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1001.2230
Andr\'es Ace\~na
Andr\'es E. Ace\~na
Minimal data at a given point of space for solutions to certain geometric systems
26 pages, no figures
null
10.1088/0264-9381/27/15/155006
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a geometrical system of equations for a three dimensional Riemannian manifold. This system of equations has been constructed as to include several physically interesting systems of equations, such as the stationary Einstein vacuum field equations or harmonic maps coupled to gravity in three dimensions. We...
[ { "created": "Wed, 13 Jan 2010 16:45:07 GMT", "version": "v1" } ]
2015-05-18
[ [ "Aceña", "Andrés E.", "" ] ]
We consider a geometrical system of equations for a three dimensional Riemannian manifold. This system of equations has been constructed as to include several physically interesting systems of equations, such as the stationary Einstein vacuum field equations or harmonic maps coupled to gravity in three dimensions. We g...
2103.06516
Tatsuki Washimi Dr.
T. Washimi, T. Yokozawa, M. Nakano, T. Tanaka, K. Kaihotsu, Y. Mori, T. Narita
Effects of lightning strokes on underground gravitational waves observatories
null
JINST 16 P07033 (2021)
10.1088/1748-0221/16/07/P07033
JGW-P2112426
gr-qc astro-ph.IM
http://creativecommons.org/licenses/by-nc-sa/4.0/
For ground-based gravitational wave (GW) detectors, lightning strokes in the atmosphere are sources of environmental noise. Some GW detectors are built or planned in underground facilities, and knowledge of how lightning strokes affect them is of interest. In this paper, the lightning detection system in KAGRA is int...
[ { "created": "Thu, 11 Mar 2021 08:03:51 GMT", "version": "v1" }, { "created": "Fri, 19 Mar 2021 00:56:28 GMT", "version": "v2" }, { "created": "Sun, 6 Jun 2021 07:42:30 GMT", "version": "v3" } ]
2021-07-22
[ [ "Washimi", "T.", "" ], [ "Yokozawa", "T.", "" ], [ "Nakano", "M.", "" ], [ "Tanaka", "T.", "" ], [ "Kaihotsu", "K.", "" ], [ "Mori", "Y.", "" ], [ "Narita", "T.", "" ] ]
For ground-based gravitational wave (GW) detectors, lightning strokes in the atmosphere are sources of environmental noise. Some GW detectors are built or planned in underground facilities, and knowledge of how lightning strokes affect them is of interest. In this paper, the lightning detection system in KAGRA is intro...
1911.06520
Srijita Sinha
Srijita Sinha and Narayan Banerjee
Density perturbation in an interacting holographic dark energy model
17 pages, 11 figures, minor changes, references added; version matches the accepted one
Eur. Phys. J. Plus 135, 779 (2020)
10.1140/epjp/s13360-020-00803-z
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The present work deals with the evolution of the density contrasts for a cosmological model where along with the standard cold dark matter (CDM), the present Universe also contains holographic dark energy (HDE). The characteristic infra-red (IR) cut-off is taken as the future event horizon. The HDE is allowed to inte...
[ { "created": "Fri, 15 Nov 2019 08:52:32 GMT", "version": "v1" }, { "created": "Fri, 3 Jan 2020 09:51:51 GMT", "version": "v2" }, { "created": "Fri, 9 Oct 2020 02:35:45 GMT", "version": "v3" } ]
2020-12-07
[ [ "Sinha", "Srijita", "" ], [ "Banerjee", "Narayan", "" ] ]
The present work deals with the evolution of the density contrasts for a cosmological model where along with the standard cold dark matter (CDM), the present Universe also contains holographic dark energy (HDE). The characteristic infra-red (IR) cut-off is taken as the future event horizon. The HDE is allowed to intera...
1601.03941
Massimo Tessarotto
Massimo Tessarotto (Department of Mathematics and Geosciences, University of Trieste, Italy and Institute of Physics, Faculty of Philosophy and Science, Silesian University in Opava, Bezru\v{c}ovo n\'am.13, CZ-74601 Opava, Czech Republic) and Claudio Cremaschini (Institute of Physics, Faculty of Philosophy and ...
Theory of non-local point transformations - Part 2: General form and Gedanken experiment
null
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The problem is posed of further extending the axiomatic construction proposed in Part 1 for non-local point transformations mapping in each other different curved space times. The new transformations apply to curved space times when expressed in arbitrary coordinate systems. It is shown that the solution permits to a...
[ { "created": "Wed, 13 Jan 2016 08:07:05 GMT", "version": "v1" } ]
2016-01-18
[ [ "Tessarotto", "Massimo", "", "Department of Mathematics and Geosciences,\n University of Trieste, Italy and Institute of Physics, Faculty of Philosophy\n and Science, Silesian University in Opava, Bezručovo nám.13, CZ-74601\n Opava, Czech Republic" ], [ "Cremaschini", "Claudio", ...
The problem is posed of further extending the axiomatic construction proposed in Part 1 for non-local point transformations mapping in each other different curved space times. The new transformations apply to curved space times when expressed in arbitrary coordinate systems. It is shown that the solution permits to ach...
1411.0125
Bushra Majeed
Bushra Majeed, Mubasher Jamil and Azad A. Siddiqui
Holographic Dark Energy with Time Varying n^2 Parameter in Non-Flat Universe
8 pages, 2 figures, Published in: International Journal of Theoretical Physics
Int. J. Theor. Phys. (2015) 54:42-49
10.1007/s10773-014-2197-3
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a holographic dark energy model, with a varying parameter, n, which evolves slowly with time. We obtain the differential equation describing evolution of the dark energy density parameter, $\Omega_d$, for the flat and non-flat FRW universes. The equation of state parameter in this generalized version of h...
[ { "created": "Sat, 1 Nov 2014 14:56:50 GMT", "version": "v1" } ]
2015-01-28
[ [ "Majeed", "Bushra", "" ], [ "Jamil", "Mubasher", "" ], [ "Siddiqui", "Azad A.", "" ] ]
We consider a holographic dark energy model, with a varying parameter, n, which evolves slowly with time. We obtain the differential equation describing evolution of the dark energy density parameter, $\Omega_d$, for the flat and non-flat FRW universes. The equation of state parameter in this generalized version of hol...
2404.16093
Prashant Kocherlakota
Prashant Kocherlakota and Ramesh Narayan
Self-Gravitating Matter in Stationary and Axisymmetric Black Hole Spacetimes
25 pages, 9 figures, 2 tables
null
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
All black holes (BHs) in nature are expected to be described by the Kerr vacuum solution of general relativity. However, the Kerr solution comes with several difficulties such as the existence of Cauchy horizons, curvature singularities, and causality-violating regions. Attempts to resolve some of these issues includ...
[ { "created": "Wed, 24 Apr 2024 18:00:01 GMT", "version": "v1" } ]
2024-04-26
[ [ "Kocherlakota", "Prashant", "" ], [ "Narayan", "Ramesh", "" ] ]
All black holes (BHs) in nature are expected to be described by the Kerr vacuum solution of general relativity. However, the Kerr solution comes with several difficulties such as the existence of Cauchy horizons, curvature singularities, and causality-violating regions. Attempts to resolve some of these issues include ...
2407.14122
Gamal G.L. Nashed
Waleed El Hanafy, Mahmoud Hashim, and G.G.L. Nashed
Revisiting Flat Rotation Curves in Chern-Simons Modified Gravity
13 pages, 2 figures, match the version that will appear in Phys. Lett. B
null
10.1016/j.physletb.2024.138882
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We revisit slow rotating black hole (BH) solutions in Chern-Simons modified gravity (CSMG) by considering perturbative solution about Schwarzschild BH. In particular, the case when nondynamical CSMG with noncanonical CS scalar is considered. We provide a new solution different from the previously obtained one \cite{K...
[ { "created": "Fri, 19 Jul 2024 08:41:58 GMT", "version": "v1" } ]
2024-07-22
[ [ "Hanafy", "Waleed El", "" ], [ "Hashim", "Mahmoud", "" ], [ "Nashed", "G. G. L.", "" ] ]
We revisit slow rotating black hole (BH) solutions in Chern-Simons modified gravity (CSMG) by considering perturbative solution about Schwarzschild BH. In particular, the case when nondynamical CSMG with noncanonical CS scalar is considered. We provide a new solution different from the previously obtained one \cite{Kon...
1909.07803
Subhajit Saha
Subhajit Saha
How to obtain a class of emergent universes with a general form of dissipation?
5 pages; Under Review
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we have assumed a flat Friedmann-Lemaitr\'e-Robertson-Walker universe endowed with a general form of dissipation. The source of dissipation is considered to be a bulk viscous pressure $\Pi$ which leads to an adiabatic creation of particles induced by the gravitational field. Further, the cosmic substra...
[ { "created": "Sun, 15 Sep 2019 10:07:14 GMT", "version": "v1" } ]
2019-09-18
[ [ "Saha", "Subhajit", "" ] ]
In this paper, we have assumed a flat Friedmann-Lemaitr\'e-Robertson-Walker universe endowed with a general form of dissipation. The source of dissipation is considered to be a bulk viscous pressure $\Pi$ which leads to an adiabatic creation of particles induced by the gravitational field. Further, the cosmic substratu...
gr-qc/0702075
Salvatore Capozziello
S. Capozziello, R. Garattini
The cosmological constant as an eigenvalue of f(R)-gravity Hamiltonian constraint
16 pages, to appear in Class. Quant. Grav
Class.Quant.Grav.24:1627-1646,2007
10.1088/0264-9381/24/6/016
null
gr-qc astro-ph hep-th
null
In the framework of ADM formalism, it is possible to find out eigenvalues of the WDW equation with the meaning of vacuum states, i.e. cosmological constants, for f(R) theories of gravity, where f(R) is a generic analytic function of the Ricci curvature scalar R. The explicit calculation is performed for a Schwarzschi...
[ { "created": "Wed, 14 Feb 2007 08:43:19 GMT", "version": "v1" } ]
2008-11-26
[ [ "Capozziello", "S.", "" ], [ "Garattini", "R.", "" ] ]
In the framework of ADM formalism, it is possible to find out eigenvalues of the WDW equation with the meaning of vacuum states, i.e. cosmological constants, for f(R) theories of gravity, where f(R) is a generic analytic function of the Ricci curvature scalar R. The explicit calculation is performed for a Schwarzschild...
