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gr-qc/0502014
Gerard Clement
G. Clement, D.V. Gal'tsov and P.S. Letelier
The Letelier-Gal'tsov spacetime revisited
3 pages
null
null
LAPTH-1087/05, DTP-MSU/05-02
gr-qc astro-ph
null
Contrary to a recent claim by Anderson ["The Mathematical Theory of Cosmic Strings", I.O.P. Publishing, Bristol 2003], we show that the Letelier-Gal'tsov metric does represent a system of crossed straight infinite cosmic strings moving with arbitrary constant velocities.
[ { "created": "Thu, 3 Feb 2005 14:05:13 GMT", "version": "v1" } ]
2007-05-23
[ [ "Clement", "G.", "" ], [ "Gal'tsov", "D. V.", "" ], [ "Letelier", "P. S.", "" ] ]
Contrary to a recent claim by Anderson ["The Mathematical Theory of Cosmic Strings", I.O.P. Publishing, Bristol 2003], we show that the Letelier-Gal'tsov metric does represent a system of crossed straight infinite cosmic strings moving with arbitrary constant velocities.
1308.1433
Majd Abdelqader
Majd Abdelqader, Kayll Lake
Visualizing Spacetime Curvature via Gradient Flows III: The Kerr Metric and the Transitional Values of the Spin Parameter
5 pages, 3 figures, twocolumn revtex 4-1. One figure updated. Final form to appear in Phys Rev D
Phys Re D 88, 064042 2013
10.1103/PhysRevD.88.064042
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Kerr metric is one of the most important solutions to Einstein's field equations, describing the gravitational field outside a rotating black hole. We thoroughly analyze the curvature scalar invariants to study the Kerr spacetime by examining and visualizing their covariant gradient fields. We discover that the p...
[ { "created": "Tue, 6 Aug 2013 22:34:29 GMT", "version": "v1" }, { "created": "Thu, 12 Sep 2013 19:54:30 GMT", "version": "v2" } ]
2013-10-10
[ [ "Abdelqader", "Majd", "" ], [ "Lake", "Kayll", "" ] ]
The Kerr metric is one of the most important solutions to Einstein's field equations, describing the gravitational field outside a rotating black hole. We thoroughly analyze the curvature scalar invariants to study the Kerr spacetime by examining and visualizing their covariant gradient fields. We discover that the par...
2310.06798
Martin Bojowald
Martin Bojowald and Erick I. Duque
Emergent modified gravity: Covariance regained
50 pages
Phys. Rev. D 108 (2023) 084066
10.1103/PhysRevD.108.084066
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In its canonical formulation, general relativity is subject to gauge transformations that are equivalent to space-time coordinate changes of general covariance only when the gauge generators, given by the Hamiltonian and diffeomorphism constraints, vanish. Since the specific form taken by Poisson brackets of the cons...
[ { "created": "Tue, 10 Oct 2023 17:09:24 GMT", "version": "v1" } ]
2023-10-31
[ [ "Bojowald", "Martin", "" ], [ "Duque", "Erick I.", "" ] ]
In its canonical formulation, general relativity is subject to gauge transformations that are equivalent to space-time coordinate changes of general covariance only when the gauge generators, given by the Hamiltonian and diffeomorphism constraints, vanish. Since the specific form taken by Poisson brackets of the constr...
0705.4043
Gilles Esposito-Farese
Jean-Philippe Bruneton and Gilles Esposito-Farese
Field-theoretical formulations of MOND-like gravity
66 pages, 6 figures, RevTeX4 format, version reflecting the changes in the published paper
Phys.Rev.D76:124012,2007; Erratum-ibid.D76:129902,2007
10.1103/PhysRevD.76.124012 10.1103/PhysRevD.76.129902
null
gr-qc
null
Modified Newtonian dynamics (MOND) is a possible way to explain the flat galaxy rotation curves without invoking the existence of dark matter. It is however quite difficult to predict such a phenomenology in a consistent field theory, free of instabilities and admitting a well-posed Cauchy problem. We examine critica...
[ { "created": "Mon, 28 May 2007 13:28:31 GMT", "version": "v1" }, { "created": "Thu, 15 Nov 2007 16:35:14 GMT", "version": "v2" } ]
2014-11-18
[ [ "Bruneton", "Jean-Philippe", "" ], [ "Esposito-Farese", "Gilles", "" ] ]
Modified Newtonian dynamics (MOND) is a possible way to explain the flat galaxy rotation curves without invoking the existence of dark matter. It is however quite difficult to predict such a phenomenology in a consistent field theory, free of instabilities and admitting a well-posed Cauchy problem. We examine criticall...
gr-qc/0411052
Jerzy Kocinski
J. Kocinski
Quantization of the Classical Maxwell-Nordstrom Fields
13 pages
null
null
null
gr-qc
null
The classical electromagnetic and gravitomagnetic fields in the vacuum, in (3+2) dimensions, described by the Maxwell-Nordstrom equations, are quantized. These equations are rederived from the field tensor which follows from a five-dimensional form of the Dirac equation. The electromagnetic field depends on the custo...
[ { "created": "Wed, 10 Nov 2004 13:51:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kocinski", "J.", "" ] ]
The classical electromagnetic and gravitomagnetic fields in the vacuum, in (3+2) dimensions, described by the Maxwell-Nordstrom equations, are quantized. These equations are rederived from the field tensor which follows from a five-dimensional form of the Dirac equation. The electromagnetic field depends on the customa...
1510.05273
Ehud Eilon
Ehud Eilon and Amos Ori
Adaptive gauge method for long-time double-null simulations of spherical black-hole spacetimes
38 pages, 18 figures. Added References
Phys. Rev. D 93, 024016 (2016)
10.1103/PhysRevD.93.024016
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Double-null coordinates are highly useful in numerical simulations of dynamical spherically-symmetric black holes (BHs). However, they become problematic in long-time simulations: Along the event horizon, the truncation error grows exponentially in the outgoing Eddington null coordinate - which we denote $v_e$ - and ...
[ { "created": "Sun, 18 Oct 2015 16:20:26 GMT", "version": "v1" }, { "created": "Wed, 28 Oct 2015 12:26:33 GMT", "version": "v2" } ]
2016-01-20
[ [ "Eilon", "Ehud", "" ], [ "Ori", "Amos", "" ] ]
Double-null coordinates are highly useful in numerical simulations of dynamical spherically-symmetric black holes (BHs). However, they become problematic in long-time simulations: Along the event horizon, the truncation error grows exponentially in the outgoing Eddington null coordinate - which we denote $v_e$ - and ru...
gr-qc/0409028
Francesco Nicol\`o FN
Giulio Caciotta, Francesco Nicol\`o
Global characteristic problem for Einstein vacuum equations with small initial data: (I) The initial data constraints
77 pages, no figures; corrected misprints and minor errors, to appear on Journal of Hyperbolic Differential Equations (JHDE)
null
null
null
gr-qc
null
We show how to prescribe the initial data of a characteristic problem satisfying the costraints, the smallness, the regularity and the asymptotic decay suitable to prove a global existence result. In this paper, the first of two, we show in detail the construction of the initial data and give a sketch of the existenc...
[ { "created": "Mon, 6 Sep 2004 22:23:16 GMT", "version": "v1" }, { "created": "Wed, 13 Oct 2004 22:31:25 GMT", "version": "v2" } ]
2007-05-23
[ [ "Caciotta", "Giulio", "" ], [ "Nicolò", "Francesco", "" ] ]
We show how to prescribe the initial data of a characteristic problem satisfying the costraints, the smallness, the regularity and the asymptotic decay suitable to prove a global existence result. In this paper, the first of two, we show in detail the construction of the initial data and give a sketch of the existence ...
2404.17267
Salvatore Capozziello
Salvatore Capozziello, Silvia De Bianchi, and Emmanuele Battista
Avoiding singularities in Lorentzian-Euclidean black holes: the role of atemporality
22 pages, 5 figures, accepted for publication in Phys. Rev. D
null
10.1103/PhysRevD.109.104060
null
gr-qc astro-ph.HE hep-th
http://creativecommons.org/licenses/by/4.0/
We investigate a Schwarzschild metric exhibiting a signature change across the event horizon, which gives rise to what we term a Lorentzian-Euclidean black hole. The resulting geometry is regularized by employing the Hadamard partie finie technique, which allows us to prove that the metric represents a solution of va...
[ { "created": "Fri, 26 Apr 2024 09:14:45 GMT", "version": "v1" } ]
2024-05-21
[ [ "Capozziello", "Salvatore", "" ], [ "De Bianchi", "Silvia", "" ], [ "Battista", "Emmanuele", "" ] ]
We investigate a Schwarzschild metric exhibiting a signature change across the event horizon, which gives rise to what we term a Lorentzian-Euclidean black hole. The resulting geometry is regularized by employing the Hadamard partie finie technique, which allows us to prove that the metric represents a solution of vacu...
gr-qc/0406120
Sigbjorn Hervik
Alan A. Coley and Sigbjorn Hervik
Bianchi Cosmologies: A Tale of Two Tilted fluids
16 pages, 1 figure, to appear in CQG
Class.Quant.Grav. 21 (2004) 4193-4208
10.1088/0264-9381/21/17/009
null
gr-qc
null
We use a dynamical systems approach to study Bianchi type VI$_0$ cosmological models containing two tilted $\gamma$-law perfect fluids. The full state space is 11-dimensional, but the existence of a monotonic function simplifies the analysis considerably. We restrict attention to a particular, physically interesting,...
[ { "created": "Wed, 30 Jun 2004 16:11:48 GMT", "version": "v1" } ]
2009-11-10
[ [ "Coley", "Alan A.", "" ], [ "Hervik", "Sigbjorn", "" ] ]
We use a dynamical systems approach to study Bianchi type VI$_0$ cosmological models containing two tilted $\gamma$-law perfect fluids. The full state space is 11-dimensional, but the existence of a monotonic function simplifies the analysis considerably. We restrict attention to a particular, physically interesting, i...
1803.00835
Pietro Don\`a
Pietro Dona
Infrared divergences in the EPRL-FK Spin Foam model
22 pages + 4 appendices, 8 figures. v2 match the published version
Class.Quant.Grav. 35 (2018) 17, 175019
10.1088/1361-6382/aad38f
IGC-18/2-2
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide an algorithm to estimate the divergence degree of the Lorentzian EPRL-FK spin foam amplitudes for arbitrary 2-complexes. We focus on the "self-energy" and "vertex renormalization" diagrams and find an upper bound estimate. We argue that our upper bound must be close to the actual value, and explain what nu...
[ { "created": "Fri, 2 Mar 2018 13:09:27 GMT", "version": "v1" }, { "created": "Mon, 16 Jul 2018 11:58:50 GMT", "version": "v2" } ]
2024-02-27
[ [ "Dona", "Pietro", "" ] ]
We provide an algorithm to estimate the divergence degree of the Lorentzian EPRL-FK spin foam amplitudes for arbitrary 2-complexes. We focus on the "self-energy" and "vertex renormalization" diagrams and find an upper bound estimate. We argue that our upper bound must be close to the actual value, and explain what nume...
gr-qc/0302038
Roberto Casadio
G.L. Alberghi, R. Casadio, G.Venturi
Thermodynamics for radiating shells in anti-de Sitter space-time
9 pages, 2 figures, PLB style
Phys.Lett.B557:7-11,2003
10.1016/S0370-2693(03)00185-0
null
gr-qc astro-ph hep-th
null
A thermodynamical description for the quasi-static collapse of radiating, self-gravitating spherical shells of matter in anti-de Sitter space-time is obtained. It is shown that the specific heat at constant area and other thermodynamical quantities may diverge before a black hole has eventually formed. This suggests ...
[ { "created": "Tue, 11 Feb 2003 10:35:50 GMT", "version": "v1" } ]
2008-11-26
[ [ "Alberghi", "G. L.", "" ], [ "Casadio", "R.", "" ], [ "Venturi", "G.", "" ] ]
A thermodynamical description for the quasi-static collapse of radiating, self-gravitating spherical shells of matter in anti-de Sitter space-time is obtained. It is shown that the specific heat at constant area and other thermodynamical quantities may diverge before a black hole has eventually formed. This suggests th...
1610.07211
Surena Rahbardehghan
Hamed Pejhan and Surena Rahbardehghan
Covariant and infrared-free graviton two-point function in de Sitter spacetime II
14 pages
Phys. Rev. D 94, 104030 (2016)
10.1103/PhysRevD.94.104030
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The solution to the linearized Einstein equation in de Sitter (dS) spacetime and the corresponding two-point function are explicitly written down in a gauge with two parameters `$a$' and `$b$'. The quantization procedure, independent of the choice of the coordinate system, is based on a rigorous group theoretical app...
[ { "created": "Sun, 23 Oct 2016 18:36:26 GMT", "version": "v1" }, { "created": "Tue, 15 Nov 2016 10:33:26 GMT", "version": "v2" } ]
2016-12-21
[ [ "Pejhan", "Hamed", "" ], [ "Rahbardehghan", "Surena", "" ] ]
The solution to the linearized Einstein equation in de Sitter (dS) spacetime and the corresponding two-point function are explicitly written down in a gauge with two parameters `$a$' and `$b$'. The quantization procedure, independent of the choice of the coordinate system, is based on a rigorous group theoretical appro...
1107.1344
Jose M. M. Senovilla
Jos\'e M.M. Senovilla
Trapped surfaces
32 pages, 12 figures, 3 Tables. Invited course at the 2011 Shanghai Asia-Pacific School and Workshop on Gravitation, version submitted to the Proceedings. Minor typos corrected
null
10.1142/S0218271811020354
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I review the definition and types of (closed) trapped surfaces. Surprising global properties are shown, such as their "clairvoyance" and the possibility that they enter into flat portions of the spacetime. Several results on the interplay of trapped surfaces with vector fields and with spatial hypersurfaces are prese...
[ { "created": "Thu, 7 Jul 2011 11:09:30 GMT", "version": "v1" }, { "created": "Wed, 14 Sep 2011 14:53:38 GMT", "version": "v2" } ]
2015-05-28
[ [ "Senovilla", "José M. M.", "" ] ]
I review the definition and types of (closed) trapped surfaces. Surprising global properties are shown, such as their "clairvoyance" and the possibility that they enter into flat portions of the spacetime. Several results on the interplay of trapped surfaces with vector fields and with spatial hypersurfaces are present...
