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2110.09230
Ramkumar Radhakrishnan
Ramkumar Radhakrishnan
A study on the Friedmann like Universe with Torsion using Noether Symmetry
null
Modern Physics Letters A Vol. 35, No. 6 (2020) 2050027
10.1142/S0217732320500273
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper deals with the symmetry analysis of the Einstein Cartan theory which is an extension of the General Relativity and it accounts for the space-time torsion. We begin by applying Noether Theorem to the Lagrangian of the FRW type cosmology with torsion and choose a point transformation: $(a,\phi,N)\rightarrow(...
[ { "created": "Thu, 7 Oct 2021 14:40:39 GMT", "version": "v1" } ]
2021-10-20
[ [ "Radhakrishnan", "Ramkumar", "" ] ]
This paper deals with the symmetry analysis of the Einstein Cartan theory which is an extension of the General Relativity and it accounts for the space-time torsion. We begin by applying Noether Theorem to the Lagrangian of the FRW type cosmology with torsion and choose a point transformation: $(a,\phi,N)\rightarrow(u,...
gr-qc/9803007
Sean Hayward
Sean A. Hayward
Relativistic thermodynamics
26 pages, plain Tex, presentational changes
null
null
null
gr-qc
null
A generally relativistic theory of thermodynamics is developed, based on four main physical principles: heat is a local form of energy, therefore described by a thermal energy tensor; conservation of mass, equivalent to conservation of heat, or the local first law; entropy is a local current; and non-destruction of e...
[ { "created": "Mon, 2 Mar 1998 05:55:50 GMT", "version": "v1" }, { "created": "Fri, 29 Jan 1999 06:12:42 GMT", "version": "v2" } ]
2007-05-23
[ [ "Hayward", "Sean A.", "" ] ]
A generally relativistic theory of thermodynamics is developed, based on four main physical principles: heat is a local form of energy, therefore described by a thermal energy tensor; conservation of mass, equivalent to conservation of heat, or the local first law; entropy is a local current; and non-destruction of ent...
gr-qc/9905064
Masaru shibata
Masaru Shibata and Misao Sasaki
Black hole formation in the Friedmann universe: Formulation and computation in numerical relativity
12 pages, to be published in Phys. Rev. D
Phys.Rev.D60:084002,1999
10.1103/PhysRevD.60.084002
OU-TAP 93
gr-qc
null
We study formation of black holes in the Friedmann universe. We present a formulation of the Einstein equations under the constant mean curvature time-slicing condition. Our formalism not only gives us the analytic solution of the perturbation equations for non-linear density and metric fluctuations on superhorizon s...
[ { "created": "Tue, 18 May 1999 22:38:56 GMT", "version": "v1" } ]
2009-10-09
[ [ "Shibata", "Masaru", "" ], [ "Sasaki", "Misao", "" ] ]
We study formation of black holes in the Friedmann universe. We present a formulation of the Einstein equations under the constant mean curvature time-slicing condition. Our formalism not only gives us the analytic solution of the perturbation equations for non-linear density and metric fluctuations on superhorizon sca...
gr-qc/0512131
Kuiroukidis
K. Kleidis, A. Kuiroukidis, D. B. Papadopoulos and L. Vlahos
Magnetohydrodynamics and Plasma Cosmology
9 pages, RevTeX, To appear in the Proceedings of the Peyresq X Meeting, IJTP Conference Series
Int.J.Theor.Phys.46:2283-2298,2007
10.1007/s10773-007-9346-x
null
gr-qc
null
We study the linear magnetohydrodynamic (MHD) equations, both in the Newtonian and the general-relativistic limit, as regards a viscous magnetized fluid of finite conductivity and discuss instability criteria. In addition, we explore the excitation of cosmological perturbations in anisotropic spacetimes, in the prese...
[ { "created": "Thu, 22 Dec 2005 12:09:52 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kleidis", "K.", "" ], [ "Kuiroukidis", "A.", "" ], [ "Papadopoulos", "D. B.", "" ], [ "Vlahos", "L.", "" ] ]
We study the linear magnetohydrodynamic (MHD) equations, both in the Newtonian and the general-relativistic limit, as regards a viscous magnetized fluid of finite conductivity and discuss instability criteria. In addition, we explore the excitation of cosmological perturbations in anisotropic spacetimes, in the presenc...
gr-qc/9612007
Patricio Anibal Letelier
D.V. Gal'tsov and P.S. Letelier
Ehlers-Harrison transformations and black holes in Dilaton-Axion Gravity with multiple vector fields
37 pages, Latex
Phys.Rev.D55:3580-3592,1997
10.1103/PhysRevD.55.3580
null
gr-qc
null
Dilaton-axion gravity with $p U(1)$ vector fields is studied on space-times admitting a timelike Killing vector field. Three-dimensional sigma-model is derived in terms of K\"ahler geometry, and holomorphic representation of the SO(2,2+p) global symmetry is constructed. A general static black hole solution depending ...
[ { "created": "Mon, 2 Dec 1996 19:51:43 GMT", "version": "v1" } ]
2014-11-17
[ [ "Gal'tsov", "D. V.", "" ], [ "Letelier", "P. S.", "" ] ]
Dilaton-axion gravity with $p U(1)$ vector fields is studied on space-times admitting a timelike Killing vector field. Three-dimensional sigma-model is derived in terms of K\"ahler geometry, and holomorphic representation of the SO(2,2+p) global symmetry is constructed. A general static black hole solution depending on...
1712.01215
Supriya Pan
Supriya Pan
Exact solutions, finite time singularities and non-singular universe models from a variety of $\Lambda(t)$ cosmologies
12 pages, some typos corrected, online ready in Mod. Phys. Lett. A
Mod. Phys. Lett. A 33, No. 1 (2018) 1850003
10.1142/S0217732318500037
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cosmological models with time dependent $\Lambda$ (read as $\Lambda (t)$) have been investigated widely in the literature. Models that solve background dynamics analytically, are of special interest. Additionally, the allowance of past or future singularities at finite cosmic time in a specific model signals for a ge...
[ { "created": "Mon, 4 Dec 2017 17:42:43 GMT", "version": "v1" }, { "created": "Fri, 5 Jan 2018 12:46:30 GMT", "version": "v2" } ]
2018-01-08
[ [ "Pan", "Supriya", "" ] ]
Cosmological models with time dependent $\Lambda$ (read as $\Lambda (t)$) have been investigated widely in the literature. Models that solve background dynamics analytically, are of special interest. Additionally, the allowance of past or future singularities at finite cosmic time in a specific model signals for a gene...
gr-qc/9605064
Roberto De Pietri
Roberto De Pietri (University of Parma)
On the relation between the connection and the loop representation of quantum gravity
19 pages, ioplppt.sty and epsfig.sty
Class.Quant.Grav. 14 (1997) 53-70
10.1088/0264-9381/14/1/009
University of Parma preprint UPRF-96-466
gr-qc
null
Using Penrose binor calculus for $SU(2)$ ($SL(2,C)$) tensor expressions, a graphical method for the connection representation of Euclidean Quantum Gravity (real connection) is constructed. It is explicitly shown that: {\it (i)} the recently proposed scalar product in the loop-representation coincide with the Ashtekar...
[ { "created": "Tue, 28 May 1996 18:11:54 GMT", "version": "v1" } ]
2009-10-28
[ [ "De Pietri", "Roberto", "", "University of Parma" ] ]
Using Penrose binor calculus for $SU(2)$ ($SL(2,C)$) tensor expressions, a graphical method for the connection representation of Euclidean Quantum Gravity (real connection) is constructed. It is explicitly shown that: {\it (i)} the recently proposed scalar product in the loop-representation coincide with the Ashtekar-L...
1902.01689
Debabrata Deb
Sourav Roy Chowdhury, Debabrata Deb, Saibal Ray, Farook Rahaman and B. K. Guha
Charged anisotropic strange stars in Finslerian geometry
21 pages, 13 figures, 4 tables
Eur.Phys.J.C Vol: 79, Article number: 547 (2019)
10.1140/epjc/s10052-019-7054-3
null
gr-qc
http://creativecommons.org/licenses/by-nc-sa/4.0/
We investigate a simplified model for the strange stars in the framework of Finslerian spacetime geometry, composed of charged fluid. It is considered that the fluid consisting of three flavor quarks including a small amount of non-interacting electrons to maintain the chemical equilibrium and assumed that the fluid ...
[ { "created": "Fri, 1 Feb 2019 22:28:27 GMT", "version": "v1" } ]
2021-06-22
[ [ "Chowdhury", "Sourav Roy", "" ], [ "Deb", "Debabrata", "" ], [ "Ray", "Saibal", "" ], [ "Rahaman", "Farook", "" ], [ "Guha", "B. K.", "" ] ]
We investigate a simplified model for the strange stars in the framework of Finslerian spacetime geometry, composed of charged fluid. It is considered that the fluid consisting of three flavor quarks including a small amount of non-interacting electrons to maintain the chemical equilibrium and assumed that the fluid is...
2103.09612
Liang-Bi Wu
Li-Ming Cao and Liang-Bi Wu
On the "Einstein-Gauss-Bonnet Gravity in Four Dimension"
revtex, 5 pages, no figures
null
10.1140/epjc/s10052-022-10079-5
ICTS-USTC/PCFT-21-11
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
To ensure the existence of a well defined linearized gravitational wave equation, we show that the spacetimes in the so-called "Einstein-Gauss-Bonnet gravity in four dimension" have to be locally conformally flat.
[ { "created": "Wed, 17 Mar 2021 12:56:04 GMT", "version": "v1" } ]
2022-02-23
[ [ "Cao", "Li-Ming", "" ], [ "Wu", "Liang-Bi", "" ] ]
To ensure the existence of a well defined linearized gravitational wave equation, we show that the spacetimes in the so-called "Einstein-Gauss-Bonnet gravity in four dimension" have to be locally conformally flat.
1510.02016
Kuantay Boshkayev
Kuantay Boshkayev, Hernando Quevedo, Marzhan Abutalip, Zhanerke Kalymova and Sharara Suleymanova
Geodesics in the field of a rotating deformed gravitational source
submitted to IJMPA, 10 pages, 3 figures
null
10.1142/S0217751X16410062
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate equatorial geodesics in the gravitational field of a rotating and deformed source described by the approximate Hartle-Thorne metric. In the case of massive particles, we derive within the same approximation analytic expressions for the orbital angular velocity, the specific angular momentum and energy,...
[ { "created": "Wed, 7 Oct 2015 16:33:09 GMT", "version": "v1" } ]
2016-02-03
[ [ "Boshkayev", "Kuantay", "" ], [ "Quevedo", "Hernando", "" ], [ "Abutalip", "Marzhan", "" ], [ "Kalymova", "Zhanerke", "" ], [ "Suleymanova", "Sharara", "" ] ]
We investigate equatorial geodesics in the gravitational field of a rotating and deformed source described by the approximate Hartle-Thorne metric. In the case of massive particles, we derive within the same approximation analytic expressions for the orbital angular velocity, the specific angular momentum and energy, a...
1801.10176
Ramon Masachs
Oscar J.C. Dias, Ramon Masachs
Charged black hole bombs in a Minkowski cavity
31 pages, 9 Figures
null
10.1088/1361-6382/aad70b
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Press and Teukolsky famously introduced the concept of a black hole bomb system: a scalar field scattering a Kerr black hole confined inside a mirror undergoes superradiant amplification that keeps repeating due to the reflecting boundary conditions at the mirror. A similar charged black hole bomb system exists if we...
[ { "created": "Tue, 30 Jan 2018 19:02:08 GMT", "version": "v1" } ]
2018-08-29
[ [ "Dias", "Oscar J. C.", "" ], [ "Masachs", "Ramon", "" ] ]
Press and Teukolsky famously introduced the concept of a black hole bomb system: a scalar field scattering a Kerr black hole confined inside a mirror undergoes superradiant amplification that keeps repeating due to the reflecting boundary conditions at the mirror. A similar charged black hole bomb system exists if we h...
1611.00738
Vasilis Oikonomou
S.D. Odintsov, V.K. Oikonomou
Inverse Symmetric Inflationary Attractors
Affiliation is corrected
null
10.1088/1361-6382/aa69a8
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a class of inflationary potentials which are invariant under a special symmetry, which depends on the parameters of the models. As we show, in certain limiting cases, the inverse symmetric potentials are qualitatively similar to the $\alpha$-attractors models, since the resulting observational indices are ...
[ { "created": "Wed, 2 Nov 2016 19:31:58 GMT", "version": "v1" }, { "created": "Thu, 30 Mar 2017 15:08:31 GMT", "version": "v2" }, { "created": "Wed, 8 Nov 2017 12:31:03 GMT", "version": "v3" } ]
2017-11-09
[ [ "Odintsov", "S. D.", "" ], [ "Oikonomou", "V. K.", "" ] ]
We present a class of inflationary potentials which are invariant under a special symmetry, which depends on the parameters of the models. As we show, in certain limiting cases, the inverse symmetric potentials are qualitatively similar to the $\alpha$-attractors models, since the resulting observational indices are id...
1904.07630
Yakov Shnir
J. Kunz, I. Perapechka, Ya. Shnir
Kerr black holes with parity-odd scalar hair
14 pages, 5 figures
Phys. Rev. D 100, 064032 (2019)
10.1103/PhysRevD.100.064032
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study Kerr black holes with synchronised non-trivial parity-odd massive scalar hair in four dimensional asymptotically flat space-time. These axially symmetric stationary spinning solutions of the minimally coupled Einstein-Klein-Gordon theory provide yet another example of bound states in synchronous rotation wit...
[ { "created": "Tue, 16 Apr 2019 12:55:37 GMT", "version": "v1" } ]
2019-09-25
[ [ "Kunz", "J.", "" ], [ "Perapechka", "I.", "" ], [ "Shnir", "Ya.", "" ] ]
We study Kerr black holes with synchronised non-trivial parity-odd massive scalar hair in four dimensional asymptotically flat space-time. These axially symmetric stationary spinning solutions of the minimally coupled Einstein-Klein-Gordon theory provide yet another example of bound states in synchronous rotation with ...