1702.05246
Tao Wang
Shao-Jun Wang, Xin-Xuan Guo, Towe Wang
Maximal volume behind horizons without curvature singularity
11 pages, 4 figures, Sect III improved
Phys. Rev. D 97, 024039 (2018)
10.1103/PhysRevD.97.024039
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The black hole information paradox is related to the area of event horizon, and potentially to the volume and singularity behind it. One example is the complexity/volume duality conjectured by Stanford and Susskind. Accepting the proposal of Christodoulou and Rovelli, we calculate the maximal volume inside regular bl...
[ { "created": "Fri, 17 Feb 2017 07:51:33 GMT", "version": "v1" }, { "created": "Tue, 9 Jan 2018 09:52:01 GMT", "version": "v2" } ]
2018-01-31
[ [ "Wang", "Shao-Jun", "" ], [ "Guo", "Xin-Xuan", "" ], [ "Wang", "Towe", "" ] ]
The black hole information paradox is related to the area of event horizon, and potentially to the volume and singularity behind it. One example is the complexity/volume duality conjectured by Stanford and Susskind. Accepting the proposal of Christodoulou and Rovelli, we calculate the maximal volume inside regular blac...
gr-qc/0002003
Leonid Ya. Kobelev
L.Ya.Kobelev
Maxwell equation, Shroedinger equation, Dirac equation, Einstein equation defined on the multifractal sets of the time and the space
RevTeX
null
null
null
gr-qc
null
What forms will have an equations of modern physics if the dimensions of our time and space are fractional? The generalized equations enumerated by title are presented by help the generalized fractional derivatives of Riemann-Liouville.
[ { "created": "Tue, 1 Feb 2000 10:23:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kobelev", "L. Ya.", "" ] ]
What forms will have an equations of modern physics if the dimensions of our time and space are fractional? The generalized equations enumerated by title are presented by help the generalized fractional derivatives of Riemann-Liouville.
1712.09878
Kristina Giesel
Kristina Giesel, Adrian Herzog
Gauge invariant canonical cosmological perturbation theory with geometrical clocks in extended phase space - a review and applications
Added some references, corrected typos
Int. J. Mod. Phys. D 27, 1830005 (2018)
10.1142/S0218271818300057
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The theory of cosmological perturbations is a well elaborated field. To deal with the diffeomorphism invariance of general relativity one generally introduces combinations of the metric and matter perturbations which are gauge invariant up to the considered order in the perturbations. For linear cosmological perturba...
[ { "created": "Thu, 28 Dec 2017 14:51:27 GMT", "version": "v1" }, { "created": "Mon, 12 Mar 2018 14:19:27 GMT", "version": "v2" } ]
2018-05-31
[ [ "Giesel", "Kristina", "" ], [ "Herzog", "Adrian", "" ] ]
The theory of cosmological perturbations is a well elaborated field. To deal with the diffeomorphism invariance of general relativity one generally introduces combinations of the metric and matter perturbations which are gauge invariant up to the considered order in the perturbations. For linear cosmological perturbati...
gr-qc/0006063
Manfred Requardt
Manfred Requardt
Let's call it Nonlocal Quantum Physics
47 pages, Latex, no figures
null
null
null
gr-qc hep-th quant-ph
null
In the following we undertake to derive quantum theory as a stochastic low-energy and coarse-grained theory from a more primordial discrete and basically geometric theory living on the Planck scale and which (as we argue) possibly underlies also \tit{string theory}. We isolate the so-called \tit{ideal elements} which...
[ { "created": "Mon, 19 Jun 2000 08:56:17 GMT", "version": "v1" } ]
2007-05-23
[ [ "Requardt", "Manfred", "" ] ]
In the following we undertake to derive quantum theory as a stochastic low-energy and coarse-grained theory from a more primordial discrete and basically geometric theory living on the Planck scale and which (as we argue) possibly underlies also \tit{string theory}. We isolate the so-called \tit{ideal elements} which r...
2402.18237
Houri Ziaeepour
Houri Ziaeepour
Quantum state of fields in $SU(\infty)$ Quantum Gravity ($SU(\infty)$-QGR)
18+12 pages, 1 figure. v2: citation extended
null
null
null
gr-qc hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Our Universe is ruled by quantum mechanics and should be treated as a quantum system. {$SU(\infty)$-QGR is a recently proposed quantum model for the Universe, in which gravity is associated to $SU(\infty)$ symmetry of its Hilbert space. Clustering/blockization of its infinite dimensional state due to random quantum f...
[ { "created": "Wed, 28 Feb 2024 11:06:45 GMT", "version": "v1" }, { "created": "Sun, 7 Jul 2024 09:20:29 GMT", "version": "v2" } ]
2024-07-09
[ [ "Ziaeepour", "Houri", "" ] ]
Our Universe is ruled by quantum mechanics and should be treated as a quantum system. {$SU(\infty)$-QGR is a recently proposed quantum model for the Universe, in which gravity is associated to $SU(\infty)$ symmetry of its Hilbert space. Clustering/blockization of its infinite dimensional state due to random quantum flu...
1802.02334
Tuhina Manna
Tuhina Manna, Farook Rahaman, Sabiruddin Molla, Jhumpa Bhadra and Hasrat Hussain Shah
Strong Lensing of a Regular Black Hole with an Electrodynamics Source
Accepted in General Relativity and Gravitation
Gen.Rel.Grav. 50 (2018) 5, 54
10.1007/s10714-018-2375-3
GERG-D-18-00048
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we have investigated the gravitational lensing phenomenon in the strong field regime for a regular, charged, static, non-linear black hole having a electrodynamics source. We have obtained the angle of deflection and compared it to a Schwarzschild black hole and Reissner Nordstrom black hole with simil...
[ { "created": "Wed, 7 Feb 2018 08:01:26 GMT", "version": "v1" }, { "created": "Wed, 28 Mar 2018 17:11:36 GMT", "version": "v2" }, { "created": "Wed, 8 Nov 2023 15:29:54 GMT", "version": "v3" } ]
2023-11-09
[ [ "Manna", "Tuhina", "" ], [ "Rahaman", "Farook", "" ], [ "Molla", "Sabiruddin", "" ], [ "Bhadra", "Jhumpa", "" ], [ "Shah", "Hasrat Hussain", "" ] ]
In this paper we have investigated the gravitational lensing phenomenon in the strong field regime for a regular, charged, static, non-linear black hole having a electrodynamics source. We have obtained the angle of deflection and compared it to a Schwarzschild black hole and Reissner Nordstrom black hole with similar...
gr-qc/9801077
Alfio Bonanno
Alfio Bonanno (Istituto di Astronomia, Catania)
The Cauchy Horizon in Higher-derivative Gravity Theories
REVTex, 13 pages, to appear on the proceedings of the workshop on " The Internal Structure of Black Holes and Spacetime Singularities", held at Technion -Israel Institute of Technology-, Haifa,Israel,June 29-July 3, 1997
null
null
Istituto di Astronomia, preprint 2-1998
gr-qc
null
A class of exact solutions of the field equations with higher derivative terms is presented when the matter field is a pressureless null fluid plus a Maxwellian static electric component. It is found that the stable solutions are black holes in anti de Sitter background. The issue of the stability of the Cauchy horiz...
[ { "created": "Thu, 22 Jan 1998 12:35:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bonanno", "Alfio", "", "Istituto di Astronomia, Catania" ] ]
A class of exact solutions of the field equations with higher derivative terms is presented when the matter field is a pressureless null fluid plus a Maxwellian static electric component. It is found that the stable solutions are black holes in anti de Sitter background. The issue of the stability of the Cauchy horizon...
1801.03426
Vasilis Oikonomou
V.K. Oikonomou
Exponential Inflation with $F(R)$ Gravity
PRD Accepted
Phys. Rev. D 97, 064001 (2018)
10.1103/PhysRevD.97.064001
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we shall consider an exponential inflationary model in the context of vacuum $F(R)$ gravity. By using well-known reconstruction techniques, we shall investigate which $F(R)$ gravity can realize the exponential inflation scenario at leading order in terms of the scalar curvature, and we shall calculate t...
[ { "created": "Wed, 10 Jan 2018 15:46:03 GMT", "version": "v1" }, { "created": "Mon, 19 Feb 2018 01:57:25 GMT", "version": "v2" } ]
2018-03-14
[ [ "Oikonomou", "V. K.", "" ] ]
In this paper we shall consider an exponential inflationary model in the context of vacuum $F(R)$ gravity. By using well-known reconstruction techniques, we shall investigate which $F(R)$ gravity can realize the exponential inflation scenario at leading order in terms of the scalar curvature, and we shall calculate the...
1411.1943
Marcello Ortaggio
Marcello Ortaggio, Jiri Podolsky, Martin Zofka
Static and radiating p-form black holes in the higher dimensional Robinson-Trautman class
34 pages. v2: improved discussion following eq. (84), references updated, minor changes to match the published version
JHEP 1502 (2015) 045
10.1007/JHEP02(2015)045
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study Robinson-Trautman spacetimes in the presence of an aligned p-form Maxwell field and an arbitrary cosmological constant in n>=4 dimensions. As it turns out, the character of these exact solutions depends significantly on the (relative) value of n and p. In odd dimensions the solutions reduce to static black h...
[ { "created": "Fri, 7 Nov 2014 15:05:15 GMT", "version": "v1" }, { "created": "Mon, 2 Mar 2015 15:20:00 GMT", "version": "v2" } ]
2015-03-03
[ [ "Ortaggio", "Marcello", "" ], [ "Podolsky", "Jiri", "" ], [ "Zofka", "Martin", "" ] ]
We study Robinson-Trautman spacetimes in the presence of an aligned p-form Maxwell field and an arbitrary cosmological constant in n>=4 dimensions. As it turns out, the character of these exact solutions depends significantly on the (relative) value of n and p. In odd dimensions the solutions reduce to static black hol...
2407.19017
Arwa Elhashash
Arwa Elhashash, David A. Nichols
Waveform models for the gravitational-wave memory effect: Extreme mass-ratio limit and final memory offset
23 pages, 13 figures
null
null
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The gravitational-wave (GW) memory effect is a strong-field relativistic phenomenon that is associated with a persistent change in the GW strain after the passage of a GW. The nonlinear effect arises from interactions of GWs themselves in the wave zone and is an observable effect connected to the infrared properties ...
