inside rotating or charged black holes, there are stable periodic planetary orbits, which neither come out nor terminate at the central singularity. Stable periodic orbits inside black holes exist even for photons. These bound orbits may be defined as orbits of the third kind, following the Chandrasekhar classi...
[ { "created": "Thu, 31 Mar 2011 10:50:03 GMT", "version": "v1" }, { "created": "Sat, 9 Apr 2011 17:04:02 GMT", "version": "v2" }, { "created": "Fri, 13 May 2011 12:34:09 GMT", "version": "v3" }, { "created": "Fri, 18 Nov 2011 17:50:52 GMT", "version": "v4" } ]
2015-03-19
[ [ "Dokuchaev", "Vyacheslav I.", "" ] ]
Bound inside rotating or charged black holes, there are stable periodic planetary orbits, which neither come out nor terminate at the central singularity. Stable periodic orbits inside black holes exist even for photons. These bound orbits may be defined as orbits of the third kind, following the Chandrasekhar classifi...
gr-qc/0009085
Rafael A. Vera
Rafael A. Vera
Conflict between the Gravitational Field Energy and the Experiments
Standard Latex, 24 pages. Submitted to Physical Reviews D Minor but important changes are made up to prevent any arguments based in non-experimental facts
null
null
null
gr-qc
null
From the equivalence principle and true gravitational (G) time dilation experiments it is concluded that ``matter is not invariable after a change of relative position with respect to other bodies''. As a general principle (GP), such variations cannot be locally detected because the basic parameters of all of the 'we...
[ { "created": "Mon, 25 Sep 2000 14:37:47 GMT", "version": "v1" }, { "created": "Wed, 7 Feb 2001 08:25:54 GMT", "version": "v2" } ]
2007-05-23
[ [ "Vera", "Rafael A.", "" ] ]
From the equivalence principle and true gravitational (G) time dilation experiments it is concluded that ``matter is not invariable after a change of relative position with respect to other bodies''. As a general principle (GP), such variations cannot be locally detected because the basic parameters of all of the 'well...
2004.12523
Osvaldo Pablo Santillan
J. Osorio Morales and O. Santill\'an
About apparent superluminal drives in generic gravity theories
Some typos corrected
null
null
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As is well known, there exists warp drives in GR, such as the Alcubierre bubbles, which achieve an apparent faster than light travel \cite{alcubierre}. A result due to Gao and Wald \cite{gaowald} suggests that such a travel is unlikely for GR with matter satisfying both the Null Energy and the Null Generic Conditions...
[ { "created": "Mon, 27 Apr 2020 00:55:03 GMT", "version": "v1" }, { "created": "Sun, 8 Aug 2021 22:54:07 GMT", "version": "v2" }, { "created": "Tue, 16 Nov 2021 00:37:13 GMT", "version": "v3" }, { "created": "Thu, 14 Apr 2022 23:52:31 GMT", "version": "v4" } ]
2022-04-18
[ [ "Morales", "J. Osorio", "" ], [ "Santillán", "O.", "" ] ]
As is well known, there exists warp drives in GR, such as the Alcubierre bubbles, which achieve an apparent faster than light travel \cite{alcubierre}. A result due to Gao and Wald \cite{gaowald} suggests that such a travel is unlikely for GR with matter satisfying both the Null Energy and the Null Generic Conditions. ...
gr-qc/0410076
Michael A. Ivanov
Michael A. Ivanov
May gravitons be super-strong interacting particles?
6 pages without figures, LaTeX. Contribution to The 14th Workshop on General Relativity and Gravitation (JGRG14), which will be held in Nov 29 - Dec 3 2004, Kyoto, Japan
null
null
null
gr-qc
null
A scheme, in which gravitons are super-strong interacting, is described. The graviton background with the Planckian spectrum and a small effective temperature is considered as a reservoir of gravitons. A cross-section of interaction of a graviton with any particle is assumed to be a bilinear function of its energies....
[ { "created": "Mon, 18 Oct 2004 06:34:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ivanov", "Michael A.", "" ] ]
A scheme, in which gravitons are super-strong interacting, is described. The graviton background with the Planckian spectrum and a small effective temperature is considered as a reservoir of gravitons. A cross-section of interaction of a graviton with any particle is assumed to be a bilinear function of its energies. A...
gr-qc/9808028
Jacob D. Bekenstein
Jacob D. Bekenstein (Hebrew University, Jerusalem)
Black Holes: Classical Properties, Thermodynamics and Heuristic Quantization
LaTeX, 44 pages, 4 eps figs. and conf_cg.sty included. Lectures delivered at the IX Brazilian School on Cosmology and Gravitation, Rio de Janeiro 7-8/98. Updated references and positioning on page corrected
in Cosmology and Gravitation, M. Novello, ed. (Atlantisciences, France 2000), pp. 1-85
null
null
gr-qc
null
I discuss the no hair principle, the recently found hairy solutions, generic properties of nonvacuum spherical static black holes, and the new no scalar hair theorems. I go into the generic phenomenon of superradiance, first uniform linear motion superradiance, then Kerr black hole superradiance, and finally general ...