1411.2892
Edward Glass
J.P. Krisch and E.N. Glass
Relativistic Bessel Cylinders
null
J. Math. Phys. vol 55, 102502 (2014)
10.1063/1.4898770
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A set of cylindrical solutions to Einstein's field equations for power law densities is described. The solutions have a Bessel function contribution to the metric. For matter cylinders regular on axis, the first two solutions are the constant density Gott-Hiscock string and a cylinder with a metric Airy function. All...
[ { "created": "Tue, 11 Nov 2014 17:25:16 GMT", "version": "v1" } ]
2015-06-23
[ [ "Krisch", "J. P.", "" ], [ "Glass", "E. N.", "" ] ]
A set of cylindrical solutions to Einstein's field equations for power law densities is described. The solutions have a Bessel function contribution to the metric. For matter cylinders regular on axis, the first two solutions are the constant density Gott-Hiscock string and a cylinder with a metric Airy function. All m...
gr-qc/0301078
Vitor Cardoso
Vitor Cardoso, Jose' P. S. Lemos
Quasinormal modes of the near extremal Schwarzschild-de Sitter black hole
REVTEX4, 4 pages. Minor improvements and references added
Phys.Rev.D67:084020,2003
10.1103/PhysRevD.67.084020
null
gr-qc hep-ph hep-th
null
We present an exact expression for the quasinormal modes of scalar, electromagnetic and gravitational perturbations of a near extremal Scwarzschild-de Sitter black hole and we show why a previous approximation holds exactly in this near extremal regime. In particular, our results give the asymptotic behavior of the q...
[ { "created": "Tue, 21 Jan 2003 15:30:28 GMT", "version": "v1" }, { "created": "Tue, 18 Feb 2003 19:19:14 GMT", "version": "v2" } ]
2016-08-31
[ [ "Cardoso", "Vitor", "" ], [ "Lemos", "Jose' P. S.", "" ] ]
We present an exact expression for the quasinormal modes of scalar, electromagnetic and gravitational perturbations of a near extremal Scwarzschild-de Sitter black hole and we show why a previous approximation holds exactly in this near extremal regime. In particular, our results give the asymptotic behavior of the qua...
1005.5217
Subenoy Chakraborty
Nairwita Mazumder, Subenoy Chakraborty
Scalar-Tensor Theory of Gravity and Generalized Second Law of Thermodynamics on the Event Horizon
8 pages
Astrophys.Space Sci.332:509-513,2011
10.1007/s10509-010-0532-6
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In blackhole physics, the second law of thermodynamics is generally valid whether the blackhole is a static or a non-static one. Considering the universe as a thermodynamical system the second law of blackhole dynamics extends to the non-negativity of the sum of the entropy of the matter and the horizon, known as gen...
[ { "created": "Fri, 28 May 2010 04:52:23 GMT", "version": "v1" } ]
2011-03-14
[ [ "Mazumder", "Nairwita", "" ], [ "Chakraborty", "Subenoy", "" ] ]
In blackhole physics, the second law of thermodynamics is generally valid whether the blackhole is a static or a non-static one. Considering the universe as a thermodynamical system the second law of blackhole dynamics extends to the non-negativity of the sum of the entropy of the matter and the horizon, known as gener...
2401.07605
Abbas Sherif
Gareth Amery, Peter K S Dunsby, Abbas M Sherif
Gradient conformal stationarity and the CMC condition in LRS spacetimes
26 pages, no figure, comments welcome
null
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We study the existence of gradient conformal Killing vectors (CKVs) in LRS spacetimes, and investigate some implications for the evolutionary character of marginally outer trapped surfaces. We first study existence of gradient CKVs via the obtention of a relationship between the Ricci curvature and the gradient of th...
[ { "created": "Mon, 15 Jan 2024 11:29:59 GMT", "version": "v1" } ]
2024-01-17
[ [ "Amery", "Gareth", "" ], [ "Dunsby", "Peter K S", "" ], [ "Sherif", "Abbas M", "" ] ]
We study the existence of gradient conformal Killing vectors (CKVs) in LRS spacetimes, and investigate some implications for the evolutionary character of marginally outer trapped surfaces. We first study existence of gradient CKVs via the obtention of a relationship between the Ricci curvature and the gradient of the ...
gr-qc/0703105
Guendelman Eduardo I
E.I. Guendelman
Child universes UV regularization?
6 pages, RevTex, discussion to the maximum curvature hypothesis added
Int.J.Mod.Phys.D17:551-555,2008
10.1142/S0218271808012243
null
gr-qc
null
It is argued that high energy density excitations, responsible for UV divergences in quantum field theories, including quantum gravity, are likely to be the source of child universes which carry them out of the original space time. This decoupling prevents these high UV excitations from having any influence on physic...
[ { "created": "Wed, 21 Mar 2007 06:38:44 GMT", "version": "v1" }, { "created": "Mon, 26 Mar 2007 10:46:54 GMT", "version": "v2" } ]
2008-11-26
[ [ "Guendelman", "E. I.", "" ] ]
It is argued that high energy density excitations, responsible for UV divergences in quantum field theories, including quantum gravity, are likely to be the source of child universes which carry them out of the original space time. This decoupling prevents these high UV excitations from having any influence on physical...
gr-qc/0701060
Joseph Katz
D. Lynden-Bell, Joseph Katz and Jiri Bicak
Energy and angular momentum densities of stationary gravity fields
Accepted for publication in Phys. Rev. D
Phys.Rev.D75:024040,2007; Erratum-ibid.D75:044901,2007
10.1103/PhysRevD.75.024040 10.1103/PhysRevD.75.044901
null
gr-qc
null
We give physical explanations of explicit invariant expressions for the energy and angular momentum densities of gravitational fields in stationary space-times. These expressions involve non-locally defined conformal factors. In certain coordinates these become locally defined in terms of the metric. These results ar...
[ { "created": "Wed, 10 Jan 2007 14:22:17 GMT", "version": "v1" } ]
2014-11-17
[ [ "Lynden-Bell", "D.", "" ], [ "Katz", "Joseph", "" ], [ "Bicak", "Jiri", "" ] ]
We give physical explanations of explicit invariant expressions for the energy and angular momentum densities of gravitational fields in stationary space-times. These expressions involve non-locally defined conformal factors. In certain coordinates these become locally defined in terms of the metric. These results are ...
1801.01209
Wu Bofeng
Bofeng Wu and Chao-Guang Huang
Multipole analysis for linearized $f(R)$ gravity with irreducible Cartesian tensors
24 pages
Published in PRD 96, 104052 2017
10.1140/epjc/s10052-019-6992-0
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The field equations of $f(R)$ gravity are rewritten in the form of obvious wave equations with the stress-energy pseudotensor of the matter fields and the gravitational field as its source under the de Donder condition. The method of multipole analysis in terms of irreducible Cartesian tensors is applied to the linea...
[ { "created": "Thu, 4 Jan 2018 00:08:36 GMT", "version": "v1" } ]
2019-07-24
[ [ "Wu", "Bofeng", "" ], [ "Huang", "Chao-Guang", "" ] ]
The field equations of $f(R)$ gravity are rewritten in the form of obvious wave equations with the stress-energy pseudotensor of the matter fields and the gravitational field as its source under the de Donder condition. The method of multipole analysis in terms of irreducible Cartesian tensors is applied to the lineari...
1110.0064
De-Cheng Zou
Peng Li, Rui-Hong Yue and De-Cheng Zou
Thermodynamics of Third Order Lovelock-Born-Infeld Black Holes
11 pages, 21 figures
Commun.Theor.Phys.56:845-850,2011
10.1088/0253-6102/56/5/10
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We here explore black holes in the third order Lovelock gravity coupling with nonlinear Born-Infeld electromagnetic field. Considering special second and third order coefficients ($\hat{\alpha}_2^2=3\hat{\alpha}_3=\alpha^2$), we analyze the thermodynamics of third order Lovelock-Born-Infeld black holes and, in 7-dime...
[ { "created": "Sat, 1 Oct 2011 02:26:54 GMT", "version": "v1" } ]
2015-05-30
[ [ "Li", "Peng", "" ], [ "Yue", "Rui-Hong", "" ], [ "Zou", "De-Cheng", "" ] ]
We here explore black holes in the third order Lovelock gravity coupling with nonlinear Born-Infeld electromagnetic field. Considering special second and third order coefficients ($\hat{\alpha}_2^2=3\hat{\alpha}_3=\alpha^2$), we analyze the thermodynamics of third order Lovelock-Born-Infeld black holes and, in 7-dimens...
2005.01848
Jerred Jesse
Jerred Jesse, Matthew D. Duez, Francois Foucart, Milad Haddadi, Alexander L. Knight, Courtney L. Cadenhead, Francois Hebert, Lawrence E. Kidder, Harald P. Pfeiffer, Mark A. Scheel
Axisymmetric Hydrodynamics in Numerical Relativity Using a Multipatch Method
33 pages, 11 figures
Classical and Quantum Gravity 37 23501 (2020)
10.1088/1361-6382/abbc8b
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe a method of implementing the axisymmetric evolution of general-relativistic hydrodynamics and magnetohydrodynamics through modification of a multipatch grid scheme. In order to ease the computational requirements required to evolve the post-merger phase of systems involving binary compact massive objects ...
[ { "created": "Mon, 4 May 2020 21:06:15 GMT", "version": "v1" }, { "created": "Thu, 2 Jul 2020 23:24:28 GMT", "version": "v2" }, { "created": "Tue, 15 Dec 2020 00:02:24 GMT", "version": "v3" } ]
2020-12-16
[ [ "Jesse", "Jerred", "" ], [ "Duez", "Matthew D.", "" ], [ "Foucart", "Francois", "" ], [ "Haddadi", "Milad", "" ], [ "Knight", "Alexander L.", "" ], [ "Cadenhead", "Courtney L.", "" ], [ "Hebert", "Francois", ...
We describe a method of implementing the axisymmetric evolution of general-relativistic hydrodynamics and magnetohydrodynamics through modification of a multipatch grid scheme. In order to ease the computational requirements required to evolve the post-merger phase of systems involving binary compact massive objects in...
1901.06423
Yeuk-Kwan Edna Cheung
Nan Zhang, and Yeuk-Kwan E. Cheung
Primordial Gravitational Waves Spectrum in the Coupled-Scalar-Tachyon Bounce Universe
38pages; 8 figures
null
10.1140/epjc/s10052-020-7610-x
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive in detail the equations of motion for the tensorial modes of primordial metric perturbations in the Coupled-Scalar-Tachyon Bounce Universe. We solve for the gravitational wave equations in the pre-bounce contraction and the post-bounce expansion epochs. To match the solutions of the tensor perturbations, we...
[ { "created": "Fri, 18 Jan 2019 21:49:27 GMT", "version": "v1" } ]
2020-03-18
[ [ "Zhang", "Nan", "" ], [ "Cheung", "Yeuk-Kwan E.", "" ] ]
We derive in detail the equations of motion for the tensorial modes of primordial metric perturbations in the Coupled-Scalar-Tachyon Bounce Universe. We solve for the gravitational wave equations in the pre-bounce contraction and the post-bounce expansion epochs. To match the solutions of the tensor perturbations, we i...
gr-qc/0612181
Pedro Marronetti
Pedro Marronetti
Constraint Relaxation
3 pages. To appear in the Proceedings of the Eleventh Marcel Grossmann Meeting, Berlin, Germany, 23-29 Jule 2006, World Scientific, Singapore (2007)
null
null
null
gr-qc
null
Full relativistic simulations in three dimensions are known to develop runaway modes that grow exponentially and are accompanied by violations of the Hamiltonian and momentum constraints. We present here a method that controls the violation of these constraints and is tested with simulations of binary neutron stars i...
[ { "created": "Thu, 28 Dec 2006 15:17:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Marronetti", "Pedro", "" ] ]
Full relativistic simulations in three dimensions are known to develop runaway modes that grow exponentially and are accompanied by violations of the Hamiltonian and momentum constraints. We present here a method that controls the violation of these constraints and is tested with simulations of binary neutron stars in ...
1905.02496
Ramil Izmailov N
A. Kulbakova, R. Kh. Karimov, R. N. Izmailov and K. K. Nandi
Upper limit on NUT charge from the observed terrestrial Sagnac effect
10 pages
A. Kulbakova et al., Class. Quantum Grav 35, 115014 (2018)
10.1088/1361-6382/aac07d
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The \textit{exact} Sagnac delay in the Kerr-Taub-NUT (Newman-Unti-Tamburino) spacetime is derived in the equatorial plane for non-geodesic as well as geodesic circular orbits. The resulting formula, being exact, can be directly applied to motion in the vicinity of any spinning object including black holes but here we...
[ { "created": "Tue, 7 May 2019 12:26:37 GMT", "version": "v1" } ]
2019-05-08
[ [ "Kulbakova", "A.", "" ], [ "Karimov", "R. Kh.", "" ], [ "Izmailov", "R. N.", "" ], [ "Nandi", "K. K.", "" ] ]
The \textit{exact} Sagnac delay in the Kerr-Taub-NUT (Newman-Unti-Tamburino) spacetime is derived in the equatorial plane for non-geodesic as well as geodesic circular orbits. The resulting formula, being exact, can be directly applied to motion in the vicinity of any spinning object including black holes but here we a...
gr-qc/0301017
Louis Crane
Louis Crane, David Yetter
A More Sensitive Lorentzian State Sum
11 pages latex
null
null
null
gr-qc
null
We give the construction modulo normalization of a new state sum model for lorentzian quantum general relativity, using the construction of Dirac's expansors to include quantum operators corresponding to edge lengths as well as the quantum bivectors of the Barrett-Crane model, and discuss the problem of its normaliza...