[ { "created": "Fri, 26 Jul 2024 18:01:06 GMT", "version": "v1" } ]
2024-07-30
[ [ "Elhashash", "Arwa", "" ], [ "Nichols", "David A.", "" ] ]
The gravitational-wave (GW) memory effect is a strong-field relativistic phenomenon that is associated with a persistent change in the GW strain after the passage of a GW. The nonlinear effect arises from interactions of GWs themselves in the wave zone and is an observable effect connected to the infrared properties of...
1903.04845
Mohammad Ali Gorji
Mohammad Ali Gorji, Shinji Mukohyama, Hassan Firouzjahi
Cosmology in Mimetic SU(2) Gauge Theory
18 pages, 14 figures
JCAP 2019 (2020) no.05, 019
10.1088/1475-7516/2019/05/019
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well known that the standard scalar field mimetic cosmology provides a dark matter-like energy density component. Considering $SU(2)$ gauge symmetry, we study the gauge field extension of the mimetic scenario in spatially flat and curved FLRW spacetimes. Because of the mimetic constraint, the standard Yang-Mill...
[ { "created": "Tue, 12 Mar 2019 11:18:06 GMT", "version": "v1" } ]
2019-06-03
[ [ "Gorji", "Mohammad Ali", "" ], [ "Mukohyama", "Shinji", "" ], [ "Firouzjahi", "Hassan", "" ] ]
It is well known that the standard scalar field mimetic cosmology provides a dark matter-like energy density component. Considering $SU(2)$ gauge symmetry, we study the gauge field extension of the mimetic scenario in spatially flat and curved FLRW spacetimes. Because of the mimetic constraint, the standard Yang-Mills ...
gr-qc/0401061
Muhammad Sharif
M. Sharif
Symmetries of the Energy-Momentum Tensor of Cylindrically Symmetric Static Spacetimes
42 pages, no figure, LaTeX, Accepted for publication in J. Math. Phys
J.Math.Phys. 45 (2004) 1532-1560
10.1063/1.1668335
null
gr-qc
null
We investigate matter symmetries of cylindrically symmetric static spacetimes. These are classified for both cases when the energy-momentum tensor is non-degenerate and also when it is degenerate. It is found that the non-degenerate energy-momentum tensor gives either three, four, five, six, seven or ten independent ...
[ { "created": "Wed, 14 Jan 2004 12:44:23 GMT", "version": "v1" } ]
2015-06-25
[ [ "Sharif", "M.", "" ] ]
We investigate matter symmetries of cylindrically symmetric static spacetimes. These are classified for both cases when the energy-momentum tensor is non-degenerate and also when it is degenerate. It is found that the non-degenerate energy-momentum tensor gives either three, four, five, six, seven or ten independent ma...
2005.02616
Konstantin Osetrin
Evgeny Osetrin, Konstantin Osetrin, Altair Filippov, Ilya Kirnos
Wave-like spatially homogeneous models of Stackel spacetimes (3.1) type in the scalar-tensor theory of gravity
7 pages
International Journal of Geometric Methods in Modern Physics, 2020
10.1142/S0219887820501844
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
All classes of spatially homogeneous space-time models in the generalized scalar-tensor theory of gravity are found that allow the integration of the equations of motion of test particles and the eikonal equation by the method of %complete separation of variables by type (3.1). Three classes of exact solutions are ob...
[ { "created": "Wed, 6 May 2020 06:54:55 GMT", "version": "v1" } ]
2020-10-06
[ [ "Osetrin", "Evgeny", "" ], [ "Osetrin", "Konstantin", "" ], [ "Filippov", "Altair", "" ], [ "Kirnos", "Ilya", "" ] ]
All classes of spatially homogeneous space-time models in the generalized scalar-tensor theory of gravity are found that allow the integration of the equations of motion of test particles and the eikonal equation by the method of %complete separation of variables by type (3.1). Three classes of exact solutions are obta...
gr-qc/0409090
Thomas Roman
Thomas A. Roman
Some Thoughts on Energy Conditions and Wormholes
24 pages; to appear in the Proceedings of the Tenth Marcel Grossmann Meeting on General Relativity and Gravitation
null
10.1142/9789812704030_0236
null
gr-qc hep-th quant-ph
null
This essay reviews some of the recent progress in the area of energy conditions and wormholes. Most of the discussion centers on the subject of ``quantum inequality'' restrictions on negative energy. These are bounds on the magnitude and duration of negative energy which put rather severe constraints on its possible ...
[ { "created": "Thu, 23 Sep 2004 15:56:37 GMT", "version": "v1" } ]
2016-11-09
[ [ "Roman", "Thomas A.", "" ] ]
This essay reviews some of the recent progress in the area of energy conditions and wormholes. Most of the discussion centers on the subject of ``quantum inequality'' restrictions on negative energy. These are bounds on the magnitude and duration of negative energy which put rather severe constraints on its possible ma...
2405.08857
Michele Vallisneri
Michele Vallisneri, Marco Crisostomi, Aaron D. Johnson, Patrick M. Meyers
Rapid parameter estimation for pulsar-timing-array datasets with variational inference and normalizing flows
6 pages, 1 figure
null
null
null
gr-qc astro-ph.HE astro-ph.IM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the gravitational-wave analysis of pulsar-timing-array datasets, parameter estimation is usually performed using Markov Chain Monte Carlo methods to explore posterior probability densities. We introduce an alternative procedure that relies instead on stochastic gradient-descent Bayesian variational inference, wher...
[ { "created": "Tue, 14 May 2024 18:00:00 GMT", "version": "v1" } ]
2024-05-16
[ [ "Vallisneri", "Michele", "" ], [ "Crisostomi", "Marco", "" ], [ "Johnson", "Aaron D.", "" ], [ "Meyers", "Patrick M.", "" ] ]
In the gravitational-wave analysis of pulsar-timing-array datasets, parameter estimation is usually performed using Markov Chain Monte Carlo methods to explore posterior probability densities. We introduce an alternative procedure that relies instead on stochastic gradient-descent Bayesian variational inference, whereb...
1605.06635
Michael Good
Michael R.R. Good, Paul R. Anderson, and Charles R. Evans
Mirror Reflections of a Black Hole
25 pages, 7 figures
Phys. Rev. D 94, 065010 (2016)
10.1103/PhysRevD.94.065010
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An exact correspondence between a black hole and an accelerating mirror is demonstrated. It is shown that for a massless minimally coupled scalar field the same Bogolubov coefficients connecting the "in" and "out" states occur for a (1+1)D flat spacetime with a particular perfectly reflecting accelerating boundary tr...
[ { "created": "Sat, 21 May 2016 12:23:10 GMT", "version": "v1" }, { "created": "Fri, 23 Sep 2016 15:10:29 GMT", "version": "v2" } ]
2016-09-26
[ [ "Good", "Michael R. R.", "" ], [ "Anderson", "Paul R.", "" ], [ "Evans", "Charles R.", "" ] ]
An exact correspondence between a black hole and an accelerating mirror is demonstrated. It is shown that for a massless minimally coupled scalar field the same Bogolubov coefficients connecting the "in" and "out" states occur for a (1+1)D flat spacetime with a particular perfectly reflecting accelerating boundary traj...
gr-qc/0006045
Marcus Ansorg
Marcus Ansorg
Differentially rotating disks of dust: Arbitrary rotation law
23 pages, 3 figures, submitted to 'General Relativity and Gravitation'
Gen.Rel.Grav. 33 (2001) 309-338
10.1023/A:1002705402248
null
gr-qc
null
In this paper, solutions to the Ernst equation are investigated that depend on two real analytic functions defined on the interval [0,1]. These solutions are introduced by a suitable limiting process of Backlund transformations applied to seed solutions of the Weyl class. It turns out that this class of solutions con...
[ { "created": "Tue, 13 Jun 2000 12:35:47 GMT", "version": "v1" } ]
2015-06-25
[ [ "Ansorg", "Marcus", "" ] ]
In this paper, solutions to the Ernst equation are investigated that depend on two real analytic functions defined on the interval [0,1]. These solutions are introduced by a suitable limiting process of Backlund transformations applied to seed solutions of the Weyl class. It turns out that this class of solutions conta...
1906.04048
Pardyumn Kumar Sahoo
Parbati Sahoo, Annika Kirschner, P.K. Sahoo
Phantom fluid wormhole in $f(R,T)$ gravity
12 pages, 8 Figures. Revision submitted to MPLA
Modern Physics Letters A 34(37), (2019), 1950303
10.1142/S0217732319503036
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Wormholes (WHs) are considered as hypothetical shortcuts or tunnels in spacetime. In general relativity (GR), the fundamental ingredient of WH geometry is the presence of exotic matter at the throat, which is responsible for the violation of null energy condition (NEC). However, the modified gravity theories has show...
[ { "created": "Fri, 7 Jun 2019 16:01:13 GMT", "version": "v1" } ]
2020-02-19
[ [ "Sahoo", "Parbati", "" ], [ "Kirschner", "Annika", "" ], [ "Sahoo", "P. K.", "" ] ]
Wormholes (WHs) are considered as hypothetical shortcuts or tunnels in spacetime. In general relativity (GR), the fundamental ingredient of WH geometry is the presence of exotic matter at the throat, which is responsible for the violation of null energy condition (NEC). However, the modified gravity theories has shown ...
gr-qc/9806084
Dr. BG Sidharth
B.G. Sidharth
Space Time Quantization and the Big Bang
5 pages, TeX
null
null
null
gr-qc
null
A recent cosmological model is recapitulated which deduces the correct mass, radius and age of the universe as also the Hubble constant and other well known apparently coincidental relations. It also predicts an ever expanding accelerating universe as is confirmed by latest supernovae observations. Finally the Big Ba...