1912.00767
Dr. Sudhaker Upadhyay
Sudhaker Upadhyay, Nadeem-ul-islam and Prince A. Ganai
A modified thermodynamics of rotating and charged BTZ black hole
20 pages, 14 captioned figures, Accepted for publication in JHAP
JHAP 2 (2022) 25
10.22128/JHAP.2021.454.1004
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the thermodynamics of a charged and rotating BTZ black holes here. In particular, we derive expressions for various macroscopic thermal quantities such as entropy, Hawking temperature, Helmholtz free energy, internal energy, enthalpy, Gibbs free energy, and specific heat. To study the effects of small stat...
[ { "created": "Thu, 28 Nov 2019 11:46:04 GMT", "version": "v1" }, { "created": "Wed, 12 Jan 2022 16:48:16 GMT", "version": "v2" } ]
2022-02-01
[ [ "Upadhyay", "Sudhaker", "" ], [ "Nadeem-ul-islam", "", "" ], [ "Ganai", "Prince A.", "" ] ]
We present the thermodynamics of a charged and rotating BTZ black holes here. In particular, we derive expressions for various macroscopic thermal quantities such as entropy, Hawking temperature, Helmholtz free energy, internal energy, enthalpy, Gibbs free energy, and specific heat. To study the effects of small statis...
gr-qc/0612118
Valentino Lacquaniti
Valentino Lacquaniti and Giovanni Montani
Hamiltonian formulation of the 5-D Kaluza-Klein model and test-particle motion
3 pages, proceedings of the XI Marcel Grossmann meeting on Relativistic Astrophysics, July 23-29, 2006, Berlin
null
null
null
gr-qc
null
We examine the ADM reformulation of the 5-D KK model: the dimensional reduction is provided to commute with the ADM splitting and we show how the time component of the gauge vector is given by combination of the Lagrangian multipliers for the 5-D gravitational field. We consider 5D particles motion and after dimensio...
[ { "created": "Tue, 19 Dec 2006 18:19:07 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lacquaniti", "Valentino", "" ], [ "Montani", "Giovanni", "" ] ]
We examine the ADM reformulation of the 5-D KK model: the dimensional reduction is provided to commute with the ADM splitting and we show how the time component of the gauge vector is given by combination of the Lagrangian multipliers for the 5-D gravitational field. We consider 5D particles motion and after dimensiona...
1501.04947
Kristina Giesel
Yu Han, Kristina Giesel, Yongge Ma
Manifestly Gauge Invariant Perturbations of Scalar-Tensor Theories of Gravity
40 pages
Class. Quantum Grav. 32 (2015) 135006
10.1088/0264-9381/32/13/135006
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The general relativistic perturbations of scalar-tensor theories (STT) of gravity are studied in a manifestly gauge invariant Hamiltonian formalism. After the derivation of the Hamiltonian equations of motion in this framework, the gauge invariant formalism is used to compute the evolution equations of linear perturb...
[ { "created": "Tue, 20 Jan 2015 20:24:54 GMT", "version": "v1" } ]
2015-06-08
[ [ "Han", "Yu", "" ], [ "Giesel", "Kristina", "" ], [ "Ma", "Yongge", "" ] ]
The general relativistic perturbations of scalar-tensor theories (STT) of gravity are studied in a manifestly gauge invariant Hamiltonian formalism. After the derivation of the Hamiltonian equations of motion in this framework, the gauge invariant formalism is used to compute the evolution equations of linear perturbat...
1511.03217
Farhad Darabi
Y. Heydarzade, F. Darabi, K. Atazadeh
Einstein static universe on the brane supported by extended Chaplygin gas
30 pages, major revision
Astrophys. Space. Sci 361: 250 (2016)
10.1007/s10509-016-2836-7
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the cosmological models in which an extended Chaplygin gas universe is merged with the braneworld scenario. In particular, we examine the realization of Einstein static universe on the brane embedded in a non-constant curvature bulk space and perform a detailed perturbation analysis. We extract the stability...
[ { "created": "Tue, 10 Nov 2015 18:32:18 GMT", "version": "v1" }, { "created": "Thu, 7 Jul 2016 10:36:29 GMT", "version": "v2" } ]
2016-07-08
[ [ "Heydarzade", "Y.", "" ], [ "Darabi", "F.", "" ], [ "Atazadeh", "K.", "" ] ]
We study the cosmological models in which an extended Chaplygin gas universe is merged with the braneworld scenario. In particular, we examine the realization of Einstein static universe on the brane embedded in a non-constant curvature bulk space and perform a detailed perturbation analysis. We extract the stability c...
0712.3129
Paingalil Kunjan Suresh
K.K.Venkataratnam and P.K.Suresh
Density Fluctuations in the Oscillatory Phase of Nonclassical Inflaton in FRW Universe
14 pages, 2 figures, To appear in Int.J.Mod.Phys.D
Int.J.Mod.Phys.D17:1991-2005,2008
10.1142/S0218271808013662
null
gr-qc
null
Using coherent and squeezed state formalisms of quantum optics for a minimally coupled non-classical inflaton in the FRW mertic is studied, in semiclassical theory of gravity. The leading order solution for the semiclassical Einstein equations in the coherent, squeezed and squeezed vacuum states are obtained perturba...
[ { "created": "Wed, 19 Dec 2007 09:46:23 GMT", "version": "v1" } ]
2009-02-11
[ [ "Venkataratnam", "K. K.", "" ], [ "Suresh", "P. K.", "" ] ]
Using coherent and squeezed state formalisms of quantum optics for a minimally coupled non-classical inflaton in the FRW mertic is studied, in semiclassical theory of gravity. The leading order solution for the semiclassical Einstein equations in the coherent, squeezed and squeezed vacuum states are obtained perturbati...
2311.12018
Jan Scheumann
Jan Scheumann (1 and 4), Dennis Philipp (1 and 4), Sven Herrmann (1 and 4), Eva Hackmann (1 and 4), Benny Rievers (1 and 4), Javier Ventura-Traveset (2), Luis Mendes (3), Claus L\"ammerzahl (1 and 4) ((1) Center of Applied Space Technology and Microgravity (ZARM), University of Bremen, (2) Centre Spatial de Tou...
Gravitomagnetic Clock Effect: Using GALILEO to explore General Relativity
13 pages, 3 figures, 3 supplemental pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
All experiments to date are in remarkable agreement with the predictions of Einstein's theory of gravity, General Relativity. Besides the classical tests, involving light deflection, orbit precession, signal delay, and the gravitational redshift, modern technology has pushed the limits even further. Gravitational wav...
[ { "created": "Mon, 20 Nov 2023 18:55:26 GMT", "version": "v1" } ]
2023-11-21
[ [ "Scheumann", "Jan", "", "1 and 4" ], [ "Philipp", "Dennis", "", "1 and 4" ], [ "Herrmann", "Sven", "", "1\n and 4" ], [ "Hackmann", "Eva", "", "1 and 4" ], [ "Rievers", "Benny", "", "1 and 4" ], [ "Ventura-Tra...
All experiments to date are in remarkable agreement with the predictions of Einstein's theory of gravity, General Relativity. Besides the classical tests, involving light deflection, orbit precession, signal delay, and the gravitational redshift, modern technology has pushed the limits even further. Gravitational waves...
2305.06997
Manuel Hohmann
Manuel Hohmann
Spatially homogeneous teleparallel spacetimes with four-dimensional groups of motions
30 pages, no figures; contribution to the Special Issue on metric-affine gravity, Tartu, 2022, of the International Journal of Geometric Methods in Modern Physics
Int. J. Geom. Meth. Mod. Phys. 20, Supp. 1 (2023) 2450046
10.1142/S0219887824500464
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study metric teleparallel geometries, which can either be defined through a Lorentzian metric and flat, metric-compatible affine connection, or a tetrad and a flat spin connection, which are invariant under the transitive action of a four-dimensional Lie group on their spatial equal-time hypersurfaces. There are t...
[ { "created": "Thu, 11 May 2023 17:32:59 GMT", "version": "v1" }, { "created": "Thu, 15 Feb 2024 21:15:02 GMT", "version": "v2" } ]
2024-02-19
[ [ "Hohmann", "Manuel", "" ] ]
We study metric teleparallel geometries, which can either be defined through a Lorentzian metric and flat, metric-compatible affine connection, or a tetrad and a flat spin connection, which are invariant under the transitive action of a four-dimensional Lie group on their spatial equal-time hypersurfaces. There are thr...
0909.0939
Marcin Kisielowski M.Sc.
Wojciech Kami\'nski, Marcin Kisielowski, Jerzy Lewandowski
Spin-Foams for All Loop Quantum Gravity
RevTex4, 23 pages, 8 figures; important references added; minor corrections, version published in Class.Quant.Grav; theorem of injectivity of EPRL map corrected
Class.Quant.Grav.27:095006,2010
10.1088/0264-9381/27/9/095006
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The simplicial framework of Engle-Pereira-Rovelli-Livine spin-foam models is generalized to match the diffeomorphism invariant framework of loop quantum gravity. The simplicial spin-foams are generalized to arbitrary linear 2-cell spin-foams. The resulting framework admits all the spin-network states of loop quantum ...
[ { "created": "Fri, 4 Sep 2009 18:44:44 GMT", "version": "v1" }, { "created": "Mon, 28 Sep 2009 11:44:07 GMT", "version": "v2" }, { "created": "Sat, 20 Mar 2010 21:42:46 GMT", "version": "v3" }, { "created": "Wed, 31 Mar 2010 21:59:52 GMT", "version": "v4" }, { "cr...
2015-03-13
[ [ "Kamiński", "Wojciech", "" ], [ "Kisielowski", "Marcin", "" ], [ "Lewandowski", "Jerzy", "" ] ]
The simplicial framework of Engle-Pereira-Rovelli-Livine spin-foam models is generalized to match the diffeomorphism invariant framework of loop quantum gravity. The simplicial spin-foams are generalized to arbitrary linear 2-cell spin-foams. The resulting framework admits all the spin-network states of loop quantum gr...
1503.08455
Carlos Augusto Romero Filho
A. B. Barreto, T. S. Almeida, C. Romero
Extending the ADM formalism to Weyl geometry
10 pages
null
10.1063/1.4913344
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In order to treat quantum cosmology in the framework of Weyl spacetimes we take the first step of extending the Arnowitt-Deser-Misner formalism to Weyl geometry. We then obtain an expression of the curvature tensor in terms of spatial quantities by splitting spacetime in (3+1)-dimensional form. We next write the Lagr...
[ { "created": "Sun, 29 Mar 2015 16:21:14 GMT", "version": "v1" } ]
2015-06-24
[ [ "Barreto", "A. B.", "" ], [ "Almeida", "T. S.", "" ], [ "Romero", "C.", "" ] ]
In order to treat quantum cosmology in the framework of Weyl spacetimes we take the first step of extending the Arnowitt-Deser-Misner formalism to Weyl geometry. We then obtain an expression of the curvature tensor in terms of spatial quantities by splitting spacetime in (3+1)-dimensional form. We next write the Lagran...
2307.12464
Pravin Dahal
Pravin Kumar Dahal
Surface gravity from tidal acceleration
11 pages, 0 figure, Matches Published Version (available at https://rdcu.be/drBzS); Comments Welcome!
European Physical Journal Plus 138, 1027 (2023)
10.1140/epjp/s13360-023-04664-0
null
gr-qc math-ph math.MP
http://creativecommons.org/licenses/by/4.0/
Surface gravity plays a pivotal role in the characterization of black holes and also in formulating the laws of black hole thermodynamics. Despite its significance, defining surface gravity in general spacetimes is a nontrivial task and thus has multiple definitions that lack equivalence in dynamical scenarios. This ...
[ { "created": "Mon, 24 Jul 2023 01:20:05 GMT", "version": "v1" }, { "created": "Tue, 21 Nov 2023 04:28:42 GMT", "version": "v2" } ]
2023-11-22
[ [ "Dahal", "Pravin Kumar", "" ] ]
Surface gravity plays a pivotal role in the characterization of black holes and also in formulating the laws of black hole thermodynamics. Despite its significance, defining surface gravity in general spacetimes is a nontrivial task and thus has multiple definitions that lack equivalence in dynamical scenarios. This pa...
0904.4496
Maria Bedran
M.L.Bedran
The function q(z) as a consistency check for cosmological parameters
10 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the Friedmann cosmology the deceleration of the expansion q plays a fundamental role. We derive the deceleration as a function of redshift $q(z)$ in two scenarios: $\Lambda$ CDM model and modified Chaplygin gas (MCG) model, without assuming spatial flatness. The expression relating the transition redshift from dec...
[ { "created": "Tue, 28 Apr 2009 21:38:41 GMT", "version": "v1" } ]
2009-04-30
[ [ "Bedran", "M. L.", "" ] ]
In the Friedmann cosmology the deceleration of the expansion q plays a fundamental role. We derive the deceleration as a function of redshift $q(z)$ in two scenarios: $\Lambda$ CDM model and modified Chaplygin gas (MCG) model, without assuming spatial flatness. The expression relating the transition redshift from decel...
gr-qc/0502030
Christian Boehmer
Christian G. Boehmer, Piotr Bronowski
A note on dilaton gravity with non-smooth potentials
10 pages, 1 table; two new references, some typos corrected, Dedicated to Wolfgang Kummer at the occasion of his Emeritierung
Mod.Phys.Lett. A20 (2005) 1057-1064
10.1142/S0217732305017172
Preprint ESI 1602, TUW-05-03
gr-qc hep-th
null
Recent interest in brane world models motivates the investigation of generic first order dilaton gravity actions, with potentials having some non-smoothness. We consider two different types of \delta-like contributions in the action and analyse their effects on the solutions. Furthermore a second source of non-smooth...
[ { "created": "Tue, 8 Feb 2005 11:39:28 GMT", "version": "v1" }, { "created": "Tue, 15 Feb 2005 09:53:39 GMT", "version": "v2" } ]
2007-05-23
[ [ "Boehmer", "Christian G.", "" ], [ "Bronowski", "Piotr", "" ] ]
Recent interest in brane world models motivates the investigation of generic first order dilaton gravity actions, with potentials having some non-smoothness. We consider two different types of \delta-like contributions in the action and analyse their effects on the solutions. Furthermore a second source of non-smoothne...
gr-qc/9912061
Pascual-Sanchez J.-F.