[ { "created": "Mon, 6 Jan 2003 19:12:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Crane", "Louis", "" ], [ "Yetter", "David", "" ] ]
We give the construction modulo normalization of a new state sum model for lorentzian quantum general relativity, using the construction of Dirac's expansors to include quantum operators corresponding to edge lengths as well as the quantum bivectors of the Barrett-Crane model, and discuss the problem of its normalizati...
1811.09524
Markus P\"ossel
Markus P\"ossel
Teaching cosmology with special relativity: Piecewise inertial frames as a model for cosmic expansion
20 pages, 4 figures
European Journal of Physics 40 (2019), article id. 025602
10.1088/1361-6404/aaf2f7
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This article presents a simple model that reproduces key concepts of modern cosmology within the framework of special relativity, at a level that is suitable for an undergraduate or high school setting. The model includes cosmic expansion governed by a universal scale factor, the Hubble relation, proper distances bet...
[ { "created": "Fri, 23 Nov 2018 15:46:44 GMT", "version": "v1" } ]
2019-01-14
[ [ "Pössel", "Markus", "" ] ]
This article presents a simple model that reproduces key concepts of modern cosmology within the framework of special relativity, at a level that is suitable for an undergraduate or high school setting. The model includes cosmic expansion governed by a universal scale factor, the Hubble relation, proper distances betwe...
2306.10579
SanthiKumar Rajamahanthi
M Krishna and SobhanBabu Kappala and R Santhikumar
Accelerating Plane Symmetric Cosmological Model with Bulk Viscous and Cosmic Strings in Lyra's Geometry
9 pages and 5 sections with references
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The present study deals with Lyra's geometry in plane symmetric metric discussed in the presence of bulk viscous fluid and one dimensional strings are assumed to be loaded with particles and the particle energy density. The variation of Hubble's parameter gives a constant value of decelerating parameter. The exact so...
[ { "created": "Sun, 18 Jun 2023 14:41:23 GMT", "version": "v1" } ]
2023-06-21
[ [ "Krishna", "M", "" ], [ "Kappala", "SobhanBabu", "" ], [ "Santhikumar", "R", "" ] ]
The present study deals with Lyra's geometry in plane symmetric metric discussed in the presence of bulk viscous fluid and one dimensional strings are assumed to be loaded with particles and the particle energy density. The variation of Hubble's parameter gives a constant value of decelerating parameter. The exact solu...
gr-qc/0603128
Valery Kiselev
V.V.Kiselev, D.I.Yudin
Gravitational lensing due to dark matter modelled by vector field
17 pages, LaTeX iopart class, 10 eps figures; explanaitions and discussion are extended and improved, reference added; version to appear in Classical and Quantum Gravity
Class.Quant.Grav. 23 (2006) 7417-7430
10.1088/0264-9381/23/24/013
null
gr-qc astro-ph hep-ph
null
The specified constant 4-vector field reproducing the spherically symmetric stationary metric of cold dark matter halo in the region of flat rotation curves results in a constant angle of light deflection at small impact distances. The effective deflecting mass is factor $\pi/2$ greater than the dark matter mass. The...
[ { "created": "Fri, 31 Mar 2006 06:01:39 GMT", "version": "v1" }, { "created": "Tue, 24 Oct 2006 07:28:12 GMT", "version": "v2" } ]
2009-11-11
[ [ "Kiselev", "V. V.", "" ], [ "Yudin", "D. I.", "" ] ]
The specified constant 4-vector field reproducing the spherically symmetric stationary metric of cold dark matter halo in the region of flat rotation curves results in a constant angle of light deflection at small impact distances. The effective deflecting mass is factor $\pi/2$ greater than the dark matter mass. The p...
2201.02211
Eric Linder
Eric V. Linder
Well Tempered Cosmology: Scales
6 pages
null
null
null
gr-qc astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Well tempered cosmology provides a well defined path for obtaining cosmology with a low energy cosmic acceleration despite a high (Planck) energy cosmological constant $\Lambda$, through a scalar field dynamically canceling $\Lambda$. We explore relations between the mass scales entering the various Horndeski gravity...
[ { "created": "Thu, 6 Jan 2022 19:02:19 GMT", "version": "v1" } ]
2022-01-10
[ [ "Linder", "Eric V.", "" ] ]
Well tempered cosmology provides a well defined path for obtaining cosmology with a low energy cosmic acceleration despite a high (Planck) energy cosmological constant $\Lambda$, through a scalar field dynamically canceling $\Lambda$. We explore relations between the mass scales entering the various Horndeski gravity t...
1411.6445
Tao Wang
Tower Wang
Cosmological horizons as new examples of membrane paradigm
24 pages, title changed, sect V and appendix enlarged
null
10.1088/0264-9381/32/19/195006
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we aim to provide new examples of the application and the generality of the membrane paradigm. The membrane paradigm is a formalism for studying the event horizon of black holes. After analyzing it with some technical details and realizing it in the Reissner-Nordstrom black hole, we apply the paradigm t...
[ { "created": "Mon, 24 Nov 2014 13:26:26 GMT", "version": "v1" }, { "created": "Tue, 1 Dec 2015 17:43:38 GMT", "version": "v2" } ]
2015-12-02
[ [ "Wang", "Tower", "" ] ]
In this paper we aim to provide new examples of the application and the generality of the membrane paradigm. The membrane paradigm is a formalism for studying the event horizon of black holes. After analyzing it with some technical details and realizing it in the Reissner-Nordstrom black hole, we apply the paradigm to ...
0802.1599
A. Yu. Ignatiev
A. Yu. Ignatiev
Newton's second law versus modified-inertia MOND: a test using the high-latitude effect
15 pages, 1 figure
Phys.Rev.D77:102001,2008
10.1103/PhysRevD.77.102001
null
gr-qc astro-ph hep-ph
null
The modified-inertia MOND is an approach that proposes a change in Newton's second law at small accelerations as an alternative to dark matter. Recently it was suggested that this approach can be tested in terrestrial laboratory experiments. One way of doing the test is based on the Static High-Latitude Equinox Modif...
[ { "created": "Tue, 12 Feb 2008 11:22:35 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ignatiev", "A. Yu.", "" ] ]
The modified-inertia MOND is an approach that proposes a change in Newton's second law at small accelerations as an alternative to dark matter. Recently it was suggested that this approach can be tested in terrestrial laboratory experiments. One way of doing the test is based on the Static High-Latitude Equinox Modifie...
2101.10302
Haryanto Siahaan
Haryanto M. Siahaan
Magnetized Reissner-Nordstrom-Taub-NUT spacetime and microscopic entropy
15 pages, no figures; v2, refs added; v3, some new materials added
null
10.1140/epjc/s10052-021-09643-2
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We present a novel solution describing magnetized spacetime outside a massive object with electric charge equipped with NUT parameter. To get the solution, we employ the Ernst magnetization to the Reissner-Nordstrom-Taub-NUT spacetime as the seed. After discussing some physical aspects of the spacetime, we show that ...
[ { "created": "Mon, 25 Jan 2021 18:36:12 GMT", "version": "v1" }, { "created": "Mon, 8 Feb 2021 16:44:10 GMT", "version": "v2" }, { "created": "Wed, 24 Mar 2021 16:02:46 GMT", "version": "v3" } ]
2021-10-04
[ [ "Siahaan", "Haryanto M.", "" ] ]
We present a novel solution describing magnetized spacetime outside a massive object with electric charge equipped with NUT parameter. To get the solution, we employ the Ernst magnetization to the Reissner-Nordstrom-Taub-NUT spacetime as the seed. After discussing some physical aspects of the spacetime, we show that th...
1109.0052
Gabriel Leon
Gabriel Le\'on and Daniel Sudarsky
Novel Possibility of Nonstandard Statistics in the Inflationary Spectrum of Primordial Inhomogeneities
null
SIGMA 8 (2012), 024, 18 pages
10.3842/SIGMA.2012.024
null
gr-qc
http://creativecommons.org/licenses/by-nc-sa/3.0/
Inflation is considered one of the cornerstones of modern cosmology. However, the account of the origin of cosmic structure, as provided by the standard inflationary paradigm, is not fully satisfactory. The fundamental issue is the inability of the usual account to point out the physical mechanism responsible for gen...
[ { "created": "Wed, 31 Aug 2011 23:33:49 GMT", "version": "v1" }, { "created": "Mon, 26 Mar 2012 15:21:37 GMT", "version": "v2" }, { "created": "Sat, 21 Apr 2012 04:30:06 GMT", "version": "v3" } ]
2012-04-24
[ [ "León", "Gabriel", "" ], [ "Sudarsky", "Daniel", "" ] ]
Inflation is considered one of the cornerstones of modern cosmology. However, the account of the origin of cosmic structure, as provided by the standard inflationary paradigm, is not fully satisfactory. The fundamental issue is the inability of the usual account to point out the physical mechanism responsible for gener...
1712.08171
Gon\c{c}alo Quinta
Gon\c{c}alo M. Quinta, Antonino Flachi, Jos\'e P. S. Lemos
Quantum vacuum polarization around a Reissner-Nordstr\"om black hole in five dimensions
6 pages, 3 figures
Phys. Rev. D 97, 025023 (2018)
10.1103/PhysRevD.97.025023
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
WKB approximation methods are applied to the case of a massive scalar field around a 5-dimensional Reissner-Nordstr\"om black hole. The divergences are explicitly isolated and the cancellation against the Schwinger-De Witt counter-terms proven. The resulting finite quantity is evaluated for different values of the fr...
[ { "created": "Thu, 21 Dec 2017 19:01:01 GMT", "version": "v1" }, { "created": "Thu, 1 Feb 2018 11:35:55 GMT", "version": "v2" } ]
2018-02-07
[ [ "Quinta", "Gonçalo M.", "" ], [ "Flachi", "Antonino", "" ], [ "Lemos", "José P. S.", "" ] ]
WKB approximation methods are applied to the case of a massive scalar field around a 5-dimensional Reissner-Nordstr\"om black hole. The divergences are explicitly isolated and the cancellation against the Schwinger-De Witt counter-terms proven. The resulting finite quantity is evaluated for different values of the free...
1310.7436
Daniela Doneva
Daniela D. Doneva, Stoytcho S. Yazadjiev, Nikolaos Stergioulas, Kostas D. Kokkotas
Breakdown of I-Love-Q universality in rapidly rotating relativistic stars
8 pages, 4 figures; v2-Results extended to additional EOS; v3-Match the journal version
2014, ApJ Letters 781, L6
10.1088/2041-8205/781/1/L6
null
gr-qc astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It was shown recently, that normalized relations between the moment of inertia (I), the quadrupole moment (Q) and the tidal deformability (Love number) exist and for slowly-rotating neutron stars they are almost independent of the equation of state (EOS). We extend the computation of the I-Q relation to models rotati...
[ { "created": "Mon, 28 Oct 2013 14:51:10 GMT", "version": "v1" }, { "created": "Tue, 12 Nov 2013 20:58:51 GMT", "version": "v2" }, { "created": "Sun, 23 Feb 2014 19:46:38 GMT", "version": "v3" } ]
2014-02-25
[ [ "Doneva", "Daniela D.", "" ], [ "Yazadjiev", "Stoytcho S.", "" ], [ "Stergioulas", "Nikolaos", "" ], [ "Kokkotas", "Kostas D.", "" ] ]
It was shown recently, that normalized relations between the moment of inertia (I), the quadrupole moment (Q) and the tidal deformability (Love number) exist and for slowly-rotating neutron stars they are almost independent of the equation of state (EOS). We extend the computation of the I-Q relation to models rotating...
gr-qc/0009102
caroline dos santos
Caroline Santos
Cosmic strings in axionic-dilatonic gravity
Latex file. 16 pages
Class.Quant.Grav.18:1835-1846,2001
10.1088/0264-9381/18/10/302
DTP/00/85
gr-qc
null
We first consider local cosmic strings in dilaton-axion gravity and show that they are singular solutions. Then we take a supermassive Higgs limit and present expressions for the fields at far distances from the core by applying a Pecci-Quinn and a duality transformation to the dilatonic Melvin's magnetic universe.
[ { "created": "Fri, 29 Sep 2000 09:35:25 GMT", "version": "v1" }, { "created": "Tue, 3 Oct 2000 16:09:07 GMT", "version": "v2" } ]
2014-11-17
[ [ "Santos", "Caroline", "" ] ]
We first consider local cosmic strings in dilaton-axion gravity and show that they are singular solutions. Then we take a supermassive Higgs limit and present expressions for the fields at far distances from the core by applying a Pecci-Quinn and a duality transformation to the dilatonic Melvin's magnetic universe.
2303.14724
Vasilis Oikonomou
V.K. Oikonomou, Konstantinos-Rafail Revis, Ilias C. Papadimitriou, Maria-Myrto Pegioudi
Swampland Criteria and Constraints on Inflation in a $f(R,T)$ Gravity Theory
IJMPD Accepted
Int.J.Mod.Phys.D 32 (2023) 06, 2350034
10.1142/S0218271823500347
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we worked in the framework of an inflationary $f(R,T)$ theory, in the presence of a canonical scalar field. More specifically, the $f(R,T)=\gamma R+2\kappa\alpha T$ gravity. The values of the dimensionless parameters $\alpha$ and $\gamma$ are taken to be $\alpha \geq 0$ and $0 < \gamma \leq 1$. The mot...
[ { "created": "Sun, 26 Mar 2023 13:42:53 GMT", "version": "v1" } ]
2023-08-01
[ [ "Oikonomou", "V. K.", "" ], [ "Revis", "Konstantinos-Rafail", "" ], [ "Papadimitriou", "Ilias C.", "" ], [ "Pegioudi", "Maria-Myrto", "" ] ]
In this paper, we worked in the framework of an inflationary $f(R,T)$ theory, in the presence of a canonical scalar field. More specifically, the $f(R,T)=\gamma R+2\kappa\alpha T$ gravity. The values of the dimensionless parameters $\alpha$ and $\gamma$ are taken to be $\alpha \geq 0$ and $0 < \gamma \leq 1$. The motiv...
gr-qc/9910060
Christopher J. Fewster
C.J. Fewster (Dept. of Mathematics, University of York, U.K.)