[ { "created": "Sun, 21 Jun 1998 02:49:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sidharth", "B. G.", "" ] ]
A recent cosmological model is recapitulated which deduces the correct mass, radius and age of the universe as also the Hubble constant and other well known apparently coincidental relations. It also predicts an ever expanding accelerating universe as is confirmed by latest supernovae observations. Finally the Big Bang...
gr-qc/9903077
N. K. Dadhich
Naresh Dadhich and L.K. Patel
A simple shear-free non-singular spherical model with heat flux
7 pages, LaTEX version
Grav.Cosmol. 6 (2000) 11-13
null
IUCAA-14/99
gr-qc
null
We obtain an exact simple solution of the Einstein equation describing a spherically symmetric cosmological model without the big-bang or any other kind of singularity. The matter content of the model is shear free isotropic fluid with radial heat flux and it satisfies the weak and strong energy conditions. It is pre...
[ { "created": "Sat, 20 Mar 1999 07:14:28 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dadhich", "Naresh", "" ], [ "Patel", "L. K.", "" ] ]
We obtain an exact simple solution of the Einstein equation describing a spherically symmetric cosmological model without the big-bang or any other kind of singularity. The matter content of the model is shear free isotropic fluid with radial heat flux and it satisfies the weak and strong energy conditions. It is press...
0901.0603
Li Xiang
Li Xiang and X. Q. Wen
Black hole thermodynamics with generalized uncertainty principle
18 pages, great improvement on the first version; a Kerr-Newman black hole is considered
JHEP 0910:046,2009
10.1088/1126-6708/2009/10/046
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the standard viewpoint, the temperature of a stationary black hole is proportional to its surface gravity, $T_H=\hbar\kappa/2\pi$. This is a semiclassical result and the quantum gravity effects are not taken into consideration. This Letter explores a unified expression for the black hole temperature in the sense o...
[ { "created": "Tue, 6 Jan 2009 08:06:13 GMT", "version": "v1" }, { "created": "Wed, 18 Mar 2009 16:06:11 GMT", "version": "v2" } ]
2009-11-19
[ [ "Xiang", "Li", "" ], [ "Wen", "X. Q.", "" ] ]
In the standard viewpoint, the temperature of a stationary black hole is proportional to its surface gravity, $T_H=\hbar\kappa/2\pi$. This is a semiclassical result and the quantum gravity effects are not taken into consideration. This Letter explores a unified expression for the black hole temperature in the sense of ...
2105.04283
Guillaume Boileau
Guillaume Boileau, Astrid Lamberts, Nelson Christensen, Neil J. Cornish, Renate Meyer
Spectral separation of the stochastic gravitational-wave background for LISA in the context of a modulated Galactic foreground
null
null
10.1093/mnras/stab2575
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within its observational band the Laser Interferometer Space Antenna, LISA, will simultaneously observe orbital modulated waveforms from Galactic white dwarf binaries, a binary black hole produced gravitational-wave background, and potentially a cosmologically created stochastic gravitational-wave background (SGWB). ...
[ { "created": "Mon, 10 May 2021 11:48:15 GMT", "version": "v1" }, { "created": "Thu, 7 Oct 2021 11:21:18 GMT", "version": "v2" } ]
2021-10-08
[ [ "Boileau", "Guillaume", "" ], [ "Lamberts", "Astrid", "" ], [ "Christensen", "Nelson", "" ], [ "Cornish", "Neil J.", "" ], [ "Meyer", "Renate", "" ] ]
Within its observational band the Laser Interferometer Space Antenna, LISA, will simultaneously observe orbital modulated waveforms from Galactic white dwarf binaries, a binary black hole produced gravitational-wave background, and potentially a cosmologically created stochastic gravitational-wave background (SGWB). Th...
2309.14375
Vladimir Kassandrov
Vladimir V. Kassandrov and Ildus Sh. Khasanov
The algebrodynamics: super-conservative collective dynamics on a "Unique Worldline'' and the Hubble's law
7 pages
Gravitation and Cosmology, 2023, Vol.29, No.1, pp.50-56
10.1134/S0202289323010048
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We study the properties of roots of a polynomial system of equations which define a set of identical point particles located on a Unique Worldline (UW), in the spirit of the old Wheeler-Feynman's conception. As a consequence of the Vieta's formulas, a great number of conservation laws is fulfilled for collective alge...
[ { "created": "Sun, 24 Sep 2023 12:06:01 GMT", "version": "v1" } ]
2023-09-27
[ [ "Kassandrov", "Vladimir V.", "" ], [ "Khasanov", "Ildus Sh.", "" ] ]
We study the properties of roots of a polynomial system of equations which define a set of identical point particles located on a Unique Worldline (UW), in the spirit of the old Wheeler-Feynman's conception. As a consequence of the Vieta's formulas, a great number of conservation laws is fulfilled for collective algebr...
2310.07872
Patryk Mach
Patryk Mach, Adam Cie\'slik, Andrzej Odrzywolek
Monte Carlo methods for stationary solutions of general-relativistic Vlasov systems: Collisionless accretion onto black holes
21 pages, 16 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a Monte Carlo simulation method for computing stationary solutions of the general-relativistic Vlasov equation describing a gas of non-colliding particles. As specific examples, we select planar or spherically symmetric accretion models on the Schwarzschild background spacetime. In all cases the gas extend...
[ { "created": "Wed, 11 Oct 2023 20:25:36 GMT", "version": "v1" } ]
2023-10-13
[ [ "Mach", "Patryk", "" ], [ "Cieślik", "Adam", "" ], [ "Odrzywolek", "Andrzej", "" ] ]
We develop a Monte Carlo simulation method for computing stationary solutions of the general-relativistic Vlasov equation describing a gas of non-colliding particles. As specific examples, we select planar or spherically symmetric accretion models on the Schwarzschild background spacetime. In all cases the gas extends ...
1704.08311
Alvaro de la Cruz-Dombriz
Artyom V. Astashenok (1), Alvaro de la Cruz-Dombriz (2) and Sergei D. Odintsov (3) ((1) I. Kant Baltic Federal University, (2) Cape Town U., Dept. Math. & Cape Town U., Cosmology & Gravity group, (3) ICREA and IEEC-CSIC)
The realistic models of relativistic stars in f(R) = R + alpha R^2 gravity
Version published in Class. Quantum Grav. 34 (2017) 205008, 15 pages, 11 figures, 3 tables, conclusions unchanged
Class. Quantum Grav. 34 (2017) 205008
10.1088/1361-6382/aa8971
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the context of f(R)=R + alpha R^2 gravity, we study the existence of neutron and quark stars with no intermediate approximations in the generalised system of Tolman-Oppenheimer-Volkov equations. Analysis shows that for positive alpha's the scalar curvature does not drop to zero at the star surface (as in General R...
[ { "created": "Wed, 26 Apr 2017 19:22:16 GMT", "version": "v1" }, { "created": "Wed, 27 Sep 2017 07:52:44 GMT", "version": "v2" } ]
2017-10-04
[ [ "Astashenok", "Artyom V.", "" ], [ "de la Cruz-Dombriz", "Alvaro", "" ], [ "Odintsov", "Sergei D.", "" ] ]
In the context of f(R)=R + alpha R^2 gravity, we study the existence of neutron and quark stars with no intermediate approximations in the generalised system of Tolman-Oppenheimer-Volkov equations. Analysis shows that for positive alpha's the scalar curvature does not drop to zero at the star surface (as in General Rel...
0910.1323
Sonia Markes
Sonia Markes and Lucien Hardy
Entropy for theories with indefinite causal structure
11 pages, 2 figures
J.Phys.Conf.Ser.306:012043,2011
10.1088/1742-6596/306/1/012043
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Entropy is a concept that has traditionally been reliant on a definite notion of causality. However, without a definite notion of causality, the concept of entropy is not all lost. Indefinite causal structure results from combining probabilistic predictions and dynamical space-time. Combining the probabilistic nature...
[ { "created": "Wed, 7 Oct 2009 17:26:15 GMT", "version": "v1" } ]
2011-07-13
[ [ "Markes", "Sonia", "" ], [ "Hardy", "Lucien", "" ] ]
Entropy is a concept that has traditionally been reliant on a definite notion of causality. However, without a definite notion of causality, the concept of entropy is not all lost. Indefinite causal structure results from combining probabilistic predictions and dynamical space-time. Combining the probabilistic nature o...
gr-qc/0507011
Sanjit Mitra
S. Mitra, S. V. Dhurandhar and L. S. Finn
Improving the efficiency of the detection of gravitational wave signals from inspiraling compact binaries: Chebyshev interpolation
23 pages, 5 figures, submitted to Phys. Rev. D
Phys.Rev. D72 (2005) 102001
10.1103/PhysRevD.72.102001
IUCAA - 19/05
gr-qc
null
Inspiraling compact binaries are promising sources of gravitational waves for ground and space-based laser interferometric detectors. The time-dependent signature of these sources in the detectors is a well-characterized function of a relatively small number of parameters; thus, the favored analysis technique makes u...
[ { "created": "Mon, 4 Jul 2005 05:24:09 GMT", "version": "v1" } ]
2015-06-25
[ [ "Mitra", "S.", "" ], [ "Dhurandhar", "S. V.", "" ], [ "Finn", "L. S.", "" ] ]
Inspiraling compact binaries are promising sources of gravitational waves for ground and space-based laser interferometric detectors. The time-dependent signature of these sources in the detectors is a well-characterized function of a relatively small number of parameters; thus, the favored analysis technique makes use...
2108.07023
Quentin Ansel
Quentin Ansel
Loop quantum gravity with optimal control path integral, and application to black hole tunneling
25 pages, 5 figures, source codes in supplementary materials
null
10.1007/s10714-022-02923-6
null
gr-qc quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents a novel path integral formalism for Einstein's theory of gravitation from the viewpoint of optimal control theory. Despite its close relation to the well-known variational principles of physicists, optimal control turns out to be more general. Within this context, a Lagrangian different from the E...
[ { "created": "Mon, 16 Aug 2021 11:24:22 GMT", "version": "v1" }, { "created": "Tue, 17 Aug 2021 08:32:43 GMT", "version": "v2" } ]
2022-05-11
[ [ "Ansel", "Quentin", "" ] ]
This paper presents a novel path integral formalism for Einstein's theory of gravitation from the viewpoint of optimal control theory. Despite its close relation to the well-known variational principles of physicists, optimal control turns out to be more general. Within this context, a Lagrangian different from the Ein...