J.-F. Pascual-S\'anchez (University of Valladolid)
The case for cosmic acceleration: Inhomogeneity versus cosmological constant
5 pages, LaTex, to appear in Proceedings of Spanish Relativity Meeting, ERE 99
null
null
null
gr-qc astro-ph
null
In this work, I develop an alternative explanation for the acceleration of the cosmic expansion, which seems to be a result of recent high redshift Supernova data. In the current interpretation, this cosmic acceleration is explained by including a positive cosmological constant term (or vacuum energy), in the standar...
[ { "created": "Wed, 15 Dec 1999 12:29:14 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pascual-Sánchez", "J. -F.", "", "University of Valladolid" ] ]
In this work, I develop an alternative explanation for the acceleration of the cosmic expansion, which seems to be a result of recent high redshift Supernova data. In the current interpretation, this cosmic acceleration is explained by including a positive cosmological constant term (or vacuum energy), in the standard ...
gr-qc/0702054
Wataru Hikida
Katsuhiko Ganz, Wataru Hikida, Hiroyuki Nakano, Norichika Sago and Takahiro Tanaka
Adiabatic Evolution of three 'Constants' of Motion for Greatly Inclined Orbits in Kerr spacetime
26pages, to be published in Progress of Theoretical Physics
Prog.Theor.Phys.117:1041-1066,2007
10.1143/PTP.117.1041
OU-TAP-276, KUNS-2061
gr-qc
null
General orbits of a particle of small mass $\mu$ around a Kerr black hole of mass $M$ are characterized by three parameters: the energy, the angular momentum and the Carter constant. The time-averaged rates of change of the energy and the angular momentum can be obtained by computing the corresponding fluxes of gravi...
[ { "created": "Fri, 9 Feb 2007 01:33:24 GMT", "version": "v1" }, { "created": "Thu, 31 May 2007 11:13:35 GMT", "version": "v2" } ]
2011-08-04
[ [ "Ganz", "Katsuhiko", "" ], [ "Hikida", "Wataru", "" ], [ "Nakano", "Hiroyuki", "" ], [ "Sago", "Norichika", "" ], [ "Tanaka", "Takahiro", "" ] ]
General orbits of a particle of small mass $\mu$ around a Kerr black hole of mass $M$ are characterized by three parameters: the energy, the angular momentum and the Carter constant. The time-averaged rates of change of the energy and the angular momentum can be obtained by computing the corresponding fluxes of gravita...
2206.06590
Apimook Watcharangkool
Nontapat Wanwieng, Narupon Chattrapiban, and Apimook Watcharangkool
The effects of gravitational waves on a hydrogen atom
8 pages, 1 figure
Classical and Quantum Gravity, 2023
10.1088/1361-6382/ad0423
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the influence of gravitational waves on a freely falling hydrogen atom by analyzing the dynamics of the bound electron described by the Dirac equation in the curved spacetime of a gravitational wave. From this, we derive the corresponding Dirac Hamiltonian in the Local Inertial Frame of the atom, assum...
[ { "created": "Tue, 14 Jun 2022 04:33:10 GMT", "version": "v1" }, { "created": "Thu, 19 Oct 2023 08:14:55 GMT", "version": "v2" } ]
2023-10-20
[ [ "Wanwieng", "Nontapat", "" ], [ "Chattrapiban", "Narupon", "" ], [ "Watcharangkool", "Apimook", "" ] ]
We investigate the influence of gravitational waves on a freely falling hydrogen atom by analyzing the dynamics of the bound electron described by the Dirac equation in the curved spacetime of a gravitational wave. From this, we derive the corresponding Dirac Hamiltonian in the Local Inertial Frame of the atom, assumin...
gr-qc/9511007
null
Sean A. Hayward
Complex lapse, complex action and path integrals
12 pages, TeX
Phys.Rev. D53 (1996) 5664-5669
10.1103/PhysRevD.53.5664
null
gr-qc
null
Imaginary time is often used in quantum tunnelling calculations. This article advocates a conceptually sounder alternative: complex lapse. In the ``3+1'' action for the Einstein gravitational field minimally coupled to a Klein-Gordon field, allowing the lapse function to be complex yields a complex action which gener...
[ { "created": "Thu, 2 Nov 1995 07:51:11 GMT", "version": "v1" } ]
2009-10-28
[ [ "Hayward", "Sean A.", "" ] ]
Imaginary time is often used in quantum tunnelling calculations. This article advocates a conceptually sounder alternative: complex lapse. In the ``3+1'' action for the Einstein gravitational field minimally coupled to a Klein-Gordon field, allowing the lapse function to be complex yields a complex action which generat...
1911.08467
Felipe Falciano
F. T. Falciano and M. L. Pe\~nafiel and Santiago Esteban Perez Bergliaffa
Entropy bounds and nonlinear electrodynamics
12 pages, 4 figures, accepted for publication in Phys. Rev. D
Phys. Rev. D 100, 125008 (2019)
10.1103/PhysRevD.100.125008
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Bekenstein's inequality sets a bound on the entropy of a charged macroscopic body. Such a bound is understood as a universal relation between physical quantities and fundamental constants of nature that should be valid for any physical system. We reanalyze the steps that lead to this entropy bound considering a charg...
[ { "created": "Tue, 19 Nov 2019 18:51:42 GMT", "version": "v1" } ]
2019-12-18
[ [ "Falciano", "F. T.", "" ], [ "Peñafiel", "M. L.", "" ], [ "Bergliaffa", "Santiago Esteban Perez", "" ] ]
Bekenstein's inequality sets a bound on the entropy of a charged macroscopic body. Such a bound is understood as a universal relation between physical quantities and fundamental constants of nature that should be valid for any physical system. We reanalyze the steps that lead to this entropy bound considering a charged...
1606.05146
Nicolas Sanchis-Gual
Nicolas Sanchis-Gual, Juan Carlos Degollado, Paula Izquierdo, Jos\'e A. Font, Pedro J. Montero
Quasistationary solutions of scalar fields around accreting black holes
null
Phys. Rev. D 94, 043004 (2016)
10.1103/PhysRevD.94.043004
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Massive scalar fields can form long-lived configurations around black holes. These configurations, dubbed quasi-bound states, have been studied both in the linear and nonlinear regimes. In this paper we show that quasi-bound states can form in a dynamical scenario in which the mass of the black hole grows significant...
[ { "created": "Thu, 16 Jun 2016 11:23:58 GMT", "version": "v1" } ]
2016-08-17
[ [ "Sanchis-Gual", "Nicolas", "" ], [ "Degollado", "Juan Carlos", "" ], [ "Izquierdo", "Paula", "" ], [ "Font", "José A.", "" ], [ "Montero", "Pedro J.", "" ] ]
Massive scalar fields can form long-lived configurations around black holes. These configurations, dubbed quasi-bound states, have been studied both in the linear and nonlinear regimes. In this paper we show that quasi-bound states can form in a dynamical scenario in which the mass of the black hole grows significantly...
2205.09311
Yen Chin Ong
Sofia Di Gennaro, Yen Chin Ong
Sign Switching Dark Energy from a Running Barrow Entropy
null
Universe 2022, 8(10), 541
10.3390/universe8100541
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Barrow proposed that the area law of the entropy associated with a horizon might receive a "fractal correction" due to quantum gravitational effects -- in place of $S\propto A$, we have instead $S\propto A^{1+\delta/2}$, where $0\leqslant \delta \leqslant 1$ measures the deviation from the standard area law ($\delta=...
[ { "created": "Thu, 19 May 2022 03:50:54 GMT", "version": "v1" }, { "created": "Sat, 22 Oct 2022 06:37:58 GMT", "version": "v2" } ]
2022-10-25
[ [ "Di Gennaro", "Sofia", "" ], [ "Ong", "Yen Chin", "" ] ]
Barrow proposed that the area law of the entropy associated with a horizon might receive a "fractal correction" due to quantum gravitational effects -- in place of $S\propto A$, we have instead $S\propto A^{1+\delta/2}$, where $0\leqslant \delta \leqslant 1$ measures the deviation from the standard area law ($\delta=0$...
gr-qc/9611053
Yongsung Yoon
C.J. Park and Yongsung Yoon
Conformal Couplings in Induced Gravity
10 pages, Revtex3.0, to appear in General Relativity and Gravitation
Gen.Rel.Grav. 29 (1997) 765-772
10.1023/A:1018838006753
HYUPT 0825/96
gr-qc
null
It is found that the induced gravity with conformal couplings requires the conformal invariance in both classical and quantum levels for consistency. This is also true for the induced gravity with an extended conformal coupling interacting with torsion.
[ { "created": "Fri, 22 Nov 1996 09:22:49 GMT", "version": "v1" } ]
2015-06-25
[ [ "Park", "C. J.", "" ], [ "Yoon", "Yongsung", "" ] ]
It is found that the induced gravity with conformal couplings requires the conformal invariance in both classical and quantum levels for consistency. This is also true for the induced gravity with an extended conformal coupling interacting with torsion.
1902.09665
Cosimo Bambi
Askar B. Abdikamalov, Dimitry Ayzenberg, Cosimo Bambi, Thomas Dauser, Javier A. Garcia, Sourabh Nampalliwar
Public Release of RELXILL_NK: A Relativistic Reflection Model for Testing Einstein's Gravity
15 pages, 8 figures. v2: refereed version. Code and documentation available at http://www.physics.fudan.edu.cn/tps/people/bambi/Site/RELXILL_NK.html and at http://www.tat.physik.uni-tuebingen.de/~nampalliwar/relxill_nk/
Astrophys.J. 878: 91 (2019)
10.3847/1538-4357/ab1f89
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the public release version of relxill_nk, an X-ray reflection model for testing the Kerr hypothesis and general relativity. This model extends the relxill model that assumes the black hole spacetime is described by the Kerr metric. We also present relxilllp_nk, the first non-Kerr X-ray reflection model wit...
[ { "created": "Mon, 25 Feb 2019 23:53:38 GMT", "version": "v1" }, { "created": "Tue, 18 Jun 2019 14:46:26 GMT", "version": "v2" } ]
2019-06-19
[ [ "Abdikamalov", "Askar B.", "" ], [ "Ayzenberg", "Dimitry", "" ], [ "Bambi", "Cosimo", "" ], [ "Dauser", "Thomas", "" ], [ "Garcia", "Javier A.", "" ], [ "Nampalliwar", "Sourabh", "" ] ]
We present the public release version of relxill_nk, an X-ray reflection model for testing the Kerr hypothesis and general relativity. This model extends the relxill model that assumes the black hole spacetime is described by the Kerr metric. We also present relxilllp_nk, the first non-Kerr X-ray reflection model with ...
2205.08660
Mahnaz Asghari
Mahnaz Asghari and Ahmad Sheykhi
Observational constraints on the fractal cosmology
7 pages, 4 figures, accepted for publication in EPJC
Eur. Phys. J. C (2022) 82: 960
10.1140/epjc/s10052-022-10927-4
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
In this paper, we explore a fractal model of the universe proposed by Calcagni [JHEP{\bf03}(2010)120] for a power-counting renormalizable field theory living in a fractal spacetime. Considering a timelike fractal profile, we derived field equations in fractal cosmology, in order to explore the structure formation and...
[ { "created": "Tue, 17 May 2022 23:14:28 GMT", "version": "v1" }, { "created": "Sun, 16 Oct 2022 13:16:01 GMT", "version": "v2" } ]
2022-11-01
[ [ "Asghari", "Mahnaz", "" ], [ "Sheykhi", "Ahmad", "" ] ]
In this paper, we explore a fractal model of the universe proposed by Calcagni [JHEP{\bf03}(2010)120] for a power-counting renormalizable field theory living in a fractal spacetime. Considering a timelike fractal profile, we derived field equations in fractal cosmology, in order to explore the structure formation and t...
2005.13367
Quentin Henry
Quentin Henry, Guillaume Faye, Luc Blanchet
Tidal effects in the gravitational-wave phase evolution of compact binary systems to next-to-next-to-leading post-Newtonian order
26 pages. A typo has been corrected in Eq. (5.4a) in the latest version
Phys. Rev. D 102, 044033 (2020)
10.1103/PhysRevD.102.044033
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the gravitational-wave (GW) energy flux up to the next-to-next-to-leading (NNL) order of tidal effects in a spinless compact binary system on quasi-circular orbits. Starting from an effective matter action, we obtain the stress-energy tensor of the system, which we use in a GW generation formalism based on...
[ { "created": "Wed, 27 May 2020 13:56:52 GMT", "version": "v1" }, { "created": "Thu, 29 Oct 2020 18:44:05 GMT", "version": "v2" }, { "created": "Mon, 25 Sep 2023 15:17:54 GMT", "version": "v3" } ]
2023-09-26
[ [ "Henry", "Quentin", "" ], [ "Faye", "Guillaume", "" ], [ "Blanchet", "Luc", "" ] ]
We compute the gravitational-wave (GW) energy flux up to the next-to-next-to-leading (NNL) order of tidal effects in a spinless compact binary system on quasi-circular orbits. Starting from an effective matter action, we obtain the stress-energy tensor of the system, which we use in a GW generation formalism based on m...
2307.16841
Prashant Kocherlakota
Prashant Kocherlakota, Luciano Rezzolla, Rittick Roy, and Maciek Wielgus
Prospects for Future Experimental Tests of Gravity with Black Hole Imaging: Spherical Symmetry
12 pages, 3 figures. To appear in PRD
null
null
null
gr-qc astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
Astrophysical black holes (BHs) are universally expected to be described by the Kerr metric, a stationary, vacuum solution of general relativity (GR). Indeed, by imaging M87$^\star$ and Sgr A$^\star$ and measuring the size of their shadows, we have substantiated this hypothesis through successful null tests. Here we ...
[ { "created": "Mon, 31 Jul 2023 17:03:48 GMT", "version": "v1" }, { "created": "Wed, 6 Mar 2024 00:52:30 GMT", "version": "v2" } ]
2024-03-07
[ [ "Kocherlakota", "Prashant", "" ], [ "Rezzolla", "Luciano", "" ], [ "Roy", "Rittick", "" ], [ "Wielgus", "Maciek", "" ] ]
Astrophysical black holes (BHs) are universally expected to be described by the Kerr metric, a stationary, vacuum solution of general relativity (GR). Indeed, by imaging M87$^\star$ and Sgr A$^\star$ and measuring the size of their shadows, we have substantiated this hypothesis through successful null tests. Here we di...
