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1910.00083
Francisco Nogueira Lima
A. S. Ribeiro and F. N. Lima
An exact solution of the orbit equation for a massive particle in Schwarzschild metric
null
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we consider a spherically curved symmetric spacetime to exact solving the orbit equation of a massive particle by using Jacobi's elliptic functions. Generally, the solution of the orbit equation provides the relativistic effects on the massive particle, absents in Newtonian mechanics. Besides, we inves...
[ { "created": "Mon, 30 Sep 2019 20:19:26 GMT", "version": "v1" }, { "created": "Fri, 25 Oct 2019 14:39:48 GMT", "version": "v2" }, { "created": "Fri, 13 Mar 2020 19:37:59 GMT", "version": "v3" } ]
2020-03-17
[ [ "Ribeiro", "A. S.", "" ], [ "Lima", "F. N.", "" ] ]
In this paper, we consider a spherically curved symmetric spacetime to exact solving the orbit equation of a massive particle by using Jacobi's elliptic functions. Generally, the solution of the orbit equation provides the relativistic effects on the massive particle, absents in Newtonian mechanics. Besides, we investi...
1706.03596
Ronaldo Vieira Lobato
G. A. Carvalho, R. V. Lobato, P. H. R. S. Moraes, Jos\'e D. V. Arba\~nil, R. M. Marinho Jr, E. Otoniel and M. Malheiro
Stellar equilibrium configurations of white dwarfs in the $f(R,T)$ gravity
To be published in EPJC
null
10.1140/epjc/s10052-017-5413-5
null
gr-qc astro-ph.SR hep-th nucl-th
http://creativecommons.org/licenses/by-nc-sa/4.0/
In this work we investigate the equilibrium configurations of white dwarfs in a modified gravity theory, na\-mely, $f(R,T)$ gravity, for which $R$ and $T$ stand for the Ricci scalar and trace of the energy-momentum tensor, respectively. Considering the functional form $f(R,T)=R+2\lambda T$, with $\lambda$ being a con...
[ { "created": "Mon, 12 Jun 2017 12:29:18 GMT", "version": "v1" }, { "created": "Fri, 24 Nov 2017 16:46:11 GMT", "version": "v2" } ]
2017-12-20
[ [ "Carvalho", "G. A.", "" ], [ "Lobato", "R. V.", "" ], [ "Moraes", "P. H. R. S.", "" ], [ "Arbañil", "José D. V.", "" ], [ "Marinho", "R. M.", "Jr" ], [ "Otoniel", "E.", "" ], [ "Malheiro", "M.", "" ] ]
In this work we investigate the equilibrium configurations of white dwarfs in a modified gravity theory, na\-mely, $f(R,T)$ gravity, for which $R$ and $T$ stand for the Ricci scalar and trace of the energy-momentum tensor, respectively. Considering the functional form $f(R,T)=R+2\lambda T$, with $\lambda$ being a const...
2109.04209
Lavinia Heisenberg
Fabio D'Ambrosio, Lavinia Heisenberg and Simon Kuhn
Revisiting Cosmologies in Teleparallelism
17 pages, no figures
null
10.1088/1361-6382/ac3f99
null
gr-qc astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
We discuss the most general field equations for cosmological spacetimes for theories of gravity based on non-linear extensions of the non-metricity scalar and the torsion scalar. Our approach is based on a systematic symmetry-reduction of the metric-affine geometry which underlies these theories. While for the simple...
[ { "created": "Thu, 9 Sep 2021 12:29:29 GMT", "version": "v1" }, { "created": "Sun, 12 Sep 2021 06:11:26 GMT", "version": "v2" } ]
2022-01-05
[ [ "D'Ambrosio", "Fabio", "" ], [ "Heisenberg", "Lavinia", "" ], [ "Kuhn", "Simon", "" ] ]
We discuss the most general field equations for cosmological spacetimes for theories of gravity based on non-linear extensions of the non-metricity scalar and the torsion scalar. Our approach is based on a systematic symmetry-reduction of the metric-affine geometry which underlies these theories. While for the simplest...
1904.12983
Luca Visinelli
Cosimo Bambi, Katherine Freese, Sunny Vagnozzi, Luca Visinelli
Testing the rotational nature of the supermassive object M87* from the circularity and size of its first image
9 pages, 4 figures, Accepted in PRD
Phys. Rev. D 100 (2019) 044057
10.1103/PhysRevD.100.044057
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Event Horizon Telescope (EHT) collaboration has recently released the first image of a black hole (BH), opening a new window onto tests of general relativity in the strong field regime. In this paper, we derive constraints on the nature of M87* (the supermassive object at the centre of the galaxy M87), exploiting...
[ { "created": "Mon, 29 Apr 2019 23:04:12 GMT", "version": "v1" }, { "created": "Thu, 15 Aug 2019 12:36:19 GMT", "version": "v2" } ]
2020-02-24
[ [ "Bambi", "Cosimo", "" ], [ "Freese", "Katherine", "" ], [ "Vagnozzi", "Sunny", "" ], [ "Visinelli", "Luca", "" ] ]
The Event Horizon Telescope (EHT) collaboration has recently released the first image of a black hole (BH), opening a new window onto tests of general relativity in the strong field regime. In this paper, we derive constraints on the nature of M87* (the supermassive object at the centre of the galaxy M87), exploiting t...
0806.0014
Sean A. Hayward
S. A. Hayward, R. Di Criscienzo, M. Nadalini, L. Vanzo and S. Zerbini
Local Hawking temperature for dynamical black holes
9 pages
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A local Hawking temperature is derived for any future outer trapping horizon in spherical symmetry, using a Hamilton-Jacobi variant of the Parikh-Wilczek tunneling method. It is given by a dynamical surface gravity as defined geometrically. The operational meaning of the temperature is that Kodama observers just outs...
[ { "created": "Fri, 30 May 2008 20:42:47 GMT", "version": "v1" }, { "created": "Wed, 11 Feb 2009 11:48:23 GMT", "version": "v2" } ]
2009-02-11
[ [ "Hayward", "S. A.", "" ], [ "Di Criscienzo", "R.", "" ], [ "Nadalini", "M.", "" ], [ "Vanzo", "L.", "" ], [ "Zerbini", "S.", "" ] ]
A local Hawking temperature is derived for any future outer trapping horizon in spherical symmetry, using a Hamilton-Jacobi variant of the Parikh-Wilczek tunneling method. It is given by a dynamical surface gravity as defined geometrically. The operational meaning of the temperature is that Kodama observers just outsid...
2011.01248
Francesco Bajardi
Francesco Bajardi, Daniele Vernieri, Salvatore Capozziello
Bouncing Cosmology in f(Q) Symmetric Teleparallel Gravity
11 pages, 1 figure, 68 references
Eur. Phys. J. Plus 135, no.11, 912 (2020)
10.1140/epjp/s13360-020-00918-3
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider f(Q) extended symmetric teleparallel cosmologies, where Q is the non-metricity scalar, and constrain its functional form through the order reduction method. By using this technique, we are able to reduce and integrate the field equations and thus to select the corresponding models giving rise to bouncing ...
[ { "created": "Mon, 2 Nov 2020 19:00:04 GMT", "version": "v1" } ]
2020-12-03
[ [ "Bajardi", "Francesco", "" ], [ "Vernieri", "Daniele", "" ], [ "Capozziello", "Salvatore", "" ] ]
We consider f(Q) extended symmetric teleparallel cosmologies, where Q is the non-metricity scalar, and constrain its functional form through the order reduction method. By using this technique, we are able to reduce and integrate the field equations and thus to select the corresponding models giving rise to bouncing co...
0806.4239
Lorenzo Sindoni
Florian Girelli, Stefano Liberati and Lorenzo Sindoni
On the emergence of Lorentzian signature and scalar gravity
10 pages, revtex4. Replaced with the published version
Phys.Rev.D79:044019,2009
10.1103/PhysRevD.79.044019
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, a growing momentum has been gained by the emergent gravity framework. Within the latter, the very concepts of geometry and gravitational interaction are not seen as elementary aspects of Nature but rather as collective phenomena associated to the dynamics of more fundamental objects. In this paper we...
[ { "created": "Thu, 26 Jun 2008 18:46:40 GMT", "version": "v1" }, { "created": "Thu, 19 Feb 2009 11:17:03 GMT", "version": "v2" } ]
2009-04-08
[ [ "Girelli", "Florian", "" ], [ "Liberati", "Stefano", "" ], [ "Sindoni", "Lorenzo", "" ] ]
In recent years, a growing momentum has been gained by the emergent gravity framework. Within the latter, the very concepts of geometry and gravitational interaction are not seen as elementary aspects of Nature but rather as collective phenomena associated to the dynamics of more fundamental objects. In this paper we w...
gr-qc/0110021
Andrzej Herdegen
Andrzej Herdegen and Jaroslaw Wawrzycki
Is Einstein's equivalence principle valid for a quantum particle?
5 pages, RevTeX, published version, references and comments added
Phys.Rev. D66 (2002) 044007
10.1103/PhysRevD.66.044007
null
gr-qc quant-ph
null
Einstein's equivalence principle in classical physics is a rule stating that the effect of gravitation is locally equivalent to the acceleration of an observer. The principle determines the motion of test particles uniquely (modulo very broad general assumptions). We show that the same principle applied to a quantum ...
[ { "created": "Wed, 3 Oct 2001 09:53:16 GMT", "version": "v1" }, { "created": "Thu, 30 Jan 2003 08:22:53 GMT", "version": "v2" } ]
2009-11-07
[ [ "Herdegen", "Andrzej", "" ], [ "Wawrzycki", "Jaroslaw", "" ] ]
Einstein's equivalence principle in classical physics is a rule stating that the effect of gravitation is locally equivalent to the acceleration of an observer. The principle determines the motion of test particles uniquely (modulo very broad general assumptions). We show that the same principle applied to a quantum pa...
1009.4544
Sergey Kozyrev
S. Kozyrev
Composite spherically symmetric configurations in Jordan-Brans-Dicke theory
6 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, a study of the scalar field shells in relativistic spherically symmetric configurations has been performed. We construct the composite solution of Jordan-Brans-Dicke field equation by matching the conformal Brans solutions at each junction surfaces. This approach allows us to associate rigorously wit...
[ { "created": "Thu, 23 Sep 2010 08:55:50 GMT", "version": "v1" } ]
2010-09-24
[ [ "Kozyrev", "S.", "" ] ]
In this article, a study of the scalar field shells in relativistic spherically symmetric configurations has been performed. We construct the composite solution of Jordan-Brans-Dicke field equation by matching the conformal Brans solutions at each junction surfaces. This approach allows us to associate rigorously with ...
gr-qc/0302057
Kouji Nakamura
Kouji Nakamura
Comparison of the oscillatory behaviors of a gravitating Nambu-Goto string with a test string
32 pages, 1 figure, PTPTeX ver.0.8 (LateX2e), Accepted for publication to Progress of Theoretical Physics
Prog.Theor.Phys. 110 (2003) 201-232
10.1143/PTP.110.201
NAOJ-TH-Ap 2003, No.4
gr-qc astro-ph hep-ph hep-th
null
Comparison of the oscillatory behavior of a gravitating infinite Nambu-Goto string and a test string is investigated using the general relativistic gauge invariant perturbation technique with two infinitesimal parameters on a flat spacetime background. Due to the existence of the pp-wave exact solution, we see that t...
[ { "created": "Fri, 14 Feb 2003 04:45:48 GMT", "version": "v1" }, { "created": "Mon, 24 Mar 2003 08:56:48 GMT", "version": "v2" }, { "created": "Wed, 14 May 2003 08:18:49 GMT", "version": "v3" }, { "created": "Mon, 21 Jul 2003 11:54:41 GMT", "version": "v4" } ]
2009-11-10
[ [ "Nakamura", "Kouji", "" ] ]
Comparison of the oscillatory behavior of a gravitating infinite Nambu-Goto string and a test string is investigated using the general relativistic gauge invariant perturbation technique with two infinitesimal parameters on a flat spacetime background. Due to the existence of the pp-wave exact solution, we see that the...
2103.13824
Behnam Pourhassan
Mir Hameeda, Behnam Pourhassan, Mario C. Rocca, and Mir Faizal
Finite Tsallis Gravitational Partition Function for a System of Galaxies
Accepted for publication in General Relativity and Gravitation
Gen.Rel.Grav. 53 (2021) 4, 41
10.1007/s10714-021-02813-3
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we will study the large scale structure formation using the gravitational partition function. We will assertively argue that the system of gravitating galaxies can be analyzed using the Tsallis statistical mechanics. The divergences in the Tsallis gravitational partition function can be removed using t...
[ { "created": "Wed, 24 Mar 2021 10:27:52 GMT", "version": "v1" } ]
2021-05-13
[ [ "Hameeda", "Mir", "" ], [ "Pourhassan", "Behnam", "" ], [ "Rocca", "Mario C.", "" ], [ "Faizal", "Mir", "" ] ]
In this paper, we will study the large scale structure formation using the gravitational partition function. We will assertively argue that the system of gravitating galaxies can be analyzed using the Tsallis statistical mechanics. The divergences in the Tsallis gravitational partition function can be removed using the...
gr-qc/9905015
Winfried Zimdahl
Winfried Zimdahl (Konstanz) and Alexander B. Balakin (Kazan)
Thermodynamic equilibrium in the expanding universe
10 pages, Latex, to appear in GRG
Gen.Rel.Grav. 31 (1999) 1395-1405
10.1023/A:1026741228100
null
gr-qc astro-ph
null
We show that a relativistic gas may be at ``global'' equilibrium in the expanding universe for any equation of state $0 < p \leq \rho /3$, provided that the gas particles move under the influence of a self-interacting, effective one-particle force in between elastic binary collisions. In the force-free limit we recov...