2205.03842
Shokoufe Faraji
Shokoufe Faraji, Audrey Trova, Hernando Quevedo
Relativistic equilibrium fluid configurations around rotating deformed compact objects
null
null
10.1140/epjc/s10052-022-11075-5
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the physical properties of equilibrium sequences of non-self-gravitating surfaces that characterize thick disks around a rotating deformed compact object described by a stationary generalization of the static q-metric. The spacetime corresponds to an exact solution of Einstein's field equations so that...
[ { "created": "Sun, 8 May 2022 11:55:17 GMT", "version": "v1" } ]
2023-01-04
[ [ "Faraji", "Shokoufe", "" ], [ "Trova", "Audrey", "" ], [ "Quevedo", "Hernando", "" ] ]
We investigate the physical properties of equilibrium sequences of non-self-gravitating surfaces that characterize thick disks around a rotating deformed compact object described by a stationary generalization of the static q-metric. The spacetime corresponds to an exact solution of Einstein's field equations so that w...
gr-qc/0307061
Yongge Ma
Xuejun Yang, Yongge Ma, Jianbing Shao, and Wei Zhou
Killing Reduction of 5-Dimensional Spacetimes
9 pages, references added
Phys.Rev. D68 (2003) 024006
10.1103/PhysRevD.68.024006
null
gr-qc hep-th
null
In a 5-dimensional spacetime ($M,g_{ab}$) with a Killing vector field $\xi ^a$ which is either everywhere timelike or everywhere spacelike, the collection of all trajectories of $\xi ^a$ gives a 4-dimensional space $S$. The reduction of ($M,g_{ab}$) is studied in the geometric language, which is a generalization of G...
[ { "created": "Sat, 12 Jul 2003 08:12:41 GMT", "version": "v1" }, { "created": "Fri, 25 Jul 2003 03:26:17 GMT", "version": "v2" } ]
2009-11-10
[ [ "Yang", "Xuejun", "" ], [ "Ma", "Yongge", "" ], [ "Shao", "Jianbing", "" ], [ "Zhou", "Wei", "" ] ]
In a 5-dimensional spacetime ($M,g_{ab}$) with a Killing vector field $\xi ^a$ which is either everywhere timelike or everywhere spacelike, the collection of all trajectories of $\xi ^a$ gives a 4-dimensional space $S$. The reduction of ($M,g_{ab}$) is studied in the geometric language, which is a generalization of Ger...
1510.00085
Shao-Wen Wei
Shao-Wen Wei, Peng Cheng, Yu-Xiao Liu
Analytical and exact critical phenomena of $d$-dimensional singly spinning Kerr-AdS black holes
16 pages, 9 figures, 3 tables
Phys. Rev. D 93, 084015 (2016)
10.1103/PhysRevD.93.084015
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the extended phase space, the $d$-dimensional singly spinning Kerr-AdS black holes exhibit the van der Waals's phase transition and reentrant phase transition. Since the black hole system is a single characteristic parameter thermodynamic system, we show that the form of the critical point can be uniquely determin...
[ { "created": "Thu, 1 Oct 2015 01:36:26 GMT", "version": "v1" }, { "created": "Tue, 12 Apr 2016 02:45:43 GMT", "version": "v2" } ]
2016-04-13
[ [ "Wei", "Shao-Wen", "" ], [ "Cheng", "Peng", "" ], [ "Liu", "Yu-Xiao", "" ] ]
In the extended phase space, the $d$-dimensional singly spinning Kerr-AdS black holes exhibit the van der Waals's phase transition and reentrant phase transition. Since the black hole system is a single characteristic parameter thermodynamic system, we show that the form of the critical point can be uniquely determined...
1812.06970
Ido Ben-Dayan
Ido Ben-Dayan, Judy Kupferman
Sourced Scalar Fluctuations in Bouncing Cosmology
Corrected an error in writing the coupling to the gauge field in terms of the scalar field and the corresponding equations. As a result, the prediction is r=1/9. Matches the published erratum
JCAP 2019 (2019) no.07, 050, JCAP 12 (2020) E01 (erratum)
10.1088/1475-7516/2019/07/050
null
gr-qc astro-ph.CO hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the scalar power spectrum generated by sourced fluctuations due to coupling between the scalar field, which holds most of the energy density of the universe, and a gauge field for a general FLRW metric. For this purpose we calculate the curvature perturbation to second order in the presence of gauge fiel...
[ { "created": "Sun, 16 Dec 2018 21:01:05 GMT", "version": "v1" }, { "created": "Wed, 7 Aug 2019 20:35:08 GMT", "version": "v2" }, { "created": "Thu, 18 Feb 2021 17:11:22 GMT", "version": "v3" } ]
2021-02-19
[ [ "Ben-Dayan", "Ido", "" ], [ "Kupferman", "Judy", "" ] ]
We calculate the scalar power spectrum generated by sourced fluctuations due to coupling between the scalar field, which holds most of the energy density of the universe, and a gauge field for a general FLRW metric. For this purpose we calculate the curvature perturbation to second order in the presence of gauge fields...
1008.1127
Francisco Lobo
Francisco S. N. Lobo
Closed timelike curves and causality violation
19 pages, 6 figures. Invited chapter to appear in an edited collection 'Classical and Quantum Gravity: Theory, Analysis and Applications'
Classical and Quantum Gravity: Theory, Analysis and Applications, chap.6 , (2008), Nova Sci. Pub
null
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The conceptual definition and understanding of time, both quantitatively and qualitatively is of the utmost difficulty and importance. As time is incorporated into the proper structure of the fabric of spacetime, it is interesting to note that General Relativity is contaminated with non-trivial geometries which gener...
[ { "created": "Fri, 6 Aug 2010 07:24:39 GMT", "version": "v1" } ]
2013-10-21
[ [ "Lobo", "Francisco S. N.", "" ] ]
The conceptual definition and understanding of time, both quantitatively and qualitatively is of the utmost difficulty and importance. As time is incorporated into the proper structure of the fabric of spacetime, it is interesting to note that General Relativity is contaminated with non-trivial geometries which generat...
2008.04737
Gabriele Umberto Varieschi
Gabriele U. Varieschi
Newtonian Fractional-Dimension Gravity and Disk Galaxies
23 pages, including 6 figures: references added and other minor changes after peer review. Final version to be published in The European Physical Journal Plus, Springer
Eur. Phys. J. Plus 136, 183 (2021)
10.1140/epjp/s13360-021-01165-w
null
gr-qc astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper continues previous work on a novel alternative model of gravity, based on the theory of fractional-dimension spaces applied to Newton's law of gravitation. In particular, our Newtonian Fractional-Dimension Gravity is now applied to axially-symmetric structures, such as thin/thick disk galaxies described by...
[ { "created": "Sat, 8 Aug 2020 05:09:38 GMT", "version": "v1" }, { "created": "Tue, 29 Sep 2020 23:36:59 GMT", "version": "v2" }, { "created": "Fri, 5 Feb 2021 01:35:59 GMT", "version": "v3" } ]
2021-02-15
[ [ "Varieschi", "Gabriele U.", "" ] ]
This paper continues previous work on a novel alternative model of gravity, based on the theory of fractional-dimension spaces applied to Newton's law of gravitation. In particular, our Newtonian Fractional-Dimension Gravity is now applied to axially-symmetric structures, such as thin/thick disk galaxies described by e...
gr-qc/0701097
Eri Mena
E. Mena, O. Obregon and M. Sabido
WKB-type Approximation to Noncommutative Quantum Cosmology
Revtex4, 6 pages, no figures
Int.J.Mod.Phys.D18:95-106,2009
10.1142/S0218271809014376
null
gr-qc
null
In this work, we develop and apply the WKB approximation to several examples of noncommutative quantum cosmology, obtaining the time evolution of the noncommutative universe, this is done starting from a noncommutative quantum formulation of cosmology where the noncommutativity is introduced by a deformation on the m...
[ { "created": "Tue, 16 Jan 2007 23:12:49 GMT", "version": "v1" } ]
2009-03-24
[ [ "Mena", "E.", "" ], [ "Obregon", "O.", "" ], [ "Sabido", "M.", "" ] ]
In this work, we develop and apply the WKB approximation to several examples of noncommutative quantum cosmology, obtaining the time evolution of the noncommutative universe, this is done starting from a noncommutative quantum formulation of cosmology where the noncommutativity is introduced by a deformation on the min...
gr-qc/9503064
Troy Schilling
Troy A. Schilling
Non-covariance of the generalized holonomies: Examples
Silly LaTeX error fixed so that figure is properly included
J.Math.Phys.37:4041-4052,1996
10.1063/1.531615
GCPG-95/3-1
gr-qc
null
A key aspect of a recent proposal for a {\em generalized loop representation} of quantum Yang-Mills theory and gravity is considered. Such a representation of the quantum theory has been expected to arise via consideration of a particular algebra of observables -- given by the traces of the holonomies of {\em general...
[ { "created": "Fri, 31 Mar 1995 21:50:30 GMT", "version": "v1" }, { "created": "Fri, 7 Apr 1995 02:03:25 GMT", "version": "v2" } ]
2010-11-01
[ [ "Schilling", "Troy A.", "" ] ]
A key aspect of a recent proposal for a {\em generalized loop representation} of quantum Yang-Mills theory and gravity is considered. Such a representation of the quantum theory has been expected to arise via consideration of a particular algebra of observables -- given by the traces of the holonomies of {\em generaliz...
1911.09639
Marcin Kisielowski PhD
Marcin Kisielowski
Homogeneous-isotropic sector of loop quantum gravity: new approach
[v2] Published version. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License. Any further distribution of this work must maintain attribution to the author and the title of the work, journal citation and DOI
Class. Quantum Grav. 37 (2020) 185004
10.1088/1361-6382/ab9bb9
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
Recently, a new class of scalar constraint operators has been introduced in loop quantum gravity. They are defined on a space of solutions to the Gauss constraint and partial solutions to the vector constraint, called a vertex Hilbert space. We propose a subspace of the vertex Hilbert space formed by homogeneous-isot...
[ { "created": "Thu, 21 Nov 2019 17:52:41 GMT", "version": "v1" }, { "created": "Fri, 30 Apr 2021 10:55:08 GMT", "version": "v2" } ]
2021-05-03
[ [ "Kisielowski", "Marcin", "" ] ]
Recently, a new class of scalar constraint operators has been introduced in loop quantum gravity. They are defined on a space of solutions to the Gauss constraint and partial solutions to the vector constraint, called a vertex Hilbert space. We propose a subspace of the vertex Hilbert space formed by homogeneous-isotro...