2002.09729
Bogeun Gwak
Bogeun Gwak
Thermodynamics in Rotating Anti-de Sitter Black Holes with Massive Scalar Field in Three Dimensions
13 pages, 9 figures
Chin. Phys. C 44 (2020) 12, 125106
10.1088/1674-1137/abb656
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the tendency in variations of the dual CFT$_2$ when a rotating AdS$_3$ black hole changes by fluxes transferred by the scattering of a massive scalar field according to the AdS/CFT correspondence. The conserved quantities of the black hole are definitely constrained by the extremal condition. Moreover,...
[ { "created": "Sat, 22 Feb 2020 16:42:50 GMT", "version": "v1" } ]
2020-12-01
[ [ "Gwak", "Bogeun", "" ] ]
We investigate the tendency in variations of the dual CFT$_2$ when a rotating AdS$_3$ black hole changes by fluxes transferred by the scattering of a massive scalar field according to the AdS/CFT correspondence. The conserved quantities of the black hole are definitely constrained by the extremal condition. Moreover, t...
gr-qc/0510032
Chongming Xu
Chongming Xu, Xuejun Wu and Erwin Bruening
General Formula for Comparison of Clock Rates -- Applications to Cosmos and Solar System
17 pages. CQG submitted
Class.Quant.Grav. 22 (2005) 5015-5028
10.1088/0264-9381/22/23/007
null
gr-qc
null
In this paper we deduce a quite general formula which allows the relation of clock rates at two different space time points to be discussed. In the case of a perturbed Robertson-Walker metric, our analysis leads to an equation for the comparison of clock rates at different cosmic space time points, which includes the...
[ { "created": "Sat, 8 Oct 2005 01:54:11 GMT", "version": "v1" } ]
2009-11-11
[ [ "Xu", "Chongming", "" ], [ "Wu", "Xuejun", "" ], [ "Bruening", "Erwin", "" ] ]
In this paper we deduce a quite general formula which allows the relation of clock rates at two different space time points to be discussed. In the case of a perturbed Robertson-Walker metric, our analysis leads to an equation for the comparison of clock rates at different cosmic space time points, which includes the H...
0906.0181
Kamal Nandi
K. K. Nandi, B. Bhattacharjee, S. M. K. Alam and J. Evans
Brans-Dicke wormholes in the Jordan and Einstein frames
Minor errors corrected, uploaded for the benefit of the researchers
Phys.Rev.D57:823-828,1998
10.1103/PhysRevD.57.823
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the possibility of static wormhole solutions in the vacuum Brans-Dicke theory both in the original (Jordan) frame and in the conformally rescaled (Einstein) frame. It turns out that, in the former frame, wormholes exist only in a very narrow interval of the coupling parameter, viz., -3/2<omega<-4/3. It is ...
[ { "created": "Sun, 31 May 2009 19:25:29 GMT", "version": "v1" } ]
2009-06-30
[ [ "Nandi", "K. K.", "" ], [ "Bhattacharjee", "B.", "" ], [ "Alam", "S. M. K.", "" ], [ "Evans", "J.", "" ] ]
We examine the possibility of static wormhole solutions in the vacuum Brans-Dicke theory both in the original (Jordan) frame and in the conformally rescaled (Einstein) frame. It turns out that, in the former frame, wormholes exist only in a very narrow interval of the coupling parameter, viz., -3/2<omega<-4/3. It is sh...
1406.6104
Todd Oliynyk
Todd A. Oliynyk
The Newtonian limit on cosmological scales
This version agrees with the published one
Commun. Math. Phys. 339 (2015), 455-512
10.1007/s00220-015-2418-5
null
gr-qc math.AP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We establish the existence of a wide class of inhomogeneous relativistic solutions to the Einstein-Euler equations that are well approximated on cosmological scales by solutions of Newtonian gravity. Error estimates measuring the difference between the Newtonian and relativistic solutions are provided.
[ { "created": "Mon, 23 Jun 2014 23:00:08 GMT", "version": "v1" }, { "created": "Tue, 10 Feb 2015 23:11:52 GMT", "version": "v2" }, { "created": "Sun, 26 Jul 2015 10:24:08 GMT", "version": "v3" } ]
2015-07-28
[ [ "Oliynyk", "Todd A.", "" ] ]
We establish the existence of a wide class of inhomogeneous relativistic solutions to the Einstein-Euler equations that are well approximated on cosmological scales by solutions of Newtonian gravity. Error estimates measuring the difference between the Newtonian and relativistic solutions are provided.
gr-qc/0408045
Ioannis Raptis
Ioannis Raptis
Finitary-Algebraic `Resolution' of the Inner Schwarzschild Singularity
41 pages, to appear in the International Journal of Theoretical Physics
Int.J.Theor.Phys. 45 (2006) 79-128
null
null
gr-qc
null
A `resolution' of the interior singularity of the spherically symmetric Schwarzschild solution of the Einstein equations for the gravitational field of a point-particle is carried out entirely and solely by finitistic and algebraic means. To this end, the background differential spacetime manifold and Calculus-free p...
[ { "created": "Mon, 16 Aug 2004 14:03:08 GMT", "version": "v1" }, { "created": "Tue, 17 Aug 2004 09:55:48 GMT", "version": "v2" }, { "created": "Fri, 20 Aug 2004 10:37:22 GMT", "version": "v3" }, { "created": "Tue, 24 Aug 2004 15:36:51 GMT", "version": "v4" }, { "c...
2007-05-23
[ [ "Raptis", "Ioannis", "" ] ]
A `resolution' of the interior singularity of the spherically symmetric Schwarzschild solution of the Einstein equations for the gravitational field of a point-particle is carried out entirely and solely by finitistic and algebraic means. To this end, the background differential spacetime manifold and Calculus-free pur...
1001.2814
A. Tawfik
A. Tawfik (ECTP & Mti U.), M. Wahba (ECTP & Mti U.), H. Mansour (Cairo U.) and T. Harko (Hong Kong U.)
Viscous Quark-Gluon Plasma in the Early Universe
19 pages, 4 figures including 7 eps graphs
Annals Phys.523:194-207,2011
10.1002/andp.201000052
ECTP-2009-05
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the evolution of a flat, isotropic and homogeneous Friedmann-Robertson-Walker Universe, filled with a causal bulk viscous cosmological fluid, that can be characterized by an ultra-relativistic equation of state and bulk viscosity coefficient obtained from recent lattice QCD calculations. The basic equatio...
[ { "created": "Sat, 16 Jan 2010 10:37:01 GMT", "version": "v1" } ]
2011-10-05
[ [ "Tawfik", "A.", "", "ECTP & Mti U." ], [ "Wahba", "M.", "", "ECTP & Mti U." ], [ "Mansour", "H.", "", "Cairo\n U." ], [ "Harko", "T.", "", "Hong Kong U." ] ]
We consider the evolution of a flat, isotropic and homogeneous Friedmann-Robertson-Walker Universe, filled with a causal bulk viscous cosmological fluid, that can be characterized by an ultra-relativistic equation of state and bulk viscosity coefficient obtained from recent lattice QCD calculations. The basic equation ...
2205.15878
Josu Aurrekoetxea
Josu C. Aurrekoetxea, Pedro G. Ferreira, Katy Clough, Eugene A. Lim, Oliver J. Tattersall
Where is the ringdown? Reconstructing quasinormal modes from dispersive waves
10 pages, 8 figures. Movies: https://youtu.be/YYBwyAbH5Fk. Matches version published in PRD
null
10.1103/PhysRevD.106.104002
null
gr-qc astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We study the generation and propagation of gravitational waves in scalar-tensor gravity using numerical relativity simulations of scalar field collapses beyond spherical symmetry. This allows us to compare the tensor and additional massive scalar waves that are excited. As shown in previous work in spherical symmetry...
[ { "created": "Tue, 31 May 2022 15:26:59 GMT", "version": "v1" }, { "created": "Wed, 2 Nov 2022 14:46:15 GMT", "version": "v2" } ]
2022-11-16
[ [ "Aurrekoetxea", "Josu C.", "" ], [ "Ferreira", "Pedro G.", "" ], [ "Clough", "Katy", "" ], [ "Lim", "Eugene A.", "" ], [ "Tattersall", "Oliver J.", "" ] ]
We study the generation and propagation of gravitational waves in scalar-tensor gravity using numerical relativity simulations of scalar field collapses beyond spherical symmetry. This allows us to compare the tensor and additional massive scalar waves that are excited. As shown in previous work in spherical symmetry, ...
2307.11790
Branislav Cvetkovi\'c
Milutin Blagojevi\'c and Branislav Cvetkovi\'c
On thermodynamics of charged black hole with scalar hair
LaTeX, 10 pages
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that energy, entropy and the first law of the Martinez-Troncoso black hole with electric charge and scalar hair (2006) can be consistently described in a general Hamiltonian approach to black hole thermodynamics.
[ { "created": "Thu, 20 Jul 2023 20:11:12 GMT", "version": "v1" } ]
2023-07-25
[ [ "Blagojević", "Milutin", "" ], [ "Cvetković", "Branislav", "" ] ]
It is shown that energy, entropy and the first law of the Martinez-Troncoso black hole with electric charge and scalar hair (2006) can be consistently described in a general Hamiltonian approach to black hole thermodynamics.
2110.07503
Keisuke Ota
Keisuke Ota, Shinpei Kobayashi and Keisuke Nakashi
Revisiting timelike geodesics in the Fisher-Janis-Newman-Winicour-Wyman spacetime
26 pages, 7 figures
null
10.1103/PhysRevD.105.024037
RUP-21-24
gr-qc astro-ph.HE hep-th
http://creativecommons.org/licenses/by/4.0/
We investigate the timelike geodesics and the periapsis precession of orbits in the Fisher-Janis-Newman-Winicour-Wyman spacetime. This spacetime represents the naked singularity spacetime in the Einstein-massless scalar system. We revisit the results in the previous studies and relax the assumptions about the eccentr...
[ { "created": "Thu, 14 Oct 2021 16:21:43 GMT", "version": "v1" }, { "created": "Tue, 4 Jan 2022 14:24:31 GMT", "version": "v2" } ]
2022-01-26
[ [ "Ota", "Keisuke", "" ], [ "Kobayashi", "Shinpei", "" ], [ "Nakashi", "Keisuke", "" ] ]
We investigate the timelike geodesics and the periapsis precession of orbits in the Fisher-Janis-Newman-Winicour-Wyman spacetime. This spacetime represents the naked singularity spacetime in the Einstein-massless scalar system. We revisit the results in the previous studies and relax the assumptions about the eccentric...
gr-qc/0509040
Yun Soo Myung
Hungsoo Kim, Hyung Won Lee, Yun Soo Myung
Equation of state for an interacting holographic dark energy model
11 pages, 2 eps figures, final version to appear in PLB
Phys.Lett. B632 (2006) 605-609
10.1016/j.physletb.2005.11.043
INJE-TP-05-07
gr-qc astro-ph
null
We investigate a model of the interacting holographic dark energy with cold dark matter (CDM). If the holographic energy density decays into CDM, we find two types of the effective equation of state. In this case we have to use the effective equations of state ($\omega^{\rm eff}_{\rm \Lambda}$) instead of the equatio...
[ { "created": "Mon, 12 Sep 2005 17:57:56 GMT", "version": "v1" }, { "created": "Wed, 16 Nov 2005 16:01:14 GMT", "version": "v2" } ]
2010-04-05
[ [ "Kim", "Hungsoo", "" ], [ "Lee", "Hyung Won", "" ], [ "Myung", "Yun Soo", "" ] ]
We investigate a model of the interacting holographic dark energy with cold dark matter (CDM). If the holographic energy density decays into CDM, we find two types of the effective equation of state. In this case we have to use the effective equations of state ($\omega^{\rm eff}_{\rm \Lambda}$) instead of the equation ...
2105.11958
Christine Cordula Dantas
Christine C. Dantas (Astrophysics Division, INPE, Brazil)
Expanding and Self-Organizing 2D Universe Models Emerging from Frozen Trivalent Spin Networks
Revised version addressing comments by the referees: 22 pages, 7 figures, one appendix; conclusions were significantly expanded
null
10.1088/1361-6382/ac25e1
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the topic of self-organized criticality (SOC) in simple statistical graph models, with the purpose of capturing essential processes leading to the emergence of macroscopic spacetime from the microscopic dynamics in loop quantum gravity (LQG). We performed a large set of simulations based on extensions of t...
[ { "created": "Tue, 25 May 2021 14:13:36 GMT", "version": "v1" }, { "created": "Mon, 23 Aug 2021 13:49:53 GMT", "version": "v2" } ]
2021-09-14
[ [ "Dantas", "Christine C.", "", "Astrophysics Division, INPE, Brazil" ] ]
We revisit the topic of self-organized criticality (SOC) in simple statistical graph models, with the purpose of capturing essential processes leading to the emergence of macroscopic spacetime from the microscopic dynamics in loop quantum gravity (LQG). We performed a large set of simulations based on extensions of the...
1807.05080
S Habib Mazharimousavi
S. Danial Forghani, S. Habib Mazharimousavi and M. Halilsoy
The Stability of Asymmetric Cylindrical Thin-Shell Wormholes
11 pages, 4 figures
null
10.1088/1475-7516/2019/10/067
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In continuation of a preceding work on introducing asymmetric thin-shell wormholes as an emerging class of traversable wormholes within the context, this time cylindrically symmetric spacetimes are exploited to construct such wormholes. Having established a generic formulation, first the Linet-Tian metric generally, ...