[ { "created": "Thu, 6 May 1999 06:50:27 GMT", "version": "v1" } ]
2015-06-25
[ [ "Zimdahl", "Winfried", "", "Konstanz" ], [ "Balakin", "Alexander B.", "", "Kazan" ] ]
We show that a relativistic gas may be at ``global'' equilibrium in the expanding universe for any equation of state $0 < p \leq \rho /3$, provided that the gas particles move under the influence of a self-interacting, effective one-particle force in between elastic binary collisions. In the force-free limit we recover...
gr-qc/0103068
Cristiano Germani
C. Germani, D. Bini, R.T. Jantzen
A Classical Interpretation of Maxwell's Equations in Curved Spacetime
MGIX proceedings, 2 pages, added a reference
null
null
null
gr-qc
null
We present an integral formulation of observer-dependent Maxwell's equations in curved spacetime and give a classical interpretation of them.
[ { "created": "Sun, 18 Mar 2001 13:26:54 GMT", "version": "v1" }, { "created": "Mon, 26 Mar 2001 08:43:49 GMT", "version": "v2" }, { "created": "Mon, 9 Apr 2001 13:48:08 GMT", "version": "v3" }, { "created": "Fri, 19 Oct 2001 14:22:36 GMT", "version": "v4" } ]
2007-05-23
[ [ "Germani", "C.", "" ], [ "Bini", "D.", "" ], [ "Jantzen", "R. T.", "" ] ]
We present an integral formulation of observer-dependent Maxwell's equations in curved spacetime and give a classical interpretation of them.
0904.0773
Sunil Maharaj
A. Beesham, S. V. Chervon, S. D. Maharaj
An emergent universe supported by a nonlinear sigma model
10 pages, To appear in Class. Quantum. Grav
Class.Quant.Grav.26:075017,2009
10.1088/0264-9381/26/7/075017
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest the use of a nonlinear sigma model as the source which supports an emergent universe. The two-component nonlinear sigma model is considered as the simplest model containing inflaton and auxiliary chiral fields.
[ { "created": "Sun, 5 Apr 2009 14:09:11 GMT", "version": "v1" } ]
2009-05-08
[ [ "Beesham", "A.", "" ], [ "Chervon", "S. V.", "" ], [ "Maharaj", "S. D.", "" ] ]
We suggest the use of a nonlinear sigma model as the source which supports an emergent universe. The two-component nonlinear sigma model is considered as the simplest model containing inflaton and auxiliary chiral fields.
gr-qc/9711083
Luis Bel
Lluis Bel
A distinguished set of modes in an accelerated frame of reference
To appear in "Analytical and Numerical Approaches to Relativity: Sources of Gravitational Radiation", ERE 1997, ed J.Stela, UIB, Palma de Mallorca, Spain
null
null
null
gr-qc
null
We construct a distinguished set of positive and negative energy modes of the Klein-Gordon equation for any Born frame of reference in Minkowski's space-time. Unlike the case of a galilean frame of reference it is unclear whether this set of modes may be an appropriate basis to define the vacuum of a quantized scalar...
[ { "created": "Thu, 27 Nov 1997 11:09:03 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bel", "Lluis", "" ] ]
We construct a distinguished set of positive and negative energy modes of the Klein-Gordon equation for any Born frame of reference in Minkowski's space-time. Unlike the case of a galilean frame of reference it is unclear whether this set of modes may be an appropriate basis to define the vacuum of a quantized scalar f...
2105.03744
Sobhan Kazempour
Amin Rezaei Akbarieh, Sobhan Kazempour and Lijing Shao
Cosmological perturbations in Gauss-Bonnet quasi-dilaton massive gravity
null
Phys. Rev. D 103, 123518 (2021)
10.1103/PhysRevD.103.123518
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We present the cosmological analysis of the Gauss-Bonnet quasi-dilaton massive gravity theory. This offers a gravitational theory with a non-zero graviton mass. We calculate the complete set of background equations of motion. Also, we obtain the self-accelerating background solutions and we present the constraints on...
[ { "created": "Sat, 8 May 2021 17:09:13 GMT", "version": "v1" }, { "created": "Mon, 12 Jul 2021 18:43:56 GMT", "version": "v2" } ]
2021-07-14
[ [ "Akbarieh", "Amin Rezaei", "" ], [ "Kazempour", "Sobhan", "" ], [ "Shao", "Lijing", "" ] ]
We present the cosmological analysis of the Gauss-Bonnet quasi-dilaton massive gravity theory. This offers a gravitational theory with a non-zero graviton mass. We calculate the complete set of background equations of motion. Also, we obtain the self-accelerating background solutions and we present the constraints on p...
gr-qc/0108058
Kayll Lake
Mustapha Ishak and Kayll Lake
Stability of Transparent Spherically Symmetric Thin Shells and Wormholes
12 pages, 7 figures, revtex. Final form to appear in Phys. Rev. D
Phys.Rev. D65 (2002) 044011
10.1103/PhysRevD.65.044011
null
gr-qc
null
The stability of transparent spherically symmetric thin shells (and wormholes) to linearized spherically symmetric perturbations about static equilibrium is examined. This work generalizes and systematizes previous studies and explores the consequences of including the cosmological constant. The approach shows how th...
[ { "created": "Fri, 24 Aug 2001 17:16:28 GMT", "version": "v1" }, { "created": "Tue, 11 Dec 2001 15:24:01 GMT", "version": "v2" } ]
2009-11-07
[ [ "Ishak", "Mustapha", "" ], [ "Lake", "Kayll", "" ] ]
The stability of transparent spherically symmetric thin shells (and wormholes) to linearized spherically symmetric perturbations about static equilibrium is examined. This work generalizes and systematizes previous studies and explores the consequences of including the cosmological constant. The approach shows how the ...
2307.10136
Antonino Marciano
Matteo Lulli, Antonino Marciano and Kristian Piscicchia
Stochastic Ricci Flow dynamics of the gravitationally induced wave-function collapse
14 pages
null
null
null
gr-qc hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In order to reconcile the wave-function collapse in quantum mechanics with the finiteness of signals' propagation in general relativity, we delve into a stochastic version of the Ricci flow and study its non-relativistic limit in presence of matter. We hence derive the Di\'osi-Penrose collapse model for the wave-func...
[ { "created": "Wed, 19 Jul 2023 17:00:48 GMT", "version": "v1" } ]
2023-07-20
[ [ "Lulli", "Matteo", "" ], [ "Marciano", "Antonino", "" ], [ "Piscicchia", "Kristian", "" ] ]
In order to reconcile the wave-function collapse in quantum mechanics with the finiteness of signals' propagation in general relativity, we delve into a stochastic version of the Ricci flow and study its non-relativistic limit in presence of matter. We hence derive the Di\'osi-Penrose collapse model for the wave-functi...
2007.14881
Brian Seymour
Brian C. Seymour, Kent Yagi
Probing Massive Scalar/Vector Fields with Binary Pulsars
minor edits, 12 pages, 3 figures
Phys. Rev. D 102, 104003 (2020)
10.1103/PhysRevD.102.104003
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Precision tests of general relativity can be conducted by observing binary pulsars. Theories with massive fields exist to explain a variety of phenomena from dark energy to the strong CP problem. Existing pulsar binaries, such as the white dwarf-pulsar binary J1738+0333, have been used to place stringent bounds on th...
[ { "created": "Wed, 29 Jul 2020 14:58:17 GMT", "version": "v1" }, { "created": "Fri, 2 Oct 2020 00:47:11 GMT", "version": "v2" } ]
2020-11-11
[ [ "Seymour", "Brian C.", "" ], [ "Yagi", "Kent", "" ] ]
Precision tests of general relativity can be conducted by observing binary pulsars. Theories with massive fields exist to explain a variety of phenomena from dark energy to the strong CP problem. Existing pulsar binaries, such as the white dwarf-pulsar binary J1738+0333, have been used to place stringent bounds on the ...
gr-qc/9606029
M. B. Paranjape
A. Edery and M. B. Paranjape
Localized Mass and Spin Sources in 2+1 Dimensional Topologically Massive Gravity
revised version, minor corrections, latex, 8 pages
Phys.Lett.B413:35-40,1997
10.1016/S0370-2693(97)01101-5
UDEM-GPP-TH-96-37
gr-qc
null
Stationary solutions to the full non-linear topologically massive gravity (TMG) are obtained for localized sources of mass $m$ and spin $\sigma$. Our results show that the topological term induces spin and that the total spin J (which is the spin observed by an asymptotic observer) ranges from 0 to $\sigma + \frac{m}...
[ { "created": "Thu, 13 Jun 1996 20:32:02 GMT", "version": "v1" }, { "created": "Mon, 16 Jun 1997 16:21:16 GMT", "version": "v2" } ]
2008-12-30
[ [ "Edery", "A.", "" ], [ "Paranjape", "M. B.", "" ] ]
Stationary solutions to the full non-linear topologically massive gravity (TMG) are obtained for localized sources of mass $m$ and spin $\sigma$. Our results show that the topological term induces spin and that the total spin J (which is the spin observed by an asymptotic observer) ranges from 0 to $\sigma + \frac{m}{\...
1411.3143
Arturo Stabile
A. Stabile, S. Capozziello
Self-gravitating systems in Extended Gravity
Review paper; 59 pages, 15 figures
Galaxies 2014, 2(4), 520-576
10.3390/galaxies2040520
null
gr-qc astro-ph.GA astro-ph.SR math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Starting from the weak field limit, we discuss astrophysical applications of Extended Theories of Gravity where higher order curvature invariants and scalar fields are considered by generalizing the Hilbert-Einstein action linear in the Ricci curvature scalar $R$. Results are compared to General Relativity in the hyp...
[ { "created": "Wed, 12 Nov 2014 11:18:46 GMT", "version": "v1" } ]
2015-02-25
[ [ "Stabile", "A.", "" ], [ "Capozziello", "S.", "" ] ]
Starting from the weak field limit, we discuss astrophysical applications of Extended Theories of Gravity where higher order curvature invariants and scalar fields are considered by generalizing the Hilbert-Einstein action linear in the Ricci curvature scalar $R$. Results are compared to General Relativity in the hypot...
2110.05176
Sandeep S. Cranganore
Sandeep S. Cranganore
The Sugawara-Sommerfield construction including canonical spin current
26 pages, Latex; typos corrected, title changed, added new subsection and references in section 7, corrected equations in section 6
null
10.1103/PhysRevD.104.124022
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We set up the Sugawara-Sommerfield (SS) construction and generalize it by the inclusion of canonical spin current. Using the techniques of current algebra, we infer that the canonical spin current are linear in the vector-axial vector currents. From a geometric perspective, the underlying manifold has a vanishing Lor...
[ { "created": "Thu, 7 Oct 2021 19:27:15 GMT", "version": "v1" }, { "created": "Tue, 9 Nov 2021 21:22:55 GMT", "version": "v2" } ]
2021-12-15
[ [ "Cranganore", "Sandeep S.", "" ] ]
We set up the Sugawara-Sommerfield (SS) construction and generalize it by the inclusion of canonical spin current. Using the techniques of current algebra, we infer that the canonical spin current are linear in the vector-axial vector currents. From a geometric perspective, the underlying manifold has a vanishing Loren...
1906.05557
Hoang Nam Cao
Cao Hoang Nam
Heat engine efficiency and Joule-Thomson expansion of non-linear charged AdS black hole in massive gravity
22 pages
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we have considered the heat engine and Joule-Thomson expansion for the charged AdS black hole in the context of the non-linear electrodynamics and massive gravity. For the black hole heat engine, we obtained the analytical expression for the efficiency in terms of either the entropies or the temperatur...
[ { "created": "Thu, 13 Jun 2019 09:14:59 GMT", "version": "v1" } ]
2019-06-14
[ [ "Nam", "Cao Hoang", "" ] ]
In this paper, we have considered the heat engine and Joule-Thomson expansion for the charged AdS black hole in the context of the non-linear electrodynamics and massive gravity. For the black hole heat engine, we obtained the analytical expression for the efficiency in terms of either the entropies or the temperatures...
2105.12582
Emmanuil Saridakis
Emmanuel N. Saridakis, Ruth Lazkoz, Vincenzo Salzano, Paulo Vargas Moniz, Salvatore Capozziello, Jose Beltr\'an Jim\'enez, Mariafelicia De Laurentis, Gonzalo J. Olmo, Yashar Akrami, Sebastian Bahamonde, Jose Luis Bl\'azquez-Salcedo, Christian G. B\"ohmer, Camille Bonvin, Mariam Bouhmadi-L\'opez, Philippe Brax, ...
Modified Gravity and Cosmology: An Update by the CANTATA Network
543 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
General Relativity and the $\Lambda$CDM framework are currently the standard lore and constitute the concordance paradigm. Nevertheless, long-standing open theoretical issues, as well as possible new observational ones arising from the explosive development of cosmology the last two decades, offer the motivation and ...
[ { "created": "Thu, 20 May 2021 17:25:53 GMT", "version": "v1" }, { "created": "Fri, 19 May 2023 08:36:12 GMT", "version": "v2" } ]
2023-05-22
[ [ "Saridakis", "Emmanuel N.", "" ], [ "Lazkoz", "Ruth", "" ], [ "Salzano", "Vincenzo", "" ], [ "Moniz", "Paulo Vargas", "" ], [ "Capozziello", "Salvatore", "" ], [ "Jiménez", "Jose Beltrán", "" ], [ "De Laurentis", ...
General Relativity and the $\Lambda$CDM framework are currently the standard lore and constitute the concordance paradigm. Nevertheless, long-standing open theoretical issues, as well as possible new observational ones arising from the explosive development of cosmology the last two decades, offer the motivation and le...
gr-qc/0101030
Lorenzo Iorio
Lorenzo Iorio and Erricos C. Pavlis
Tidal satellite perturbations and the Lense-Thirring effect
6 pages, LaTex, to appear in Journal of the Geodetic Society of Japan, vol. 47, no. 1, special issue for the Proceedings of The XIV International Symposium on Earth tides (ETS 2000) held at Mizusawa, Iwate, Japan from August 28 to September 1, 2000
J.Geodet.Soc.Jap.47:1-7,2001
10.11366/sokuchi1954.47.169
null
gr-qc astro-ph physics.geo-ph physics.space-ph
null
The tiny general relativistic Lense-Thirring effect can be measured by means of a suitable combination of the orbital residuals of the nodes of LAGEOS and LAGEOS II and the perigee of LAGEOS II. This observable is affected, among other factors, by the Earth' s solid and ocean tides. They induce long-period orbital pe...