1507.07845
Yen Chin Ong
Yen Chin Ong
Hawking Evaporation Time Scale of Topological Black Holes in Anti-de Sitter Spacetime
Published version
Nucl. Phys. B 903 (2016) 387
10.1016/j.nuclphysb.2016.01.005
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It was recently pointed out that if an absorbing boundary condition is imposed at infinity, an asymptotically anti-de Sitter Schwarzschild black hole with a spherical horizon takes only a finite amount of time to evaporate away even if its initial mass is arbitrarily large. We show that this is a rather generic prope...
[ { "created": "Tue, 28 Jul 2015 16:55:33 GMT", "version": "v1" }, { "created": "Sat, 13 Feb 2016 21:26:05 GMT", "version": "v2" } ]
2016-02-16
[ [ "Ong", "Yen Chin", "" ] ]
It was recently pointed out that if an absorbing boundary condition is imposed at infinity, an asymptotically anti-de Sitter Schwarzschild black hole with a spherical horizon takes only a finite amount of time to evaporate away even if its initial mass is arbitrarily large. We show that this is a rather generic propert...
2403.09388
Che-Yu Chen
Che-Yu Chen, Yuki Yokokura
Imaging a semi-classical horizonless compact object with strong redshift
15 pages, 10 figures. Matching published version
Phys. Rev. D 109 (2024) 104058
10.1103/PhysRevD.109.104058
RIKEN-iTHEMS-Report-24
gr-qc astro-ph.HE hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent advancements in black hole imaging have opened a new era of probing horizon-scale physics with electromagnetic radiation. However, a feature of the observed images, a bright ring encircling a relatively dark region, has not sufficiently proved the existence of event horizons. It thus requires extreme care ...
[ { "created": "Thu, 14 Mar 2024 13:39:18 GMT", "version": "v1" }, { "created": "Tue, 21 May 2024 08:47:48 GMT", "version": "v2" } ]
2024-05-22
[ [ "Chen", "Che-Yu", "" ], [ "Yokokura", "Yuki", "" ] ]
The recent advancements in black hole imaging have opened a new era of probing horizon-scale physics with electromagnetic radiation. However, a feature of the observed images, a bright ring encircling a relatively dark region, has not sufficiently proved the existence of event horizons. It thus requires extreme care wh...
1010.1124
Stefan Danilishin
Farid Khalili, Stefan Danilishin, Helge Mueller-Ebhardt, Haixing Miao, Yanbei Chen and Chunnong Zhao
Negative optical inertia for enhancing the sensitivity of future gravitational-wave detectors
7 pages, 3 figures
Phys.Rev.D83:062003,2011
10.1103/PhysRevD.83.062003
null
gr-qc physics.optics
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider enhancing the sensitivity of future gravitational-wave detectors by using double optical spring. When the power, detuning and bandwidth of the two carriers are chosen appropriately, the effect of the double optical spring can be described as a "negative inertia", which cancels the positive inertia of the ...
[ { "created": "Wed, 6 Oct 2010 11:21:52 GMT", "version": "v1" } ]
2011-03-22
[ [ "Khalili", "Farid", "" ], [ "Danilishin", "Stefan", "" ], [ "Mueller-Ebhardt", "Helge", "" ], [ "Miao", "Haixing", "" ], [ "Chen", "Yanbei", "" ], [ "Zhao", "Chunnong", "" ] ]
We consider enhancing the sensitivity of future gravitational-wave detectors by using double optical spring. When the power, detuning and bandwidth of the two carriers are chosen appropriately, the effect of the double optical spring can be described as a "negative inertia", which cancels the positive inertia of the te...
gr-qc/0607125
Farook Rahaman
F.Rahaman, M.Kalam, R.Mondal and B.Raychaudhuri
Global monopole, dark matter and scalar tensor theory
8 pages, Accepted in Mod. Phys. Lett. A
Mod.Phys.Lett.A22:971-978,2007
10.1142/S0217732307021317
null
gr-qc
null
In this article, we discuss the space-time of a global monopole field as a candidate for galactic dark matter in the context of scalar tensor theory.
[ { "created": "Thu, 27 Jul 2006 08:50:29 GMT", "version": "v1" } ]
2008-11-26
[ [ "Rahaman", "F.", "" ], [ "Kalam", "M.", "" ], [ "Mondal", "R.", "" ], [ "Raychaudhuri", "B.", "" ] ]
In this article, we discuss the space-time of a global monopole field as a candidate for galactic dark matter in the context of scalar tensor theory.
2107.14522
Fabrizio Esposito
Fabrizio Esposito, Sante Carloni, Roberto Cianci, Stefano Vignolo
Reconstructing isotropic and anisotropic $f(\mathcal{Q})$ cosmologies
12 pages, 16 figures
Phys. Rev. D 105, 084061 (2022)
10.1103/PhysRevD.105.084061
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We present a reconstruction algorithm for cosmological models based on $f(\mathcal{Q})$ gravity. We specifically focus on obtaining exact Bianchi Type-I and Friedmann-Lema\^{\i}tre-Robertson-Walker solutions, finding solutions that might have application in a variety of scenarios such as spontaneous isotropization of...
[ { "created": "Fri, 30 Jul 2021 10:10:39 GMT", "version": "v1" }, { "created": "Fri, 22 Oct 2021 08:06:54 GMT", "version": "v2" }, { "created": "Wed, 11 May 2022 09:47:36 GMT", "version": "v3" } ]
2022-05-12
[ [ "Esposito", "Fabrizio", "" ], [ "Carloni", "Sante", "" ], [ "Cianci", "Roberto", "" ], [ "Vignolo", "Stefano", "" ] ]
We present a reconstruction algorithm for cosmological models based on $f(\mathcal{Q})$ gravity. We specifically focus on obtaining exact Bianchi Type-I and Friedmann-Lema\^{\i}tre-Robertson-Walker solutions, finding solutions that might have application in a variety of scenarios such as spontaneous isotropization of B...
2309.10282
Vinod Kumar Bhardwaj Dr.
Vinod Kumar Bhardwaj, Anil Kumar Yadav, Lalit Kumar Gupta, Rajendra Prasad, Sudhir Kumar Srivastava
Constraining hybrid potential scalar field cosmological model in Lyra's geometry with recent observational data
24 pages, 12 figures
null
null
null
gr-qc
http://creativecommons.org/licenses/by-nc-sa/4.0/
In the current study, we investigate a scalar field cosmological model with Lyra's geometry to explain the present cosmic expansion in a homogeneous and isotropic flat FRW universe. In Einstein's field equations, we presupposed a variable displacement vector as an element of Lyra's geometry. In the context of the con...
[ { "created": "Tue, 19 Sep 2023 03:11:07 GMT", "version": "v1" }, { "created": "Sun, 14 Jul 2024 06:37:36 GMT", "version": "v2" } ]
2024-07-16
[ [ "Bhardwaj", "Vinod Kumar", "" ], [ "Yadav", "Anil Kumar", "" ], [ "Gupta", "Lalit Kumar", "" ], [ "Prasad", "Rajendra", "" ], [ "Srivastava", "Sudhir Kumar", "" ] ]
In the current study, we investigate a scalar field cosmological model with Lyra's geometry to explain the present cosmic expansion in a homogeneous and isotropic flat FRW universe. In Einstein's field equations, we presupposed a variable displacement vector as an element of Lyra's geometry. In the context of the conve...
gr-qc/9902082
Leor Barack
Leor Barack and Amos Ori
Late-time decay of scalar perturbations outside rotating black holes
Submitted to PRL in 16Nov98, resubmitted in 3Feb99; Reference added
Phys.Rev.Lett. 82 (1999) 4388
10.1103/PhysRevLett.82.4388
null
gr-qc
null
We present an analytic method for calculating the late-time tails of a linear scalar field outside a Kerr black hole. We give the asymptotic behavior at timelike infinity (for fixed $r$), at future null infinity, and along the event horizon (EH). In all three asymptotic regions we find a power-law decay. We show that...
[ { "created": "Thu, 25 Feb 1999 21:07:47 GMT", "version": "v1" }, { "created": "Sun, 28 Feb 1999 20:13:15 GMT", "version": "v2" } ]
2009-10-31
[ [ "Barack", "Leor", "" ], [ "Ori", "Amos", "" ] ]
We present an analytic method for calculating the late-time tails of a linear scalar field outside a Kerr black hole. We give the asymptotic behavior at timelike infinity (for fixed $r$), at future null infinity, and along the event horizon (EH). In all three asymptotic regions we find a power-law decay. We show that t...
2207.10039
Bernardo Araneda
Steffen Aksteiner, Bernardo Araneda
Kaehler geometry of black holes and gravitational instantons
6 pages
null
10.1103/PhysRevLett.130.161502
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We obtain a closed formula for the Kaehler potential of a broad class of four-dimensional Lorentzian or Euclidean conformal "Kaehler" geometries, including the Plebanski-Demianski class and various gravitational instantons such as Fubini-Study and Chen-Teo. We show that the Kaehler potentials of Schwarzschild and Ker...
[ { "created": "Wed, 20 Jul 2022 17:08:18 GMT", "version": "v1" } ]
2023-05-03
[ [ "Aksteiner", "Steffen", "" ], [ "Araneda", "Bernardo", "" ] ]
We obtain a closed formula for the Kaehler potential of a broad class of four-dimensional Lorentzian or Euclidean conformal "Kaehler" geometries, including the Plebanski-Demianski class and various gravitational instantons such as Fubini-Study and Chen-Teo. We show that the Kaehler potentials of Schwarzschild and Kerr ...
2002.03186
Tiberiu Harko
Shahab Shahidi, Tiberiu Harko, Zolt\'an Kov\'acs
Distinguishing Brans-Dicke-Kerr type naked singularities and black holes with their thin disk electromagnetic radiation properties
20 pages, 6 figures, accepted for publication in EPJC; references added
The European Physical Journal C 80, 162 (2020)
10.1140/epjc/s10052-020-7736-x
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The possible existence of naked singularities, hypothetical astrophysical objects, characterized by a gravitational singularity without an event horizon is still an open problem in present day astrophysics. From an observational point of view distinguishing between astrophysical black holes and naked singularities al...