A general worldline quantum inequality
19pp, LaTeX2e. The statement of the main result is changed slightly. Several typos fixed, references added. To appear in Class Quantum Grav
Class.Quant.Grav. 17 (2000) 1897-1911
10.1088/0264-9381/17/9/302
null
gr-qc hep-th math-ph math.MP
null
Worldline quantum inequalities provide lower bounds on weighted averages of the renormalised energy density of a quantum field along the worldline of an observer. In the context of real, linear scalar field theory on an arbitrary globally hyperbolic spacetime, we establish a worldline quantum inequality on the normal...
[ { "created": "Mon, 18 Oct 1999 14:32:49 GMT", "version": "v1" }, { "created": "Mon, 21 Feb 2000 14:43:42 GMT", "version": "v2" } ]
2009-10-31
[ [ "Fewster", "C. J.", "", "Dept. of Mathematics, University of York, U.K." ] ]
Worldline quantum inequalities provide lower bounds on weighted averages of the renormalised energy density of a quantum field along the worldline of an observer. In the context of real, linear scalar field theory on an arbitrary globally hyperbolic spacetime, we establish a worldline quantum inequality on the normal o...
gr-qc/0508024
Yuri Obukhov
Friedrich W. Hehl, Yuri N. Obukhov
Spacetime metric from local and linear electrodynamics: a new axiomatic scheme
Latex, 27 pages, 8 eps figures (better quality files are available from the authors). Invited lecture, 339th WE Heraeus Seminar on Special Relativity, Potsdam, Germany, 13-18 February 2005, To be published in the Proceedings
Lect.NotesPhys.702:163-187,2006
10.1007/3-540-34523-X_7
null
gr-qc hep-th physics.class-ph
null
We consider spacetime to be a 4-dimensional differentiable manifold that can be split locally into time and space. No metric, no linear connection are assumed. Matter is described by classical fields/fluids. We distinguish electrically charged from neutral matter. Electric charge and magnetic flux are postulated to b...
[ { "created": "Sun, 7 Aug 2005 08:39:28 GMT", "version": "v1" } ]
2008-11-26
[ [ "Hehl", "Friedrich W.", "" ], [ "Obukhov", "Yuri N.", "" ] ]
We consider spacetime to be a 4-dimensional differentiable manifold that can be split locally into time and space. No metric, no linear connection are assumed. Matter is described by classical fields/fluids. We distinguish electrically charged from neutral matter. Electric charge and magnetic flux are postulated to be ...
gr-qc/0008060
Viqar Husain
Viqar Husain and Michel Olivier
Scalar field collapse in three-dimensional AdS spacetime
10 pages, 1 figure; references added, to appear in CQG(L)
Class.Quant.Grav.18:L1-L10,2001
10.1088/0264-9381/18/2/101
UNB Report 2000-02
gr-qc hep-th physics.comp-ph
null
We describe results of a numerical calculation of circularly symmetric scalar field collapse in three spacetime dimensions with negative cosmological constant. The procedure uses a double null formulation of the Einstein-scalar equations. We see evidence of black hole formation on first implosion of a scalar pulse if...
[ { "created": "Thu, 24 Aug 2000 17:02:10 GMT", "version": "v1" }, { "created": "Mon, 11 Dec 2000 21:46:27 GMT", "version": "v2" } ]
2010-04-06
[ [ "Husain", "Viqar", "" ], [ "Olivier", "Michel", "" ] ]
We describe results of a numerical calculation of circularly symmetric scalar field collapse in three spacetime dimensions with negative cosmological constant. The procedure uses a double null formulation of the Einstein-scalar equations. We see evidence of black hole formation on first implosion of a scalar pulse if t...
1701.00486
Piotr T. Chru\'sciel
R. Beig, P.T. Chru\'sciel
Shielding linearised gravity
new sections on the Weyl tensor formulation added
Phys. Rev. D 95, 064063 (2017)
10.1103/PhysRevD.95.064063
Preprint UWThPh-2016-31
gr-qc math.DG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an elementary argument that one can shield linearised gravitational fields using linearised gravitational fields. This is done by using third-order potentials for the metric, which avoids the need to solve singular equations in shielding or gluing constructions for the linearised metric.
[ { "created": "Mon, 2 Jan 2017 09:41:33 GMT", "version": "v1" }, { "created": "Sun, 12 Mar 2017 14:56:10 GMT", "version": "v2" } ]
2017-04-05
[ [ "Beig", "R.", "" ], [ "Chruściel", "P. T.", "" ] ]
We present an elementary argument that one can shield linearised gravitational fields using linearised gravitational fields. This is done by using third-order potentials for the metric, which avoids the need to solve singular equations in shielding or gluing constructions for the linearised metric.
gr-qc/9801071
Arlen Anderson
Arlen Anderson, Andrew M. Abrahams, and Chris Lea
Curvature-based Gauge-Invariant Perturbation Theory for Gravity: A New Paradigm
32 pp., LaTeX
Phys.Rev.D58:064015,1998
10.1103/PhysRevD.58.064015
IFP-UNC-522
gr-qc
null
A new approach to gravitational gauge-invariant perturbation theory begins from the fourth-order Einstein-Ricci system, a hyperbolic formulation of gravity for arbitrary lapse and shift whose centerpiece is a wave equation for curvature. In the Minkowski and Schwarzschild backgrounds, an intertwining operator procedu...
[ { "created": "Tue, 20 Jan 1998 21:58:33 GMT", "version": "v1" } ]
2011-04-21
[ [ "Anderson", "Arlen", "" ], [ "Abrahams", "Andrew M.", "" ], [ "Lea", "Chris", "" ] ]
A new approach to gravitational gauge-invariant perturbation theory begins from the fourth-order Einstein-Ricci system, a hyperbolic formulation of gravity for arbitrary lapse and shift whose centerpiece is a wave equation for curvature. In the Minkowski and Schwarzschild backgrounds, an intertwining operator procedure...
2112.10773
Oleg Bulashenko
Oleg Bulashenko and Helena Ubach
Lensing of gravitational waves: universal signatures in the beating pattern
31 pages, 13 figs. Some modifications, version accepted by JCAP
JCAP 07 (2022) 022
10.1088/1475-7516/2022/07/022
null
gr-qc astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
When gravitational waves propagate near massive objects, their paths curve resulting in gravitational lensing, which is expected to be a promising new instrument in astrophysics. If the time delay between different paths is comparable with the wave period, lensing may induce beating patterns in the waveform, and it i...
[ { "created": "Mon, 20 Dec 2021 12:09:45 GMT", "version": "v1" }, { "created": "Mon, 11 Jul 2022 18:18:56 GMT", "version": "v2" } ]
2022-07-14
[ [ "Bulashenko", "Oleg", "" ], [ "Ubach", "Helena", "" ] ]
When gravitational waves propagate near massive objects, their paths curve resulting in gravitational lensing, which is expected to be a promising new instrument in astrophysics. If the time delay between different paths is comparable with the wave period, lensing may induce beating patterns in the waveform, and it is ...
1404.7631
Alessandro Pesci
Alessandro Pesci
Entropy bounds and field equations
8 pages, 1 figure; v4: some typos corrected, one reference and some clarifications added, some editing
Entropy 17 (2015) 5799
10.3390/e17085799
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For general metric theories of gravity, we compare the approach that describes-derives the field equations of gravity as a thermodynamic identity with the one which looks at them from entropy bounds. The comparison is made through the consideration of the matter entropy flux across (Rindler) horizons, studied by maki...
[ { "created": "Wed, 30 Apr 2014 08:35:57 GMT", "version": "v1" }, { "created": "Wed, 28 May 2014 13:43:39 GMT", "version": "v2" }, { "created": "Fri, 27 Mar 2015 07:50:46 GMT", "version": "v3" }, { "created": "Thu, 13 Aug 2015 14:55:03 GMT", "version": "v4" } ]
2015-10-28
[ [ "Pesci", "Alessandro", "" ] ]
For general metric theories of gravity, we compare the approach that describes-derives the field equations of gravity as a thermodynamic identity with the one which looks at them from entropy bounds. The comparison is made through the consideration of the matter entropy flux across (Rindler) horizons, studied by making...
gr-qc/0701021
Marc Lachieze-Rey
Marc Lachieze-Rey (APC)
Cosmology in the Solar System: Pioneer effect is not cosmological
null
Class.Quant.Grav.24:2735-2742,2007
10.1088/0264-9381/24/10/016
null
gr-qc astro-ph
null
Does the Solar System and, more generally, a gravitationally bound system follow the cosmic expansion law ? Is there a cosmological influence on the dynamics or optics in such systems ? The general relativity theory provides an unique and unambiguous answer, as a solution of Einstein equations with a local source in ...
[ { "created": "Tue, 2 Jan 2007 16:00:09 GMT", "version": "v1" }, { "created": "Wed, 28 Feb 2007 14:12:29 GMT", "version": "v2" } ]
2008-11-26
[ [ "Lachieze-Rey", "Marc", "", "APC" ] ]
Does the Solar System and, more generally, a gravitationally bound system follow the cosmic expansion law ? Is there a cosmological influence on the dynamics or optics in such systems ? The general relativity theory provides an unique and unambiguous answer, as a solution of Einstein equations with a local source in ad...
gr-qc/0407032
Yuan-Zhong Zhang
Kamal Kanti Nandi, Yuan-Zhong Zhang and K.B.Vijaya Kumar
Semiclassical and Quantum Field Theoretic Bounds for Traversable Lorentzian Stringy Wormholes
15 pages
Phys.Rev. D70 (2004) 064018
10.1103/PhysRevD.70.064018
null
gr-qc
null
A lower bound on the size of a Lorentzian wormhole can be obtained by semiclassically introducing the Planck cut-off on the magnitude of tidal forces (Horowitz-Ross constraint). Also, an upper bound is provided by the quantum field theoretic constraint in the form of the Ford-Roman Quantum Inequality for massless min...
[ { "created": "Thu, 8 Jul 2004 02:58:18 GMT", "version": "v1" } ]
2009-11-10
[ [ "Nandi", "Kamal Kanti", "" ], [ "Zhang", "Yuan-Zhong", "" ], [ "Kumar", "K. B. Vijaya", "" ] ]
A lower bound on the size of a Lorentzian wormhole can be obtained by semiclassically introducing the Planck cut-off on the magnitude of tidal forces (Horowitz-Ross constraint). Also, an upper bound is provided by the quantum field theoretic constraint in the form of the Ford-Roman Quantum Inequality for massless minim...
0806.0443
Alex Kirillov
A.A. Kirillov, E.P. Savelova
Spacetime foam
minor corrections
null
null
null
gr-qc astro-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Spacetime foam is analyzed within the simplistic model of a set of scalar fields on a flat background. We suggest the formula for the path integral which allows to account for the all possible topologies of spacetime. We show that the proper path integral defines a cutoff for the field theory. The form of the cutoff ...
[ { "created": "Tue, 3 Jun 2008 06:18:46 GMT", "version": "v1" }, { "created": "Wed, 18 Jun 2008 13:42:31 GMT", "version": "v2" } ]
2008-09-11
[ [ "Kirillov", "A. A.", "" ], [ "Savelova", "E. P.", "" ] ]
Spacetime foam is analyzed within the simplistic model of a set of scalar fields on a flat background. We suggest the formula for the path integral which allows to account for the all possible topologies of spacetime. We show that the proper path integral defines a cutoff for the field theory. The form of the cutoff is...
0810.5419
Shahar Hod
Shahar Hod
Quasinormal resonances of near-extremal Kerr-Newman black holes
4 pages
Phys.Lett.B666:483-485,2008
10.1016/j.physletb.2008.08.002
null
gr-qc astro-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study analytically the fundamental resonances of near-extremal, slowly rotating Kerr-Newman black holes. We find a simple analytic expression for these black-hole quasinormal frequencies in terms of the black-hole physical parameters: omega=m Omega-2i pi T(l+1+n), where T and Omega are the temperature and angular ...
[ { "created": "Thu, 30 Oct 2008 05:45:20 GMT", "version": "v1" } ]
2009-01-16
[ [ "Hod", "Shahar", "" ] ]
We study analytically the fundamental resonances of near-extremal, slowly rotating Kerr-Newman black holes. We find a simple analytic expression for these black-hole quasinormal frequencies in terms of the black-hole physical parameters: omega=m Omega-2i pi T(l+1+n), where T and Omega are the temperature and angular ve...
1606.08049
Parthapratim Pradhan
Parthapratim Pradhan
Horizon Areas and Logarithmic Correction to the Charged Accelerating Black Hole Entropy
Accepted in Universe,2019, Invited article
Universe 2019, 5(2), 57
10.3390/universe5020057
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been shown by explicit and exact calculation that the geometric product formula i.e. horizon area (or entropy) product formula of outer horizon (${\cal H}^{+}$) and inner horizon (${\cal H}^{-}$) for charged accelerating black hole (BH) should \emph{ neither be mass-independent nor it be quantized}. This impli...
[ { "created": "Sun, 26 Jun 2016 16:25:13 GMT", "version": "v1" }, { "created": "Mon, 6 Nov 2017 15:40:29 GMT", "version": "v2" }, { "created": "Mon, 11 Feb 2019 17:08:42 GMT", "version": "v3" } ]
2019-02-12
[ [ "Pradhan", "Parthapratim", "" ] ]
It has been shown by explicit and exact calculation that the geometric product formula i.e. horizon area (or entropy) product formula of outer horizon (${\cal H}^{+}$) and inner horizon (${\cal H}^{-}$) for charged accelerating black hole (BH) should \emph{ neither be mass-independent nor it be quantized}. This implies...