[ { "created": "Tue, 9 Jan 2001 09:39:35 GMT", "version": "v1" } ]
2013-11-12
[ [ "Iorio", "Lorenzo", "" ], [ "Pavlis", "Erricos C.", "" ] ]
The tiny general relativistic Lense-Thirring effect can be measured by means of a suitable combination of the orbital residuals of the nodes of LAGEOS and LAGEOS II and the perigee of LAGEOS II. This observable is affected, among other factors, by the Earth' s solid and ocean tides. They induce long-period orbital pert...
2407.12954
Edward Timoshenko G
G. A. Sardanashvily, E. G. Timoshenko
Caustics type of gravitational singularities
4 pages. Translated from Russian by author on 07.07.2024
Bulletin of Moscow State University, ISSN 2074-6636, UDC 530.12, Series 3, Physics and astronomy, Vol. 30, No 3, pp. 75-77 (1989)
10.6084/m9.figshare.26213036
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We describe a new type of gravitational singularities which are caustics of spatial-temporal foliations. An example of gravitational wave solution forming a singularity with caustics is given.
[ { "created": "Wed, 17 Jul 2024 18:56:38 GMT", "version": "v1" } ]
2024-07-19
[ [ "Sardanashvily", "G. A.", "" ], [ "Timoshenko", "E. G.", "" ] ]
We describe a new type of gravitational singularities which are caustics of spatial-temporal foliations. An example of gravitational wave solution forming a singularity with caustics is given.
1408.3465
Tiberiu Harko
Tiberiu Harko
Thermodynamic interpretation of the generalized gravity models with geometry - matter coupling
12 pages, no figures, accepted for publication in PRD; references added. arXiv admin note: text overlap with arXiv:gr-qc/0404045 by other authors without attribution
Physical Review D 90, 044067 (2014)
10.1103/PhysRevD.90.044067
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Modified gravity theories with geometry - matter coupling, in which the action is an arbitrary function of the Ricci scalar and the matter Lagrangian ($f\left(R,L_m\right)$ gravity), and of the Ricci scalar and of the trace of the matter energy-momentum tensor ($f(R,T)$ gravity), respectively, have the intriguing pro...
[ { "created": "Fri, 15 Aug 2014 05:04:17 GMT", "version": "v1" }, { "created": "Fri, 22 Aug 2014 02:06:42 GMT", "version": "v2" } ]
2015-06-22
[ [ "Harko", "Tiberiu", "" ] ]
Modified gravity theories with geometry - matter coupling, in which the action is an arbitrary function of the Ricci scalar and the matter Lagrangian ($f\left(R,L_m\right)$ gravity), and of the Ricci scalar and of the trace of the matter energy-momentum tensor ($f(R,T)$ gravity), respectively, have the intriguing prope...
2404.19423
De-Cheng Zou
Shan Wu, Kai-Qiang Qian, Rui-Hong Yue, Ming Zhang and De-Cheng Zou
Thermodynamics of charged Lifshitz black holes with scalar hair
12 pages, 2 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we discuss the generalized Einstein-Maxwell-Dilaton gravity theory with a nonminimal coupling between the Maxwell field and scalar field. Considering different geometric properties of black hole horizon structure, the charged dilaton Lifshitz black hole solutions are presented in 4-dimensional spacetime...
[ { "created": "Tue, 30 Apr 2024 10:13:01 GMT", "version": "v1" }, { "created": "Wed, 1 May 2024 01:38:44 GMT", "version": "v2" } ]
2024-05-02
[ [ "Wu", "Shan", "" ], [ "Qian", "Kai-Qiang", "" ], [ "Yue", "Rui-Hong", "" ], [ "Zhang", "Ming", "" ], [ "Zou", "De-Cheng", "" ] ]
In this work, we discuss the generalized Einstein-Maxwell-Dilaton gravity theory with a nonminimal coupling between the Maxwell field and scalar field. Considering different geometric properties of black hole horizon structure, the charged dilaton Lifshitz black hole solutions are presented in 4-dimensional spacetimes....
gr-qc/0304025
Carlos Augusto Romero Filho
A. Barros and C. Romero
Gravitomagnetic time delay and the Lense-Thirring effect in Brans-Dicke theory of gravity
10 pages Typeset using REVTEX
Mod.Phys.Lett.A18:2117-2124,2003
10.1142/S0217732303011721
null
gr-qc
null
We discuss the gravitomagnetic time delay and the Lense-Thirring effect in the context of Brans-Dicke theory of gravity. We compare the theoretical results obtained with those predicted by general relativity. We show that within the accuracy of experiments designed to measure these effects both theories predict essen...
[ { "created": "Sat, 5 Apr 2003 14:08:57 GMT", "version": "v1" } ]
2011-09-13
[ [ "Barros", "A.", "" ], [ "Romero", "C.", "" ] ]
We discuss the gravitomagnetic time delay and the Lense-Thirring effect in the context of Brans-Dicke theory of gravity. We compare the theoretical results obtained with those predicted by general relativity. We show that within the accuracy of experiments designed to measure these effects both theories predict essenti...
1501.01053
Krishnamohan Parattu
Krishnamohan Parattu, Sumanta Chakraborty, Bibhas Ranjan Majhi and T. Padmanabhan
A Boundary Term for the Gravitational Action with Null Boundaries
47 pages, no figures, title changed
Gen.Rel.Grav. 48 (2016) no.7, 94
10.1007/s10714-016-2093-7
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Constructing a well-posed variational principle is a non-trivial issue in general relativity. For spacelike and timelike boundaries, one knows that the addition of the Gibbons-Hawking-York (GHY) counter-term will make the variational principle well-defined. This result, however, does not directly generalize to null b...
[ { "created": "Tue, 6 Jan 2015 01:09:13 GMT", "version": "v1" }, { "created": "Mon, 1 Aug 2016 17:48:04 GMT", "version": "v2" } ]
2016-08-02
[ [ "Parattu", "Krishnamohan", "" ], [ "Chakraborty", "Sumanta", "" ], [ "Majhi", "Bibhas Ranjan", "" ], [ "Padmanabhan", "T.", "" ] ]
Constructing a well-posed variational principle is a non-trivial issue in general relativity. For spacelike and timelike boundaries, one knows that the addition of the Gibbons-Hawking-York (GHY) counter-term will make the variational principle well-defined. This result, however, does not directly generalize to null bou...
1407.0744
Leo Stein
Leo C. Stein
Note on Legendre decomposition of the Pontryagin density in Kerr
3 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In arXiv:1406.0957v1 ("Scalar field excited around a rapidly rotating black hole in Chern-Simons modified gravity"), Konno and Takahashi have recently developed some analytical results for the scalar field about a Kerr black hole in the decoupling limit of dynamical Chern-Simons gravity. This involved a decomposition...
[ { "created": "Wed, 2 Jul 2014 23:43:39 GMT", "version": "v1" } ]
2014-07-04
[ [ "Stein", "Leo C.", "" ] ]
In arXiv:1406.0957v1 ("Scalar field excited around a rapidly rotating black hole in Chern-Simons modified gravity"), Konno and Takahashi have recently developed some analytical results for the scalar field about a Kerr black hole in the decoupling limit of dynamical Chern-Simons gravity. This involved a decomposition o...
2004.08027
Yen-Kheng Lim PhD
Yen-Kheng Lim
Hypocycloid motion in the Melvin magnetic universe
18 pages, 4 figures. Typos corrected. Introduction and conclusion improved thanks to the suggestions of the anonymous referee
Phys. Rev. D 101, 104031 (2020)
10.1103/PhysRevD.101.104031
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The trajectory of a charged test particle in the Melvin magnetic universe is shown to take the form of hypocycloids in two different regimes, first of which is the class of perturbed circular orbits, and secondly in the weak-field approximation. In the latter case we find a simple relation between the charge of the p...
[ { "created": "Fri, 17 Apr 2020 01:53:35 GMT", "version": "v1" }, { "created": "Mon, 18 May 2020 01:56:11 GMT", "version": "v2" } ]
2020-05-19
[ [ "Lim", "Yen-Kheng", "" ] ]
The trajectory of a charged test particle in the Melvin magnetic universe is shown to take the form of hypocycloids in two different regimes, first of which is the class of perturbed circular orbits, and secondly in the weak-field approximation. In the latter case we find a simple relation between the charge of the par...
1902.07411
Daniel Pollack
Madeleine Burkhart, Martin Lesourd, and Daniel Pollack
Null geodesic incompleteness of spacetimes with no CMC Cauchy surfaces
All comments welcome! (v3: Dedication and reference added, minor changes)
null
null
null
gr-qc math.DG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Chru\'sciel, Isenberg, and Pollack constructed a class of vacuum cosmological spacetimes that do not admit Cauchy surfaces with constant mean curvature. We prove that, for sufficiently large values of the gluing parameter, these examples are both future and past null geodesically incomplete. The authors are honored...
[ { "created": "Wed, 20 Feb 2019 05:27:40 GMT", "version": "v1" }, { "created": "Thu, 21 Feb 2019 04:42:14 GMT", "version": "v2" }, { "created": "Thu, 28 Feb 2019 07:01:02 GMT", "version": "v3" } ]
2019-03-01
[ [ "Burkhart", "Madeleine", "" ], [ "Lesourd", "Martin", "" ], [ "Pollack", "Daniel", "" ] ]
Chru\'sciel, Isenberg, and Pollack constructed a class of vacuum cosmological spacetimes that do not admit Cauchy surfaces with constant mean curvature. We prove that, for sufficiently large values of the gluing parameter, these examples are both future and past null geodesically incomplete. The authors are honored to ...
1605.00497
Giovanni Amelino-Camelia
Giovanni Amelino-Camelia, Mal\'u Maira da Silva, Michele Ronco, Lorenzo Cesarini, Orchidea Maria Lecian
Spacetime-noncommutativity regime of Loop Quantum Gravity
null
Phys. Rev. D 95, 024028 (2017)
10.1103/PhysRevD.95.024028
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A recent study by Bojowald and Paily provided a path toward the identification of an effective quantum-spacetime picture of Loop Quantum Gravity, applicable in the "Minkowski regime", the regime where the large-scale (coarse-grained) spacetime metric is flat. A pivotal role in the analysis is played by Loop-Quantum-G...
[ { "created": "Mon, 2 May 2016 14:14:10 GMT", "version": "v1" } ]
2017-01-25
[ [ "Amelino-Camelia", "Giovanni", "" ], [ "da Silva", "Malú Maira", "" ], [ "Ronco", "Michele", "" ], [ "Cesarini", "Lorenzo", "" ], [ "Lecian", "Orchidea Maria", "" ] ]
A recent study by Bojowald and Paily provided a path toward the identification of an effective quantum-spacetime picture of Loop Quantum Gravity, applicable in the "Minkowski regime", the regime where the large-scale (coarse-grained) spacetime metric is flat. A pivotal role in the analysis is played by Loop-Quantum-Gra...
0709.0872
Golam Mortuza Hossain
Martin Bojowald and Golam Mortuza Hossain
Cosmological vector modes and quantum gravity effects
20 pages
Class.Quant.Grav.24:4801-4816,2007
10.1088/0264-9381/24/18/015
IGPG-07/6-5
gr-qc astro-ph hep-th
null
In contrast to scalar and tensor modes, vector modes of linear perturbations around an expanding Friedmann--Robertson--Walker universe decay. This makes them largely irrelevant for late time cosmology, assuming that all modes started out at a similar magnitude at some early stage. By now, however, bouncing models are...
[ { "created": "Thu, 6 Sep 2007 14:33:31 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bojowald", "Martin", "" ], [ "Hossain", "Golam Mortuza", "" ] ]
In contrast to scalar and tensor modes, vector modes of linear perturbations around an expanding Friedmann--Robertson--Walker universe decay. This makes them largely irrelevant for late time cosmology, assuming that all modes started out at a similar magnitude at some early stage. By now, however, bouncing models are f...
2204.06750
Yun Soo Myung
Yun Soo Myung
Conditions for superradiant instability of the Kerr-Newman black holes
15 pages, 7 figures, a version to appear in PRD
null
10.1103/PhysRevD.105.124015
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We find two conditions for superradiant instability of Kerr-Newman black holes under a charged massive scalar perturbation by analyzing asymptotic scalar potential and far-region wave function. Actually, they correspond to the condition for getting a trapping well. Also, we obtain the conditions for superradiant stab...
[ { "created": "Thu, 14 Apr 2022 04:20:01 GMT", "version": "v1" }, { "created": "Tue, 26 Apr 2022 03:26:38 GMT", "version": "v2" }, { "created": "Wed, 25 May 2022 21:57:12 GMT", "version": "v3" } ]
2022-06-22
[ [ "Myung", "Yun Soo", "" ] ]
We find two conditions for superradiant instability of Kerr-Newman black holes under a charged massive scalar perturbation by analyzing asymptotic scalar potential and far-region wave function. Actually, they correspond to the condition for getting a trapping well. Also, we obtain the conditions for superradiant stabil...
2204.08113
Vilson T. Zanchin
Angel D. Masa and Vilson T. Zanchin
Rotating regular black holes and other compact objects with a Tolman type potential as a regular interior for the Kerr metric
New references added, text improved
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We obtain a new class of stationary axisymmetric spacetimes by using the G\"urses-G\"ursey metric with an appropriate mass function in order to generate a rotating core of matter that may be smoothly matched to the exterior Kerr metric. The same stationary spacetimes may be obtained by applying a slightly modified ve...
[ { "created": "Mon, 18 Apr 2022 00:28:21 GMT", "version": "v1" }, { "created": "Wed, 8 Nov 2023 21:29:12 GMT", "version": "v2" } ]
2023-11-10
[ [ "Masa", "Angel D.", "" ], [ "Zanchin", "Vilson T.", "" ] ]
We obtain a new class of stationary axisymmetric spacetimes by using the G\"urses-G\"ursey metric with an appropriate mass function in order to generate a rotating core of matter that may be smoothly matched to the exterior Kerr metric. The same stationary spacetimes may be obtained by applying a slightly modified vers...