[ { "created": "Tue, 11 Aug 1998 08:12:01 GMT", "version": "v1" }, { "created": "Fri, 30 Oct 1998 07:40:51 GMT", "version": "v2" }, { "created": "Mon, 2 Nov 1998 10:33:31 GMT", "version": "v3" } ]
2007-05-23
[ [ "Bekenstein", "Jacob D.", "", "Hebrew University, Jerusalem" ] ]
I discuss the no hair principle, the recently found hairy solutions, generic properties of nonvacuum spherical static black holes, and the new no scalar hair theorems. I go into the generic phenomenon of superradiance, first uniform linear motion superradiance, then Kerr black hole superradiance, and finally general ro...
1901.02785
Dmitri Gal'tsov
D.V. Gal'tsov and K.V. Kobialko
Completing characterization of photon orbits in Kerr and Kerr-Newman metrics
Minor corrections, editing, Appendix added. 33 pages, 52 figures
Phys. Rev. D 99, 084043 (2019)
10.1103/PhysRevD.99.084043
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, several new characteristics have been introduced to describe null geodesic structure of stationary spacetimes, such as photon regions (PR) and transversely trapping surfaces (TTS). The former are three-dimensional domains confining the spherical photon orbits, while the latter are closed two-surface of sphe...
[ { "created": "Wed, 9 Jan 2019 15:43:57 GMT", "version": "v1" }, { "created": "Wed, 16 Jan 2019 16:07:57 GMT", "version": "v2" } ]
2019-05-01
[ [ "Gal'tsov", "D. V.", "" ], [ "Kobialko", "K. V.", "" ] ]
Recently, several new characteristics have been introduced to describe null geodesic structure of stationary spacetimes, such as photon regions (PR) and transversely trapping surfaces (TTS). The former are three-dimensional domains confining the spherical photon orbits, while the latter are closed two-surface of spheri...
1005.3110
Morteza Mohseni
Morteza Mohseni
Stability of circular orbits of spinning particles in Schwarzschild-like space-times
eps figures, submitted to General Relativity and Gravitation
Gen.Rel.Grav.42:2477-2490,2010
10.1007/s10714-010-0995-3
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Circular orbits of spinning test particles and their stability in Schwarzschild-like backgrounds are investigated. For these space-times the equations of motion admit solutions representing circular orbits with particles spins being constant and normal to the plane of orbits. For the de Sitter background the orbits a...
[ { "created": "Tue, 18 May 2010 06:32:12 GMT", "version": "v1" } ]
2014-11-21
[ [ "Mohseni", "Morteza", "" ] ]
Circular orbits of spinning test particles and their stability in Schwarzschild-like backgrounds are investigated. For these space-times the equations of motion admit solutions representing circular orbits with particles spins being constant and normal to the plane of orbits. For the de Sitter background the orbits are...
2009.05459
Christian Pfeifer
Manuel Hohmann, Christian Pfeifer, Nicoleta Voicu
Canonical variational completion and 4D Gauss-Bonnet gravity
16 pages
The European Physical Journal Plus volume 136, Article number: 180 (2021)
10.1140/epjp/s13360-021-01153-0
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, a proposal to obtain a finite contribution of second derivative order to the gravitational field equations in \(D = 4\) dimensions from a renormalized Gauss-Bonnet term in the action has received a wave of attention. It triggered a discussion whether the employed renormalization procedure yields a well-defi...
[ { "created": "Fri, 11 Sep 2020 14:12:29 GMT", "version": "v1" }, { "created": "Wed, 16 Dec 2020 11:22:54 GMT", "version": "v2" }, { "created": "Tue, 9 Feb 2021 10:50:30 GMT", "version": "v3" } ]
2021-02-10
[ [ "Hohmann", "Manuel", "" ], [ "Pfeifer", "Christian", "" ], [ "Voicu", "Nicoleta", "" ] ]
Recently, a proposal to obtain a finite contribution of second derivative order to the gravitational field equations in \(D = 4\) dimensions from a renormalized Gauss-Bonnet term in the action has received a wave of attention. It triggered a discussion whether the employed renormalization procedure yields a well-define...