[ { "created": "Thu, 12 Jul 2018 07:38:28 GMT", "version": "v1" }, { "created": "Thu, 26 Jul 2018 20:49:31 GMT", "version": "v2" } ]
2019-11-06
[ [ "Forghani", "S. Danial", "" ], [ "Mazharimousavi", "S. Habib", "" ], [ "Halilsoy", "M.", "" ] ]
In continuation of a preceding work on introducing asymmetric thin-shell wormholes as an emerging class of traversable wormholes within the context, this time cylindrically symmetric spacetimes are exploited to construct such wormholes. Having established a generic formulation, first the Linet-Tian metric generally, an...
gr-qc/9606057
Steve Liebling
Steven L. Liebling and Matthew W. Choptuik
Black Hole Criticality in the Brans-Dicke Model
4 pages, REVTeX 3.0, 5 figures included
Phys.Rev.Lett. 77 (1996) 1424-1427
10.1103/PhysRevLett.77.1424
null
gr-qc hep-ph
null
We study the collapse of a free scalar field in the Brans-Dicke model of gravity. At the critical point of black hole formation, the model admits two distinctive solutions dependent on the value of the coupling parameter. We find one solution to be discretely self-similar and the other to exhibit continuous self-simi...
[ { "created": "Tue, 18 Jun 1996 19:54:18 GMT", "version": "v1" } ]
2009-10-28
[ [ "Liebling", "Steven L.", "" ], [ "Choptuik", "Matthew W.", "" ] ]
We study the collapse of a free scalar field in the Brans-Dicke model of gravity. At the critical point of black hole formation, the model admits two distinctive solutions dependent on the value of the coupling parameter. We find one solution to be discretely self-similar and the other to exhibit continuous self-simila...
gr-qc/9812029
John Schwarz
John H. Schwarz
From Superstrings to M Theory
7 pages; To be published in the Proceedings of COSMO-98
null
10.1063/1.59438
CALT-68-2207
gr-qc
null
In this talk I will survey some of the basic facts about superstring theories in 10 dimensions and the dualities that relate them to M theory in 11 dimensions. Then I will mention some important unresolved issues.
[ { "created": "Tue, 8 Dec 1998 19:35:20 GMT", "version": "v1" } ]
2009-10-31
[ [ "Schwarz", "John H.", "" ] ]
In this talk I will survey some of the basic facts about superstring theories in 10 dimensions and the dualities that relate them to M theory in 11 dimensions. Then I will mention some important unresolved issues.
1306.6758
Orlando Luongo
Alessandro Bravetti, Orlando Luongo
Dark energy from Geometrothermodynamics
9 pages; 2 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Geometrothermodynamics is a geometric theory which combines thermodynamics with contact and Riemannian geometry. In this work we use the formalism of geometrothermodynamics to infer cosmological models which predict the observed speed up. As a relevant consequence, our simple model shows dynamical properties which se...
[ { "created": "Fri, 28 Jun 2013 08:58:52 GMT", "version": "v1" } ]
2013-07-01
[ [ "Bravetti", "Alessandro", "" ], [ "Luongo", "Orlando", "" ] ]
Geometrothermodynamics is a geometric theory which combines thermodynamics with contact and Riemannian geometry. In this work we use the formalism of geometrothermodynamics to infer cosmological models which predict the observed speed up. As a relevant consequence, our simple model shows dynamical properties which seem...
2109.02880
Neven Bili\'c
Neven Bili\'c and Hrvoje Nikoli\'c
Analog Schwarzschild black hole from a nonisentropic fluid
8 pages, minor revision, discussion on previous works expanded, conclusions expanded, typos corrected, results unchanged
Universe 2021, 7, 413
null
RBI-ThPhys-2021-33
gr-qc
http://creativecommons.org/licenses/by/4.0/
We study the conditions under which an analog acoustic geometry of a relativistic fluid in flat spacetime can take the same form as the Schwarzschild black hole geometry. We find that the speed of sound must necessarily be equal to the speed of light. Since the speed of the fluid cannot exceed the speed of light, thi...
[ { "created": "Tue, 7 Sep 2021 05:43:20 GMT", "version": "v1" }, { "created": "Fri, 29 Oct 2021 09:33:44 GMT", "version": "v2" } ]
2021-11-01
[ [ "Bilić", "Neven", "" ], [ "Nikolić", "Hrvoje", "" ] ]
We study the conditions under which an analog acoustic geometry of a relativistic fluid in flat spacetime can take the same form as the Schwarzschild black hole geometry. We find that the speed of sound must necessarily be equal to the speed of light. Since the speed of the fluid cannot exceed the speed of light, this ...
2210.07299
Tib\'erio Pereira
Tib\'erio Pereira, Riccardo Sturani
Deep learning waveform anomaly detector for numerical relativity catalogs
15 pages, 16 figures
null
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
Numerical Relativity has been of fundamental importance for studying compact binary coalescence dynamics, waveform modelling, and eventually for gravitational waves observations. As the sensitivity of the detector network improves, more precise template modelling will be necessary to guarantee a more accurate estimat...
[ { "created": "Thu, 13 Oct 2022 18:59:42 GMT", "version": "v1" }, { "created": "Wed, 21 Feb 2024 13:43:57 GMT", "version": "v2" } ]
2024-02-22
[ [ "Pereira", "Tibério", "" ], [ "Sturani", "Riccardo", "" ] ]
Numerical Relativity has been of fundamental importance for studying compact binary coalescence dynamics, waveform modelling, and eventually for gravitational waves observations. As the sensitivity of the detector network improves, more precise template modelling will be necessary to guarantee a more accurate estimatio...
0808.1704
L\'aszl\'o \'A Gergely
L\'aszl\'o \'A. Gergely, Bal\'azs Mik\'oczi
Renormalized 2PN spin contributions to the accumulated orbital phase for LISA sources
v2: 14 pages, 6 figures, 2 animated gifs; new section on the comparison of the analytical results with numerical evolution; published version
Phys.Rev.D79:064023,2009
10.1103/PhysRevD.79.064023
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We give here a new third post-Newtonisn (3PN) spin-spin contribution (in the PN parameter $\epsilon $) to the accumulated orbital phase of a compact binary, arising from the spin-orbit precessional motion of the spins. In the equal mass case this contribution vanishes, but LISA sources of merging supermassive binary ...
[ { "created": "Tue, 12 Aug 2008 18:51:05 GMT", "version": "v1" }, { "created": "Tue, 21 Apr 2009 11:57:52 GMT", "version": "v2" } ]
2009-11-13
[ [ "Gergely", "László Á.", "" ], [ "Mikóczi", "Balázs", "" ] ]
We give here a new third post-Newtonisn (3PN) spin-spin contribution (in the PN parameter $\epsilon $) to the accumulated orbital phase of a compact binary, arising from the spin-orbit precessional motion of the spins. In the equal mass case this contribution vanishes, but LISA sources of merging supermassive binary bl...
1501.07605
Joao G. Rosa
Joao G. Rosa
Testing black hole superradiance with pulsar companions
5 pages, 3 figures; matches published version in Physics Letters B
Phys. Lett. B 749, 226 (2015)
10.1016/j.physletb.2015.07.063
null
gr-qc astro-ph.SR hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the magnetic dipole and gravitational radiation emitted by a pulsar can undergo superradiant scattering off a spinning black hole companion. We find that the relative amount of superradiant modes in the radiation depends on the pulsar's angular position relative to the black hole's equatorial plane. In p...
[ { "created": "Thu, 29 Jan 2015 21:00:12 GMT", "version": "v1" }, { "created": "Thu, 13 Aug 2015 09:30:14 GMT", "version": "v2" } ]
2015-08-14
[ [ "Rosa", "Joao G.", "" ] ]
We show that the magnetic dipole and gravitational radiation emitted by a pulsar can undergo superradiant scattering off a spinning black hole companion. We find that the relative amount of superradiant modes in the radiation depends on the pulsar's angular position relative to the black hole's equatorial plane. In par...
gr-qc/0206019
Luis Herrera
M. F. A. da Silva, L.Herrera, N. O.Santos and A. Z. Wang
Rotating cylindrical shell source for Lewis spacetime
18 pages Latex, to appear in Class.Quantum Grav
Class.Quant.Grav. 19 (2002) 3809-3820
10.1088/0264-9381/19/14/319
null
gr-qc
null
Rotating thin-shell-like sources for the stationary cylindrically symmetric vacuum solutions (Lewis) are constructed and studied. It is found, by imposing the non existence of timelike curves in the exterior of the shell, and that the source satisfies the weak, dominant and strong energy conditions that the parameter...
[ { "created": "Thu, 6 Jun 2002 19:39:38 GMT", "version": "v1" } ]
2009-11-07
[ [ "da Silva", "M. F. A.", "" ], [ "Herrera", "L.", "" ], [ "Santos", "N. O.", "" ], [ "Wang", "A. Z.", "" ] ]
Rotating thin-shell-like sources for the stationary cylindrically symmetric vacuum solutions (Lewis) are constructed and studied. It is found, by imposing the non existence of timelike curves in the exterior of the shell, and that the source satisfies the weak, dominant and strong energy conditions that the parameters,...
2212.08089
Pau Beltr\'an Palau
Pau Beltr\'an-Palau, Adri\'an del R\'io and Jos\'e Navarro-Salas
Quantum corrections to the Schwarzschild metric from vacuum polarization
16 pages, 6 figures
Phys. Rev. D 107, 085023 (2023)
10.1103/PhysRevD.107.085023
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore static and spherically symmetric solutions of the 4-dimensional semiclassical Einstein's equations using the quantum vacuum polarization of a conformal field as a source. These solutions may be of interest for \black{the study of} exotic, compact objects (ECOs). The full backreaction problem is addressed b...
[ { "created": "Thu, 15 Dec 2022 19:02:44 GMT", "version": "v1" }, { "created": "Mon, 15 May 2023 11:13:34 GMT", "version": "v2" } ]
2023-05-16
[ [ "Beltrán-Palau", "Pau", "" ], [ "del Río", "Adrián", "" ], [ "Navarro-Salas", "José", "" ] ]
We explore static and spherically symmetric solutions of the 4-dimensional semiclassical Einstein's equations using the quantum vacuum polarization of a conformal field as a source. These solutions may be of interest for \black{the study of} exotic, compact objects (ECOs). The full backreaction problem is addressed by ...
0911.5635
Kostiantyn Ropotenko
Kostiantyn Ropotenko
The quantum of area $\Delta A = 8\pi l_P^{2}$ and a statistical interpretation of black hole entropy
12 pages, revtex, no figures; v.3, revised and enlarged; Sec. III "Quantization of black hole as Landau quantization" added; references added; conclusions changed in some points
Phys.Rev.D82:044037,2010
10.1103/PhysRevD.82.044037
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In contrast to alternative values, the quantum of area $\Delta A = 8\pi l_P^{2}$ does not follow from the usual statistical interpretation of black hole entropy; on the contrary, a statistical interpretation follows from it. This interpretation is based on the two concepts: nonadditivity of black hole entropy and Lan...
[ { "created": "Mon, 30 Nov 2009 13:13:55 GMT", "version": "v1" }, { "created": "Fri, 26 Feb 2010 16:04:59 GMT", "version": "v2" }, { "created": "Wed, 30 Jun 2010 15:25:57 GMT", "version": "v3" }, { "created": "Thu, 1 Jul 2010 07:18:47 GMT", "version": "v4" } ]
2014-11-20
[ [ "Ropotenko", "Kostiantyn", "" ] ]
In contrast to alternative values, the quantum of area $\Delta A = 8\pi l_P^{2}$ does not follow from the usual statistical interpretation of black hole entropy; on the contrary, a statistical interpretation follows from it. This interpretation is based on the two concepts: nonadditivity of black hole entropy and Landa...
gr-qc/0702149
Jorge P\'aramos
O. Bertolami and J. Paramos
A mission to test the Pioneer anomaly: estimating the main systematic effects
9 pages, 1 table, 2 figures; based on a talk presented by one of us (O.B.) at the 2nd. Pioneer Anomaly Group Meeting at the International Space Science Institute, 19-23 February 2007
Int.J.Mod.Phys.D16:1611-1623,2007
10.1142/S0218271807011000
null
gr-qc
null
We estimate the main systematic effects relevant in a mission to test and characterize the Pioneer anomaly through the flight formation concept, by launching probing spheres from a mother spacecraft and tracking their motion via laser ranging.
[ { "created": "Wed, 28 Feb 2007 18:21:25 GMT", "version": "v1" }, { "created": "Wed, 20 Jun 2007 10:56:29 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bertolami", "O.", "" ], [ "Paramos", "J.", "" ] ]
We estimate the main systematic effects relevant in a mission to test and characterize the Pioneer anomaly through the flight formation concept, by launching probing spheres from a mother spacecraft and tracking their motion via laser ranging.
2310.11041
Tsutomu Kobayashi
Tsutomu Kobayashi, Takashi Hiramatsu
Weak-field regime of scalar-tensor theories with an instantaneous mode
12 pages, published version in PRD
null
null
RUP-23-21
gr-qc
http://creativecommons.org/licenses/by/4.0/
Higher-order scalar-tensor theories having an instantaneous mode do not develop the Ostrogradsky instability even if a seemingly dangerous mode is present. Such theories satisfy only partially the degeneracy conditions that are usually imposed to remove the dangerous mode completely, and are dubbed as U-DHOST theorie...
[ { "created": "Tue, 17 Oct 2023 07:14:02 GMT", "version": "v1" }, { "created": "Sat, 23 Mar 2024 06:29:51 GMT", "version": "v2" } ]
2024-03-26
[ [ "Kobayashi", "Tsutomu", "" ], [ "Hiramatsu", "Takashi", "" ] ]
Higher-order scalar-tensor theories having an instantaneous mode do not develop the Ostrogradsky instability even if a seemingly dangerous mode is present. Such theories satisfy only partially the degeneracy conditions that are usually imposed to remove the dangerous mode completely, and are dubbed as U-DHOST theories....
2304.12024
Hiroki Matsui
Hiroki Matsui
Summing over Non-singular Paths in Quantum Cosmology
24 pages, references added, published version
Class. Quantum Grav. 41 (2024) 5, 055005
10.1088/1361-6382/ad1fc9
YITP-23-55
gr-qc hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we provide the DeWitt propagator and its wave function in quantum cosmology using the path integral formulation of quantum gravity. The DeWitt boundary condition is introduced as a way to avoid the Big Bang singularity by positing that the wave function of the universe vanishes near the Big Bang. Howeve...
[ { "created": "Mon, 24 Apr 2023 11:48:21 GMT", "version": "v1" }, { "created": "Thu, 25 Jan 2024 10:06:50 GMT", "version": "v2" } ]
2024-02-05
[ [ "Matsui", "Hiroki", "" ] ]
In this paper we provide the DeWitt propagator and its wave function in quantum cosmology using the path integral formulation of quantum gravity. The DeWitt boundary condition is introduced as a way to avoid the Big Bang singularity by positing that the wave function of the universe vanishes near the Big Bang. However,...