2107.09536
Neev Khera
Neev Khera, Abhay Ashtekar, Badri Krishnan
Testing gravitational waveform models using angular momentum
12 pages, 6 figures. Appendix B added to provide heat maps showing the degree of violation of the angular momentum balance law in various non-precessing and precessing models, as functions of the binary parameters
Phys. Rev. D104, 124071 (2021)
10.1103/PhysRevD.104.124071
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The anticipated enhancements in detector sensitivity and the corresponding increase in the number of gravitational wave detections will make it possible to estimate parameters of compact binaries with greater accuracy assuming general relativity(GR), and also to carry out sharper tests of GR itself. Crucial to these ...
[ { "created": "Tue, 20 Jul 2021 14:50:35 GMT", "version": "v1" }, { "created": "Mon, 13 Dec 2021 18:23:59 GMT", "version": "v2" } ]
2021-12-30
[ [ "Khera", "Neev", "" ], [ "Ashtekar", "Abhay", "" ], [ "Krishnan", "Badri", "" ] ]
The anticipated enhancements in detector sensitivity and the corresponding increase in the number of gravitational wave detections will make it possible to estimate parameters of compact binaries with greater accuracy assuming general relativity(GR), and also to carry out sharper tests of GR itself. Crucial to these pr...
2406.11626
Tobias Weinzierl
Han Zhang (1 and 2), Baojiu Li (2), Tobias Weinzierl (1), Cristian Barrera-Hinojosa (3) ((1) Department of Computer Science, Durham University, (2) Institute for Computational Cosmology, Durham University (3) Instituto de F\'isica y Astronom\'ia, Universidad de Valpara\'iso)
ExaGRyPE: Numerical General Relativity Solvers Based upon the Hyperbolic PDEs Solver Engine ExaHyPE
null
null
null
null
gr-qc astro-ph.HE
http://creativecommons.org/licenses/by-nc-nd/4.0/
ExaGRyPE describes a suite of solvers for numerical relativity, based upon ExaHyPE 2, the second generation of our Exascale Hyperbolic PDE Engine. The presented generation of ExaGRyPE solves the Einstein equations in the CCZ4 formulation under a 3+1 foliation and focuses on black hole spacetimes. It employs a block-s...
[ { "created": "Mon, 17 Jun 2024 15:08:40 GMT", "version": "v1" }, { "created": "Tue, 18 Jun 2024 09:41:55 GMT", "version": "v2" } ]
2024-06-19
[ [ "Zhang", "Han", "", "1 and 2" ], [ "Li", "Baojiu", "" ], [ "Weinzierl", "Tobias", "" ], [ "Barrera-Hinojosa", "Cristian", "" ] ]
ExaGRyPE describes a suite of solvers for numerical relativity, based upon ExaHyPE 2, the second generation of our Exascale Hyperbolic PDE Engine. The presented generation of ExaGRyPE solves the Einstein equations in the CCZ4 formulation under a 3+1 foliation and focuses on black hole spacetimes. It employs a block-str...
1308.4306
Oldrich Semerak
P. Sukov\'a, O. Semer\'ak
Free motion around black holes with discs or rings: between integrability and chaos - III
19 pages, 10 figures; accepted in MNRAS
MNRAS 436 (2013) 978-996
10.1093/mnras/stt1587
null
gr-qc astro-ph.GA nlin.CD
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We continue the study of time-like geodesic dynamics in exact static, axially and reflection symmetric space-times describing the fields of a Schwarzschild black hole surrounded by thin discs or rings. In the first paper of this series, the rise (and decline) of geodesic chaos with ring/disc mass and position and wit...
[ { "created": "Tue, 20 Aug 2013 13:31:55 GMT", "version": "v1" } ]
2013-11-15
[ [ "Suková", "P.", "" ], [ "Semerák", "O.", "" ] ]
We continue the study of time-like geodesic dynamics in exact static, axially and reflection symmetric space-times describing the fields of a Schwarzschild black hole surrounded by thin discs or rings. In the first paper of this series, the rise (and decline) of geodesic chaos with ring/disc mass and position and with ...
2207.11721
Shu-Min Wu
Shu-Min Wu, Chun-Xu Wang, Dan-Dan Liu, Xiao-Li Huang, Hao-Sheng Zeng
Would quantum coherence be increased by curvature effect in de Sitter space?
24 pages, 5 figures
JHEP 02 (2023) 115
10.1007/JHEP02(2023)115
null
gr-qc hep-th quant-ph
http://creativecommons.org/licenses/by/4.0/
We study the quantum coherence in de Sitter space for the bipartite system of Alice and Bob who initially share an entangled state between the two modes of a free massive scalar field. It is shown that the space-curvature effect can produce both local coherence and correlated coherence, leading to the increase of the...
[ { "created": "Sun, 24 Jul 2022 11:35:06 GMT", "version": "v1" }, { "created": "Sun, 12 Feb 2023 08:25:04 GMT", "version": "v2" } ]
2023-03-01
[ [ "Wu", "Shu-Min", "" ], [ "Wang", "Chun-Xu", "" ], [ "Liu", "Dan-Dan", "" ], [ "Huang", "Xiao-Li", "" ], [ "Zeng", "Hao-Sheng", "" ] ]
We study the quantum coherence in de Sitter space for the bipartite system of Alice and Bob who initially share an entangled state between the two modes of a free massive scalar field. It is shown that the space-curvature effect can produce both local coherence and correlated coherence, leading to the increase of the t...
1007.4129
Diego Pavon
Ninfa Radicella and Diego Pavon
On the $c^{2}$ term in the holographic formula for dark energy
10 pages, 1 figure
JCAP 1010:005,2010
10.1088/1475-7516/2010/10/005
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is argued that the $c^{2}$ term that appears in the conventional formula for holographic dark energy should not be assumed constant in general. Notwithstanding, there is at least an exception, namely, when the Ricci scale is chosen as the infrared cutoff length.
[ { "created": "Fri, 23 Jul 2010 13:45:20 GMT", "version": "v1" } ]
2014-11-21
[ [ "Radicella", "Ninfa", "" ], [ "Pavon", "Diego", "" ] ]
It is argued that the $c^{2}$ term that appears in the conventional formula for holographic dark energy should not be assumed constant in general. Notwithstanding, there is at least an exception, namely, when the Ricci scale is chosen as the infrared cutoff length.
1407.8139
Firmin Oliveira
Firmin J. Oliveira
Cosmological General Relativity With Scale Factor and Dark Energy
28 pages, 9 figures, 1 table. The final publication is available at springerlink.com
null
10.1007/s10773-014-2138-1
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper the four-dimensional space-velocity Cosmological General Relativity of Carmeli is developed by a general solution to the Einstein field equations. The metric is given in the Tolman form and the vacuum mass density is included in the energy-momentum tensor. The scale factor redshift equation is obtained,...
[ { "created": "Wed, 30 Jul 2014 17:41:07 GMT", "version": "v1" } ]
2014-07-31
[ [ "Oliveira", "Firmin J.", "" ] ]
In this paper the four-dimensional space-velocity Cosmological General Relativity of Carmeli is developed by a general solution to the Einstein field equations. The metric is given in the Tolman form and the vacuum mass density is included in the energy-momentum tensor. The scale factor redshift equation is obtained, f...
1310.3949
Omid Jalili
O.Jalili, S.Rouhani and M.V.Takook
Gravitational wave detection by bounded cold electronic plasma in a long pipe
14 pages, 5 figures
International Journal of Theoretical Physics: Volume 49, Issue 1 (2010), Page 84
10.1007/s10773-009-0181-0
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We intend to propose an experimental sketch to detect gravitational waves (GW) directly, using an cold electronic plasma in a long pipe. By considering an cold electronic plasma in a long pipe, the Maxwell equations in 3+1 formalism will be invoked to relate gravitational waves to the perturbations of plasma particle...
[ { "created": "Tue, 15 Oct 2013 08:13:56 GMT", "version": "v1" } ]
2015-06-17
[ [ "Jalili", "O.", "" ], [ "Rouhani", "S.", "" ], [ "Takook", "M. V.", "" ] ]
We intend to propose an experimental sketch to detect gravitational waves (GW) directly, using an cold electronic plasma in a long pipe. By considering an cold electronic plasma in a long pipe, the Maxwell equations in 3+1 formalism will be invoked to relate gravitational waves to the perturbations of plasma particles....
1808.01891
Everton Murilo Carvalho Abreu
Everton M. C. Abreu, Jorge Ananias Neto, Albert C. R. Mendes and Rodrigo M. de Paula
Loop Quantum Gravity Immirzi parameter and the Kaniadakis statistics
7 pages. Preprint format
null
10.1016/j.chaos.2018.11.033
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this letter we have shown that a possible connection between the LQG Immirzi parameter and the area of a punctured surface can emerge depending on the thermostatistics theory previously chosen. Starting from the Boltzmann-Gibbs entropy, the Immirzi parameter can be reobtained. Using the Kaniadakis statistics, whic...
[ { "created": "Tue, 31 Jul 2018 19:29:06 GMT", "version": "v1" } ]
2018-12-26
[ [ "Abreu", "Everton M. C.", "" ], [ "Neto", "Jorge Ananias", "" ], [ "Mendes", "Albert C. R.", "" ], [ "de Paula", "Rodrigo M.", "" ] ]
In this letter we have shown that a possible connection between the LQG Immirzi parameter and the area of a punctured surface can emerge depending on the thermostatistics theory previously chosen. Starting from the Boltzmann-Gibbs entropy, the Immirzi parameter can be reobtained. Using the Kaniadakis statistics, which ...
1603.01221
Niels Warburton
Samuel E. Gralla, Scott A. Hughes, Niels Warburton
Inspiral into Gargantua
10 pages, 5 figures, updated to journal version
Class. Quant. Grav. 33 155002 (2016)
10.1088/0264-9381/33/15/155002
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We model the inspiral of a compact object into a more massive black hole rotating very near the theoretical maximum. We find that once the body enters the near-horizon regime the gravitational radiation is characterized by a constant frequency, equal to (twice) the horizon frequency, with an exponentially damped prof...
[ { "created": "Thu, 3 Mar 2016 18:54:59 GMT", "version": "v1" }, { "created": "Mon, 19 Sep 2016 20:45:13 GMT", "version": "v2" } ]
2016-09-21
[ [ "Gralla", "Samuel E.", "" ], [ "Hughes", "Scott A.", "" ], [ "Warburton", "Niels", "" ] ]
We model the inspiral of a compact object into a more massive black hole rotating very near the theoretical maximum. We find that once the body enters the near-horizon regime the gravitational radiation is characterized by a constant frequency, equal to (twice) the horizon frequency, with an exponentially damped profil...
2107.09800
Jian-Hua He
Jian-Hua He
GWsim: a code to simulate gravitational waves propagating in a potential well
17 pages, 11 figures, substantial text overlap with arXiv:1912.00325, accepted for publication in MNRAS
MNRAS, 506, 5278 (2021)
10.1093/mnras/stab2080
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a code to simulate the propagation of GWs in a potential well in the time domain. Our code uses the finite element method (FEM) based on the publicly available code {\it deal.ii}. We test our code using a point source monochromatic spherical wave. We examine not only the waveform observed by a local observ...
[ { "created": "Wed, 21 Jul 2021 00:52:04 GMT", "version": "v1" } ]
2021-08-12
[ [ "He", "Jian-Hua", "" ] ]
We present a code to simulate the propagation of GWs in a potential well in the time domain. Our code uses the finite element method (FEM) based on the publicly available code {\it deal.ii}. We test our code using a point source monochromatic spherical wave. We examine not only the waveform observed by a local observer...
1804.00594
Fethi M. Ramazanoglu
Fethi M Ramazano\u{g}lu
Spontaneous growth of spinor fields in gravity
This version incorporates the corrections due to some missing terms in the equations which were published in the erratum at 10.1103/PhysRevD.100.029903. Conclusions are unchanged
Phys. Rev. D 98, 044011 (2018)
10.1103/PhysRevD.98.044011
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that spinor fields nonminimally coupled to gravity can grow spontaneously in the presence of matter. We name this phenomenon spontaneous spinorization after the spontaneous scalarization scenario in scalar-tensor theories. Underlying reason for the growth of the spinor is an instability similar to the tachyon...
[ { "created": "Mon, 2 Apr 2018 15:39:01 GMT", "version": "v1" }, { "created": "Wed, 15 Aug 2018 12:36:13 GMT", "version": "v2" }, { "created": "Mon, 7 Oct 2019 14:24:03 GMT", "version": "v3" } ]
2019-10-08
[ [ "Ramazanoğlu", "Fethi M", "" ] ]
We show that spinor fields nonminimally coupled to gravity can grow spontaneously in the presence of matter. We name this phenomenon spontaneous spinorization after the spontaneous scalarization scenario in scalar-tensor theories. Underlying reason for the growth of the spinor is an instability similar to the tachyon o...
0708.2783
Janusz Garecki Prof
Janusz Garecki
On Energy of the Friedman Universes in Conformally Flat Coordinates
11 pages, no figures, Revtex4. Abstract extended. Acknowledgements added. References added
Acta Phys.Polon.B39:781-797,2008
null
null
gr-qc
null
Recently many authors have calculated the energy of the Friedman universes by using double index energy-momentum complexes in Cartesian comoving coordinates $(t,x,y,z)$ and concluded that the flat and closed Friedman universes are energy-free. We show in this paper by using Einstein canonical energy-momentum complex ...
[ { "created": "Tue, 21 Aug 2007 12:53:32 GMT", "version": "v1" }, { "created": "Fri, 24 Aug 2007 12:45:14 GMT", "version": "v2" }, { "created": "Mon, 3 Sep 2007 12:30:28 GMT", "version": "v3" }, { "created": "Tue, 2 Oct 2007 11:58:35 GMT", "version": "v4" } ]
2011-04-26
[ [ "Garecki", "Janusz", "" ] ]
Recently many authors have calculated the energy of the Friedman universes by using double index energy-momentum complexes in Cartesian comoving coordinates $(t,x,y,z)$ and concluded that the flat and closed Friedman universes are energy-free. We show in this paper by using Einstein canonical energy-momentum complex an...