2005.12384
Davi Rodrigues
Davi C. Rodrigues, Valerio Marra
The radial acceleration relation and its emergent nature
2 pages, 1 figure. To appear in the Proceedings IAU Symposium No. 359, 2020. Galaxy evolution and feedback across different environments (Galfeed)
Proc. IAU 15 (2020) 457-459
10.1017/S1743921320001684
null
gr-qc astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review some of our recent results about the Radial Acceleration Relation (RAR) and its interpretation as either a fundamental or an emergent law. The former interpretation is in agreement with a class of modified gravity theories that dismiss the need for dark matter in galaxies (MOND in particular). Our most rece...
[ { "created": "Mon, 25 May 2020 20:30:08 GMT", "version": "v1" } ]
2021-07-01
[ [ "Rodrigues", "Davi C.", "" ], [ "Marra", "Valerio", "" ] ]
We review some of our recent results about the Radial Acceleration Relation (RAR) and its interpretation as either a fundamental or an emergent law. The former interpretation is in agreement with a class of modified gravity theories that dismiss the need for dark matter in galaxies (MOND in particular). Our most recent...
0706.3538
Fabrizio Canfora
F. Canfora
Some solutions with torsion in Chern-Simons gravity and observable effects
17 pages, no figures; test polished; references added; physical interpretation clarified;
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that in all odd dimensional Chern-Simons theories states in which the torsion is non zero (but it can approach smoothly to zero outside suitable regions) do exist. Some possible observational effects related to neutrino oscillations are pointed out. In the theory of continuum media (in which suitable defe...
[ { "created": "Sun, 24 Jun 2007 22:31:19 GMT", "version": "v1" }, { "created": "Wed, 2 Jul 2008 15:41:53 GMT", "version": "v2" } ]
2008-07-02
[ [ "Canfora", "F.", "" ] ]
It is shown that in all odd dimensional Chern-Simons theories states in which the torsion is non zero (but it can approach smoothly to zero outside suitable regions) do exist. Some possible observational effects related to neutrino oscillations are pointed out. In the theory of continuum media (in which suitable defect...
1910.09245
Manuel Hohmann
Manuel Hohmann
Gauge-invariant approach to the parametrized post-Newtonian formalism
LaTeX, 21 pages, no figures; published version
Phys. Rev. D 101, 024061 (2020)
10.1103/PhysRevD.101.024061
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an approach to the parametrized post-Newtonian (PPN) formalism which is based on gauge-invariant higher order perturbation theory. This approach divides the components of the metric perturbations into gauge-invariant quantities, which carry information about the physical system under consideration, and pur...
[ { "created": "Mon, 21 Oct 2019 10:02:09 GMT", "version": "v1" }, { "created": "Tue, 4 Feb 2020 06:27:44 GMT", "version": "v2" } ]
2020-02-05
[ [ "Hohmann", "Manuel", "" ] ]
We present an approach to the parametrized post-Newtonian (PPN) formalism which is based on gauge-invariant higher order perturbation theory. This approach divides the components of the metric perturbations into gauge-invariant quantities, which carry information about the physical system under consideration, and pure ...
1309.4685
Andrzej Okolow
Andrzej Okolow
ADM-like Hamiltonian formulation of gravity in the teleparallel geometry: derivation of constraint algebra
50 pages, LaTeX2e. The original 73 page paper arXiv:1111.5498v1 was revised and divided into two parts. The present paper is the second part of the original one (the first part is available as arXiv:1111.5498v2)
Gen. Rel. Grav. 46, 1636 (2014)
10.1007/s10714-013-1636-4
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive a new constraint algebra for a Hamiltonian formulation of the Teleparallel Equivalent of General Relativity treated as a theory of cotetrad fields on a spacetime. The algebra turns out to be closed.
[ { "created": "Wed, 18 Sep 2013 15:46:24 GMT", "version": "v1" } ]
2021-06-22
[ [ "Okolow", "Andrzej", "" ] ]
We derive a new constraint algebra for a Hamiltonian formulation of the Teleparallel Equivalent of General Relativity treated as a theory of cotetrad fields on a spacetime. The algebra turns out to be closed.
gr-qc/0504090
Kourosh Nozari
Kourosh Nozari and Tahereh Azizi
Coherent States of Harmonic Oscillator and Generalized Uncertainty Principle
12 pages, no figure
Int.J.Quant.Inf. 3 (2005) 623-632
10.1142/S0219749905001468
null
gr-qc
null
In this paper dynamics and quantum mechanical coherent states of a simple harmonic oscillator are considered in the framework of Generalized Uncertainty Principle(GUP). Equations of motion for simple harmonic oscillator are derived and some of their new implications are discussed. Then coherent states of harmonic osc...