1502.01225
Sean Gryb B
Sean Gryb and Karim Thebault
Schrodinger Evolution for the Universe: Reparametrization
25 pages (including title page and references), 1 figure
Class.Quant.Grav. 33 (2016) no.6, 065004
10.1088/0264-9381/33/6/065004
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Starting from a generalized Hamilton-Jacobi formalism, we develop a new framework for constructing observables and their evolution in theories invariant under global time reparametrizations. Our proposal relaxes the usual Dirac prescription for the observables of a totally constrained system (`perennials') and allows...
[ { "created": "Wed, 4 Feb 2015 15:08:55 GMT", "version": "v1" } ]
2017-11-15
[ [ "Gryb", "Sean", "" ], [ "Thebault", "Karim", "" ] ]
Starting from a generalized Hamilton-Jacobi formalism, we develop a new framework for constructing observables and their evolution in theories invariant under global time reparametrizations. Our proposal relaxes the usual Dirac prescription for the observables of a totally constrained system (`perennials') and allows o...
2105.01546
Gauranga Samanta
Nisha Godani and Gauranga C Samanta
FRW Cosmology in $f(Q,T)$ Gravity
15 pages, 8 figures, accepted for publication in Int. J. Geom. Method. Mod. Phys
null
10.1142/S0219887821501346
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we considered the study of Friedmann-Robertson-Walker (FRW) model in the framework of $f(Q,T)$ gravity, an extension of symmetric teleparallel gravity, recently defined by Y. Xu et al. \cite{Xu}. The non-linear model $f(Q,T)=-\alpha Q-\beta T^2$, where $\alpha>0$ and $\beta>0$ are constants, is taken i...
[ { "created": "Sat, 1 May 2021 11:17:56 GMT", "version": "v1" } ]
2021-05-05
[ [ "Godani", "Nisha", "" ], [ "Samanta", "Gauranga C", "" ] ]
In this paper, we considered the study of Friedmann-Robertson-Walker (FRW) model in the framework of $f(Q,T)$ gravity, an extension of symmetric teleparallel gravity, recently defined by Y. Xu et al. \cite{Xu}. The non-linear model $f(Q,T)=-\alpha Q-\beta T^2$, where $\alpha>0$ and $\beta>0$ are constants, is taken int...
1111.7254
Roberto B. Salgado
Roberto B. Salgado
Relativity on Rotated Graph Paper
30 pages, 17 figures. For an earlier approach, see arXiv:physics/0505134v1
Am. J. Phys. 84, 344 (2016)
10.1119/1.4943251
null
gr-qc physics.class-ph physics.ed-ph physics.pop-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present visual calculations in special relativity using spacetime diagrams drawn on graph paper that has been rotated by 45 degrees. The rotated lines represent lightlike directions in Minkowski spacetime, and the boxes in the grid (called "light-clock diamonds") represent units of measurement modeled on the ticks...
[ { "created": "Wed, 30 Nov 2011 18:01:46 GMT", "version": "v1" } ]
2016-04-21
[ [ "Salgado", "Roberto B.", "" ] ]
We present visual calculations in special relativity using spacetime diagrams drawn on graph paper that has been rotated by 45 degrees. The rotated lines represent lightlike directions in Minkowski spacetime, and the boxes in the grid (called "light-clock diamonds") represent units of measurement modeled on the ticks o...
gr-qc/9412031
Ulvi Yurtsever
Ulvi Yurtsever
Geometry of chaos in the two-center problem in General Relativity
14 pages, 7 figures
Phys.Rev.D52:3176-3183,1995
10.1103/PhysRevD.52.3176
null
gr-qc
null
The now-famous Majumdar-Papapetrou exact solution of the Einstein-Maxwell equations describes, in general, $N$ static, maximally charged black holes balanced under mutual gravitational and electrostatic interaction. When $N=2$, this solution defines the two-black-hole spacetime, and the relativistic two-center proble...
[ { "created": "Sat, 10 Dec 1994 00:54:34 GMT", "version": "v1" } ]
2010-01-15
[ [ "Yurtsever", "Ulvi", "" ] ]
The now-famous Majumdar-Papapetrou exact solution of the Einstein-Maxwell equations describes, in general, $N$ static, maximally charged black holes balanced under mutual gravitational and electrostatic interaction. When $N=2$, this solution defines the two-black-hole spacetime, and the relativistic two-center problem ...
2205.05132
Hector O. Silva
Hector O. Silva, Abhirup Ghosh, Alessandra Buonanno
Black-hole ringdown as a probe of higher-curvature gravity theories
21 pages, 12 figures. v2. Matches published version
Phys. Rev. D 107, 044030 (2023)
10.1103/PhysRevD.107.044030
null
gr-qc astro-ph.HE hep-th
http://creativecommons.org/licenses/by/4.0/
Detecting gravitational waves from coalescing compact binaries allows us to explore the dynamical, nonlinear regime of general relativity and constrain modifications to it. Some of the gravitational-wave events observed by the LIGO-Virgo Collaboration have sufficiently high signal-to-noise ratio in the merger, allowi...
[ { "created": "Tue, 10 May 2022 19:33:39 GMT", "version": "v1" }, { "created": "Wed, 22 Feb 2023 14:47:48 GMT", "version": "v2" } ]
2023-02-23
[ [ "Silva", "Hector O.", "" ], [ "Ghosh", "Abhirup", "" ], [ "Buonanno", "Alessandra", "" ] ]
Detecting gravitational waves from coalescing compact binaries allows us to explore the dynamical, nonlinear regime of general relativity and constrain modifications to it. Some of the gravitational-wave events observed by the LIGO-Virgo Collaboration have sufficiently high signal-to-noise ratio in the merger, allowing...
1912.11490
Parampreet Singh
John L. Dupuy, Parampreet Singh
Hysteresis and beats in loop quantum cosmology
12 pages, 17 figures
Phys. Rev. D 101, 086016 (2020)
10.1103/PhysRevD.101.086016
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Differences in pressure during expansion and contraction stages in cosmic evolution can result in a hysteresis-like phenomena in non-singular cyclic models sourced with scalar fields. We discuss this phenomena for spatially closed isotropic spacetime in loop quantum cosmology (LQC) for a quadratic and a cosh-like pot...
[ { "created": "Tue, 24 Dec 2019 19:02:08 GMT", "version": "v1" } ]
2020-04-22
[ [ "Dupuy", "John L.", "" ], [ "Singh", "Parampreet", "" ] ]
Differences in pressure during expansion and contraction stages in cosmic evolution can result in a hysteresis-like phenomena in non-singular cyclic models sourced with scalar fields. We discuss this phenomena for spatially closed isotropic spacetime in loop quantum cosmology (LQC) for a quadratic and a cosh-like poten...
0807.0300
Alessandro Pesci
Alessandro Pesci
A note on the connection between the universal relaxation bound and the covariant entropy bound
One reference added; some editing
Int.J.Mod.Phys.D18:831-835,2009
10.1142/S0218271809014789
null
gr-qc cond-mat.stat-mech
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A recently proposed universal lower-bound to the characteristic relaxation times of perturbed thermodynamic systems, derived from quantum information theory and (classical) thermodynamics and known to be saturated for (certain) black holes, is investigated in the light of the gravity/thermodynamics connection. A stat...
[ { "created": "Wed, 2 Jul 2008 08:58:27 GMT", "version": "v1" }, { "created": "Wed, 24 Jun 2009 14:51:17 GMT", "version": "v2" } ]
2009-07-22
[ [ "Pesci", "Alessandro", "" ] ]
A recently proposed universal lower-bound to the characteristic relaxation times of perturbed thermodynamic systems, derived from quantum information theory and (classical) thermodynamics and known to be saturated for (certain) black holes, is investigated in the light of the gravity/thermodynamics connection. A statis...
2101.00856
Steffen Aksteiner
Steffen Aksteiner, Lars Andersson, Bernardo Araneda, Bernard Whiting
On the geometry of Petrov type II spacetimes
null
null
10.1088/1361-6382/abf542
null
gr-qc math-ph math.MP
http://creativecommons.org/licenses/by/4.0/
In general, geometries of Petrov type II do not admit symmetries in terms of Killing vectors or spinors. We introduce a weaker form of Killing equations which do admit solutions. In particular, there is an analog of the Penrose-Walker Killing spinor. Some of its properties, including associated conservation laws, are...
[ { "created": "Mon, 4 Jan 2021 10:02:19 GMT", "version": "v1" } ]
2021-07-07
[ [ "Aksteiner", "Steffen", "" ], [ "Andersson", "Lars", "" ], [ "Araneda", "Bernardo", "" ], [ "Whiting", "Bernard", "" ] ]
In general, geometries of Petrov type II do not admit symmetries in terms of Killing vectors or spinors. We introduce a weaker form of Killing equations which do admit solutions. In particular, there is an analog of the Penrose-Walker Killing spinor. Some of its properties, including associated conservation laws, are d...
2112.08290
Matteo Luca Ruggiero
Matteo Luca Ruggiero, Antonello Ortolan, Clive C. Speake
Galactic Dynamics in General Relativity: the Role of Gravitomagnetism
10 pages, revised to match the version accepted for publication in Classical and Quantum Gravity
Class. Quantum Grav. 39 (2022) 225015
10.1088/1361-6382/ac9949
null
gr-qc astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is a well known fact that, in the absence of Dark Matter, the observation of the rotation curves of galaxies cannot be explained in terms of Newtonian gravity. Rotation curves become flat in the outer regions, in contrast to what is expected according to Keplerian motion. Far from the galactic center, the gravitat...
[ { "created": "Wed, 15 Dec 2021 17:36:17 GMT", "version": "v1" }, { "created": "Tue, 4 Oct 2022 15:04:47 GMT", "version": "v2" } ]
2022-11-01
[ [ "Ruggiero", "Matteo Luca", "" ], [ "Ortolan", "Antonello", "" ], [ "Speake", "Clive C.", "" ] ]
It is a well known fact that, in the absence of Dark Matter, the observation of the rotation curves of galaxies cannot be explained in terms of Newtonian gravity. Rotation curves become flat in the outer regions, in contrast to what is expected according to Keplerian motion. Far from the galactic center, the gravitatio...
1107.5250
Eva Hackmann
Eva Hackmann and Claus L\"ammerzahl
Observables for bound orbital motion in axially symmetric space-times
18 pages, revised version
Phys. Rev. D 85, 044049 (2012)
10.1103/PhysRevD.85.044049
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The periastron shift and the Lense-Thirring effect of bound orbital motion in a general axially symmetric space-time given by Pleba\'nski and Demia\'nski are analyzed. We also define a measure for the conicity of the orbit and give analytic expressions for all three observables in terms of hyperelliptic integrals and...
[ { "created": "Tue, 26 Jul 2011 16:02:25 GMT", "version": "v1" }, { "created": "Tue, 6 Sep 2011 10:33:38 GMT", "version": "v2" }, { "created": "Wed, 11 Apr 2012 10:33:58 GMT", "version": "v3" } ]
2012-04-12
[ [ "Hackmann", "Eva", "" ], [ "Lämmerzahl", "Claus", "" ] ]
The periastron shift and the Lense-Thirring effect of bound orbital motion in a general axially symmetric space-time given by Pleba\'nski and Demia\'nski are analyzed. We also define a measure for the conicity of the orbit and give analytic expressions for all three observables in terms of hyperelliptic integrals and L...
2204.11617
Luca Guido Molinari
Carlo Alberto Mantica and Luca Guido Molinari
Spherical doubly warped spacetimes for radiating stars and cosmology
27 pages, submitted to GERG
General Relativity and Gravitation (2022) 54:98 (open access)
10.1007/s10714-022-02984-7
null
gr-qc math.DG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Spherically symmetric spacetimes are ambient spaces for models of stellar collapse and inhomogeneous cosmology. We obtain results for the Weyl tensor and the covariant form of the Ricci tensor on general doubly warped (DW) spacetimes. In a spherically symmetric metric, the Ricci and electric tensors become rank-2, bu...
[ { "created": "Fri, 22 Apr 2022 14:51:58 GMT", "version": "v1" } ]
2022-09-08
[ [ "Mantica", "Carlo Alberto", "" ], [ "Molinari", "Luca Guido", "" ] ]
Spherically symmetric spacetimes are ambient spaces for models of stellar collapse and inhomogeneous cosmology. We obtain results for the Weyl tensor and the covariant form of the Ricci tensor on general doubly warped (DW) spacetimes. In a spherically symmetric metric, the Ricci and electric tensors become rank-2, buil...
1108.6067
Erico Goulart
E. Goulart, M. Novello, F. T. Falciano, J. D. Toniato
Hidden geometries in nonlinear theories: a novel aspect of analogue gravity
null
E Goulart et al 2011 Class. Quantum Grav. 28 245008
10.1088/0264-9381/28/24/245008
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that non-linear dynamics of a scalar field {\phi} may be described as a mod- ification of the spacetime geometry. Thus, the self-interaction is interpreted as a coupling of the scalar field with an effective gravitational metric that is constructed with {\phi} itself. We prove that this process is universal, ...
[ { "created": "Tue, 30 Aug 2011 20:12:32 GMT", "version": "v1" } ]
2013-06-07
[ [ "Goulart", "E.", "" ], [ "Novello", "M.", "" ], [ "Falciano", "F. T.", "" ], [ "Toniato", "J. D.", "" ] ]
We show that non-linear dynamics of a scalar field {\phi} may be described as a mod- ification of the spacetime geometry. Thus, the self-interaction is interpreted as a coupling of the scalar field with an effective gravitational metric that is constructed with {\phi} itself. We prove that this process is universal, th...
1004.1017
Mohammad Malekjani
M. Malekjani and A. Khodam-Mohammadi
Interacting entropy-corrected agegraphic Chaplygin gas model of dark energy
15 pages, no figure
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we consider the interacting agegraphic dark energy models with entropy correction terms due to loop quantum gravity. We study the correspondence between the Chaplygin gas energy density with the interacting entropy-corrected agegraphic dark energy models in non-flat FRW universe. We reconstruct the pote...