0807.0885
Ming Lei Tong
Ming-lei Tong, Yang Zhang, Fang-Yu Li
Using polarized maser to detect high-frequency relic gravitational waves
20 pages, 6 figures, accepted for Phys. Rev. D
Phys.Rev.D78:024041,2008
10.1103/PhysRevD.78.024041
null
gr-qc
http://creativecommons.org/licenses/by-nc-sa/3.0/
A GHz maser beam with Gaussian-type distribution passing through a homogenous static magnetic field can be used to detect gravitational waves (GWs) with the same frequency. The presence of GWs will perturb the electromagnetic (EM) fields, giving rise to perturbed photon fluxes (PPFs). After being reflected by a fract...
[ { "created": "Sun, 6 Jul 2008 03:45:11 GMT", "version": "v1" } ]
2008-11-26
[ [ "Tong", "Ming-lei", "" ], [ "Zhang", "Yang", "" ], [ "Li", "Fang-Yu", "" ] ]
A GHz maser beam with Gaussian-type distribution passing through a homogenous static magnetic field can be used to detect gravitational waves (GWs) with the same frequency. The presence of GWs will perturb the electromagnetic (EM) fields, giving rise to perturbed photon fluxes (PPFs). After being reflected by a fractal...
2403.02119
Jos\'e De Jes\'us Padua Arg\"uelles
Bianca Dittrich, Ted Jacobson, Jos\'e Padua-Arg\"uelles
De Sitter horizon entropy from a simplicial Lorentzian path integral
24 pages, 12 figures
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The dimension of the Hilbert space of a quantum gravitational system can be written formally as a path integral partition function over Lorentzian metrics. We implement this in a 2+1 dimensional simplicial minisuperspace model in which the system is a spatial topological disc, and recover by contour deformation throu...
[ { "created": "Mon, 4 Mar 2024 15:24:22 GMT", "version": "v1" } ]
2024-03-05
[ [ "Dittrich", "Bianca", "" ], [ "Jacobson", "Ted", "" ], [ "Padua-Argüelles", "José", "" ] ]
The dimension of the Hilbert space of a quantum gravitational system can be written formally as a path integral partition function over Lorentzian metrics. We implement this in a 2+1 dimensional simplicial minisuperspace model in which the system is a spatial topological disc, and recover by contour deformation through...
1410.5104
Felipe Faria
F. F. Faria
Late cosmology in massive conformal gravity
v2: 11 pages, 1 figure, title changed, cosmological solutions added; v3: 8 pages, major changes; v4: 11 pages, updated version; v5: title changed, stability analysis included, matches the published version
Mod. Phys. Lett. A. 36, 2150115 (2021)
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we find the cosmological solutions of the massive conformal gravity field equations in the presence of matter fields. In particular, we show that the solution of negative curvature is in good agreement with the late universe.
[ { "created": "Sun, 19 Oct 2014 19:10:09 GMT", "version": "v1" }, { "created": "Fri, 25 Sep 2015 04:11:04 GMT", "version": "v2" }, { "created": "Mon, 14 Aug 2017 01:57:08 GMT", "version": "v3" }, { "created": "Wed, 6 Mar 2019 01:59:39 GMT", "version": "v4" }, { "cr...
2021-06-14
[ [ "Faria", "F. F.", "" ] ]
In this paper we find the cosmological solutions of the massive conformal gravity field equations in the presence of matter fields. In particular, we show that the solution of negative curvature is in good agreement with the late universe.
2203.13914
Lavinia Heisenberg
Lavinia Heisenberg, Simon Kuhn and Laurens Walleghem
Wald's entropy in Coincident General Relativity
30 pages
null
10.1088/1361-6382/ac987d
null
gr-qc hep-th math-ph math.MP
http://creativecommons.org/licenses/by/4.0/
The equivalence principle and its universality enables the geometrical formulation of gravity. In the standard formulation of General Relativity \'a la Einstein, the gravitational interaction is geometrized in terms of the spacetime curvature. However, if we embrace the geometrical character of gravity, two alternati...
[ { "created": "Fri, 25 Mar 2022 21:17:32 GMT", "version": "v1" } ]
2022-11-23
[ [ "Heisenberg", "Lavinia", "" ], [ "Kuhn", "Simon", "" ], [ "Walleghem", "Laurens", "" ] ]
The equivalence principle and its universality enables the geometrical formulation of gravity. In the standard formulation of General Relativity \'a la Einstein, the gravitational interaction is geometrized in terms of the spacetime curvature. However, if we embrace the geometrical character of gravity, two alternative...
1602.04337
Pedro Bicudo
Pedro Bicudo
Tighter bounds on a hypothetical graviton screening mass from the gravitational wave observation GW150914 at LIGO
6 pages, 1 figure, 1 table, new version with more clarified details and references added
null
null
null
gr-qc hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While quantum gravity is not solved yet, a screening mass for the graviton remains theoretically possible. If such a mass would screen gravity at distances of the order of the cluster galaxy radius, it could account for the universe expansion. The modified Newtonian dynamics model also could be related to a screening...
[ { "created": "Sat, 13 Feb 2016 14:28:07 GMT", "version": "v1" }, { "created": "Sun, 21 Feb 2016 00:30:51 GMT", "version": "v2" }, { "created": "Tue, 29 Mar 2016 15:38:29 GMT", "version": "v3" } ]
2016-03-30
[ [ "Bicudo", "Pedro", "" ] ]
While quantum gravity is not solved yet, a screening mass for the graviton remains theoretically possible. If such a mass would screen gravity at distances of the order of the cluster galaxy radius, it could account for the universe expansion. The modified Newtonian dynamics model also could be related to a screening g...
gr-qc/0504147
Hanno Sahlmann
Jerzy Lewandowski, Andrzej Okolow, Hanno Sahlmann and Thomas Thiemann
Uniqueness of diffeomorphism invariant states on holonomy-flux algebras
38 pages, one figure. v2: Minor changes, final version, as published in CMP
Commun.Math.Phys.267:703-733,2006
10.1007/s00220-006-0100-7
AEI-2005-093, CGPG-04/5-3
gr-qc hep-th math-ph math.MP
null
Loop quantum gravity is an approach to quantum gravity that starts from the Hamiltonian formulation in terms of a connection and its canonical conjugate. Quantization proceeds in the spirit of Dirac: First one defines an algebra of basic kinematical observables and represents it through operators on a suitable Hilber...
[ { "created": "Fri, 29 Apr 2005 18:34:19 GMT", "version": "v1" }, { "created": "Fri, 15 Sep 2006 09:46:38 GMT", "version": "v2" } ]
2008-11-26
[ [ "Lewandowski", "Jerzy", "" ], [ "Okolow", "Andrzej", "" ], [ "Sahlmann", "Hanno", "" ], [ "Thiemann", "Thomas", "" ] ]
Loop quantum gravity is an approach to quantum gravity that starts from the Hamiltonian formulation in terms of a connection and its canonical conjugate. Quantization proceeds in the spirit of Dirac: First one defines an algebra of basic kinematical observables and represents it through operators on a suitable Hilbert ...
1912.10690
Che-Yu Chen
Che-Yu Chen
Threshold of primordial black hole formation in Eddington-inspired-Born-Infeld gravity
14 pages, 1 figure. Updated to match the published version
Int.J.Mod.Phys.D 30 (2021) 02, 2150010
10.1142/S0218271821500103
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is believed that primordial black holes (PBHs), if they exist, can serve as a powerful tool to probe the early stage of the cosmic history. Essentially, in the radiation dominated universe, PBHs could form by the gravitational collapse of overdense primordial perturbations produced during inflation. In this pictur...
[ { "created": "Mon, 23 Dec 2019 08:54:58 GMT", "version": "v1" }, { "created": "Fri, 27 Dec 2019 04:35:36 GMT", "version": "v2" }, { "created": "Thu, 23 Apr 2020 09:55:22 GMT", "version": "v3" }, { "created": "Wed, 10 Feb 2021 06:59:01 GMT", "version": "v4" } ]
2021-02-11
[ [ "Chen", "Che-Yu", "" ] ]
It is believed that primordial black holes (PBHs), if they exist, can serve as a powerful tool to probe the early stage of the cosmic history. Essentially, in the radiation dominated universe, PBHs could form by the gravitational collapse of overdense primordial perturbations produced during inflation. In this picture,...
2110.02353
Gabriela Carvalho
G. C. Carvalho, M. E. X. Guimar\~aes, P. O. Mesquita and J. L. Neto
Formation and Evolution of Wakes in the Spacetime Generated by a Cosmic String in $f(R)$ Theory of Gravity
null
Journal of High Energy Physics, Gravitation and Cosmology 2021
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The formation and evolution of cosmic string wakes in the framework of a $f(R)$ theory of gravity are investigated in this work. We consider a simple model in which baryonic matter flows past a cosmic string. We treat this problem in the Zel'dovich approximation. We compare our results with previous results obtained ...
[ { "created": "Tue, 5 Oct 2021 20:48:59 GMT", "version": "v1" } ]
2021-10-07
[ [ "Carvalho", "G. C.", "" ], [ "Guimarães", "M. E. X.", "" ], [ "Mesquita", "P. O.", "" ], [ "Neto", "J. L.", "" ] ]
The formation and evolution of cosmic string wakes in the framework of a $f(R)$ theory of gravity are investigated in this work. We consider a simple model in which baryonic matter flows past a cosmic string. We treat this problem in the Zel'dovich approximation. We compare our results with previous results obtained in...
1402.0261
Friedrich W. Hehl
Friedrich W. Hehl (Cologne and Columbia, MO)
On energy-momentum and spin/helicity of quark and gluon fields
10 pages latex. Invited talk delivered at the XV Workshop on High Energy Spin Physics `DSPIN-13' in Dubna, Russia, 08--12 October 2013
null
null
null
gr-qc hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In special relativity, quantum matter can be classified according to mass-energy and spin. The corresponding field-theoretical notions are the energy-momentum-stress tensor T and the spin angular momentum tensor S. Since each object in physics carries energy and, if fermionic, also spin, the notions of T and S can be...
[ { "created": "Sun, 2 Feb 2014 23:32:10 GMT", "version": "v1" } ]
2014-02-04
[ [ "Hehl", "Friedrich W.", "", "Cologne and Columbia, MO" ] ]
In special relativity, quantum matter can be classified according to mass-energy and spin. The corresponding field-theoretical notions are the energy-momentum-stress tensor T and the spin angular momentum tensor S. Since each object in physics carries energy and, if fermionic, also spin, the notions of T and S can be s...
1108.2650
Aharon Davidson
Aharon Davidson
Holographic Shell Model: Stack Data Structure inside Black Holes
4 pages, 3 figures
Int. J. Mod. Phys. D, 23, 1450041 (2014)
10.1142/S0218271814500412
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest that bits of information inhabit, universally and holographically, the entire black hole interior, a bit per a light sheet unit interval of order Planck area difference. The number of distinguishable (tagged by a binary code) configurations, counted within the context of a discrete holographic shell model,...
[ { "created": "Fri, 12 Aug 2011 16:00:29 GMT", "version": "v1" } ]
2015-03-19
[ [ "Davidson", "Aharon", "" ] ]
We suggest that bits of information inhabit, universally and holographically, the entire black hole interior, a bit per a light sheet unit interval of order Planck area difference. The number of distinguishable (tagged by a binary code) configurations, counted within the context of a discrete holographic shell model, i...
1210.6833
Laszlo Arpad Gergely
Marek Dwornik, Zolt\'an Keresztes, L\'aszl\'o \'Arp\'ad Gergely
Modified gravity theories and dark matter models tested by galactic rotation curves
submitted to the proceedings of the conference on Relativity and Gravitation: 100 Years after Einstein in Prague
Springer Proceedings in Physics 157, 427-430 (2014)
10.1007/978-3-319-06761-2_59
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Bose-Einstein condensate dark matter model and Randall-Sundrum type 2 brane-world theory are tested with galactic rotation curves. Analytical expressions are derived for the rotational velocities of test particles around the galactic center in both cases. The velocity profiles are fitted to the observed rotation curv...
[ { "created": "Thu, 25 Oct 2012 13:39:48 GMT", "version": "v1" } ]
2014-09-12
[ [ "Dwornik", "Marek", "" ], [ "Keresztes", "Zoltán", "" ], [ "Gergely", "László Árpád", "" ] ]
Bose-Einstein condensate dark matter model and Randall-Sundrum type 2 brane-world theory are tested with galactic rotation curves. Analytical expressions are derived for the rotational velocities of test particles around the galactic center in both cases. The velocity profiles are fitted to the observed rotation curve ...
1812.01809
Carlos A. S. Almeida
L. J. S. Sousa, J. E. G. Silva, W. T. Cruz and C. A. S. Almeida
Geometric standing wave braneworld and field localization in Lyra manifold
16 pages, 1 figure
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we propose a standing wave braneworld based on Lyra geometry scenario. The Lyra displacement vector provides a modification in Einstein equations which can be interpreted as a noninteracting phantom scalar. From the Einstein's equation in Lyra manifold, a 5D standing wave braneworld is constructed in th...
[ { "created": "Wed, 5 Dec 2018 04:02:44 GMT", "version": "v1" } ]
2018-12-06
[ [ "Sousa", "L. J. S.", "" ], [ "Silva", "J. E. G.", "" ], [ "Cruz", "W. T.", "" ], [ "Almeida", "C. A. S.", "" ] ]
In this work, we propose a standing wave braneworld based on Lyra geometry scenario. The Lyra displacement vector provides a modification in Einstein equations which can be interpreted as a noninteracting phantom scalar. From the Einstein's equation in Lyra manifold, a 5D standing wave braneworld is constructed in the ...
2112.06821
Eirini C. Telali
Eirini C. Telali, Emmanuel N. Saridakis
Power-law holographic dark energy and cosmology
6 pages, 3 figures
null
10.1140/epjc/s10052-022-10411-z
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We formulate power-law holographic dark energy, which is a modified holographic dark energy model based on the extended entropy relation arising from the consideration of state mixing between the ground and the excited ones in the calculation of the entanglement entropy. We construct two cases of the scenario, imposi...
[ { "created": "Mon, 13 Dec 2021 17:33:30 GMT", "version": "v1" }, { "created": "Tue, 24 May 2022 08:41:18 GMT", "version": "v2" } ]
2022-05-25
[ [ "Telali", "Eirini C.", "" ], [ "Saridakis", "Emmanuel N.", "" ] ]
We formulate power-law holographic dark energy, which is a modified holographic dark energy model based on the extended entropy relation arising from the consideration of state mixing between the ground and the excited ones in the calculation of the entanglement entropy. We construct two cases of the scenario, imposing...