[ { "created": "Wed, 20 Apr 2005 11:12:37 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nozari", "Kourosh", "" ], [ "Azizi", "Tahereh", "" ] ]
In this paper dynamics and quantum mechanical coherent states of a simple harmonic oscillator are considered in the framework of Generalized Uncertainty Principle(GUP). Equations of motion for simple harmonic oscillator are derived and some of their new implications are discussed. Then coherent states of harmonic oscil...
gr-qc/0601134
Alfredo Henriques Barbosa
Alfredo B. Henriques
Loop quantum cosmology and the Wheeler-De Witt equation
17 pages; 5 figures
Gen.Rel.Grav. 38 (2006) 1645-1659
10.1007/s10714-006-0330-1
null
gr-qc
null
We present some results concerning the large volume limit of loop quantum cosmology in the flat homogeneous and isotropic case. We derive the Wheeler-De Witt equation in this limit. Looking for the action from which this equation can also be obtained, we then address the problem of the modifications to be brought to ...
[ { "created": "Mon, 30 Jan 2006 15:33:33 GMT", "version": "v1" } ]
2009-11-11
[ [ "Henriques", "Alfredo B.", "" ] ]
We present some results concerning the large volume limit of loop quantum cosmology in the flat homogeneous and isotropic case. We derive the Wheeler-De Witt equation in this limit. Looking for the action from which this equation can also be obtained, we then address the problem of the modifications to be brought to th...
1910.13448
Matteo Braglia
M. Ballardini, M. Braglia, F. Finelli, G. Marozzi, A. A. Starobinsky
Energy-momentum tensor and helicity for gauge fields coupled to a pseudo-scalar inflaton
18 pages, 9 figures. Corrected some typos and removed Appendix B. The results are unchanged
Phys. Rev. D 100, 123542 (2019)
10.1103/PhysRevD.100.123542
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the energy-momentum tensor and helicity of gauge fields coupled through $g \phi F \tilde{F}/4$ to a pseudo-scalar field $\phi$ driving inflation. Under the assumption of a constant time derivative of the background inflaton, we compute analitically divergent and finite terms of the energy density and helicit...
[ { "created": "Tue, 29 Oct 2019 15:38:58 GMT", "version": "v1" }, { "created": "Wed, 25 Dec 2019 11:04:30 GMT", "version": "v2" }, { "created": "Sat, 15 Jan 2022 09:44:32 GMT", "version": "v3" } ]
2022-01-19
[ [ "Ballardini", "M.", "" ], [ "Braglia", "M.", "" ], [ "Finelli", "F.", "" ], [ "Marozzi", "G.", "" ], [ "Starobinsky", "A. A.", "" ] ]
We study the energy-momentum tensor and helicity of gauge fields coupled through $g \phi F \tilde{F}/4$ to a pseudo-scalar field $\phi$ driving inflation. Under the assumption of a constant time derivative of the background inflaton, we compute analitically divergent and finite terms of the energy density and helicity ...
1210.7499
Naonori Sugiyama
Naonori S. Sugiyama and Toshifumi Futamase
Toward an accurate Dark Matter power spectrum beyond BAO scales
4 pages, 1 figure
null
null
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new approximated expression for non-linear Dark Matter power spectrum much beyond BAO scales. The proposed expression agrees with the result of N-body simulation with the accuracy better than 2 % up to k=1.0 [h/Mpc] and k=0.7 [h/Mpc] at z=3.0 and z=1.0, respectively. Even at z=0.35, the accuracy remains ...
[ { "created": "Sun, 28 Oct 2012 19:53:30 GMT", "version": "v1" }, { "created": "Mon, 5 Nov 2012 11:29:25 GMT", "version": "v2" }, { "created": "Fri, 30 Nov 2012 19:25:03 GMT", "version": "v3" } ]
2012-12-03
[ [ "Sugiyama", "Naonori S.", "" ], [ "Futamase", "Toshifumi", "" ] ]
We propose a new approximated expression for non-linear Dark Matter power spectrum much beyond BAO scales. The proposed expression agrees with the result of N-body simulation with the accuracy better than 2 % up to k=1.0 [h/Mpc] and k=0.7 [h/Mpc] at z=3.0 and z=1.0, respectively. Even at z=0.35, the accuracy remains wi...
2303.02877
Jose Miguel Ladino
Jose Miguel Ladino and Eduard Larra\~naga
Eikonal quasinormal modes, photon sphere and shadow of a charged black hole in the 4D Einstein-Gauss-Bonnet gravity
16 pages, 5 figures, 5 tables
Int J Theor Phys 62, 209 (2023)
10.1007/s10773-023-05440-7
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we investigate the relationship between the geometrical properties, the photon sphere, the shadow, and the eikonal quasinormal modes of electrically charged black holes in 4D Einstein-Gauss-Bonnet gravity. Quasinormal modes are complex frequency oscillations that are dependent on the geometry of spaceti...