[ { "created": "Wed, 7 Apr 2010 07:15:43 GMT", "version": "v1" }, { "created": "Sat, 17 Apr 2010 13:26:37 GMT", "version": "v2" } ]
2010-04-20
[ [ "Malekjani", "M.", "" ], [ "Khodam-Mohammadi", "A.", "" ] ]
In this work, we consider the interacting agegraphic dark energy models with entropy correction terms due to loop quantum gravity. We study the correspondence between the Chaplygin gas energy density with the interacting entropy-corrected agegraphic dark energy models in non-flat FRW universe. We reconstruct the potent...
1710.05832
The LIGO Scientific Collaboration and The Virgo Collaboration
The LIGO Scientific Collaboration and The Virgo Collaboration
GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
null
Phys. Rev. Lett. 119 161101 (2017)
10.1103/PhysRevLett.119.161101
LIGO-P170817
gr-qc astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
On August 17, 2017 at 12:41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per $8.0\times10^4$ yea...
[ { "created": "Mon, 16 Oct 2017 16:57:17 GMT", "version": "v1" } ]
2017-10-17
[ [ "The LIGO Scientific Collaboration", "", "" ], [ "The Virgo Collaboration", "", "" ] ]
On August 17, 2017 at 12:41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per $8.0\times10^4$ years...
2006.16153
Patricia Schmidt
Geraint Pratten, Patricia Schmidt, Riccardo Buscicchio, Lucy M. Thomas
Measuring precession in asymmetric compact binaries
18 pages incl. appendices and bibliography, 12 figures, 4 tables; accepted for publication in Phys. Rev. Research
Phys. Rev. Research 2, 043096 (2020)
10.1103/PhysRevResearch.2.043096
LIGO-DCC P2000224
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gravitational-wave observations of merging compact binaries hold the key to precision measurements of the objects' masses and spins. General-relativistic precession, caused by spins misaligned with the orbital angular momentum, is considered a crucial tracer for determining the binary's formation history and environm...
[ { "created": "Mon, 29 Jun 2020 16:14:54 GMT", "version": "v1" }, { "created": "Wed, 30 Sep 2020 15:15:51 GMT", "version": "v2" } ]
2020-10-28
[ [ "Pratten", "Geraint", "" ], [ "Schmidt", "Patricia", "" ], [ "Buscicchio", "Riccardo", "" ], [ "Thomas", "Lucy M.", "" ] ]
Gravitational-wave observations of merging compact binaries hold the key to precision measurements of the objects' masses and spins. General-relativistic precession, caused by spins misaligned with the orbital angular momentum, is considered a crucial tracer for determining the binary's formation history and environmen...
gr-qc/9304012
Karel Kuchar
Karel Kuchar
Canonical Quantum Gravity
Latex, 35 pages. arXiv admin note: figures missing
null
null
UU-REL-92/12/10
gr-qc
null
This is a review of the aspirations and disappointments of the canonical quantization of geometry. I compare the two chief ways of looking at canonical gravity, geometrodynamics and connection dynamics. I capture as much of the classical theory as I can by pictorial visualization. Algebraic aspects dominate my descri...
[ { "created": "Thu, 8 Apr 1993 22:00:56 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kuchar", "Karel", "" ] ]
This is a review of the aspirations and disappointments of the canonical quantization of geometry. I compare the two chief ways of looking at canonical gravity, geometrodynamics and connection dynamics. I capture as much of the classical theory as I can by pictorial visualization. Algebraic aspects dominate my descript...
1406.3931
Hemwati Nandan
Rashmi Uniyal, N. Chandrachani Devi, Hemwati Nandan and K.D. Purohit
Geodesic Motion in Schwarzschild Spacetime Surrounded by Quintessence
20 pages, 8 figures
null
10.1007/s10714-015-1857-9
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the time-like geodesic congruences, in the space-time geometry of a Schwarzschild black hole surrounded by quintessence. The nature of effective potential along with the structure of the possible orbits for test particles in view of the different values of quintessence parameter are analysed in detail. %wher...
[ { "created": "Mon, 16 Jun 2014 08:32:15 GMT", "version": "v1" }, { "created": "Thu, 8 Jan 2015 10:49:00 GMT", "version": "v2" } ]
2015-06-22
[ [ "Uniyal", "Rashmi", "" ], [ "Devi", "N. Chandrachani", "" ], [ "Nandan", "Hemwati", "" ], [ "Purohit", "K. D.", "" ] ]
We study the time-like geodesic congruences, in the space-time geometry of a Schwarzschild black hole surrounded by quintessence. The nature of effective potential along with the structure of the possible orbits for test particles in view of the different values of quintessence parameter are analysed in detail. %wherev...
1504.05529
Miguel Pino
Ashok Das, Jorge Gamboa, Miguel Pino
Cosmological Kinetic Mixing
13pp, 18 figures
Phys. Rev. D 91, 123528 (2015)
10.1103/PhysRevD.91.123528
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we generalize the kinetic mixing idea to time reparametrization invariant theories, namely, relativistic point particles and cosmology in order to obtain new insights for dark matter and energy. In the first example, two relativistic particles interact through an appropriately chosen coupling term. It i...
[ { "created": "Wed, 15 Apr 2015 15:10:31 GMT", "version": "v1" }, { "created": "Mon, 22 Jun 2015 14:49:28 GMT", "version": "v2" } ]
2015-06-30
[ [ "Das", "Ashok", "" ], [ "Gamboa", "Jorge", "" ], [ "Pino", "Miguel", "" ] ]
In this paper we generalize the kinetic mixing idea to time reparametrization invariant theories, namely, relativistic point particles and cosmology in order to obtain new insights for dark matter and energy. In the first example, two relativistic particles interact through an appropriately chosen coupling term. It is ...
2311.15671
Vitalii Vertogradov
Vitalii Vertogradov
The generalized Vaidya spacetime with polytropic equation of state
10 pages, no figures
null
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
The process of the gravitational collapse might lead not only to a black hole but also to naked singularity formation. In this paper, we consider the generalized Vaidya spacetime with polytropic and generalized polytropic equations of state. We solve the Einstein and Einstein-Maxwell equations to obtain the explicit ...
[ { "created": "Mon, 27 Nov 2023 10:01:00 GMT", "version": "v1" }, { "created": "Sun, 25 Feb 2024 15:20:06 GMT", "version": "v2" } ]
2024-02-27
[ [ "Vertogradov", "Vitalii", "" ] ]
The process of the gravitational collapse might lead not only to a black hole but also to naked singularity formation. In this paper, we consider the generalized Vaidya spacetime with polytropic and generalized polytropic equations of state. We solve the Einstein and Einstein-Maxwell equations to obtain the explicit fo...
1410.6709
Prabir Rudra
Prabir Rudra (Indian Instt. of Engg. Sci. & Tech., Pailan Colg. of Mgmt. & Tech.)
Loop Quantum effects on Om-diagnostic and its Cosmological Implications
9 pages, 5 figures, Accepted for publication in Canadian Journal of Physics
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we study the Loop quantum effects on the \textit{Om} diagnostic and subsequently on the universe. We reconstruct the \textit{Om} diagnostic in the background of Loop quantum gravity and then study the behaviour of various Chaplygin gas dark energy models using the modified diagnostic in a comparative sc...
[ { "created": "Sun, 19 Oct 2014 17:07:58 GMT", "version": "v1" } ]
2014-10-27
[ [ "Rudra", "Prabir", "", "Indian Instt. of Engg. Sci. & Tech., Pailan Colg. of\n Mgmt. & Tech." ] ]
In this paper we study the Loop quantum effects on the \textit{Om} diagnostic and subsequently on the universe. We reconstruct the \textit{Om} diagnostic in the background of Loop quantum gravity and then study the behaviour of various Chaplygin gas dark energy models using the modified diagnostic in a comparative scen...
gr-qc/0504113
Allan Joseph Michael Medved
A.J.M. Medved and Elias C. Vagenas
On Hawking Radiation as Tunneling with Back-Reaction
5 pages, latex
Mod.Phys.Lett.A20:2449-2454,2005
10.1142/S021773230501861X
null
gr-qc hep-th
null
Recently, Angheben et.al. [hep-th/0503081] have presented a refined method for calculating the (tree-level) black hole temperature by way of the tunneling paradigm. In the current letter, we demonstrate how their formalism can be suitably adapted to accommodate the (higher-order) effects of the gravitational back-rea...
[ { "created": "Fri, 22 Apr 2005 19:22:27 GMT", "version": "v1" } ]
2011-07-18
[ [ "Medved", "A. J. M.", "" ], [ "Vagenas", "Elias C.", "" ] ]
Recently, Angheben et.al. [hep-th/0503081] have presented a refined method for calculating the (tree-level) black hole temperature by way of the tunneling paradigm. In the current letter, we demonstrate how their formalism can be suitably adapted to accommodate the (higher-order) effects of the gravitational back-react...
2406.05650
Mohsen Fathi
Mohsen Fathi, J.R. Villanueva, Gilberto Aguilar-P\'erez, and Miguel Cruz
Black hole in a generalized Chaplygin-Jacobi dark fluid: shadow and light deflection angle
24 pages, 10 figures, 2 tables
null
10.1016/j.dark.2024.101598
null
gr-qc astro-ph.CO astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
We investigate a generalized Chaplygin-like gas with an anisotropic equation of state, characterizing a dark fluid within which a static spherically symmetric black hole is assumed. By solving the Einstein equations for this black hole spacetime, we explicitly derive the metric function. The spacetime is parametrized...
[ { "created": "Sun, 9 Jun 2024 05:21:43 GMT", "version": "v1" }, { "created": "Wed, 31 Jul 2024 15:26:30 GMT", "version": "v2" }, { "created": "Thu, 1 Aug 2024 21:23:48 GMT", "version": "v3" } ]
2024-08-05
[ [ "Fathi", "Mohsen", "" ], [ "Villanueva", "J. R.", "" ], [ "Aguilar-Pérez", "Gilberto", "" ], [ "Cruz", "Miguel", "" ] ]
We investigate a generalized Chaplygin-like gas with an anisotropic equation of state, characterizing a dark fluid within which a static spherically symmetric black hole is assumed. By solving the Einstein equations for this black hole spacetime, we explicitly derive the metric function. The spacetime is parametrized b...
2304.01995
Dawood Kothawala Dr.
Dawood Kothawala
Synge's World function and the quantum spacetime
Based on the talk "Relics of the quantum spacetime: from Synge's world function as the fundamental probe of spacetime architecture to the emergent description of gravity", presented at DICE2022, Castiglioncello, Italy, Sep 19-23, 2022
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
All our observations that characterise space and time are expressed in terms of non-local, bi-tensorial objects such as geodesic intervals between events and two-point (Green) functions. In this contribution, I highlight the importance of characterising spacetime geometry in terms of such non-local objects, focusing ...
[ { "created": "Tue, 4 Apr 2023 17:53:45 GMT", "version": "v1" } ]
2023-04-05
[ [ "Kothawala", "Dawood", "" ] ]
All our observations that characterise space and time are expressed in terms of non-local, bi-tensorial objects such as geodesic intervals between events and two-point (Green) functions. In this contribution, I highlight the importance of characterising spacetime geometry in terms of such non-local objects, focusing pa...
1008.5280
Miquel Nofrarias
M. Nofrarias, C. R\"over, M. Hewitson, A. Monsky, G. Heinzel, K. Danzmann, L. Ferraioli, M. Hueller, S. Vitale
Bayesian parameter estimation in the second LISA Pathfinder Mock Data Challenge
14 pages, 4 figures, submitted to PRD
Phys.Rev.D82:122002,2010
10.1103/PhysRevD.82.122002
null
gr-qc physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A main scientific output of the LISA Pathfinder mission is to provide a noise model that can be extended to the future gravitational wave observatory, LISA. The success of the mission depends thus upon a deep understanding of the instrument, especially the ability to correctly determine the parameters of the underlyi...
[ { "created": "Tue, 31 Aug 2010 10:48:38 GMT", "version": "v1" } ]
2010-12-28
[ [ "Nofrarias", "M.", "" ], [ "Röver", "C.", "" ], [ "Hewitson", "M.", "" ], [ "Monsky", "A.", "" ], [ "Heinzel", "G.", "" ], [ "Danzmann", "K.", "" ], [ "Ferraioli", "L.", "" ], [ "Hueller", "M.",...
A main scientific output of the LISA Pathfinder mission is to provide a noise model that can be extended to the future gravitational wave observatory, LISA. The success of the mission depends thus upon a deep understanding of the instrument, especially the ability to correctly determine the parameters of the underlying...
gr-qc/9503047
Piljin Yi
Piljin Yi
Vanishing Hawking Radiation from a Uniformly Accelerated Black Hole
LaTeX, 10pages, 2 figures (a typo in Eq.(3) corrected; minor revisions to accomodate the length limitation of the journal)
Phys.Rev.Lett. 75 (1995) 382-385
10.1103/PhysRevLett.75.382
CU-TP-683
gr-qc hep-ph hep-th
null
We consider quantum fields around uniformly accelerated black holes. At a particular value of the acceleration, the Bogolubov transformation which would be responsible for the late-time Hawking radiation, is found to be trivial. When this happens, Hawking's thermal radiation, Doppler-shifted or not, is absent to the ...
[ { "created": "Sun, 26 Mar 1995 21:21:39 GMT", "version": "v1" }, { "created": "Mon, 31 Jul 1995 13:39:03 GMT", "version": "v2" } ]
2009-10-28
[ [ "Yi", "Piljin", "" ] ]
We consider quantum fields around uniformly accelerated black holes. At a particular value of the acceleration, the Bogolubov transformation which would be responsible for the late-time Hawking radiation, is found to be trivial. When this happens, Hawking's thermal radiation, Doppler-shifted or not, is absent to the as...