2203.11143
Mohamed Benali
A. Belhaj, H. Belmahi, M. Benali, H. El Moumni
Light Deflection Angle by Superentropic Black Holes
latex, 12 pages, 2 figures. Accepted version in IJMPD 2022
null
10.1142/S0218271822500547
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by recent works on light deflection and shadow behaviors on AdS geometries, we investigate the deflection angle of light rays by superentropic black holes. Taking appropriate approximations, we first obtain the involved expression. For large values of the impact parameter, we get a specific value being zero...
[ { "created": "Mon, 21 Mar 2022 17:23:41 GMT", "version": "v1" } ]
2022-06-29
[ [ "Belhaj", "A.", "" ], [ "Belmahi", "H.", "" ], [ "Benali", "M.", "" ], [ "Moumni", "H. El", "" ] ]
Motivated by recent works on light deflection and shadow behaviors on AdS geometries, we investigate the deflection angle of light rays by superentropic black holes. Taking appropriate approximations, we first obtain the involved expression. For large values of the impact parameter, we get a specific value being zero f...
gr-qc/0501017
Jose Geraldo Pereira
H. I. Arcos and J. G. Pereira
Torsion Gravity: a Reappraisal
RevTeX, 34 pages. Review article to be published by Int. J. Mod. Phys. D
Int.J.Mod.Phys. D13 (2004) 2193-2240
10.1142/S0218271804006462
null
gr-qc
null
The role played by torsion in gravitation is critically reviewed. After a description of the problems and controversies involving the physics of torsion, a comprehensive presentation of the teleparallel equivalent of general relativity is made. According to this theory, curvature and torsion are alternative ways of d...
[ { "created": "Fri, 7 Jan 2005 12:50:38 GMT", "version": "v1" } ]
2009-11-11
[ [ "Arcos", "H. I.", "" ], [ "Pereira", "J. G.", "" ] ]
The role played by torsion in gravitation is critically reviewed. After a description of the problems and controversies involving the physics of torsion, a comprehensive presentation of the teleparallel equivalent of general relativity is made. According to this theory, curvature and torsion are alternative ways of des...
1706.06597
Carlos A. R. Herdeiro
Carlos A. R. Herdeiro and Eugen Radu
Kerr black holes with synchronised hair: an analytic model and dynamical formation
5+2 pages, 7 figures; data files and Mathematica notebooks can be found in this URL: http://gravitation.web.ua.pt/index.php?q=node/716
Phys. Rev. Lett. 119, 261101 (2017)
10.1103/PhysRevLett.119.261101
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
East and Pretorius (arXiv:1704.04791) have successfully evolved, using fully non-linear numerical simulations, the superradiant instability of the Kerr black hole (BH) triggered by a massive, complex vector field. Evolutions terminate in stationary states of a vector field condensate synchronised with a rotating BH h...
[ { "created": "Tue, 20 Jun 2017 18:00:03 GMT", "version": "v1" } ]
2018-01-03
[ [ "Herdeiro", "Carlos A. R.", "" ], [ "Radu", "Eugen", "" ] ]
East and Pretorius (arXiv:1704.04791) have successfully evolved, using fully non-linear numerical simulations, the superradiant instability of the Kerr black hole (BH) triggered by a massive, complex vector field. Evolutions terminate in stationary states of a vector field condensate synchronised with a rotating BH hor...
1403.5484
Thomas W. Baumgarte
Kenneth A. Dennison and Thomas W. Baumgarte
A Simple Family of Analytical Trumpet Slices of the Schwarzschild Spacetime
7 pages, 3 figures
null
10.1088/0264-9381/31/11/117001
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe a simple family of analytical coordinate systems for the Schwarzschild spacetime. The coordinates penetrate the horizon smoothly and are spatially isotropic. Spatial slices of constant coordinate time $t$ feature a trumpet geometry with an asymptotically cylindrical end inside the horizon at a prescribed ...
[ { "created": "Fri, 21 Mar 2014 15:03:33 GMT", "version": "v1" } ]
2015-06-19
[ [ "Dennison", "Kenneth A.", "" ], [ "Baumgarte", "Thomas W.", "" ] ]
We describe a simple family of analytical coordinate systems for the Schwarzschild spacetime. The coordinates penetrate the horizon smoothly and are spatially isotropic. Spatial slices of constant coordinate time $t$ feature a trumpet geometry with an asymptotically cylindrical end inside the horizon at a prescribed ar...
1609.07804
Ali \"Ovg\"un Dr.
A. \"Ovg\"un
The Bekenstein-Hawking Corpuscular Cascading from the Backreacted Black Hole
10 pages, accepted for publication in Advances in High Energy Physics
Advances in High Energy Physics, vol. 2017, Article ID 1573904, 9 pages, 2017
10.1155/2017/1573904
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Exciting peculiarities of Planck-scale physics have immediate effects on the Bekenstein-Hawking radiation emitted from black holes (BHs). In this paper, using the tunneling formalism, we determine the Bekenstein-Hawking temperature for the vector particles from a backreacted black hole (BBH) constructed from a confor...
[ { "created": "Sun, 25 Sep 2016 21:22:32 GMT", "version": "v1" }, { "created": "Wed, 5 Jul 2017 15:39:11 GMT", "version": "v2" } ]
2017-08-22
[ [ "Övgün", "A.", "" ] ]
Exciting peculiarities of Planck-scale physics have immediate effects on the Bekenstein-Hawking radiation emitted from black holes (BHs). In this paper, using the tunneling formalism, we determine the Bekenstein-Hawking temperature for the vector particles from a backreacted black hole (BBH) constructed from a conforma...
1808.10413
Shuxun Tian
Shuxun Tian
Scalar-tensor nonlocal gravity
5 pages, accepted for publication in PRD
Phys. Rev. D 98, 084040 (2018)
10.1103/PhysRevD.98.084040
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In order to explain the late-time cosmological acceleration, we propose a new pure geometric gravity based on Deser-Woodard theory, in which the expansion of a matter-dominated universe can be accelerating. This new theory behaves as well as general relativity in solar system and gravitational waves, which is an impo...
[ { "created": "Thu, 30 Aug 2018 17:32:16 GMT", "version": "v1" }, { "created": "Wed, 24 Oct 2018 04:17:07 GMT", "version": "v2" } ]
2018-10-31
[ [ "Tian", "Shuxun", "" ] ]
In order to explain the late-time cosmological acceleration, we propose a new pure geometric gravity based on Deser-Woodard theory, in which the expansion of a matter-dominated universe can be accelerating. This new theory behaves as well as general relativity in solar system and gravitational waves, which is an import...
2106.16014
Lloren\c{c} Espinosa-Portal\'es
Juan Garcia-Bellido and Llorenc Espinosa-Portales
Cosmic acceleration from first principles
6 pages, 5 figures. Comments added. Matches version accepted by PDU
Physics of the Dark Universe 34 (2021) 100892
10.1016/j.dark.2021.100892
IFT-UAM/CSIC-21-75
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
General relativistic entropic acceleration theory may explain the present cosmic acceleration from first principles without the need of introducing a cosmological constant. Following the covariant formulation of non-equilibrium phenomena in the context of a homogeneous and isotropic Friedmann-Lemaitre-Robertson-Walke...
[ { "created": "Wed, 30 Jun 2021 12:30:26 GMT", "version": "v1" }, { "created": "Tue, 19 Oct 2021 15:33:49 GMT", "version": "v2" } ]
2021-10-20
[ [ "Garcia-Bellido", "Juan", "" ], [ "Espinosa-Portales", "Llorenc", "" ] ]
General relativistic entropic acceleration theory may explain the present cosmic acceleration from first principles without the need of introducing a cosmological constant. Following the covariant formulation of non-equilibrium phenomena in the context of a homogeneous and isotropic Friedmann-Lemaitre-Robertson-Walker ...
2004.12320
{\L}ukasz Nakonieczny
{\L}ukasz Nakonieczny
Top-down approach to the curved spacetime effective feld theory (cEFT) -- theory and examples
4 pages, 2 figures, proceedings of 6th Conference of the Polish Society on Relativity to be published in Acta Physica Polonica B
Acta Physica Polonica B Proceedings Supplement, vol 13 (2020) no 2
10.5506/APhysPolBSupp.13.209
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The effective field theory (EFT) turns out to be an instrument of an immense value in all aspects of modern particle physics being theory, phenomenology or experiment. In the paper I will show how to extend the systematic top down approach to construction of the EFT proposed by Hitoshi Murayama (LBL, Berkeley) and se...
[ { "created": "Sun, 26 Apr 2020 08:59:15 GMT", "version": "v1" } ]
2021-02-18
[ [ "Nakonieczny", "Łukasz", "" ] ]
The effective field theory (EFT) turns out to be an instrument of an immense value in all aspects of modern particle physics being theory, phenomenology or experiment. In the paper I will show how to extend the systematic top down approach to construction of the EFT proposed by Hitoshi Murayama (LBL, Berkeley) and sepa...
2103.02057
Paolo Meda
Paolo Meda, Nicola Pinamonti, Simone Roncallo, Nino Zangh\`i
Evaporation of four-dimensional dynamical black holes sourced by the quantum trace anomaly
21 pages, 2 figure. Changed abstract and introduction, modified section 3, added figure about the smearing function. Added some references and made minor corrections. Made slightly modifications of the ANEC and of the smearing function presented in the statement of Theorem 4.1 (p.10). Added corrections to the f...
Classical and Quantum Gravity (2021)
10.1088/1361-6382/ac1fd2
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the evaporation of a four-dimensional spherically symmetric black hole formed in a gravitational collapse. We analyze the back-reaction of a massless quantum scalar field conformally coupled to the scalar curvature by means of the semiclassical Einstein equations. We show that the evaporation is linked to an...
[ { "created": "Tue, 2 Mar 2021 22:13:19 GMT", "version": "v1" }, { "created": "Fri, 3 Sep 2021 21:05:15 GMT", "version": "v2" }, { "created": "Mon, 29 Nov 2021 15:38:18 GMT", "version": "v3" } ]
2021-11-30
[ [ "Meda", "Paolo", "" ], [ "Pinamonti", "Nicola", "" ], [ "Roncallo", "Simone", "" ], [ "Zanghì", "Nino", "" ] ]
We study the evaporation of a four-dimensional spherically symmetric black hole formed in a gravitational collapse. We analyze the back-reaction of a massless quantum scalar field conformally coupled to the scalar curvature by means of the semiclassical Einstein equations. We show that the evaporation is linked to an i...
gr-qc/0406008
Jose Manuel Velhinho
J. M. Velhinho
Comments on the kinematical structure of loop quantum cosmology
7 pages
Class.Quant.Grav. 21 (2004) L109
10.1088/0264-9381/21/15/L01
null
gr-qc
null
We comment on the presence of spurious observables and on a subtle violation of irreducibility in loop quantum cosmology.
[ { "created": "Wed, 2 Jun 2004 19:28:00 GMT", "version": "v1" } ]
2009-11-10
[ [ "Velhinho", "J. M.", "" ] ]
We comment on the presence of spurious observables and on a subtle violation of irreducibility in loop quantum cosmology.
1304.0594
Ruxandra Bondarescu
Andrew P. Lundgren (Max Planck Institute for Gravitational Physics, Hannover), Ruxandra Bondarescu (University of Zurich) and Mihai Bondarescu (Universitatea de Vest Timisoara and University of Mississippi)
Merging Gravitation with Thermodynamics to Understand Cosmology
6 pages, no figures
null
null
null
gr-qc astro-ph.CO math-ph math.MP physics.space-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the evolution of the universe in the context of the second law of thermodynamics from its early stages to the far future. Cosmological observations suggest that most matter and radiation will be absorbed by the cosmological horizon. On the local scale, the matter that is not ejected from our supercluster w...
[ { "created": "Tue, 2 Apr 2013 11:43:14 GMT", "version": "v1" } ]
2013-04-03
[ [ "Lundgren", "Andrew P.", "", "Max Planck Institute for Gravitational Physics,\n Hannover" ], [ "Bondarescu", "Ruxandra", "", "University of Zurich" ], [ "Bondarescu", "Mihai", "", "Universitatea de Vest Timisoara and University of Mississippi" ] ]
We discuss the evolution of the universe in the context of the second law of thermodynamics from its early stages to the far future. Cosmological observations suggest that most matter and radiation will be absorbed by the cosmological horizon. On the local scale, the matter that is not ejected from our supercluster wil...
gr-qc/9910072
B. V. Ivanov
B. V. Ivanov
Towards a regular type N vacuum gravitational field
4 pages, RevTeX
null
null
null
gr-qc
null
An exact twisting type N vacuum solution is found. It has regular gauge and curvature invariants and decays to flat spacetime for big retarded times.
[ { "created": "Thu, 21 Oct 1999 07:54:42 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ivanov", "B. V.", "" ] ]
An exact twisting type N vacuum solution is found. It has regular gauge and curvature invariants and decays to flat spacetime for big retarded times.
2302.00950
Jia-Xi Feng
Jia-Xi Feng, Fengge Zhang, and Xian Gao
Scalar induced gravitational waves from Chern-Simons gravity during inflation era
23 pages, references added, and a new discussion about a linear coupling function added. Version to be published in JCAP
null
10.1088/1475-7516/2023/07/047
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the scalar induced gravitational waves (SIGWs) in the Chern-Simons (CS) gravity with a dynamical scalar field during slow roll inflation. Due to the parity violation in the CS term, the SIGWs are generally polarized, which are effectively characterized by the degree of circular polarization. We derive ...
[ { "created": "Thu, 2 Feb 2023 08:43:28 GMT", "version": "v1" }, { "created": "Sun, 16 Jul 2023 13:12:21 GMT", "version": "v2" } ]
2023-07-26
[ [ "Feng", "Jia-Xi", "" ], [ "Zhang", "Fengge", "" ], [ "Gao", "Xian", "" ] ]
We investigate the scalar induced gravitational waves (SIGWs) in the Chern-Simons (CS) gravity with a dynamical scalar field during slow roll inflation. Due to the parity violation in the CS term, the SIGWs are generally polarized, which are effectively characterized by the degree of circular polarization. We derive th...