[ { "created": "Mon, 6 Mar 2023 04:09:49 GMT", "version": "v1" }, { "created": "Sun, 12 Mar 2023 05:59:03 GMT", "version": "v2" } ]
2023-10-03
[ [ "Ladino", "Jose Miguel", "" ], [ "Larrañaga", "Eduard", "" ] ]
In this work, we investigate the relationship between the geometrical properties, the photon sphere, the shadow, and the eikonal quasinormal modes of electrically charged black holes in 4D Einstein-Gauss-Bonnet gravity. Quasinormal modes are complex frequency oscillations that are dependent on the geometry of spacetime...
0709.1680
Madhavan Varadarajan
Madhavan Varadarajan
Towards new background independent representations for Loop Quantum Gravity
22 pages, minor changes
Class.Quant.Grav.25:105011,2008
10.1088/0264-9381/25/10/105011
null
gr-qc
null
Recently, uniqueness theorems were constructed for the representation used in Loop Quantum Gravity. We explore the existence of alternate representations by weakening the assumptions of the so called LOST uniqueness theorem. The weakened assumptions seem physically reasonable and retain the key requirement of explici...
[ { "created": "Tue, 11 Sep 2007 17:21:48 GMT", "version": "v1" }, { "created": "Tue, 11 Sep 2007 23:55:13 GMT", "version": "v2" } ]
2015-01-30
[ [ "Varadarajan", "Madhavan", "" ] ]
Recently, uniqueness theorems were constructed for the representation used in Loop Quantum Gravity. We explore the existence of alternate representations by weakening the assumptions of the so called LOST uniqueness theorem. The weakened assumptions seem physically reasonable and retain the key requirement of explicit ...
gr-qc/9710119
Roland Steinbauer
Roland Steinbauer
Geodesics and geodesic deviation for impulsive gravitational waves
final version, minor grammatical changes
J.Math.Phys. 39 (1998) 2201-2212
10.1063/1.532283
null
gr-qc math-ph math.MP
null
The geometry of impulsive pp-waves is explored via the analysis of the geodesic and geodesic deviation equation using the distributional form of the metric. The geodesic equation involves formally ill-defined products of distributions due to the nonlinearity of the equations and the presence of the Dirac $\de$-distri...
[ { "created": "Tue, 28 Oct 1997 16:14:15 GMT", "version": "v1" }, { "created": "Fri, 27 Mar 1998 12:09:29 GMT", "version": "v2" } ]
2015-06-25
[ [ "Steinbauer", "Roland", "" ] ]
The geometry of impulsive pp-waves is explored via the analysis of the geodesic and geodesic deviation equation using the distributional form of the metric. The geodesic equation involves formally ill-defined products of distributions due to the nonlinearity of the equations and the presence of the Dirac $\de$-distribu...
1003.3324
Bernard J. Carr
B. J. Carr, Tomohiro Harada and Hideki Maeda
Can a primordial black hole or wormhole grow as fast as the universe?
17 pages, 9 figures
null
10.1088/0264-9381/27/18/183101
RESCEU-8/10, CECS-PH-10/02
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This review addresses the issue of whether there are physically realistic self-similar solutions in which a primordial black hole is attached to an exact or asymptotically Friedmann model for an equation of state of the form $p=(\gamma-1)\rho c^2$. In the positive pressure case ($1 < \gamma < 2$), there is no such so...
[ { "created": "Wed, 17 Mar 2010 08:47:00 GMT", "version": "v1" } ]
2015-05-18
[ [ "Carr", "B. J.", "" ], [ "Harada", "Tomohiro", "" ], [ "Maeda", "Hideki", "" ] ]
This review addresses the issue of whether there are physically realistic self-similar solutions in which a primordial black hole is attached to an exact or asymptotically Friedmann model for an equation of state of the form $p=(\gamma-1)\rho c^2$. In the positive pressure case ($1 < \gamma < 2$), there is no such solu...
gr-qc/0403116
Christos G. Tsagas
N.K. Spyrou (Thessaloniki), C.G. Tsagas (UCT/DAMTP)
Covariant approach to the conformal dynamical equivalence in astrophysics
10 pages, to appear in Class. Quantum Grav
Class.Quant.Grav. 21 (2004) 2435-2444
10.1088/0264-9381/21/9/017
null
gr-qc astro-ph
null
We use covariant techniques to examine the implications of the dynamical equivalence between geodesic motions and adiabatic hydrodynamic flows. Assuming that the metrics of a geodesically and a non-geodesically moving fluid are conformally related, we calculate and compare their mass densities. The density difference...
[ { "created": "Tue, 30 Mar 2004 19:33:24 GMT", "version": "v1" } ]
2016-08-31
[ [ "Spyrou", "N. K.", "", "Thessaloniki" ], [ "Tsagas", "C. G.", "", "UCT/DAMTP" ] ]
We use covariant techniques to examine the implications of the dynamical equivalence between geodesic motions and adiabatic hydrodynamic flows. Assuming that the metrics of a geodesically and a non-geodesically moving fluid are conformally related, we calculate and compare their mass densities. The density difference i...