1801.05843
Zachary Fifer
Zack Fifer, Theo Torres, Sebastian Erne, Anastasios Avgoustidis, Richard J. A. Hill, and Silke Weinfurtner
Mimicking inflation with 2-fluid systems in a strong gradient magnetic field
6 pages, 3 figures
Phys. Rev. E 99, 031101 (2019)
10.1103/PhysRevE.99.031101
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the standard cosmological picture the Universe underwent a brief period of near-exponential expansion, known as Inflation. This provides an explanation for structure formation through the amplification of perturbations by the rapid expansion of the fabric of space. Although this mech- anism is theoretically well u...
[ { "created": "Wed, 17 Jan 2018 19:47:55 GMT", "version": "v1" } ]
2019-04-03
[ [ "Fifer", "Zack", "" ], [ "Torres", "Theo", "" ], [ "Erne", "Sebastian", "" ], [ "Avgoustidis", "Anastasios", "" ], [ "Hill", "Richard J. A.", "" ], [ "Weinfurtner", "Silke", "" ] ]
In the standard cosmological picture the Universe underwent a brief period of near-exponential expansion, known as Inflation. This provides an explanation for structure formation through the amplification of perturbations by the rapid expansion of the fabric of space. Although this mech- anism is theoretically well und...
1505.00714
Hirotaka Yoshino
Hirotaka Yoshino, Hideo Kodama
Bosenova and Axiverse
56 pages, 30 figures, Invited contribution to the Focus Issue on "Black holes and fundamental fields" to appear in Classical and Quantum Gravity
Class. Quantum Grav. 32 (2015) 214001
10.1088/0264-9381/32/21/214001
KEK-TH-1820, KEK-Cosmo-169
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report some new interesting features of the dynamics of a string axion field (i.e., a (pseudo-)scalar field with tiny mass with sine-Gordon-type self-interaction) around a rotating black hole in three respects. First, we revisit the calculation of the growth rate of superradiant instability, and show that in some ...
[ { "created": "Mon, 4 May 2015 17:03:43 GMT", "version": "v1" } ]
2015-10-19
[ [ "Yoshino", "Hirotaka", "" ], [ "Kodama", "Hideo", "" ] ]
We report some new interesting features of the dynamics of a string axion field (i.e., a (pseudo-)scalar field with tiny mass with sine-Gordon-type self-interaction) around a rotating black hole in three respects. First, we revisit the calculation of the growth rate of superradiant instability, and show that in some ca...
1807.09787
Adam Rebei
Adam Rebei, E. A. Huerta, Sibo Wang, Sarah Habib, Roland Haas, Daniel Johnson, Daniel George
Fusing numerical relativity and deep learning to detect higher-order multipole waveforms from eccentric binary black hole mergers
17 pages, 11 figures, 1 appendix, accepted to Phys. Rev. D
Phys. Rev. D 100, 044025 (2019)
10.1103/PhysRevD.100.044025
null
gr-qc astro-ph.HE physics.comp-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine the mass-ratio, eccentricity and binary inclination angles that maximize the contribution of the higher-order waveform multipoles $(\ell, \, |m|)= \{(2,\,2),\, (2,\,1),\, (3,\,3),\, (3,\,2), \, (3,\,1),\, (4,\,4),\, (4,\,3),\, (4,\,2),\,(4,\,1)\}$ for the gravitational wave detection of eccentric binary ...
[ { "created": "Wed, 25 Jul 2018 18:00:05 GMT", "version": "v1" }, { "created": "Thu, 15 Aug 2019 20:47:44 GMT", "version": "v2" } ]
2019-08-19
[ [ "Rebei", "Adam", "" ], [ "Huerta", "E. A.", "" ], [ "Wang", "Sibo", "" ], [ "Habib", "Sarah", "" ], [ "Haas", "Roland", "" ], [ "Johnson", "Daniel", "" ], [ "George", "Daniel", "" ] ]
We determine the mass-ratio, eccentricity and binary inclination angles that maximize the contribution of the higher-order waveform multipoles $(\ell, \, |m|)= \{(2,\,2),\, (2,\,1),\, (3,\,3),\, (3,\,2), \, (3,\,1),\, (4,\,4),\, (4,\,3),\, (4,\,2),\,(4,\,1)\}$ for the gravitational wave detection of eccentric binary bl...
1103.4121
Mona Kamal
M. I. Wanas and Mona M. Kamal
An AP-Structure with Finslerian Flavor II: Torsion, Curvature and Other Objects
15 pages, LaTeX file, revised version, Journal reference inserted
Mod.Phys.Lett.A26:2065-2078,2011
10.1142/S021773231103653X
null
gr-qc math.DG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An absolute parallelism (AP-) space having Finslerian properties is called FAP-space. This FAP-structure is more wider than both conventional AP and Finsler structures. In the present work, more geometric objects as curvature and torsion tensors are derived in the context of this structure. Also second order tensors,...
[ { "created": "Mon, 21 Mar 2011 19:42:02 GMT", "version": "v1" }, { "created": "Wed, 14 Sep 2011 10:05:42 GMT", "version": "v2" } ]
2011-09-15
[ [ "Wanas", "M. I.", "" ], [ "Kamal", "Mona M.", "" ] ]
An absolute parallelism (AP-) space having Finslerian properties is called FAP-space. This FAP-structure is more wider than both conventional AP and Finsler structures. In the present work, more geometric objects as curvature and torsion tensors are derived in the context of this structure. Also second order tensors, u...
1110.1018
Miguel Socolovsky
Miguel Socolovsky
Fibre bundles, connections, general relativity, and Einstein-Cartan theory
60 pages
null
null
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present in the most natural way, that is, in the context of the theory of vector and principal bundles and connections in them, fundamental geometrical concepts related to General Relativity and one of its extensions, the Einstein-Cartan theory.
[ { "created": "Wed, 5 Oct 2011 15:12:15 GMT", "version": "v1" } ]
2015-03-13
[ [ "Socolovsky", "Miguel", "" ] ]
We present in the most natural way, that is, in the context of the theory of vector and principal bundles and connections in them, fundamental geometrical concepts related to General Relativity and one of its extensions, the Einstein-Cartan theory.
1602.01152
George F. Chapline
George Chapline and James Barbieri
Was there a negative vacuum energy in your past?
16 pages, 3 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A model for gravitational collapse where the event horizon is a quantum critical phase transition is extended to provide an explanation for the origin of the observable universe, where the expanding universe that we observe today was proceeded by a flat universe with a negative cosmological constant. In principal thi...
[ { "created": "Tue, 2 Feb 2016 23:12:25 GMT", "version": "v1" }, { "created": "Sat, 6 Feb 2016 01:57:57 GMT", "version": "v2" } ]
2016-02-09
[ [ "Chapline", "George", "" ], [ "Barbieri", "James", "" ] ]
A model for gravitational collapse where the event horizon is a quantum critical phase transition is extended to provide an explanation for the origin of the observable universe, where the expanding universe that we observe today was proceeded by a flat universe with a negative cosmological constant. In principal this ...
2310.12138
Dallas DeGan
Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Jeremy Baier, Paul T. Baker, Bence B\'ecsy, Laura Blecha, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, Rand Burnette, Robin Case, J. Andrew Casey-Clyde, Maria Charisi, Shami Chatterjee, Tyler Cohen, James M. Cordes, Neil J. Cornish...
The NANOGrav 15-year data set: Search for Transverse Polarization Modes in the Gravitational-Wave Background
11 pages, 5 figures
null
null
null
gr-qc astro-ph.GA astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
Recently we found compelling evidence for a gravitational wave background with Hellings and Downs (HD) correlations in our 15-year data set. These correlations describe gravitational waves as predicted by general relativity, which has two transverse polarization modes. However, more general metric theories of gravity...
[ { "created": "Wed, 18 Oct 2023 17:49:33 GMT", "version": "v1" } ]
2023-10-19
[ [ "Agazie", "Gabriella", "" ], [ "Anumarlapudi", "Akash", "" ], [ "Archibald", "Anne M.", "" ], [ "Arzoumanian", "Zaven", "" ], [ "Baier", "Jeremy", "" ], [ "Baker", "Paul T.", "" ], [ "Bécsy", "Bence", "" ...
Recently we found compelling evidence for a gravitational wave background with Hellings and Downs (HD) correlations in our 15-year data set. These correlations describe gravitational waves as predicted by general relativity, which has two transverse polarization modes. However, more general metric theories of gravity c...
0712.4301
J. Ponce de Leon
J. Ponce de Leon
Embeddings for 4D Einstein equations with a cosmological constant
null
Grav.Cosmol.14:241-247,2008
10.1134/S0202289308030067
null
gr-qc
null
There are many ways of embedding a 4D spacetime in a given higher-dimensional manifold while, satisfying the field equations. In this work we extend and generalize a recent paper by Mashhoon and Wesson ({\it Gen. Rel. Gravit.} {\bf 39}, 1403(2007)) by showing different ways of embedding a solution of the 4D Einstein ...
[ { "created": "Fri, 28 Dec 2007 01:43:28 GMT", "version": "v1" }, { "created": "Mon, 31 Dec 2007 02:23:54 GMT", "version": "v2" } ]
2009-11-13
[ [ "de Leon", "J. Ponce", "" ] ]
There are many ways of embedding a 4D spacetime in a given higher-dimensional manifold while, satisfying the field equations. In this work we extend and generalize a recent paper by Mashhoon and Wesson ({\it Gen. Rel. Gravit.} {\bf 39}, 1403(2007)) by showing different ways of embedding a solution of the 4D Einstein eq...
2204.05996
Jainendra Kumar Singh Dr.
Ashima Sood, Arun Kumar, J. K. Singh and Sushant G. Ghosh
Thermodynamic stability and P-V criticality of nonsingular-AdS black holes endowed with clouds of strings
12 pages, 16 figures
European Physical Journal C, (2022) 82:227
10.1140/epjc/s10052-022-10181-8
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We investigate the extended phase space thermodynamics of nonsingular-AdS black holes minimally coupled to clouds of strings in which we consider the cosmological constant ($\Lambda$) as the pressure ($P$) of the black holes and its conjugate variable thermodynamical volume ($V$) of the black holes. Owing to the back...
[ { "created": "Tue, 12 Apr 2022 12:04:06 GMT", "version": "v1" } ]
2022-04-14
[ [ "Sood", "Ashima", "" ], [ "Kumar", "Arun", "" ], [ "Singh", "J. K.", "" ], [ "Ghosh", "Sushant G.", "" ] ]
We investigate the extended phase space thermodynamics of nonsingular-AdS black holes minimally coupled to clouds of strings in which we consider the cosmological constant ($\Lambda$) as the pressure ($P$) of the black holes and its conjugate variable thermodynamical volume ($V$) of the black holes. Owing to the backgr...
gr-qc/0607088
Christian Boehmer
Christian G. Boehmer
The Einstein-Cartan-Elko system
12 pages, no figures
AnnalenPhys.16:38-44,2007
10.1002/andp.200610216
null
gr-qc hep-th
null
The present paper analyses the Einstein-Cartan theory of gravitation with Elko spinors as sources of curvature and torsion. After minimally coupling the Elko spinors to torsion, the spin angular momentum tensor is derived and its structure is discussed. It shows a much richer structure than the Dirac analogue and hen...
[ { "created": "Fri, 21 Jul 2006 14:30:50 GMT", "version": "v1" } ]
2008-11-26
[ [ "Boehmer", "Christian G.", "" ] ]
The present paper analyses the Einstein-Cartan theory of gravitation with Elko spinors as sources of curvature and torsion. After minimally coupling the Elko spinors to torsion, the spin angular momentum tensor is derived and its structure is discussed. It shows a much richer structure than the Dirac analogue and hence...
gr-qc/9812091
Mark D. Roberts
Mark D. Roberts
Non Metric Mass
37 pages, no diagrams, LaTex2e
null
null
null
gr-qc hep-th
null
In general relativity g_ab;c=0 implies that the wave equation (\Box^2-M)g_ab=0 always has M=0. If the underlying geometry is generalized to include non-metricity this incurs M \neq 0, and the above wave equation can be rewritten as M(x)+\td{\na}_a Q_.^a+(\ep+\fr{d}{2}-2)Q_a Q_.^a=0, where \ep=0, 1, 2, or 3, d is the ...
[ { "created": "Tue, 29 Dec 1998 16:49:17 GMT", "version": "v1" }, { "created": "Wed, 30 Dec 1998 14:27:52 GMT", "version": "v2" } ]
2007-05-23
[ [ "Roberts", "Mark D.", "" ] ]
In general relativity g_ab;c=0 implies that the wave equation (\Box^2-M)g_ab=0 always has M=0. If the underlying geometry is generalized to include non-metricity this incurs M \neq 0, and the above wave equation can be rewritten as M(x)+\td{\na}_a Q_.^a+(\ep+\fr{d}{2}-2)Q_a Q_.^a=0, where \ep=0, 1, 2, or 3, d is the di...
1509.06967
S Habib Mazharimousavi
Z. Amirabi, M. Halilsoy and S. Habib Mazharimousavi
Generation of spherically symmetric metrics in $f\left( R\right) $ gravity
8 pages, no figure, revised version accepted for publication in EPJC
Eur. Phys. J. C 76, 338 (2016)
10.1140/epjc/s10052-016-4164-z
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In $D-$dimensional spherically symmetric $f\left( R\right) $ gravity there are three unknown functions to be determined from the fourth order differential equations. It is shown that the system remarkably integrates to relate two functions through the third one to provide reduction to second order equations accompani...
[ { "created": "Wed, 16 Sep 2015 09:03:55 GMT", "version": "v1" }, { "created": "Tue, 29 Sep 2015 07:59:55 GMT", "version": "v2" }, { "created": "Mon, 30 May 2016 06:05:49 GMT", "version": "v3" } ]
2016-06-23
[ [ "Amirabi", "Z.", "" ], [ "Halilsoy", "M.", "" ], [ "Mazharimousavi", "S. Habib", "" ] ]
In $D-$dimensional spherically symmetric $f\left( R\right) $ gravity there are three unknown functions to be determined from the fourth order differential equations. It is shown that the system remarkably integrates to relate two functions through the third one to provide reduction to second order equations accompanied...