[ { "created": "Sat, 8 Feb 2020 15:37:20 GMT", "version": "v1" }, { "created": "Fri, 14 Feb 2020 08:25:29 GMT", "version": "v2" } ]
2020-05-19
[ [ "Shahidi", "Shahab", "" ], [ "Harko", "Tiberiu", "" ], [ "Kovács", "Zoltán", "" ] ]
The possible existence of naked singularities, hypothetical astrophysical objects, characterized by a gravitational singularity without an event horizon is still an open problem in present day astrophysics. From an observational point of view distinguishing between astrophysical black holes and naked singularities also...
1105.1540
Yuri Pavlov
A. A. Grib, Yu. V. Pavlov, O. F. Piattella
High energy processes in the vicinity of the Kerr's black hole horizon
13 pages, 2 figures, added some formulas and one reference
Int. J. Mod. Phys. A 26, No. 22 (2011) 3856-3867
10.1142/S0217751X11054310
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Two particle collisions close to the horizon of the rotating nonextremal black hole are analyzed. It is shown that high energy of the order of the Grand Unification scale in the centre of mass of colliding particles can be obtained when there is a multiple collision - the particle from the accretion disc gets the cri...
[ { "created": "Sun, 8 May 2011 18:11:32 GMT", "version": "v1" }, { "created": "Thu, 19 May 2011 15:29:18 GMT", "version": "v2" } ]
2012-03-23
[ [ "Grib", "A. A.", "" ], [ "Pavlov", "Yu. V.", "" ], [ "Piattella", "O. F.", "" ] ]
Two particle collisions close to the horizon of the rotating nonextremal black hole are analyzed. It is shown that high energy of the order of the Grand Unification scale in the centre of mass of colliding particles can be obtained when there is a multiple collision - the particle from the accretion disc gets the criti...
gr-qc/0508035
David Delphenich
David Delphenich
Symmetries and pre-metric electromagnetism
53 pages. Annalen der Physik (Leipzig) (2005), to be published
AnnalenPhys.14:663-704,2005
10.1002/andp.200510159
null
gr-qc hep-th
null
The equations of pre-metric electromagnetism are formulated as an exterior differential system on the bundle of exterior differential 2-forms over the spacetime manifold. The general form for the symmetry equations of the system is computed and then specialized to various possible forms for an electromagnetic constit...
[ { "created": "Tue, 9 Aug 2005 20:15:35 GMT", "version": "v1" } ]
2008-11-26
[ [ "Delphenich", "David", "" ] ]
The equations of pre-metric electromagnetism are formulated as an exterior differential system on the bundle of exterior differential 2-forms over the spacetime manifold. The general form for the symmetry equations of the system is computed and then specialized to various possible forms for an electromagnetic constitut...
gr-qc/9707056
Yoonbai Kim
Nakwoo Kim, Yoonbai Kim and Kyoungtae Kimm
Global Vortex and Black Cosmic String
35 pages, Latex
Phys.Rev. D56 (1997) 8029-8044
10.1103/PhysRevD.56.8029
SNUTP-97-088
gr-qc hep-th
null
We study global vortices coupled to (2+1) dimensional gravity with negative cosmological constant. We found nonsingular vortex solutions in $\phi^4$-theory with a broken U(1) symmetry, of which the spacetimes do not involve physical curvature singularity. When the magnitude of negative cosmological constant is larger...
[ { "created": "Sun, 27 Jul 1997 10:20:13 GMT", "version": "v1" } ]
2009-10-30
[ [ "Kim", "Nakwoo", "" ], [ "Kim", "Yoonbai", "" ], [ "Kimm", "Kyoungtae", "" ] ]
We study global vortices coupled to (2+1) dimensional gravity with negative cosmological constant. We found nonsingular vortex solutions in $\phi^4$-theory with a broken U(1) symmetry, of which the spacetimes do not involve physical curvature singularity. When the magnitude of negative cosmological constant is larger t...
1806.03924
Jakub Mielczarek Ph.D.
Michal Artymowski, Jakub Mielczarek
Quantum Hubble horizon
15 pages, 3 figures
null
10.1140/epjc/s10052-019-7131-7
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The article addresses a possibility of obtaining cosmologically relevant effects from the quantum nature of the Hubble horizon. Following the observation made by E.~Bianchi and C.~Rovelli in Phys.\ Rev.\ D {\bf 84} (2011) 027502 we explore relationship between the Planck scale discreteness of the Hubble horizon and d...
[ { "created": "Mon, 11 Jun 2018 11:43:45 GMT", "version": "v1" } ]
2019-09-04
[ [ "Artymowski", "Michal", "" ], [ "Mielczarek", "Jakub", "" ] ]
The article addresses a possibility of obtaining cosmologically relevant effects from the quantum nature of the Hubble horizon. Following the observation made by E.~Bianchi and C.~Rovelli in Phys.\ Rev.\ D {\bf 84} (2011) 027502 we explore relationship between the Planck scale discreteness of the Hubble horizon and def...
gr-qc/0602020
Plyatsko Roman
Roman Plyatsko
Some partial solutions of Mathisson-Papapetrou equations in a Schwarzschild field
27 pages, 8 figures
null
null
null
gr-qc
null
The analytical and numerical solutions of the Mathisson-Papapetrou equations under the Mathisson-Pirani supplementary condition describing highly relativistic (ultrarelativistic) motions of a spinning particle in a Schwarzschild field are investigated. The known condition S/mr<<1, which is necessary for a test partic...
[ { "created": "Mon, 6 Feb 2006 14:21:40 GMT", "version": "v1" }, { "created": "Tue, 7 Feb 2006 09:28:24 GMT", "version": "v2" } ]
2007-05-23
[ [ "Plyatsko", "Roman", "" ] ]
The analytical and numerical solutions of the Mathisson-Papapetrou equations under the Mathisson-Pirani supplementary condition describing highly relativistic (ultrarelativistic) motions of a spinning particle in a Schwarzschild field are investigated. The known condition S/mr<<1, which is necessary for a test particle...
1511.03578
Maria Laura Pucheu
F. Briscese and M. L. Pucheu
Palatini formulation of non-local gravity
10 pages
null
10.1142/S0219887817500190
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the dynamical equations for a non-local gravity model in the Palatini formalism and we discuss some of the properties of this model. We have shown that, in some specific cases, the vacuum solutions of general relativity are also vacuum solutions of the non-local model, so we conclude that, at least in this ...
[ { "created": "Wed, 11 Nov 2015 17:11:43 GMT", "version": "v1" }, { "created": "Mon, 11 Jan 2016 22:27:33 GMT", "version": "v2" }, { "created": "Wed, 30 Nov 2016 12:42:11 GMT", "version": "v3" } ]
2016-12-16
[ [ "Briscese", "F.", "" ], [ "Pucheu", "M. L.", "" ] ]
We derive the dynamical equations for a non-local gravity model in the Palatini formalism and we discuss some of the properties of this model. We have shown that, in some specific cases, the vacuum solutions of general relativity are also vacuum solutions of the non-local model, so we conclude that, at least in this ca...
1912.04604
Mar\'ia Jos\'e Guzm\'an
Alexey Golovnev, Maria Jose Guzman
Disformal transformations in modified teleparallel gravity
12 pages, no figures; prepared for proceedings of the 10th Mathematical Physics Meeting: School and Conference on Modern Mathematical Physics, 9 - 14 September 2019, Belgrade, Serbia, in which one of us (AG) participated; matches the published version
Symmetry 12 (2020) 152
10.3390/sym12010152
null
gr-qc hep-th
http://creativecommons.org/licenses/by-nc-sa/4.0/
In this work, we explore disformal transformations in the context of the teleparallel equivalent of general relativity and modified teleparallel gravity. We present explicit formulas in components for disformal transformations of the main geometric objects in these theories such as torsion tensor, torsion vector and ...
[ { "created": "Tue, 10 Dec 2019 10:01:20 GMT", "version": "v1" }, { "created": "Tue, 14 Jan 2020 03:22:18 GMT", "version": "v2" } ]
2020-01-15
[ [ "Golovnev", "Alexey", "" ], [ "Guzman", "Maria Jose", "" ] ]
In this work, we explore disformal transformations in the context of the teleparallel equivalent of general relativity and modified teleparallel gravity. We present explicit formulas in components for disformal transformations of the main geometric objects in these theories such as torsion tensor, torsion vector and co...
gr-qc/0307001
Richard O'Shaughenssy
R. O'Shaughnessy
Geometrical optics analysis of the short-time stability properties of the Einstein evolution equations
Submitted to Phys. Rev. D
Phys.Rev.D68:084024,2003
10.1103/PhysRevD.68.084024
null
gr-qc
null
Many alternative formulations of Einstein's evolution have lately been examined, in an effort to discover one which yields slow growth of constraint-violating errors. In this paper, rather than directly search for well-behaved formulations, we instead develop analytic tools to discover which formulations are particul...
[ { "created": "Mon, 30 Jun 2003 20:08:07 GMT", "version": "v1" } ]
2009-04-03
[ [ "O'Shaughnessy", "R.", "" ] ]
Many alternative formulations of Einstein's evolution have lately been examined, in an effort to discover one which yields slow growth of constraint-violating errors. In this paper, rather than directly search for well-behaved formulations, we instead develop analytic tools to discover which formulations are particular...
0801.0212
Sergey Cherkas L
K. A. Viarenich, V. L. Kalashnikov, S. L. Cherkas
Quantum mechanics of the closed collapsing Universe
8 pages 1 figire
Vestnik Belarus State U., ser. Fiz. 2 (2007) 3-7
null
null
gr-qc
null
Two approaches to quantization of Freedman's closed Universe are compared. In the first approach, the Shrodinger's norm of the wave function of Universe is used, and in the second approach, the Klein-Gordon's norm is used. The second one allows building the quasi-Heisenberg operators as functions of time and finding ...
[ { "created": "Mon, 31 Dec 2007 14:52:18 GMT", "version": "v1" } ]
2008-01-03
[ [ "Viarenich", "K. A.", "" ], [ "Kalashnikov", "V. L.", "" ], [ "Cherkas", "S. L.", "" ] ]
Two approaches to quantization of Freedman's closed Universe are compared. In the first approach, the Shrodinger's norm of the wave function of Universe is used, and in the second approach, the Klein-Gordon's norm is used. The second one allows building the quasi-Heisenberg operators as functions of time and finding th...