2312.05065
Luca Santoni
Massimiliano Maria Riva, Luca Santoni, Nikola Savi\'c and Filippo Vernizzi
Vanishing of Nonlinear Tidal Love Numbers of Schwarzschild Black Holes
11 pages, 3 figures
null
null
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
It is well known that asymptotically flat Schwarzschild black holes in general relativity in four spacetime dimensions have vanishing induced linear tidal response. We extend this result beyond linear order for the polar sector, by solving the static nonlinear Einstein equations for the perturbations of the Schwarzsc...
[ { "created": "Fri, 8 Dec 2023 14:35:21 GMT", "version": "v1" }, { "created": "Tue, 28 May 2024 13:21:55 GMT", "version": "v2" } ]
2024-05-29
[ [ "Riva", "Massimiliano Maria", "" ], [ "Santoni", "Luca", "" ], [ "Savić", "Nikola", "" ], [ "Vernizzi", "Filippo", "" ] ]
It is well known that asymptotically flat Schwarzschild black holes in general relativity in four spacetime dimensions have vanishing induced linear tidal response. We extend this result beyond linear order for the polar sector, by solving the static nonlinear Einstein equations for the perturbations of the Schwarzschi...
1404.5821
Aurelien Barrau
Aurelien Barrau and Carlo Rovelli
Planck star phenomenology
5 pages, 4 figues
Physics Letters B 739 (2014) 405
10.1016/j.physletb.2014.11.020
null
gr-qc astro-ph.CO hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is possible that black holes hide a core of Planckian density, sustained by quantum-gravitational pressure. As a black hole evaporates, the core remembers the initial mass and the final explosion occurs at macroscopic scale. We investigate possible phenomenological consequences of this idea. Under several rough as...
[ { "created": "Wed, 23 Apr 2014 13:38:41 GMT", "version": "v1" }, { "created": "Sat, 3 May 2014 09:21:43 GMT", "version": "v2" } ]
2015-06-19
[ [ "Barrau", "Aurelien", "" ], [ "Rovelli", "Carlo", "" ] ]
It is possible that black holes hide a core of Planckian density, sustained by quantum-gravitational pressure. As a black hole evaporates, the core remembers the initial mass and the final explosion occurs at macroscopic scale. We investigate possible phenomenological consequences of this idea. Under several rough assu...
2302.04808
Richard Woodard
E. Kasdagli, Martha Ulloa and R. P. Woodard
Coincident Massless, Minimally Coupled Scalar Correlators on General Cosmological Backgrounds
30 pages, 5 figures, uses LaTeX2e, Version 2 revised for publication with improved figures and length of 34 pages
Phys. Rev. D107 (2023) 105023
10.1103/PhysRevD.107.105023
UFIFT-QG-23-02
gr-qc astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
The coincidence limits of the massless, minimally coupled scalar propagator and its first two derivatives have great relevance for the project of summing up the leading logarithms induced by loops of inflationary gravitons. We use dimensional regularization to derive good analytic approximations for the three quantit...
[ { "created": "Thu, 9 Feb 2023 17:56:34 GMT", "version": "v1" }, { "created": "Thu, 1 Jun 2023 03:18:46 GMT", "version": "v2" } ]
2023-06-02
[ [ "Kasdagli", "E.", "" ], [ "Ulloa", "Martha", "" ], [ "Woodard", "R. P.", "" ] ]
The coincidence limits of the massless, minimally coupled scalar propagator and its first two derivatives have great relevance for the project of summing up the leading logarithms induced by loops of inflationary gravitons. We use dimensional regularization to derive good analytic approximations for the three quantitie...
1405.0363
Christodoulakis Theodosios
T. Christodoulakis, N. Dimakis, Petros A. Terzis and G. Doulis
Canonical Quantization of the BTZ Black Hole using Noether Symmetries
24 pages, no figures, LaTeX 2e source file
null
10.1103/PhysRevD.90.024052
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The well-known BTZ black hole solution of (2+1) Einstein's gravity, in the presence of a cosmological constant, is treated both at the classical and quantum level. Classically, the imposition of the two manifest local Killing fields of the BTZ geometry at the level of the full action results in a mini-superspace cons...
[ { "created": "Fri, 2 May 2014 09:21:15 GMT", "version": "v1" } ]
2015-06-19
[ [ "Christodoulakis", "T.", "" ], [ "Dimakis", "N.", "" ], [ "Terzis", "Petros A.", "" ], [ "Doulis", "G.", "" ] ]
The well-known BTZ black hole solution of (2+1) Einstein's gravity, in the presence of a cosmological constant, is treated both at the classical and quantum level. Classically, the imposition of the two manifest local Killing fields of the BTZ geometry at the level of the full action results in a mini-superspace constr...
gr-qc/0204061
Alexander Vilenkin
Alexander Vilenkin
Quantum cosmology and eternal inflation
To appear in "The Future of Theoretical Physics and Cosmology", proceedings of the conference in honor of Stephen Hawking's 60'th birthday
null
null
null
gr-qc
null
This contribution consists of two parts. In the first part, I review the tunneling approach to quantum cosmology and comment on the alternative approaches. In the second part, I discuss the relation between quantum cosmology and eternal inflation. In particular, I discuss whether or not we need quantum cosmology in t...
[ { "created": "Thu, 18 Apr 2002 21:13:48 GMT", "version": "v1" } ]
2007-05-23
[ [ "Vilenkin", "Alexander", "" ] ]
This contribution consists of two parts. In the first part, I review the tunneling approach to quantum cosmology and comment on the alternative approaches. In the second part, I discuss the relation between quantum cosmology and eternal inflation. In particular, I discuss whether or not we need quantum cosmology in the...
1401.0774
Joseph Samuel
Supurna Sinha and Joseph Samuel
Quantum Limit on Stability of Clocks in a Gravitational Field
10 pages, 2 figures, 1 table, ms improved and tightened after discussions, references and acknowledgements inserted, clock instability emphasized not decoherence
null
10.1088/0264-9381/32/1/015018
null
gr-qc quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Good clocks are of importance both to fundamental physics and for applications in astronomy, metrology and global positioning systems. In a recent technological breakthrough, researchers at NIST have been able to achieve a stability of 1 part in $10^{18}$ using an Ytterbium clock. This naturally raises the question o...
[ { "created": "Sat, 4 Jan 2014 04:30:21 GMT", "version": "v1" }, { "created": "Thu, 20 Mar 2014 06:20:19 GMT", "version": "v2" }, { "created": "Fri, 21 Mar 2014 10:39:08 GMT", "version": "v3" } ]
2015-06-18
[ [ "Sinha", "Supurna", "" ], [ "Samuel", "Joseph", "" ] ]
Good clocks are of importance both to fundamental physics and for applications in astronomy, metrology and global positioning systems. In a recent technological breakthrough, researchers at NIST have been able to achieve a stability of 1 part in $10^{18}$ using an Ytterbium clock. This naturally raises the question of ...
2003.05657
Ji-Yao Wang
Ji-Yao Wang, Chao-Jun Feng, Xiang-Hua Zhai, and Xin-Zhou Li
Dynamics of Viscous Phantom Universe
14 pages, 7 figures
null
null
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The phantom dark energy remarkably boosts our prehension of the accelerating Universe. Various models are widely discussed in the phantom Universe without bulk viscosity. From the hydrodynamics' point of view, it is natural to introduce the nonperfect fluid in the study of the Universe, as an ideal fluid just an appr...
[ { "created": "Thu, 12 Mar 2020 08:18:53 GMT", "version": "v1" }, { "created": "Fri, 20 Mar 2020 09:30:53 GMT", "version": "v2" }, { "created": "Tue, 9 Jun 2020 07:33:54 GMT", "version": "v3" } ]
2020-06-11
[ [ "Wang", "Ji-Yao", "" ], [ "Feng", "Chao-Jun", "" ], [ "Zhai", "Xiang-Hua", "" ], [ "Li", "Xin-Zhou", "" ] ]
The phantom dark energy remarkably boosts our prehension of the accelerating Universe. Various models are widely discussed in the phantom Universe without bulk viscosity. From the hydrodynamics' point of view, it is natural to introduce the nonperfect fluid in the study of the Universe, as an ideal fluid just an approx...
1901.07383
Rhiannon Cuttell
Rhiannon Cuttell and Mairi Sakellariadou
The general gravitational Lagrangian with deformed covariance
15 pages, 2 figures. arXiv admin note: text overlap with arXiv:1812.07530
Phys. Rev. D 102, 104048 (2020)
10.1103/PhysRevD.102.104048
KCL-PH-TH/2019-08
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the gravitational Lagrangian to all orders of curvature when the canonical constraint algebra is deformed by a phase space function as predicted by some studies into loop quantum cosmology. The deformation function seems to be required to satisfy a non-linear equation usually found in fluid mechanics, and c...
[ { "created": "Fri, 18 Jan 2019 16:54:58 GMT", "version": "v1" } ]
2020-11-25
[ [ "Cuttell", "Rhiannon", "" ], [ "Sakellariadou", "Mairi", "" ] ]
We derive the gravitational Lagrangian to all orders of curvature when the canonical constraint algebra is deformed by a phase space function as predicted by some studies into loop quantum cosmology. The deformation function seems to be required to satisfy a non-linear equation usually found in fluid mechanics, and can...
2404.06870
Sanjar Shaymatov
Sanjar Shaymatov, Naresh Dadhich, Arman Tursunov
Energetics of Buchdahl stars and the magnetic Penrose process
10 pages, 4 captioned figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Buchdahl star is the most compact object without an event horizon and is an excellent candidate for a black hole mimicker. Unlike black holes, rotating Buchdahl star can be over-extremal with respect to the black hole, sustaining a larger spin. We show that it can also develop an ergosphere above the threshold spin $...
[ { "created": "Wed, 10 Apr 2024 09:47:55 GMT", "version": "v1" } ]
2024-04-11
[ [ "Shaymatov", "Sanjar", "" ], [ "Dadhich", "Naresh", "" ], [ "Tursunov", "Arman", "" ] ]
Buchdahl star is the most compact object without an event horizon and is an excellent candidate for a black hole mimicker. Unlike black holes, rotating Buchdahl star can be over-extremal with respect to the black hole, sustaining a larger spin. We show that it can also develop an ergosphere above the threshold spin $\b...
1610.02720
Alexei Zayats
Alexei E. Zayats
Self-interaction in the Bopp-Podolsky electrodynamics: Spacetimes with angular defects
9 pages, 2 figures, final version
Phys. Rev. D 94, 105026 (2016)
10.1103/PhysRevD.94.105026
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the self-interaction phenomenon in the framework of the Bopp-Podolsky electrodynamics. In the present paper, we obtain the self-interaction potential energy of a charge at rest for the spacetimes with topological defects of two types: for the axially symmetric spacetime of the straight cosmic string and t...
[ { "created": "Sun, 9 Oct 2016 21:00:57 GMT", "version": "v1" }, { "created": "Mon, 28 Nov 2016 18:17:34 GMT", "version": "v2" } ]
2016-11-29
[ [ "Zayats", "Alexei E.", "" ] ]
We consider the self-interaction phenomenon in the framework of the Bopp-Podolsky electrodynamics. In the present paper, we obtain the self-interaction potential energy of a charge at rest for the spacetimes with topological defects of two types: for the axially symmetric spacetime of the straight cosmic string and the...
1508.02306
Muhammad Sharif
M. Sharif and Rubab Manzoor
Hydrodynamics of Gaseous System in Massive Brans-Dicke Gravity
22 pages, no figure, title is changed, some instability conditions are developed, references are updated
Eur. Phys. J. Plus 131 (2016)64
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper explores hydrodynamics and hydrostatic of a star in post-Newtonian approximation of massive Bran-Dicke gravity. We study approximated solution of the field equations upto $O(c^{-4})$ and generalize Euler equation of motion. We then formulate equations governing hydrodynamics, stability and instability of t...
[ { "created": "Fri, 7 Aug 2015 10:58:33 GMT", "version": "v1" }, { "created": "Fri, 16 Oct 2015 09:08:37 GMT", "version": "v2" } ]
2016-05-11
[ [ "Sharif", "M.", "" ], [ "Manzoor", "Rubab", "" ] ]
This paper explores hydrodynamics and hydrostatic of a star in post-Newtonian approximation of massive Bran-Dicke gravity. We study approximated solution of the field equations upto $O(c^{-4})$ and generalize Euler equation of motion. We then formulate equations governing hydrodynamics, stability and instability of the...
gr-qc/9711030
Larry Ford
L.H. Ford, Michael J. Pfenning and Thomas A. Roman
Quantum Inequalities and Singular Energy Densities
18 pages, LaTex, 2 figures, uses epsf
Phys. Rev. D 57, 4839 (1998)
10.1103/PhysRevD.57.4839
TUTP-97-11
gr-qc hep-th quant-ph
null
There has been much recent work on quantum inequalities to constrain negative energy. These are uncertainty principle-type restrictions on the magnitude and duration of negative energy densities or fluxes. We consider several examples of apparent failures of the quantum inequalities, which involve passage of an obser...
[ { "created": "Mon, 10 Nov 1997 00:20:31 GMT", "version": "v1" } ]
2016-08-25
[ [ "Ford", "L. H.", "" ], [ "Pfenning", "Michael J.", "" ], [ "Roman", "Thomas A.", "" ] ]
There has been much recent work on quantum inequalities to constrain negative energy. These are uncertainty principle-type restrictions on the magnitude and duration of negative energy densities or fluxes. We consider several examples of apparent failures of the quantum inequalities, which involve passage of an observe...
1608.07466
Yongwan Gim
Yongwan Gim and Wontae Kim
On the thermodynamic origin of the initial radiation energy density in warm inflation
17 pages, 1 figure, version to appear in JCAP
JCAP, 11 (2016) 022
10.1088/1475-7516/2016/11/022
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In warm inflation scenarios, radiation always exists, so that the radiation energy density is also assumed to be finite when inflation starts. To find out the origin of the non-vanishing initial radiation energy density, we revisit thermodynamic analysis for a warm inflation model and then derive an effective Stefan-...