0706.1899
Lorenzo Fatibene
L. Fatibene, M. Francaviglia, C. Rovelli
Spacetime Lagrangian Formulation of Barbero-Immirzi Gravity
12 pages, no figures
Class.Quant.Grav.24:4207-4218,2007
10.1088/0264-9381/24/16/014
null
gr-qc
null
We shall here discuss a new spacetime gauge-covariant Lagrangian formulation of General Relativity by means of the Barbero-Immirzi SU(2)-connection on spacetime. To the best of our knowledge the Lagrangian based on SU(2) spacetime fields seems to appear here for the first time.
[ { "created": "Wed, 13 Jun 2007 13:39:53 GMT", "version": "v1" } ]
2008-11-26
[ [ "Fatibene", "L.", "" ], [ "Francaviglia", "M.", "" ], [ "Rovelli", "C.", "" ] ]
We shall here discuss a new spacetime gauge-covariant Lagrangian formulation of General Relativity by means of the Barbero-Immirzi SU(2)-connection on spacetime. To the best of our knowledge the Lagrangian based on SU(2) spacetime fields seems to appear here for the first time.
1009.1884
Philippe G. LeFloch
Philippe G. LeFloch
Einstein spacetimes with weak regularity
15 pages
AMS/IP Stud.Adv.Math.49:81-96,2011
null
null
gr-qc math.AP math.DG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review recent work on the Einstein equations of general relativity when the curvature is defined in a weak sense. Weakly regular spacetimes are constructed, in which impulsive gravitational waves, as well as shock waves, propagate.
[ { "created": "Thu, 9 Sep 2010 20:42:46 GMT", "version": "v1" }, { "created": "Thu, 13 Jan 2011 19:49:57 GMT", "version": "v2" } ]
2011-08-09
[ [ "LeFloch", "Philippe G.", "" ] ]
We review recent work on the Einstein equations of general relativity when the curvature is defined in a weak sense. Weakly regular spacetimes are constructed, in which impulsive gravitational waves, as well as shock waves, propagate.
2403.07130
Hermano Velten
Jonas Pinheiro da Silva and Hermano Velten
Selecting energy-momentum trace dependent gravity theories with LSS
V2 substantially improved after the comments we received. Main results unchanged. This version also revisits the conclusion of our previous work in Phys. Dark Univ. 43 (2024) 101401
null
null
null
gr-qc astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We study scalar cosmological perturbations in $f(R, T)$ modified gravity theories being $T$ the trace of the energy-momentum tensor. We provide detailed equations for the matter energy density contrast. We solve then numerically to promote a comparison with available large scale structure (LSS) formation observationa...
[ { "created": "Mon, 11 Mar 2024 19:54:30 GMT", "version": "v1" }, { "created": "Mon, 8 Apr 2024 18:46:14 GMT", "version": "v2" } ]
2024-04-10
[ [ "da Silva", "Jonas Pinheiro", "" ], [ "Velten", "Hermano", "" ] ]
We study scalar cosmological perturbations in $f(R, T)$ modified gravity theories being $T$ the trace of the energy-momentum tensor. We provide detailed equations for the matter energy density contrast. We solve then numerically to promote a comparison with available large scale structure (LSS) formation observational ...
2112.11982
Atsushi Nishizawa
Atsushi Nishizawa, Shoki Iwaguchi, Yanbei Chen, Taigen Morimoto, Tomohiro Ishikawa, Bin Wu, Izumi Watanabe, Yuki Kawasaki, Ryuma Shimizu, Hirohiko Shimizu, Masaaki Kitaguchi, Yuta Michimura, and Seiji Kawamura
Neutron displacement noise-free interferometer for gravitational-wave detection
7 pages, 5 figures. Published version in Physical Review D
null
10.1103/PhysRevD.105.124017
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An interferometer design that cancels all displacement noises of its test masses and maintains a gravitational-wave (GW) signal by combining multiple detector signals is called a displacement noise-free interferometer (DFI). The idea has been considered previously for a laser interferometer. However, a limitation of ...
[ { "created": "Wed, 22 Dec 2021 15:53:24 GMT", "version": "v1" }, { "created": "Sun, 13 Feb 2022 06:19:53 GMT", "version": "v2" }, { "created": "Tue, 24 May 2022 02:11:55 GMT", "version": "v3" } ]
2022-06-22
[ [ "Nishizawa", "Atsushi", "" ], [ "Iwaguchi", "Shoki", "" ], [ "Chen", "Yanbei", "" ], [ "Morimoto", "Taigen", "" ], [ "Ishikawa", "Tomohiro", "" ], [ "Wu", "Bin", "" ], [ "Watanabe", "Izumi", "" ], [ ...
An interferometer design that cancels all displacement noises of its test masses and maintains a gravitational-wave (GW) signal by combining multiple detector signals is called a displacement noise-free interferometer (DFI). The idea has been considered previously for a laser interferometer. However, a limitation of a ...
gr-qc/0612135
Mariam Bouhmadi-Lopez
Mariam Bouhmadi-Lopez, Pedro F. Gonzalez-Diaz and Prado Martin-Moruno
Worse than a big rip?
6 pages, 4 figures, RevTeX 4. Discussion expanded and references added. Version to appear in PLB
Phys.Lett.B659:1-5,2008
10.1016/j.physletb.2007.10.079
null
gr-qc
null
We show that a generalised phantom Chaplygin gas can present a future singularity in a finite future cosmic time. Unlike the big rip singularity, this singularity happens for a finite scale factor, but like the big rip singularity, it would also take place at a finite future cosmic time. In addition, we define a dual...
[ { "created": "Thu, 21 Dec 2006 15:22:33 GMT", "version": "v1" }, { "created": "Tue, 30 Oct 2007 14:39:53 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bouhmadi-Lopez", "Mariam", "" ], [ "Gonzalez-Diaz", "Pedro F.", "" ], [ "Martin-Moruno", "Prado", "" ] ]
We show that a generalised phantom Chaplygin gas can present a future singularity in a finite future cosmic time. Unlike the big rip singularity, this singularity happens for a finite scale factor, but like the big rip singularity, it would also take place at a finite future cosmic time. In addition, we define a dual o...
gr-qc/9501004
Franz Embacher
Franz Embacher
Actions for signature change
36 pages, LaTeX, no figures; some corrections have been made, several Comments and further references are included and a note has been added.
Phys.Rev. D51 (1995) 6764-6777
10.1103/PhysRevD.51.6764
UWThPh-1995-1
gr-qc
null
This is a contribution on the controversy about junction conditions for classical signature change. The central issue in this debate is whether the extrinsic curvature on slices near the hypersurface of signature change has to be continuous ({\it weak} signature change) or to vanish ({\it strong} signature change). L...
[ { "created": "Mon, 9 Jan 1995 11:03:00 GMT", "version": "v1" }, { "created": "Fri, 3 Feb 1995 10:55:00 GMT", "version": "v2" }, { "created": "Fri, 3 Feb 1995 11:27:00 GMT", "version": "v3" }, { "created": "Mon, 13 Feb 1995 10:57:00 GMT", "version": "v4" } ]
2016-08-31
[ [ "Embacher", "Franz", "" ] ]
This is a contribution on the controversy about junction conditions for classical signature change. The central issue in this debate is whether the extrinsic curvature on slices near the hypersurface of signature change has to be continuous ({\it weak} signature change) or to vanish ({\it strong} signature change). Led...
1908.10370
Horng Sheng Chia
Daniel Baumann, Horng Sheng Chia, John Stout, Lotte ter Haar
The Spectra of Gravitational Atoms
47+25 pages, 16 figures
null
10.1088/1475-7516/2019/12/006
null
gr-qc hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the quasi-bound state spectra of ultralight scalar and vector fields around rotating black holes. These spectra are determined by the gravitational fine structure constant $\alpha$, which is the ratio of the size of the black hole to the Compton wavelength of the field. When $\alpha$ is small, the energy e...
[ { "created": "Tue, 27 Aug 2019 18:00:01 GMT", "version": "v1" } ]
2019-12-11
[ [ "Baumann", "Daniel", "" ], [ "Chia", "Horng Sheng", "" ], [ "Stout", "John", "" ], [ "ter Haar", "Lotte", "" ] ]
We compute the quasi-bound state spectra of ultralight scalar and vector fields around rotating black holes. These spectra are determined by the gravitational fine structure constant $\alpha$, which is the ratio of the size of the black hole to the Compton wavelength of the field. When $\alpha$ is small, the energy eig...
gr-qc/9912102
William A. Hiscock
Shane L. Larson and William A. Hiscock (Montana State University)
Using binary stars to bound the mass of the graviton
21 pages plus 4 figures; ReVTeX
Phys.Rev. D61 (2000) 104008
10.1103/PhysRevD.61.104008
MSUPHY99.08
gr-qc
null
Interacting white dwarf binary star systems, including helium cataclysmic variable (HeCV) systems, are expected to be strong sources of gravitational radiation, and should be detectable by proposed space-based laser interferometer gravitational wave observatories such as LISA. Several HeCV star systems are presently ...
[ { "created": "Thu, 23 Dec 1999 21:38:15 GMT", "version": "v1" } ]
2009-10-31
[ [ "Larson", "Shane L.", "", "Montana State University" ], [ "Hiscock", "William A.", "", "Montana State University" ] ]
Interacting white dwarf binary star systems, including helium cataclysmic variable (HeCV) systems, are expected to be strong sources of gravitational radiation, and should be detectable by proposed space-based laser interferometer gravitational wave observatories such as LISA. Several HeCV star systems are presently kn...
1205.1917
Mikel Fern\'andez-M\'endez
Mikel Fern\'andez-M\'endez, Guillermo A. Mena Marug\'an, Javier Olmedo
Hybrid quantization of an inflationary universe
16 pages, no figures
Phys. Rev. D 86, 024003 (2012)
10.1103/PhysRevD.86.024003
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We quantize to completion an inflationary universe with small inhomogeneities in the framework of loop quantum cosmology. The homogeneous setting consists of a massive scalar field propagating in a closed, homogeneous scenario. We provide a complete quantum description of the system employing loop quantization techni...
[ { "created": "Wed, 9 May 2012 09:09:39 GMT", "version": "v1" } ]
2012-07-20
[ [ "Fernández-Méndez", "Mikel", "" ], [ "Marugán", "Guillermo A. Mena", "" ], [ "Olmedo", "Javier", "" ] ]
We quantize to completion an inflationary universe with small inhomogeneities in the framework of loop quantum cosmology. The homogeneous setting consists of a massive scalar field propagating in a closed, homogeneous scenario. We provide a complete quantum description of the system employing loop quantization techniqu...
gr-qc/0201080
Lorenzo Iorio
Lorenzo Iorio
Light deflection and time delay in the gravitational field of a spinning mass
LaTex, 10 pages, no figures, no tables. Accepted for publication in Il Nuovo Cimento B. References added, small errors corrected
Nuovo Cim.B118:249-258,2003
null
null
gr-qc astro-ph physics.space-ph
null
In this paper we consider the possibility of measuring the corrections induced by the square of the parameter a_g of the Kerr metric to the general relativistic deflection of electromagnetic waves and time delay in an Earth based experiment. It turns out that, while at astronomical scale the well known gravitoelectri...
[ { "created": "Thu, 24 Jan 2002 14:04:52 GMT", "version": "v1" }, { "created": "Fri, 1 Feb 2002 20:50:44 GMT", "version": "v2" }, { "created": "Thu, 21 Feb 2002 23:10:21 GMT", "version": "v3" }, { "created": "Wed, 18 Jun 2003 11:24:33 GMT", "version": "v4" } ]
2010-11-19
[ [ "Iorio", "Lorenzo", "" ] ]
In this paper we consider the possibility of measuring the corrections induced by the square of the parameter a_g of the Kerr metric to the general relativistic deflection of electromagnetic waves and time delay in an Earth based experiment. It turns out that, while at astronomical scale the well known gravitoelectric ...
1305.6138
Alessandro Tronconi
Alexander Y. Kamenshchik, Alessandro Tronconi, Giovanni Venturi
Inflation and Quantum Gravity in a Born-Oppenheimer Context
13 pages, no figures. Final version, accepted for publication in PLB
null
10.1016/j.physletb.2013.08.067
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A general equation, describing the lowest order corrections coming from quantum gravitational effects to the spectrum of cosmological scalar fluctuations is obtained. These corrections are explicitly estimated for the case of a de Sitter evolution.
[ { "created": "Mon, 27 May 2013 08:07:29 GMT", "version": "v1" }, { "created": "Wed, 4 Sep 2013 07:11:46 GMT", "version": "v2" } ]
2015-06-16
[ [ "Kamenshchik", "Alexander Y.", "" ], [ "Tronconi", "Alessandro", "" ], [ "Venturi", "Giovanni", "" ] ]
A general equation, describing the lowest order corrections coming from quantum gravitational effects to the spectrum of cosmological scalar fluctuations is obtained. These corrections are explicitly estimated for the case of a de Sitter evolution.
gr-qc/9709036
Neil John Cornish
Neil J. Cornish (DAMTP, Cambridge University)
Fractals and Symbolic Dynamics as Invariant Descriptors of Chaos in General Relativity
3 pages, 4 figures. To appear in the proceedings of the Eighth Marcel Grossmann Meeting, Jerusalem, June 1997 (WSP)
null
null
DAMTP-R97-48
gr-qc
null
The study of dynamics in general relativity has been hampered by a lack of coordinate independent measures of chaos. Here I review a variety of invariant measures for quantifying chaotic dynamics in relativity that exploit the coordinate independence of fractal dimensions and symbolic entropies.
[ { "created": "Mon, 15 Sep 1997 12:42:16 GMT", "version": "v1" } ]
2009-09-25
[ [ "Cornish", "Neil J.", "", "DAMTP, Cambridge University" ] ]
The study of dynamics in general relativity has been hampered by a lack of coordinate independent measures of chaos. Here I review a variety of invariant measures for quantifying chaotic dynamics in relativity that exploit the coordinate independence of fractal dimensions and symbolic entropies.
1001.4227
Chen Songbai
Jiliang Jing, Songbai Chen
Holographic superconductors in the Born-Infeld electrodynamics
9 pages, 2 figures, references added and corrected, the version appears in PLB
Physics Letters B 686 (2010) 68-71
10.1016/j.physletb.2010.02.022
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the effects of the Born-Infeld electrodynamics on the holographic superconductors in the background of a Schwarzschild AdS black hole spacetime. We find that the presence of Born-Infeld scale parameter decreases the critical temperature and the ratio of the gap frequency in conductivity to the critical tempe...