0709.1603
Jose Geraldo Pereira
R. Aldrovandi, J. G. Pereira, K. H. Vu
The Nonlinear Essence of Gravitational Waves
Plain Latex, 13 pages, no figures. Accepted for publication in Foundations of Physiscs
Found.Phys.37:1503-1517,2007
10.1007/s10701-007-9180-2
null
gr-qc hep-th
null
A critical review of gravitational wave theory is made. It is pointed out that the usual linear approach to the gravitational wave theory is neither conceptually consistent nor mathematically justified. Relying upon that analysis it is then argued that -- analogously to a Yang-Mills propagating field, which must be n...
[ { "created": "Tue, 11 Sep 2007 12:33:40 GMT", "version": "v1" } ]
2008-11-26
[ [ "Aldrovandi", "R.", "" ], [ "Pereira", "J. G.", "" ], [ "Vu", "K. H.", "" ] ]
A critical review of gravitational wave theory is made. It is pointed out that the usual linear approach to the gravitational wave theory is neither conceptually consistent nor mathematically justified. Relying upon that analysis it is then argued that -- analogously to a Yang-Mills propagating field, which must be non...
1911.04482
Alexander Oliveros <
A. Oliveros and Mario A. Acero
Inflation driven by a holographic energy density
7 pages, 2 figures, references added, minor changes, accepted for publication in EPL
EPL 128 (2019) 5, 59001
10.1209/0295-5075/128/59001
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this letter we study a model of inflation in which the inflationary regimen comes from a type of holographic energy density. In particular, we consider the Granda-Oliveros proposal for the holographic energy density, which contains two free dimensionless parameters, $\alpha$ and $\beta$. This holographic energy de...
[ { "created": "Mon, 11 Nov 2019 13:42:10 GMT", "version": "v1" }, { "created": "Thu, 23 Jan 2020 19:26:52 GMT", "version": "v2" } ]
2023-02-15
[ [ "Oliveros", "A.", "" ], [ "Acero", "Mario A.", "" ] ]
In this letter we study a model of inflation in which the inflationary regimen comes from a type of holographic energy density. In particular, we consider the Granda-Oliveros proposal for the holographic energy density, which contains two free dimensionless parameters, $\alpha$ and $\beta$. This holographic energy dens...
2303.12656
Mohamed Ould El Hadj
Mohamed Ould El Hadj
Scattering and conversion of electromagnetic and gravitational waves by Reissner-Nordstr\"om black holes: The Regge pole description
v2: minor changes and a few typos corrected in the text to match the published version
Phys. Rev. D 107, 104051 (2023)
10.1103/PhysRevD.107.104051
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the problem of scattering and conversion of monochromatic planar gravitational and electromagnetic waves impinging upon a Reissner-Nordstr\"om black hole using a Regge pole description, i.e., a complex angular momentum approach. For this purpose, we first compute numerically the Regge pole spectrum for...
[ { "created": "Wed, 22 Mar 2023 15:34:16 GMT", "version": "v1" }, { "created": "Thu, 25 May 2023 14:16:26 GMT", "version": "v2" } ]
2023-05-26
[ [ "Hadj", "Mohamed Ould El", "" ] ]
We investigate the problem of scattering and conversion of monochromatic planar gravitational and electromagnetic waves impinging upon a Reissner-Nordstr\"om black hole using a Regge pole description, i.e., a complex angular momentum approach. For this purpose, we first compute numerically the Regge pole spectrum for v...
1006.4806
Sunil Maharaj
S. Thirukkanesh, S. D. Maharaj
Mixed potentials in radiative stellar collapse
10 pages, To appear in J. Math. Phys
J.Math.Phys.51:072502,2010
10.1063/1.3456081
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the behaviour of a radiating star when the interior expanding, shearing fluid particles are traveling in geodesic motion. We demonstrate that it is possible to obtain new classes of exact solutions in terms of elementary functions without assuming a separable form for the gravitational potentials or initiall...
[ { "created": "Thu, 24 Jun 2010 14:50:27 GMT", "version": "v1" } ]
2011-08-23
[ [ "Thirukkanesh", "S.", "" ], [ "Maharaj", "S. D.", "" ] ]
We study the behaviour of a radiating star when the interior expanding, shearing fluid particles are traveling in geodesic motion. We demonstrate that it is possible to obtain new classes of exact solutions in terms of elementary functions without assuming a separable form for the gravitational potentials or initially ...
0806.3066
Nicoleta Brinzei
Sergey Siparov (1), Nicoleta Brinzei (2) ((1) State University of civil aviation, St-Petersburg, Russia, (2) "Transilvania" University, Brasov, Romania)
Space-time anisotropy: theoretical issues and the possibility of an observational test
17 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The specific astrophysical data collected during the last decade causes the need for the modification of the expression for the Einstein-Hilbert action, and several attempts sufficing this need are known. The modification suggested in this paper stems from the possible anisotropy of space-time and this means the natu...
[ { "created": "Wed, 18 Jun 2008 19:04:04 GMT", "version": "v1" }, { "created": "Sat, 2 Aug 2008 16:59:59 GMT", "version": "v2" } ]
2012-07-04
[ [ "Siparov", "Sergey", "" ], [ "Brinzei", "Nicoleta", "" ] ]
The specific astrophysical data collected during the last decade causes the need for the modification of the expression for the Einstein-Hilbert action, and several attempts sufficing this need are known. The modification suggested in this paper stems from the possible anisotropy of space-time and this means the natura...
1804.05883
Changqing Liu Lcqliu
Changqing Liu, Chikun Ding, Jiliang Jing
Periodic orbits around Kerr Sen black holes
14 pages 8 figures
Commun. Theor. Phys. 71 (12), 1461, 2019
10.1088/0253-6102/71/12/1461
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate periodic orbits and zoom-whirl behaviors around a Kerr Sen black hole with a rational number $q$ in terms of three integers $(z,w,v)$, from which one can immediately read off the number of leaves(or zooms), the ordering of the leaves, and the number of whirls. The characteristic of zoom-whirl periodic ...
[ { "created": "Mon, 16 Apr 2018 18:29:50 GMT", "version": "v1" }, { "created": "Sat, 23 Nov 2019 01:58:51 GMT", "version": "v2" } ]
2019-12-10
[ [ "Liu", "Changqing", "" ], [ "Ding", "Chikun", "" ], [ "Jing", "Jiliang", "" ] ]
We investigate periodic orbits and zoom-whirl behaviors around a Kerr Sen black hole with a rational number $q$ in terms of three integers $(z,w,v)$, from which one can immediately read off the number of leaves(or zooms), the ordering of the leaves, and the number of whirls. The characteristic of zoom-whirl periodic or...
1604.06576
J.J.L. Velazquez
Alan D. Rendall and Juan J. L. Vel\'azquez
Veiled singularities for the spherically symmetric massless Einstein-Vlasov system
67 pages, 1 figure
null
10.1007/s00023-017-0607-9
null
gr-qc math.AP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper continues the investigation of the formation of naked singularities in the collapse of collisionless matter initiated in [RV]. There the existence of certain classes of non-smooth solutions of the Einstein-Vlasov system was proved. Those solutions are self-similar and hence not asymptotically flat. To obta...
[ { "created": "Fri, 22 Apr 2016 08:58:51 GMT", "version": "v1" } ]
2018-03-28
[ [ "Rendall", "Alan D.", "" ], [ "Velázquez", "Juan J. L.", "" ] ]
This paper continues the investigation of the formation of naked singularities in the collapse of collisionless matter initiated in [RV]. There the existence of certain classes of non-smooth solutions of the Einstein-Vlasov system was proved. Those solutions are self-similar and hence not asymptotically flat. To obtain...
gr-qc/0703121
Roy Maartens
George Ellis, Roy Maartens, Malcolm MacCallum
Causality and the speed of sound
v2: additional discussion on models that appear to have superluminal signal speeds; version to appear in GRG
Gen.Rel.Grav.39:1651-1660,2007
10.1007/s10714-007-0479-2
null
gr-qc astro-ph hep-th
null
A usual causal requirement on a viable theory of matter is that the speed of sound be at most the speed of light. In view of various recent papers querying this limit, the question is revisited here. We point to various issues confronting theories that violate the usual constraint.
[ { "created": "Sun, 25 Mar 2007 20:20:00 GMT", "version": "v1" }, { "created": "Tue, 29 May 2007 12:16:24 GMT", "version": "v2" } ]
2008-11-26
[ [ "Ellis", "George", "" ], [ "Maartens", "Roy", "" ], [ "MacCallum", "Malcolm", "" ] ]
A usual causal requirement on a viable theory of matter is that the speed of sound be at most the speed of light. In view of various recent papers querying this limit, the question is revisited here. We point to various issues confronting theories that violate the usual constraint.
1505.01990
Izzet Sakalli
I. Sakalli and H. Gursel
Quantum tunneling from rotating black holes with scalar hair in three dimensions
null
European Physical Journal C Volume: 76 Issue: 6 Article Number: 318 (2016)
10.1140/epjc/s10052-016-4158-x
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the Hawking radiation (HR) of scalar and Dirac particles (fermions) emitted from a rotating scalar hair black hole (RSHBH) within the context of three dimensional ($3D$) Einstein gravity using non-minimally coupled scalar field theory. Amalgamating the quantum tunneling approach with the Wentzel--Kramers--Br...
[ { "created": "Fri, 8 May 2015 10:49:02 GMT", "version": "v1" } ]
2016-10-24
[ [ "Sakalli", "I.", "" ], [ "Gursel", "H.", "" ] ]
We study the Hawking radiation (HR) of scalar and Dirac particles (fermions) emitted from a rotating scalar hair black hole (RSHBH) within the context of three dimensional ($3D$) Einstein gravity using non-minimally coupled scalar field theory. Amalgamating the quantum tunneling approach with the Wentzel--Kramers--Bril...
2312.07486
Stylianos A. Tsilioukas
Stylianos A. Tsilioukas, Emmanuel N. Saridakis, Charalampos Tzerefos
Dark energy from topology change induced by microscopic Gauss-Bonnet wormholes
9 pages, 1 figure, version to appear in Phys. Rev. D
Phys.Rev.D 109 (2024), 084010
10.1103/PhysRevD.109.084010
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is known that the appearance of microscopic objects with distinct topologies and different Euler characteristics, such as instatons and wormholes, at the spacetime-foam level in Euclidean quantum gravity approaches, leads to spacetime topology changes. Such changes, in principle, may affect the field equations tha...
[ { "created": "Tue, 12 Dec 2023 18:21:41 GMT", "version": "v1" }, { "created": "Wed, 28 Feb 2024 14:54:28 GMT", "version": "v2" } ]
2024-04-08
[ [ "Tsilioukas", "Stylianos A.", "" ], [ "Saridakis", "Emmanuel N.", "" ], [ "Tzerefos", "Charalampos", "" ] ]
It is known that the appearance of microscopic objects with distinct topologies and different Euler characteristics, such as instatons and wormholes, at the spacetime-foam level in Euclidean quantum gravity approaches, leads to spacetime topology changes. Such changes, in principle, may affect the field equations that ...
2102.09456
Orfeu Bertolami
Orfeu Bertolami
Inflation, phase transitions and the cosmological constant
9 pages. Version to match to one to be published in General Relativity and Gravitation
null
10.1007/s10714-021-02877-1
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
Cosmological phase transitions are thought to have taken place at the early Universe imprinting their properties on the observable Universe. There is strong evidence that, through the dynamics of a scalar field that lead a second order phase transition, inflation shaped the Universe accounting for the most conspicuou...
[ { "created": "Wed, 17 Feb 2021 14:52:01 GMT", "version": "v1" }, { "created": "Sat, 15 May 2021 09:32:28 GMT", "version": "v2" }, { "created": "Wed, 3 Nov 2021 18:21:39 GMT", "version": "v3" } ]
2021-12-08
[ [ "Bertolami", "Orfeu", "" ] ]
Cosmological phase transitions are thought to have taken place at the early Universe imprinting their properties on the observable Universe. There is strong evidence that, through the dynamics of a scalar field that lead a second order phase transition, inflation shaped the Universe accounting for the most conspicuous ...
1807.01381
Lee Smolin
Stephon Alexander, Joao Magueijo and Lee Smolin
The quantum cosmological constant
15 pages. no figures, minor improvments
null
null
null
gr-qc hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an extension of general relativity in which the cosmological constant becomes dynamical and turns out to be conjugate to the Chern-Simons invariant of the Ashtekar connection on a spatial slicing. The latter has been proposed in \cite{Chopin-Lee} as a time variable for quantum gravity: the Chern-Simons tim...
[ { "created": "Tue, 3 Jul 2018 21:58:47 GMT", "version": "v1" }, { "created": "Sat, 21 Jul 2018 16:02:09 GMT", "version": "v2" } ]
2018-07-24
[ [ "Alexander", "Stephon", "" ], [ "Magueijo", "Joao", "" ], [ "Smolin", "Lee", "" ] ]
We present an extension of general relativity in which the cosmological constant becomes dynamical and turns out to be conjugate to the Chern-Simons invariant of the Ashtekar connection on a spatial slicing. The latter has been proposed in \cite{Chopin-Lee} as a time variable for quantum gravity: the Chern-Simons time....
gr-qc/0210045
Thomas Buchert
Thomas Buchert and Mauro Carfora
Cosmological parameters are dressed
LateX, PRLstyle, 4 pages; submitted to PRL
Phys.Rev.Lett.90:031101,2003
10.1103/PhysRevLett.90.031101
null
gr-qc astro-ph hep-ph hep-th
null
In the context of the averaging problem in relativistic cosmology, we provide a key to the interpretation of cosmological parameters by taking into account the actual inhomogeneous geometry of the Universe. We discuss the relation between `bare' cosmological parameters determining the cosmological model, and the para...