1407.7038
Laura Sampson
Laura Sampson, Nicolas Yunes, Neil Cornish, Marcelo Ponce, Enrico Barausse, Antoine Klein, Carlos Palenzuela, and Luis Lehner
Projected Constraints on Scalarization with Gravitational Waves from Neutron Star Binaries
26 pages, 15 figures, 2 tables. Version resubmitted to PRD after referee report. Discussion added to the conclusions addressing questions raised in arXiv:1410.0738
Phys. Rev. D 90, 124091 (2014)
10.1103/PhysRevD.90.124091
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Certain scalar-tensor theories have the property of endowing stars with scalar hair, sourced either by the star's own compactness (spontaneous scalarization) or, for binary systems, by the companion's scalar hair (induced scalarization) or by the orbital binding energy (dynamical scalarization). Scalarized stars in b...
[ { "created": "Fri, 25 Jul 2014 20:00:08 GMT", "version": "v1" }, { "created": "Fri, 28 Nov 2014 20:44:43 GMT", "version": "v2" } ]
2015-01-07
[ [ "Sampson", "Laura", "" ], [ "Yunes", "Nicolas", "" ], [ "Cornish", "Neil", "" ], [ "Ponce", "Marcelo", "" ], [ "Barausse", "Enrico", "" ], [ "Klein", "Antoine", "" ], [ "Palenzuela", "Carlos", "" ], [ ...
Certain scalar-tensor theories have the property of endowing stars with scalar hair, sourced either by the star's own compactness (spontaneous scalarization) or, for binary systems, by the companion's scalar hair (induced scalarization) or by the orbital binding energy (dynamical scalarization). Scalarized stars in bin...
gr-qc/0001018
Michael T. Anderson
Michael T. Anderson (SUNY Stony Brook)
On the structure of solutions to the static vacuum Einstein equations
34 pages, Final version - contains corrections and improvements to initial version. Annales Henri Poincare, (to appear)
Annales Henri Poincare 1 (2000) 995
10.1007/PL00001026
null
gr-qc math.DG
null
A complete characterization is obtained of the asymptotic behavior of solutions of the static vacuum Einstein equations which have a (pseudo)-compact horizon or boundary and are complete away from the boundary. It is proved that the time-symmetric space-like hypersurface has only finitely many ends, each of which is ...
[ { "created": "Fri, 7 Jan 2000 16:25:05 GMT", "version": "v1" }, { "created": "Sun, 29 Oct 2000 19:40:37 GMT", "version": "v2" } ]
2009-10-31
[ [ "Anderson", "Michael T.", "", "SUNY Stony Brook" ] ]
A complete characterization is obtained of the asymptotic behavior of solutions of the static vacuum Einstein equations which have a (pseudo)-compact horizon or boundary and are complete away from the boundary. It is proved that the time-symmetric space-like hypersurface has only finitely many ends, each of which is ei...
gr-qc/9510063
Chris Isham
Chris Isham
Structural Issues in Quantum Gravity
42 pages, latex, no figures. Writeup of GR14 plenary lecture
null
null
IMPERIAL/TP/95-96/07
gr-qc hep-th quant-ph
null
A discursive, non-technical, analysis is made of some of the basic issues that arise in almost any approach to quantum gravity, and of how these issues stand in relation to recent developments in the field. Specific topics include the applicability of the conceptual and mathematical structures of both classical gener...
[ { "created": "Tue, 31 Oct 1995 22:45:43 GMT", "version": "v1" } ]
2007-05-23
[ [ "Isham", "Chris", "" ] ]
A discursive, non-technical, analysis is made of some of the basic issues that arise in almost any approach to quantum gravity, and of how these issues stand in relation to recent developments in the field. Specific topics include the applicability of the conceptual and mathematical structures of both classical general...
1408.0306
Elias C. Vagenas
Leonardo Balart and Elias C. Vagenas
Regular black holes with a nonlinear electrodynamics source
v1: 19 pages, LaTeX, no figures; v2: typos corrected and one reference removed to match published version in Phys. Rev. D
Phys. Rev. D 90, 124045 (2014)
10.1103/PhysRevD.90.124045
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct several charged regular black hole metrics employing mass distribution functions which are inspired by continuous probability distributions. Some of these metrics satisfy the weak energy condition and asymptotically behave as the Reissner--Nordstrom black hole. In each case, the source to the Einstein eq...