[ { "created": "Sun, 24 Jan 2010 07:48:59 GMT", "version": "v1" }, { "created": "Thu, 25 Feb 2010 07:03:25 GMT", "version": "v2" }, { "created": "Tue, 8 Jun 2010 03:58:11 GMT", "version": "v3" } ]
2015-05-18
[ [ "Jing", "Jiliang", "" ], [ "Chen", "Songbai", "" ] ]
We study the effects of the Born-Infeld electrodynamics on the holographic superconductors in the background of a Schwarzschild AdS black hole spacetime. We find that the presence of Born-Infeld scale parameter decreases the critical temperature and the ratio of the gap frequency in conductivity to the critical tempera...
gr-qc/9912003
Marco Montuori
Yurij V. Baryshev (Astronomical Institute of the Saint-Petersburg University, St.-Petersburg, Russia)
Field Theory of Gravitation: Desire and Reality
17 pages, no figures, edited and updated from journal version
Gravitation, vol.2, p69-81 (1996)
null
null
gr-qc astro-ph hep-th
null
A retrospective analysis of the field theory of gravitation, describing gravitational field in the same way as other fields of matter in the flat space-time, is done. The field approach could be called "quantum gravidynamics" to distinguish it from the "geometrodynamics" or general relativity. The basic propositions ...
[ { "created": "Wed, 1 Dec 1999 10:07:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Baryshev", "Yurij V.", "", "Astronomical Institute of the Saint-Petersburg\n University, St.-Petersburg, Russia" ] ]
A retrospective analysis of the field theory of gravitation, describing gravitational field in the same way as other fields of matter in the flat space-time, is done. The field approach could be called "quantum gravidynamics" to distinguish it from the "geometrodynamics" or general relativity. The basic propositions an...
1707.07235
J. Arturo Olvera
R. Cartas-Fuentevilla, A. Herrera-Aguilar, J. A. Olvera-Santamar\'ia
Evolution and metric signature change of maximally symmetric spaces under the Ricci flow
16 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we present solutions to the Ricci flow equations in arbitrary dimensions, particularizing for the $3d$ and $4d$ cases. We start by considering the $3d$ case and note that our solutions belong to the family of maximally symmetric spaces that can be extended to the $d\geq 4$ case following an analogue trea...
[ { "created": "Sun, 23 Jul 2017 01:04:24 GMT", "version": "v1" }, { "created": "Mon, 20 Nov 2017 23:33:51 GMT", "version": "v2" }, { "created": "Mon, 21 May 2018 15:04:20 GMT", "version": "v3" } ]
2018-05-22
[ [ "Cartas-Fuentevilla", "R.", "" ], [ "Herrera-Aguilar", "A.", "" ], [ "Olvera-Santamaría", "J. A.", "" ] ]
In this work we present solutions to the Ricci flow equations in arbitrary dimensions, particularizing for the $3d$ and $4d$ cases. We start by considering the $3d$ case and note that our solutions belong to the family of maximally symmetric spaces that can be extended to the $d\geq 4$ case following an analogue treatm...
gr-qc/0311030
Bahram Mashhoon
Bahram Mashhoon
Gravitoelectromagnetism: A Brief Review
15 pages, no figures; v2: slightly improved version published as the third chapter of The Measurement of Gravitomagnetism: A Challenging Enterprise, edited by L. Iorio (Nova Science, New York, 2007), pp. 29-39
null
null
null
gr-qc astro-ph
null
The main theoretical aspects of gravitoelectromagnetism ("GEM") are presented. Two basic approaches to this subject are described and the role of the gravitational Larmor theorem is emphasized. Some of the consequences of GEM are briefly mentioned.
[ { "created": "Sat, 8 Nov 2003 19:39:33 GMT", "version": "v1" }, { "created": "Thu, 17 Apr 2008 18:32:41 GMT", "version": "v2" } ]
2008-04-17
[ [ "Mashhoon", "Bahram", "" ] ]
The main theoretical aspects of gravitoelectromagnetism ("GEM") are presented. Two basic approaches to this subject are described and the role of the gravitational Larmor theorem is emphasized. Some of the consequences of GEM are briefly mentioned.
gr-qc/9704072
Gary Horowitz
Gary T. Horowitz
Quantum States of Black Holes
33 pages, Latex, a few clarifying comments added
null
null
null
gr-qc astro-ph hep-th
null
I review the recent progress in providing a statistical foundation for black hole thermodynamics. In the context of string theory, one can now identify and count quantum states associated with black holes. One can also compute the analog of Hawking radiation (in a certain low energy regime) in a manifestly unitary wa...
[ { "created": "Fri, 25 Apr 1997 20:37:45 GMT", "version": "v1" }, { "created": "Tue, 13 May 1997 21:10:10 GMT", "version": "v2" }, { "created": "Wed, 30 Jul 1997 17:20:28 GMT", "version": "v3" } ]
2008-02-03
[ [ "Horowitz", "Gary T.", "" ] ]
I review the recent progress in providing a statistical foundation for black hole thermodynamics. In the context of string theory, one can now identify and count quantum states associated with black holes. One can also compute the analog of Hawking radiation (in a certain low energy regime) in a manifestly unitary way....
2307.10368
Lorenzo Annulli
Lorenzo Annulli and Carlos A. R. Herdeiro
Non-linear tides and Gauss-Bonnet scalarization
13 pages, 13 figures
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In linear perturbation theory, a static perturber in the vicinity of a Schwarzschild black hole (BH) enhances [suppresses] the Gauss-Bonnet (GB) curvature invariant, $\mathcal{R}_{\rm GB}$, in the high [low] tide regions. By analysing exact solutions of the vacuum Einstein field equations describing one or two BHs im...
[ { "created": "Wed, 19 Jul 2023 18:00:02 GMT", "version": "v1" } ]
2023-07-21
[ [ "Annulli", "Lorenzo", "" ], [ "Herdeiro", "Carlos A. R.", "" ] ]
In linear perturbation theory, a static perturber in the vicinity of a Schwarzschild black hole (BH) enhances [suppresses] the Gauss-Bonnet (GB) curvature invariant, $\mathcal{R}_{\rm GB}$, in the high [low] tide regions. By analysing exact solutions of the vacuum Einstein field equations describing one or two BHs imme...
2012.10471
Branislav Cvetkovi\'c
Milutin Blagojevi\'c and Branislav Cvetkovi\'c
Thermodynamics of Kerr-AdS black holes in general Poincar\'e gauge theory
LaTex, 12 pages; v2 minor corrections
Phys. Rev. D 103, 064034 (2021)
10.1103/PhysRevD.103.064034
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A Hamiltonian variational approach is used to study asymptotic charges and entropy of Kerr-AdS black holes in the general Poincar\'e gauge theory, with both even and odd parity modes. The results turn out to be the same as those found earlier in the sector of parity invariant Lagrangians.
[ { "created": "Fri, 18 Dec 2020 19:16:55 GMT", "version": "v1" }, { "created": "Mon, 15 Mar 2021 19:20:13 GMT", "version": "v2" } ]
2021-03-24
[ [ "Blagojević", "Milutin", "" ], [ "Cvetković", "Branislav", "" ] ]
A Hamiltonian variational approach is used to study asymptotic charges and entropy of Kerr-AdS black holes in the general Poincar\'e gauge theory, with both even and odd parity modes. The results turn out to be the same as those found earlier in the sector of parity invariant Lagrangians.
1107.4469
Bijan Saha Dr.
Bijan Saha
Some remarks on Bianchi type-II, VIII and IX models
8 pages
Gravitation & Cosmology 19(1), (2013) 65 - 69
10.1134/S0202289313010088
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the scope of anisotropic non-diagonal Bianchi type-II, VIII and IX spacetime it is shown that the off-diagonal components of the corresponding metric impose severe restrictions on the components of the energy momentum tensor in general. If the energy momentum tensor is considered to be diagonal one, the spacet...
[ { "created": "Fri, 22 Jul 2011 10:06:09 GMT", "version": "v1" } ]
2020-07-17
[ [ "Saha", "Bijan", "" ] ]
Within the scope of anisotropic non-diagonal Bianchi type-II, VIII and IX spacetime it is shown that the off-diagonal components of the corresponding metric impose severe restrictions on the components of the energy momentum tensor in general. If the energy momentum tensor is considered to be diagonal one, the spacetim...
1310.5587
Karl Wette
Karl Wette and Reinhard Prix
Flat parameter-space metric for all-sky searches for gravitational-wave pulsars
19 pages, 20 figures
Phys. Rev. D 88, 123005 (2013)
10.1103/PhysRevD.88.123005
AEI-2013-247; LIGO-P1300155-v3
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
All-sky, broadband, coherent searches for gravitational-wave pulsars are computationally limited. It is therefore important to make efficient use of available computational resources, notably by minimizing the number of templates used to cover the signal parameter space of sky position and frequency evolution. For se...
[ { "created": "Mon, 21 Oct 2013 15:09:30 GMT", "version": "v1" }, { "created": "Mon, 2 Dec 2013 17:33:57 GMT", "version": "v2" } ]
2013-12-16
[ [ "Wette", "Karl", "" ], [ "Prix", "Reinhard", "" ] ]
All-sky, broadband, coherent searches for gravitational-wave pulsars are computationally limited. It is therefore important to make efficient use of available computational resources, notably by minimizing the number of templates used to cover the signal parameter space of sky position and frequency evolution. For sear...
1911.07645
Jan Patrick Hackstein
Jan P. Hackstein, Eva Hackmann
Influence of weak electromagnetic fields on charged particle ISCOs
19 pages, 9 figues; v2: typos corrected
Gen. Relativ. Gravit. 52:22 (2020)
10.1007/s10714-020-02675-1
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Astrophysical black holes are often embedded into electromagnetic fields, that can usually be treated as test fields not influencing the spacetime geometry. Here we analyse the innermost stable circular orbit (ISCO) of charged particles moving around a Schwarzschild black hole in the presence of a radial electric tes...
[ { "created": "Mon, 18 Nov 2019 13:57:02 GMT", "version": "v1" }, { "created": "Tue, 10 Mar 2020 10:47:17 GMT", "version": "v2" } ]
2020-03-11
[ [ "Hackstein", "Jan P.", "" ], [ "Hackmann", "Eva", "" ] ]
Astrophysical black holes are often embedded into electromagnetic fields, that can usually be treated as test fields not influencing the spacetime geometry. Here we analyse the innermost stable circular orbit (ISCO) of charged particles moving around a Schwarzschild black hole in the presence of a radial electric test ...
1801.05138
Ramon Herrera
Ramon Herrera
Reconstructing warm inflation
Tensor to scalar ratio was given incorrect in previous version. Update here
null
10.1140/epjc/s10052-018-5741-0
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The reconstruction of a warm inflationary universe model from the scalar spectral index $n_S(N)$ and the tensor to scalar ratio $r(N)$ as a function of the number of e-folds $N$ is studied. Under a general formalism we find the effective potential and the dissipative coefficient in terms of the cosmological parameter...
[ { "created": "Tue, 16 Jan 2018 07:21:40 GMT", "version": "v1" }, { "created": "Mon, 22 Jan 2018 06:54:49 GMT", "version": "v2" } ]
2018-04-18
[ [ "Herrera", "Ramon", "" ] ]
The reconstruction of a warm inflationary universe model from the scalar spectral index $n_S(N)$ and the tensor to scalar ratio $r(N)$ as a function of the number of e-folds $N$ is studied. Under a general formalism we find the effective potential and the dissipative coefficient in terms of the cosmological parameters ...
2012.08413
Miguel Zilhao
Raimon Luna, Miguel Zilh\~ao, Vitor Cardoso, Jo\~ao L. Costa, Jos\'e Nat\'ario
Addendum to "Strong cosmic censorship: The nonlinear story"
4 pages, 2 figures. Updates title to match published version
Phys. Rev. D 103, 104043 (2021)
10.1103/PhysRevD.103.104043
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We clarify a number of issues that arise when extending the analysis of Strong Cosmic Censorship (SCC) to perturbations of highly charged Reissner-Nordstr\"{o}m de Sitter (RNdS) spacetimes. The linear stability of the Cauchy horizon can be determined from the spectral gap of quasinormal modes, thus giving a clear ide...
[ { "created": "Tue, 15 Dec 2020 16:47:07 GMT", "version": "v1" }, { "created": "Mon, 10 May 2021 19:17:17 GMT", "version": "v2" }, { "created": "Thu, 20 May 2021 10:30:04 GMT", "version": "v3" } ]
2021-05-21
[ [ "Luna", "Raimon", "" ], [ "Zilhão", "Miguel", "" ], [ "Cardoso", "Vitor", "" ], [ "Costa", "João L.", "" ], [ "Natário", "José", "" ] ]
We clarify a number of issues that arise when extending the analysis of Strong Cosmic Censorship (SCC) to perturbations of highly charged Reissner-Nordstr\"{o}m de Sitter (RNdS) spacetimes. The linear stability of the Cauchy horizon can be determined from the spectral gap of quasinormal modes, thus giving a clear idea ...
2001.06310
\.Ibrahim Semiz
\.Ibrahim Semiz
On the (non)genericity of the Kiselev spacetime
No figures, one table. v2: Format change from "Comment" to short paper; one reference added
IOP SciNotes 1 025206 (2020)
10.1088/2633-1357/aba1f5
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In many works in the literature, the Kiselev spacetime is interpreted as the "blackhole surrounded by quintessence"; an interpretation not really tenable. For example, it has recently been pointed out that the expressions "perfect fluid" and "quintessence" are used improperly in most of the articles that build on tha...
[ { "created": "Thu, 16 Jan 2020 18:49:55 GMT", "version": "v1" }, { "created": "Sat, 29 Feb 2020 12:41:25 GMT", "version": "v2" } ]
2020-12-15
[ [ "Semiz", "İbrahim", "" ] ]
In many works in the literature, the Kiselev spacetime is interpreted as the "blackhole surrounded by quintessence"; an interpretation not really tenable. For example, it has recently been pointed out that the expressions "perfect fluid" and "quintessence" are used improperly in most of the articles that build on that ...