[ { "created": "Tue, 23 Aug 2016 02:38:57 GMT", "version": "v1" }, { "created": "Thu, 10 Nov 2016 08:24:03 GMT", "version": "v2" } ]
2016-11-11
[ [ "Gim", "Yongwan", "" ], [ "Kim", "Wontae", "" ] ]
In warm inflation scenarios, radiation always exists, so that the radiation energy density is also assumed to be finite when inflation starts. To find out the origin of the non-vanishing initial radiation energy density, we revisit thermodynamic analysis for a warm inflation model and then derive an effective Stefan-Bo...
gr-qc/9703042
Jorge Pullin
Rodolfo Gambini, Jorge Griego and Jorge Pullin
Chern--Simons states in spin-network quantum gravity
8 pages, RevTeX, 17 figures included
Phys.Lett. B413 (1997) 260-266
10.1016/S0370-2693(97)01048-4
CGPG-97/3-4
gr-qc
null
In the context of canonical quantum gravity in terms of Ashtekar's new variables, it is known that there exists a state that is annihilated by all the quantum constraints and that is given by the exponential of the Chern--Simons form constructed with the Asthekar connection. We make a first exploration of the transfo...
[ { "created": "Mon, 17 Mar 1997 21:25:50 GMT", "version": "v1" } ]
2009-10-30
[ [ "Gambini", "Rodolfo", "" ], [ "Griego", "Jorge", "" ], [ "Pullin", "Jorge", "" ] ]
In the context of canonical quantum gravity in terms of Ashtekar's new variables, it is known that there exists a state that is annihilated by all the quantum constraints and that is given by the exponential of the Chern--Simons form constructed with the Asthekar connection. We make a first exploration of the transform...
1402.0704
Fabio Briscese
Fabio Briscese and Francesco Calogero
Isochronous Cosmologies
null
IJGMMP Vol. 11 (2014) 1450054 (19 pages)
10.1142/S0219887814500546
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The possibility has been recently demonstrated to manufacture (nonrelativistic, Hamiltonian) many-body problems which feature an isochronous time evolution with an arbitrarily assigned period $T$ yet mimic with good approximation, or even exactly, any given many-body problem (within a large, physically relevant, clas...
[ { "created": "Tue, 4 Feb 2014 12:01:41 GMT", "version": "v1" }, { "created": "Tue, 6 May 2014 15:53:41 GMT", "version": "v2" } ]
2014-05-07
[ [ "Briscese", "Fabio", "" ], [ "Calogero", "Francesco", "" ] ]
The possibility has been recently demonstrated to manufacture (nonrelativistic, Hamiltonian) many-body problems which feature an isochronous time evolution with an arbitrarily assigned period $T$ yet mimic with good approximation, or even exactly, any given many-body problem (within a large, physically relevant, class)...
gr-qc/0502081
Rituparno Goswami
T. Arun Madhav, Rituparno Goswami, Pankaj S. Joshi
Gravitational collapse in asymptotically Anti-de Sitter/de Sitter backgrounds
11 pages, 1 figure, Revtex4
Phys.Rev. D72 (2005) 084029
10.1103/PhysRevD.72.084029
null
gr-qc hep-th
null
We study here the gravitational collapse of a matter cloud with a non-vanishing tangential pressure in the presence of a non-zero cosmological term. Conditions for bounce and singularity formation are derived for the model. It is also shown that when the tangential pressures vanish, the bounce and singularity conditi...
[ { "created": "Sat, 19 Feb 2005 15:53:23 GMT", "version": "v1" } ]
2015-06-25
[ [ "Madhav", "T. Arun", "" ], [ "Goswami", "Rituparno", "" ], [ "Joshi", "Pankaj S.", "" ] ]
We study here the gravitational collapse of a matter cloud with a non-vanishing tangential pressure in the presence of a non-zero cosmological term. Conditions for bounce and singularity formation are derived for the model. It is also shown that when the tangential pressures vanish, the bounce and singularity condition...
2405.02709
Jared Fuchs
Jared Fuchs, Christopher Helmerich, Alexey Bobrick, Luke Sellers, Brandon Melcher, Gianni Martire
Constant Velocity Physical Warp Drive Solution
null
Jared Fuchs et al 2024 Class. Quantum Grav. 41 095013
10.1088/1361-6382/ad26aa
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
Warp drives are exotic solutions of general relativity that offer novel means of transportation. In this study, we present a solution for a constant-velocity subluminal warp drive that satisfies all of the energy conditions. The solution involves combining a stable matter shell with a shift vector distribution that c...
[ { "created": "Sat, 4 May 2024 16:44:49 GMT", "version": "v1" } ]
2024-05-07
[ [ "Fuchs", "Jared", "" ], [ "Helmerich", "Christopher", "" ], [ "Bobrick", "Alexey", "" ], [ "Sellers", "Luke", "" ], [ "Melcher", "Brandon", "" ], [ "Martire", "Gianni", "" ] ]
Warp drives are exotic solutions of general relativity that offer novel means of transportation. In this study, we present a solution for a constant-velocity subluminal warp drive that satisfies all of the energy conditions. The solution involves combining a stable matter shell with a shift vector distribution that clo...
1111.4009
Michael Horbatsch W
M. W. Horbatsch and C. P. Burgess
Cosmic Black-Hole Hair Growth and Quasar OJ287
20 pages
JCAP 1205 (2012) 010
10.1088/1475-7516/2012/05/010
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An old result ({\tt astro-ph/9905303}) by Jacobson implies that a black hole with Schwarzschild radius $r_s$ acquires scalar hair, $Q \propto r_s^2 \mu$, when the (canonically normalized) scalar field in question is slowly time-dependent far from the black hole, $\partial_t \phi \simeq \mu M_p$ with $\mu r_s \ll 1$ t...
[ { "created": "Thu, 17 Nov 2011 02:26:12 GMT", "version": "v1" } ]
2015-06-03
[ [ "Horbatsch", "M. W.", "" ], [ "Burgess", "C. P.", "" ] ]
An old result ({\tt astro-ph/9905303}) by Jacobson implies that a black hole with Schwarzschild radius $r_s$ acquires scalar hair, $Q \propto r_s^2 \mu$, when the (canonically normalized) scalar field in question is slowly time-dependent far from the black hole, $\partial_t \phi \simeq \mu M_p$ with $\mu r_s \ll 1$ tim...
1510.01126
Irina Dymnikova
Irina Dymnikova
Elementary Superconductivity in Nonlinear Electrodynamics Coupled to Gravity
10 pages, 1 figure
Journal of Gravity Volume 2015, Article ID 904171, 7 pages
10.1155/2015/904171
null
gr-qc cond-mat.supr-con
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Source-free equations of nonlinear electrodynamics minimally coupled to gravity admit regular axially symmetric asymptotically Kerr-Newman solutions which describe charged rotating black holes and electromagnetic spinning solitons (lumps). Asymptotic analysis of solutions shows, for both black holes and solitons, the...
[ { "created": "Mon, 5 Oct 2015 12:25:29 GMT", "version": "v1" } ]
2015-10-06
[ [ "Dymnikova", "Irina", "" ] ]
Source-free equations of nonlinear electrodynamics minimally coupled to gravity admit regular axially symmetric asymptotically Kerr-Newman solutions which describe charged rotating black holes and electromagnetic spinning solitons (lumps). Asymptotic analysis of solutions shows, for both black holes and solitons, the e...
0805.4033
Slava G. Turyshev
Slava G. Turyshev, Benjamin Lane, Michael Shao, and Andre Girerd
A Search for New Physics with the BEACON Mission
8 pages, 2 figures, 2 tables
Int.J.Mod.Phys.D18:1025-1038,2009
10.1142/S0218271809014893
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The primary objective of the Beyond Einstein Advanced Coherent Optical Network (BEACON) mission is a search for new physics beyond general relativity by measuring the curvature of relativistic space-time around Earth. This curvature is characterized by the Eddington parameter \gamma -- the most fundamental relativist...
[ { "created": "Tue, 27 May 2008 02:45:07 GMT", "version": "v1" } ]
2009-07-22
[ [ "Turyshev", "Slava G.", "" ], [ "Lane", "Benjamin", "" ], [ "Shao", "Michael", "" ], [ "Girerd", "Andre", "" ] ]
The primary objective of the Beyond Einstein Advanced Coherent Optical Network (BEACON) mission is a search for new physics beyond general relativity by measuring the curvature of relativistic space-time around Earth. This curvature is characterized by the Eddington parameter \gamma -- the most fundamental relativistic...
0711.0288
Edward Anderson
Edward Anderson
New interpretation of variational principles for gauge theories. I. Cyclic coordinate alternative to ADM split
11 pages
Class.Quant.Grav.25:175011,2008
10.1088/0264-9381/25/17/175011
null
gr-qc
null
I show how there is an ambiguity in how one treats auxiliary variables in gauge theories including general relativity cast as 3 + 1 geometrodynamics. Auxiliary variables may be treated pre-variationally as multiplier coordinates or as the velocities corresponding to cyclic coordinates. The latter treatment works thro...
[ { "created": "Fri, 2 Nov 2007 11:30:05 GMT", "version": "v1" } ]
2008-11-26
[ [ "Anderson", "Edward", "" ] ]
I show how there is an ambiguity in how one treats auxiliary variables in gauge theories including general relativity cast as 3 + 1 geometrodynamics. Auxiliary variables may be treated pre-variationally as multiplier coordinates or as the velocities corresponding to cyclic coordinates. The latter treatment works throug...
gr-qc/0301026
Iver. H. Brevik
Iver Brevik
Viscous Cosmology and the Cardy-Verlinde Formula
10 pages, no figures. Contribution to the Proceedings of the Second Londrina Winter School "Mathematical Methods in Physics", August 25-30, 2002, Londrina-Parana, Brazil
Int.J.Mod.Phys.A18:2145-2152,2003
10.1142/S0217751X03015593
null
gr-qc
null
The holographic principle in a radiation dominated universe is extended to incorporate the case of a bulk-viscous cosmic fluid. This corresponds to a nonconformally invariant theory. Generalization of the Cardy-Verlinde entropy formula to the viscous case appears to be possible from a formal point of view, although w...
[ { "created": "Wed, 8 Jan 2003 12:35:52 GMT", "version": "v1" } ]
2009-01-14
[ [ "Brevik", "Iver", "" ] ]
The holographic principle in a radiation dominated universe is extended to incorporate the case of a bulk-viscous cosmic fluid. This corresponds to a nonconformally invariant theory. Generalization of the Cardy-Verlinde entropy formula to the viscous case appears to be possible from a formal point of view, although we ...
0902.4439
Tonatiuh Matos
Tonatiuh Matos
Class of Einstein-Maxwell Phantom Fields: Rotating and Magnetised Wormholes
15 pages, no figures
Gen.Rel.Grav.42:1969-1990,2010
10.1007/s10714-010-0976-6
CIEA/09-gr5
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using a new ansatz for solving the Einstein equations with a scalar field with the sign of the kinetic term inverted, I find a series of formulae to derive axial symmetric stationary exact solutions of the Phantom scalar field in general relativity. We focus on the solutions which represent wormholes. The procedure p...
[ { "created": "Wed, 25 Feb 2009 18:43:22 GMT", "version": "v1" } ]
2014-11-18
[ [ "Matos", "Tonatiuh", "" ] ]
Using a new ansatz for solving the Einstein equations with a scalar field with the sign of the kinetic term inverted, I find a series of formulae to derive axial symmetric stationary exact solutions of the Phantom scalar field in general relativity. We focus on the solutions which represent wormholes. The procedure pre...
2402.03154
Gaoping Long
Gaoping Long, Hongguang Liu
Holonomy operator for spin connection and spatial scalar curvature operator in loop quantum gravity
null
null
null
null
gr-qc
http://creativecommons.org/licenses/by-nc-sa/4.0/
In this article we propose a new construction of the spatial scalar curvature operator in (1+3)-dimensional LQG based on the twisted geometry. The starting point of the construction is to express the holonomy of the spin connection on a graph in terms of the twisted geometry variables, and we check that this expressi...
[ { "created": "Mon, 5 Feb 2024 16:19:55 GMT", "version": "v1" } ]
2024-02-06
[ [ "Long", "Gaoping", "" ], [ "Liu", "Hongguang", "" ] ]
In this article we propose a new construction of the spatial scalar curvature operator in (1+3)-dimensional LQG based on the twisted geometry. The starting point of the construction is to express the holonomy of the spin connection on a graph in terms of the twisted geometry variables, and we check that this expression...
2101.05006
Francesco Di Filippo
Ra\'ul Carballo-Rubio, Francesco Di Filippo, Stefano Liberati, Costantino Pacilio, Matt Visser
Inner horizon instability and the unstable cores of regular black holes
17 pages, 5 figures. Major changes in the presentation to improve clarity, physical conclusions unchanged, matches the version accepted on JHEP
null
10.1007/JHEP05(2021)132
YITP-21-02
gr-qc
http://creativecommons.org/licenses/by/4.0/
Regular black holes with nonsingular cores have been considered in several approaches to quantum gravity, and as agnostic frameworks to address the singularity problem and Hawking's information paradox. While in a recent work we argued that the inner core is destabilized by linear perturbations, opposite claims were ...
[ { "created": "Wed, 13 Jan 2021 11:17:30 GMT", "version": "v1" }, { "created": "Wed, 21 Apr 2021 09:06:25 GMT", "version": "v2" } ]
2021-06-02
[ [ "Carballo-Rubio", "Raúl", "" ], [ "Di Filippo", "Francesco", "" ], [ "Liberati", "Stefano", "" ], [ "Pacilio", "Costantino", "" ], [ "Visser", "Matt", "" ] ]
Regular black holes with nonsingular cores have been considered in several approaches to quantum gravity, and as agnostic frameworks to address the singularity problem and Hawking's information paradox. While in a recent work we argued that the inner core is destabilized by linear perturbations, opposite claims were ra...