[ { "created": "Fri, 1 Aug 2014 21:08:40 GMT", "version": "v1" }, { "created": "Wed, 10 Dec 2014 18:59:50 GMT", "version": "v2" } ]
2014-12-24
[ [ "Balart", "Leonardo", "" ], [ "Vagenas", "Elias C.", "" ] ]
We construct several charged regular black hole metrics employing mass distribution functions which are inspired by continuous probability distributions. Some of these metrics satisfy the weak energy condition and asymptotically behave as the Reissner--Nordstrom black hole. In each case, the source to the Einstein equa...
gr-qc/0608110
Burkhard Kleihaus
Theodora Ioannidou, Burkhard Kleihaus and Jutta Kunz
Spinning Gravitating Skyrmions
13 pages, 6 figures
Phys.Lett.B643:213-220,2006
10.1016/j.physletb.2006.10.055
null
gr-qc hep-th
null
We investigate self-gravitating rotating solutions in the Einstein-Skyrme theory. These solutions are globally regular and asymptotically flat. We present a new kind of solutions with zero baryon number, which possess neither a flat limit nor a static limit.
[ { "created": "Fri, 25 Aug 2006 15:24:50 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ioannidou", "Theodora", "" ], [ "Kleihaus", "Burkhard", "" ], [ "Kunz", "Jutta", "" ] ]
We investigate self-gravitating rotating solutions in the Einstein-Skyrme theory. These solutions are globally regular and asymptotically flat. We present a new kind of solutions with zero baryon number, which possess neither a flat limit nor a static limit.
gr-qc/0309088
Stephane Fay
Stephane Fay
Noether Symmetry of the Hyperextended Scalar Tensor theory for the FLRW models
11 pages
Class.Quant.Grav. 18 (2001) 4863-4870
10.1088/0264-9381/18/22/311
null
gr-qc
null
We study in which conditions the Hyperextended Scalar Tensor theory in an FLRW background admits a Noether symmetry and derive the vectors field generating it.
[ { "created": "Thu, 18 Sep 2003 12:25:49 GMT", "version": "v1" } ]
2009-11-10
[ [ "Fay", "Stephane", "" ] ]
We study in which conditions the Hyperextended Scalar Tensor theory in an FLRW background admits a Noether symmetry and derive the vectors field generating it.
2003.01070
Shahram Jalalzadeh
P.V. Moniz and S. Jalalzadeh
From Fractional Quantum Mechanics to Quantum Cosmology: An Overture
21 pages, 1 figure
Mathematics 8(3), 313 (2020)
10.3390/math8030313
null
gr-qc hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fractional calculus is a couple of centuries old, but its development has been less embraced and it was only within the last century that a program of applications for physics started. Regarding quantum physics, it has been only in the previous decade or so that the corresponding literature resulted in a set of defyi...
[ { "created": "Mon, 2 Mar 2020 18:01:34 GMT", "version": "v1" } ]
2020-03-03
[ [ "Moniz", "P. V.", "" ], [ "Jalalzadeh", "S.", "" ] ]
Fractional calculus is a couple of centuries old, but its development has been less embraced and it was only within the last century that a program of applications for physics started. Regarding quantum physics, it has been only in the previous decade or so that the corresponding literature resulted in a set of defying...
2304.08659
Alfredo D. Millano
Alfredo D. Millano (Catolica del Norte U.), Genly Leon (Catolica del Norte U. and DUT, Durban), Andronikos Paliathanasis (Catolica del Norte U. and DUT, Durban)
Global dynamics in Einstein-Gauss-Bonnet scalar field cosmology with matter
33 pages, 11 compound figures
null
10.1103/PhysRevD.108.023519
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the dynamics of the field equations in a four-dimensional isotropic and homogeneous spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker geometry in the context of Einstein-Gauss-Bonnet theory with a matter source and a scalar field coupled to the Gauss-Bonnet scalar. In this theory, the Gauss-Bonnet t...
[ { "created": "Mon, 17 Apr 2023 23:20:03 GMT", "version": "v1" } ]
2023-08-02
[ [ "Millano", "Alfredo D.", "", "Catolica del Norte U." ], [ "Leon", "Genly", "", "Catolica del\n Norte U. and DUT, Durban" ], [ "Paliathanasis", "Andronikos", "", "Catolica del Norte U.\n and DUT, Durban" ] ]
We study the dynamics of the field equations in a four-dimensional isotropic and homogeneous spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker geometry in the context of Einstein-Gauss-Bonnet theory with a matter source and a scalar field coupled to the Gauss-Bonnet scalar. In this theory, the Gauss-Bonnet ter...
gr-qc/0512166
Aleksandr Zheltukhin
A.A. Zheltukhin
Supersymmetric Lorentz invariant deformations of superspaces
Latex, 13 pages, no figures; Talk at the Conference ``Cosmology 2005: a reality check'', December 14-17, 2005, Copenhagen, Denmark; To appear at http://www.astro.ku.dk/dark/workshops/dark05/presentations.html
Mod.Phys.Lett.A21:2117-2132,2006
10.1142/S0217732306021517
null
gr-qc
null
Lorentz invariant supersymmetric deformations of superspaces based on Moyal star product parametrized by Majorana spinor $\lambda_{a}$ and Ramond grassmannian vector $\psi_{m}=-{1\over 2}(\bar\theta\gamma_{m}\lambda)$ in the spinor realization \cite{VZ} are proposed. The map of supergravity background into composite ...