[ { "created": "Tue, 15 Oct 2002 08:04:14 GMT", "version": "v1" } ]
2009-07-10
[ [ "Buchert", "Thomas", "" ], [ "Carfora", "Mauro", "" ] ]
In the context of the averaging problem in relativistic cosmology, we provide a key to the interpretation of cosmological parameters by taking into account the actual inhomogeneous geometry of the Universe. We discuss the relation between `bare' cosmological parameters determining the cosmological model, and the parame...
2307.02567
Yuri Obukhov
Yuri N. Obukhov
Spin as a probe of axion physics in general relativity
14 pages, Revtex, no figures. Accepted for publication in International Journal of Modern Physics A
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The dynamics of spin in external electromagnetic, gravitational, and axion fields is analysed in the framework of the gravitoelectromagnetism approach in Einstein's general relativity theory. We consistently extend the recent studies from the flat Minkowski geometry to the curved spacetime manifolds, contributing to ...
[ { "created": "Wed, 5 Jul 2023 18:08:15 GMT", "version": "v1" } ]
2023-07-07
[ [ "Obukhov", "Yuri N.", "" ] ]
The dynamics of spin in external electromagnetic, gravitational, and axion fields is analysed in the framework of the gravitoelectromagnetism approach in Einstein's general relativity theory. We consistently extend the recent studies from the flat Minkowski geometry to the curved spacetime manifolds, contributing to th...
1312.2866
Marc Lachieze-Rey
Marc Lachieze-Rey (APC)
In search of relativistic time
to appear in Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper explores the status of some notions which are usually associated to time, like datations, chronology, durations, causality, cosmic time and time functions in the Einsteinian relativistic theories. It shows how, even if some of these notions do exist in the theory or for some particular solution of it, they...
[ { "created": "Mon, 9 Dec 2013 20:18:35 GMT", "version": "v1" } ]
2013-12-11
[ [ "Lachieze-Rey", "Marc", "", "APC" ] ]
This paper explores the status of some notions which are usually associated to time, like datations, chronology, durations, causality, cosmic time and time functions in the Einsteinian relativistic theories. It shows how, even if some of these notions do exist in the theory or for some particular solution of it, they a...
2111.02462
Charis Anastopoulos
Charis Anastopoulos and Bei-Lok Hu
Gravitational Decoherence: A Thematic Overview
26 pages, Article prepared for the Special Topic Collection "Celebrating Sir Roger Penrose's Nobel Prize"
null
10.1116/5.0077536
null
gr-qc hep-th quant-ph
http://creativecommons.org/licenses/by/4.0/
Gravitational decoherence (GD) refers to the effects of gravity in actuating the classical appearance of a quantum system. Because the underlying processes involve issues in general relativity (GR), quantum field theory (QFT) and quantum information, GD has fundamental theoretical significance. There is a great varie...
[ { "created": "Wed, 3 Nov 2021 18:37:40 GMT", "version": "v1" } ]
2024-06-19
[ [ "Anastopoulos", "Charis", "" ], [ "Hu", "Bei-Lok", "" ] ]
Gravitational decoherence (GD) refers to the effects of gravity in actuating the classical appearance of a quantum system. Because the underlying processes involve issues in general relativity (GR), quantum field theory (QFT) and quantum information, GD has fundamental theoretical significance. There is a great variety...
2204.06420
Francesco Pace
Francesco Pace and Noemi Frusciante
A 3D Phase Space Analysis of Scalar Field Potentials
23 pages, 3 figures. 4 tables. Accepted for publication on Universe for the Special Issue entitled "Large Scale Structure of the Universe", led by the authors, and belongs to the section "Cosmology"
Universe 2022, 8(3), 145
null
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this study, we present the phase-space analysis of Quintessence models specified by the choice of two potentials, namely the Recliner potential and what we call the broken exponential-law potential, which is a new proposal. Using a dynamical system analysis we provide a systematic study of the cosmological evoluti...
[ { "created": "Wed, 13 Apr 2022 14:30:48 GMT", "version": "v1" } ]
2022-04-14
[ [ "Pace", "Francesco", "" ], [ "Frusciante", "Noemi", "" ] ]
In this study, we present the phase-space analysis of Quintessence models specified by the choice of two potentials, namely the Recliner potential and what we call the broken exponential-law potential, which is a new proposal. Using a dynamical system analysis we provide a systematic study of the cosmological evolution...
2104.09972
Justin Ripley
Justin L. Ripley
A symmetric hyperbolic formulation of the vacuum Einstein equations in affine-null coordinates
updated to match journal version
Journal of Mathematical Physics 62, 062501 (2021)
10.1063/5.0055561
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a symmetric hyperbolic formulation of the Einstein equations in affine-null coordinates. Giannakopoulos et. al. (arXiv:2007.06419) recently showed that the most commonly numerically implemented formulations of the Einstein equations in affine-null coordinates (and other single-null coordinate systems) are ...
[ { "created": "Tue, 20 Apr 2021 14:04:03 GMT", "version": "v1" }, { "created": "Wed, 2 Jun 2021 20:37:16 GMT", "version": "v2" } ]
2021-06-04
[ [ "Ripley", "Justin L.", "" ] ]
We present a symmetric hyperbolic formulation of the Einstein equations in affine-null coordinates. Giannakopoulos et. al. (arXiv:2007.06419) recently showed that the most commonly numerically implemented formulations of the Einstein equations in affine-null coordinates (and other single-null coordinate systems) are on...
1705.09470
Alexander Kamenshchik
A.O. Barvinsky and A.Yu. Kamenshchik
Darkness without dark matter and energy -- generalized unimodular gravity
11 pages, final version, to be published in Physics Letters B
Physics Letters B 774, 59-63 (2017)
10.1016/j.physletb.2017.09.045
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest a Lorentz non-invariant generalization of the unimodular gravity theory, which is classically equivalent to general relativity with a locally inert (devoid of local degrees of freedom) perfect fluid having an equation of state with a constant parameter $w$. For the range of $w$ near $-1$ this dark fluid ca...
[ { "created": "Fri, 26 May 2017 08:17:11 GMT", "version": "v1" }, { "created": "Fri, 15 Sep 2017 13:30:05 GMT", "version": "v2" } ]
2017-10-02
[ [ "Barvinsky", "A. O.", "" ], [ "Kamenshchik", "A. Yu.", "" ] ]
We suggest a Lorentz non-invariant generalization of the unimodular gravity theory, which is classically equivalent to general relativity with a locally inert (devoid of local degrees of freedom) perfect fluid having an equation of state with a constant parameter $w$. For the range of $w$ near $-1$ this dark fluid can ...
1604.07213
Muhammad Zubair
M. Zubair, Farzana Kousar and Sebastian Bahamonde
Thermodynamics in $f(R,R_{\alpha\beta}R^{\alpha\beta},\phi)$ theory of gravity
29 pages, 4 figures
Physics of the Dark Universe Vol. 14, (2016)116-125
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
First and second laws of black hole thermodynamics are examined at the apparent horizon of FRW spacetime in $f(R,R_{\alpha\beta}R^{\alpha\beta} ,\phi)$ gravity, where $R$, $R_{\alpha\beta}R^{\alpha\beta}$ and $\phi$ are the Ricci scalar, Ricci invariant and the scalar field respectively. In this modified theory, Frie...
[ { "created": "Mon, 25 Apr 2016 11:47:38 GMT", "version": "v1" }, { "created": "Wed, 16 Nov 2016 15:02:07 GMT", "version": "v2" } ]
2016-11-17
[ [ "Zubair", "M.", "" ], [ "Kousar", "Farzana", "" ], [ "Bahamonde", "Sebastian", "" ] ]
First and second laws of black hole thermodynamics are examined at the apparent horizon of FRW spacetime in $f(R,R_{\alpha\beta}R^{\alpha\beta} ,\phi)$ gravity, where $R$, $R_{\alpha\beta}R^{\alpha\beta}$ and $\phi$ are the Ricci scalar, Ricci invariant and the scalar field respectively. In this modified theory, Friedm...
2208.01987
Guillermo A. Mena Marugan
Simon Iteanu and Guillermo A. Mena Marug\'an
Mass of cosmological perturbations in the hybrid and dressed metric formalisms of Loop Quantum Cosmology for the Starobinsky and exponential potentials
13 pages
Universe 8, 463 (2022)
10.3390/universe8090463
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The hybrid and the dressed metric formalisms for the study of primordial perturbations in Loop Quantum Cosmology lead to dynamical equations for the modes of these perturbations that are of a generalized harmonic-oscillator type, with a mass that depends on the background but is the same for all modes. For quantum ba...
[ { "created": "Wed, 3 Aug 2022 11:28:21 GMT", "version": "v1" }, { "created": "Fri, 23 Sep 2022 09:17:23 GMT", "version": "v2" } ]
2022-09-26
[ [ "Iteanu", "Simon", "" ], [ "Marugán", "Guillermo A. Mena", "" ] ]
The hybrid and the dressed metric formalisms for the study of primordial perturbations in Loop Quantum Cosmology lead to dynamical equations for the modes of these perturbations that are of a generalized harmonic-oscillator type, with a mass that depends on the background but is the same for all modes. For quantum back...
gr-qc/9212009
null
Peter C. Aichelburg and Piotr Bizon
Magnetically Charged Black Holes and their Stability
19 pages, 5 figures available upon request, Latex
Phys.Rev.D48:607-615,1993
10.1103/PhysRevD.48.607
UWThPh-1992-63
gr-qc hep-th
null
We study magnetically charged black holes in the Einstein-Yang-Mills-Higgs theory in the limit of infinitely strong coupling of the Higgs field. Using mixed analytical and numerical methods we give a complete description of static spherically symmetric black hole solutions, both abelian and nonabelian. In particular,...
[ { "created": "Mon, 14 Dec 1992 14:17:00 GMT", "version": "v1" } ]
2010-11-01
[ [ "Aichelburg", "Peter C.", "" ], [ "Bizon", "Piotr", "" ] ]
We study magnetically charged black holes in the Einstein-Yang-Mills-Higgs theory in the limit of infinitely strong coupling of the Higgs field. Using mixed analytical and numerical methods we give a complete description of static spherically symmetric black hole solutions, both abelian and nonabelian. In particular, w...
gr-qc/0309063
Edward Anderson
Edward Anderson and Reza Tavakol
PDE System Approach to Large Extra Dimensions
33 pages and 9 figures
null
null
null
gr-qc hep-th
null
We explore some fundational issues regarding the splitting of D-dimensional EFE's w.r.t timelike and spacelike (D-1)-dimensional hypersurfaces, first without and then with thin matter sheets such as branes. We begin to implement methodology, that is well-established for the GR CP and IVP, in the new field of GR-based...
[ { "created": "Fri, 12 Sep 2003 16:21:16 GMT", "version": "v1" } ]
2007-05-23
[ [ "Anderson", "Edward", "" ], [ "Tavakol", "Reza", "" ] ]
We explore some fundational issues regarding the splitting of D-dimensional EFE's w.r.t timelike and spacelike (D-1)-dimensional hypersurfaces, first without and then with thin matter sheets such as branes. We begin to implement methodology, that is well-established for the GR CP and IVP, in the new field of GR-based b...
2307.14862
Artyom Astashenok V
Artyom V. Astashenok, Sergey D. Odintsov, Vasilis K. Oikonomou
Compact Stars with Dark Energy in General Relativity and Modified Gravity
accepted in Phys. Dark Univ
null
null
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate realistic models of compact objects, focusing on neutron and strange stars, composed by dense matter and dark energy in the form of a simple fluid or scalar field interacting with matter. For the dark energy component, we use equations of state compatible with cosmological observations. This requiremen...
[ { "created": "Thu, 27 Jul 2023 13:46:30 GMT", "version": "v1" } ]
2023-08-01
[ [ "Astashenok", "Artyom V.", "" ], [ "Odintsov", "Sergey D.", "" ], [ "Oikonomou", "Vasilis K.", "" ] ]
We investigate realistic models of compact objects, focusing on neutron and strange stars, composed by dense matter and dark energy in the form of a simple fluid or scalar field interacting with matter. For the dark energy component, we use equations of state compatible with cosmological observations. This requirement ...
2009.07732
Tanmoy Paul
Tanmoy Paul
Antisymmetric tensor fields in modified gravity: a summary
Invited review paper from Symmetry for special issue Feature Papers 2020, Symmetry Accepted
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide various aspects of second rank antisymmetric Kalb-Ramond (KR) field in modified theories of gravity. The KR field energy density is found to decrease with the expansion of our universe at a faster rate in comparison to radiation and matter components. Thus as the Universe evolves and cools down, the contri...
[ { "created": "Wed, 16 Sep 2020 15:05:21 GMT", "version": "v1" } ]
2020-09-17
[ [ "Paul", "Tanmoy", "" ] ]
We provide various aspects of second rank antisymmetric Kalb-Ramond (KR) field in modified theories of gravity. The KR field energy density is found to decrease with the expansion of our universe at a faster rate in comparison to radiation and matter components. Thus as the Universe evolves and cools down, the contribu...
1910.08756
Thomas B\"ackdahl
Steffen Aksteiner, Lars Andersson, Thomas B\"ackdahl, Igor Khavkine, Bernard Whiting
Compatibility complex for black hole spacetimes
23 pages. Some remarks added
Commun. Math. Phys. (2021)
10.1007/s00220-021-04078-y
null
gr-qc math-ph math.DG math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The set of local gauge invariant quantities for linearized gravity on the Kerr spacetime presented by two of the authors (S.A, T.B.) in (arXiv:1803.05341) is shown to be complete. In particular, any gauge invariant quantity for linearized gravity on Kerr that is local and of finite order in derivatives can be express...
[ { "created": "Sat, 19 Oct 2019 11:54:12 GMT", "version": "v1" }, { "created": "Mon, 10 May 2021 05:14:08 GMT", "version": "v2" } ]
2021-05-11
[ [ "Aksteiner", "Steffen", "" ], [ "Andersson", "Lars", "" ], [ "Bäckdahl", "Thomas", "" ], [ "Khavkine", "Igor", "" ], [ "Whiting", "Bernard", "" ] ]
The set of local gauge invariant quantities for linearized gravity on the Kerr spacetime presented by two of the authors (S.A, T.B.) in (arXiv:1803.05341) is shown to be complete. In particular, any gauge invariant quantity for linearized gravity on Kerr that is local and of finite order in derivatives can be expressed...