[ { "created": "Fri, 30 Dec 2005 17:04:34 GMT", "version": "v1" } ]
2009-11-11
[ [ "Zheltukhin", "A. A.", "" ] ]
Lorentz invariant supersymmetric deformations of superspaces based on Moyal star product parametrized by Majorana spinor $\lambda_{a}$ and Ramond grassmannian vector $\psi_{m}=-{1\over 2}(\bar\theta\gamma_{m}\lambda)$ in the spinor realization \cite{VZ} are proposed. The map of supergravity background into composite su...
gr-qc/0408095
Spiros Cotsakis
Spiros Cotsakis
Slice Energy in Higher Order Gravity Theories and Conformal Transformations
18 pages, references added, remark added in last Section related to the choice of physical frame, various other improvements, final version to appear in Gravitation and Cosmology
Grav.Cosmol.14:176-183,2008
10.1134/S0202289308020096
null
gr-qc
null
We study the generic transport of slice energy between the scalar field generated by the conformal transformation of higher-order gravity theories and the matter component. We give precise relations for this exchange in the cases of dust and perfect fluids. We show that, unless we are in a stationary spacetime where ...
[ { "created": "Mon, 30 Aug 2004 13:29:57 GMT", "version": "v1" }, { "created": "Wed, 22 Dec 2004 10:05:56 GMT", "version": "v2" }, { "created": "Wed, 30 Jan 2008 15:08:49 GMT", "version": "v3" } ]
2009-11-10
[ [ "Cotsakis", "Spiros", "" ] ]
We study the generic transport of slice energy between the scalar field generated by the conformal transformation of higher-order gravity theories and the matter component. We give precise relations for this exchange in the cases of dust and perfect fluids. We show that, unless we are in a stationary spacetime where sl...
1407.6294
Chandrachur Chakraborty
Chandrachur Chakraborty
Anomalous Lense-Thirring precession in Kerr-Taub-NUT spacetimes
LaTex; 12 pages including 16 figures, modified version, accepted for publication in Eur. Phys. J. C
Eur. Phys. J. C (2015) 75:572
10.1140/epjc/s10052-015-3785-y
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Exact Lense-Thirring (LT) precession in Kerr-Taub-NUT spacetime is reviewed. It is shown that the LT precession does not obey the general inverse cube law of distance at strong gravity regime in Kerr-Taub-NUT spacetime. Rather, it becomes maximum just near the horizon, falls sharply and becomes zero near the horizon....
[ { "created": "Wed, 23 Jul 2014 17:00:53 GMT", "version": "v1" }, { "created": "Sun, 27 Jul 2014 08:57:03 GMT", "version": "v2" }, { "created": "Mon, 11 May 2015 15:23:08 GMT", "version": "v3" }, { "created": "Sat, 7 Nov 2015 08:34:39 GMT", "version": "v4" } ]
2015-12-02
[ [ "Chakraborty", "Chandrachur", "" ] ]
Exact Lense-Thirring (LT) precession in Kerr-Taub-NUT spacetime is reviewed. It is shown that the LT precession does not obey the general inverse cube law of distance at strong gravity regime in Kerr-Taub-NUT spacetime. Rather, it becomes maximum just near the horizon, falls sharply and becomes zero near the horizon. T...
1112.3629
Neelima Kelkar Dr
D. Batic, N. G. Kelkar, M. Nowakowski
On Born approximation in black hole scattering
null
Eur. Phys. J. C 71, 1831 (2011)
10.1140/epjc/s10052-011-1831-y
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A massless field propagating on spherically symmetric black hole metrics such as the Schwarzschild, Reissner-Nordstr\"{o}m and Reissner-Nordstr\"{o}m-de Sitter backgrounds is considered. In particular, explicit formulae in terms of transcendental functions for the scattering of massless scalar particles off black hol...
[ { "created": "Thu, 15 Dec 2011 20:11:51 GMT", "version": "v1" } ]
2011-12-16
[ [ "Batic", "D.", "" ], [ "Kelkar", "N. G.", "" ], [ "Nowakowski", "M.", "" ] ]
A massless field propagating on spherically symmetric black hole metrics such as the Schwarzschild, Reissner-Nordstr\"{o}m and Reissner-Nordstr\"{o}m-de Sitter backgrounds is considered. In particular, explicit formulae in terms of transcendental functions for the scattering of massless scalar particles off black holes...