0705.1565
Christopher Eling
Christopher Eling, Ted Jacobson, M. Coleman Miller
Neutron stars in Einstein-aether theory
25 pages, 4 figures; v2: simplified the discussion of aether-matter couplings, removed one extraneous mass vs. pressure plot, added brief discussion of ae-theory effects in Ozel's mass determination method; v3: corrected the equation for aether stress tensor, results unchanged since correct form was used in cal...
Phys.Rev.D76:042003,2007; Erratum-ibid.D80:129906,2009
10.1103/PhysRevD.76.042003 10.1103/PhysRevD.80.129906
null
gr-qc astro-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As current and future experiments probe strong gravitational regimes around neutron stars and black holes, it is desirable to have theoretically sound alternatives to general relativity against which to test observations. Here we study the consequences of one such generalization, Einstein-aether theory, for the prope...
[ { "created": "Thu, 10 May 2007 23:16:38 GMT", "version": "v1" }, { "created": "Mon, 13 Aug 2007 20:01:02 GMT", "version": "v2" }, { "created": "Sun, 6 Dec 2009 14:19:48 GMT", "version": "v3" } ]
2014-11-18
[ [ "Eling", "Christopher", "" ], [ "Jacobson", "Ted", "" ], [ "Miller", "M. Coleman", "" ] ]
As current and future experiments probe strong gravitational regimes around neutron stars and black holes, it is desirable to have theoretically sound alternatives to general relativity against which to test observations. Here we study the consequences of one such generalization, Einstein-aether theory, for the propert...
2107.05656
Theodoros Nakas
Athanasios Bakopoulos and Theodoros Nakas
Analytic and asymptotically flat hairy (ultra-compact) black-hole solutions and their axial perturbations
23 pages, 8 figures, title changed, analysis extended, references updated, typos corrected, matches published version (to appear in JHEP)
null
10.1007/JHEP04(2022)096
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we consider a very simple gravitational theory that contains a scalar field with its kinetic and potential terms minimally coupled to gravity, while the scalar field is assumed to have a coulombic form. In the context of this theory, we study an analytic, asymptotically flat, and regular (ultra-compact)...
[ { "created": "Mon, 12 Jul 2021 18:00:13 GMT", "version": "v1" }, { "created": "Thu, 14 Apr 2022 17:00:33 GMT", "version": "v2" } ]
2022-04-21
[ [ "Bakopoulos", "Athanasios", "" ], [ "Nakas", "Theodoros", "" ] ]
In this work, we consider a very simple gravitational theory that contains a scalar field with its kinetic and potential terms minimally coupled to gravity, while the scalar field is assumed to have a coulombic form. In the context of this theory, we study an analytic, asymptotically flat, and regular (ultra-compact) b...
gr-qc/0406005
Grigory Volovik
G.E. Volovik
On thermodynamic and quantum fluctuations of cosmological constant
4 pages, version submitted to JETP Letters
JETP Lett. 80 (2004) 465-468
10.1134/1.1839291
null
gr-qc cond-mat.stat-mech hep-ph
null
We discuss from the condensed-matter point of view the recent idea that the Poisson fluctuations of cosmological constant about zero could be a source of the observed dark energy. We argue that the thermodynamic fluctuations of Lambda are much bigger. Since the amplitude of fluctuations is proportional to V^{-1/2}, w...
[ { "created": "Wed, 2 Jun 2004 13:36:02 GMT", "version": "v1" }, { "created": "Mon, 7 Jun 2004 12:26:58 GMT", "version": "v2" }, { "created": "Mon, 12 Jul 2004 14:56:18 GMT", "version": "v3" }, { "created": "Fri, 23 Jul 2004 13:55:49 GMT", "version": "v4" }, { "cre...
2009-11-10
[ [ "Volovik", "G. E.", "" ] ]
We discuss from the condensed-matter point of view the recent idea that the Poisson fluctuations of cosmological constant about zero could be a source of the observed dark energy. We argue that the thermodynamic fluctuations of Lambda are much bigger. Since the amplitude of fluctuations is proportional to V^{-1/2}, whe...
1812.09623
\.Izzet Sakall{\i}
\.Izzet Sakall{\i} and G\"ulnihal Tokg\"oz
Spectroscopy of Stringy Black Hole
Some typos have been fixed. 8 pages & 1 figure. The 10th International Physics Conference of the Balkan Physical Union (BPU10), 26-30 August 2018. To be published in AIP Conference Proceedings in April 2019
AIP Conference Proceedings 2075, 040001 (2019)
10.1063/1.5091161
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Maggiore's method, which evaluates the transition frequency that appears in the adiabatic invariant from the highly damped modes, is used to investigate the entropy/area spectra of the Garfinkle-Horowitz-Strominger black hole (GHS-BH). We compute the resonance modes of the GHS-BH by using the confined scalar wave...
[ { "created": "Sat, 22 Dec 2018 23:21:18 GMT", "version": "v1" }, { "created": "Sat, 16 Feb 2019 20:44:39 GMT", "version": "v2" } ]
2020-02-11
[ [ "Sakallı", "İzzet", "" ], [ "Tokgöz", "Gülnihal", "" ] ]
The Maggiore's method, which evaluates the transition frequency that appears in the adiabatic invariant from the highly damped modes, is used to investigate the entropy/area spectra of the Garfinkle-Horowitz-Strominger black hole (GHS-BH). We compute the resonance modes of the GHS-BH by using the confined scalar waves ...
gr-qc/0512027
Peter Kuhfittig K.F.
Peter K.F. Kuhfittig
More on wormholes supported by small amounts of exotic matter
8 pages AMSTeX; 3 figures added
Phys.Rev. D73 (2006) 084014
10.1103/PhysRevD.73.084014
null
gr-qc
null
Recent papers by Fewster and Roman have emphasized that wormholes supported by arbitrarily small amounts of exotic matter will have to be incredibly fine-tuned if they are to be traversable. This paper discusses a wormhole model that strikes a balance between two conflicting requirements, reducing the amount of exoti...
[ { "created": "Mon, 5 Dec 2005 15:34:59 GMT", "version": "v1" }, { "created": "Fri, 28 Apr 2006 20:24:13 GMT", "version": "v2" } ]
2009-11-11
[ [ "Kuhfittig", "Peter K. F.", "" ] ]
Recent papers by Fewster and Roman have emphasized that wormholes supported by arbitrarily small amounts of exotic matter will have to be incredibly fine-tuned if they are to be traversable. This paper discusses a wormhole model that strikes a balance between two conflicting requirements, reducing the amount of exotic ...
2401.12454
Ming Chen
Ming Chen, Gabriele Tartaglino-Mazzucchelli, Yao-Zhong Zhang
Charged massless scalar fields in a charged $C$-metric black hole: Exact solutions, Hawking radiation and scattering of scalar waves
33 pages
null
null
null
gr-qc hep-th math-ph math.MP
http://creativecommons.org/licenses/by/4.0/
We study Hawking radiation and wave scattering of charged scalar fields in a charged $C$-metric black hole background. The conformally invariant wave equation for charged scalar fields can be separated into radial and angular parts, each with five singularities. We show that the radial and angular equations can be re...
[ { "created": "Tue, 23 Jan 2024 02:50:12 GMT", "version": "v1" }, { "created": "Sun, 11 Feb 2024 01:00:10 GMT", "version": "v2" } ]
2024-02-13
[ [ "Chen", "Ming", "" ], [ "Tartaglino-Mazzucchelli", "Gabriele", "" ], [ "Zhang", "Yao-Zhong", "" ] ]
We study Hawking radiation and wave scattering of charged scalar fields in a charged $C$-metric black hole background. The conformally invariant wave equation for charged scalar fields can be separated into radial and angular parts, each with five singularities. We show that the radial and angular equations can be resp...
0710.1430
Natalia Kiriushcheva
K. R. Green, N. Kiriushcheva, S. V. Kuzmin
Analysis of Hamiltonian formulations of linearized General Relativity
Section Discussion is modified and references are added; 19 pages
Eur. Phys. J. C71:1678,2011
10.1140/epjc/s10052-011-1678-2
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The different forms of the Hamiltonian formulations of linearized General Relativity/spin-two theories are discussed in order to show their similarities and differences. It is demonstrated that in the linear model, non-covariant modifications to the initial covariant Lagrangian (similar to those modifications used in...
[ { "created": "Sun, 7 Oct 2007 16:28:33 GMT", "version": "v1" }, { "created": "Tue, 5 Aug 2008 17:53:21 GMT", "version": "v2" }, { "created": "Mon, 11 Jul 2011 00:20:04 GMT", "version": "v3" } ]
2011-07-18
[ [ "Green", "K. R.", "" ], [ "Kiriushcheva", "N.", "" ], [ "Kuzmin", "S. V.", "" ] ]
The different forms of the Hamiltonian formulations of linearized General Relativity/spin-two theories are discussed in order to show their similarities and differences. It is demonstrated that in the linear model, non-covariant modifications to the initial covariant Lagrangian (similar to those modifications used in f...
1701.06087
Anzhong Wang
Anzhong Wang
Ho\v{r}ava Gravity at a Lifshitz Point: A Progress Report
revtex4, three figures. Corrected various typos. Int. J. Mod. Phys. D26 (2017) 1730014
Int. J. Mod. Phys. D26 (2017) 1730014
10.1142/S0218271817300142
null
gr-qc astro-ph.CO hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ho\v{r}ava gravity at a Lifshitz point is a theory intended to quantize gravity by using techniques of traditional quantum field theories. To avoid Ostrogradsky's ghosts, a problem that has been plaguing quantization of general relativity since the middle of 1970's, Ho\v{r}ava chose to break the Lorentz invariance by...
[ { "created": "Sat, 21 Jan 2017 21:12:15 GMT", "version": "v1" }, { "created": "Thu, 2 Feb 2017 00:27:23 GMT", "version": "v2" }, { "created": "Tue, 4 Apr 2017 00:53:16 GMT", "version": "v3" } ]
2017-04-05
[ [ "Wang", "Anzhong", "" ] ]
Ho\v{r}ava gravity at a Lifshitz point is a theory intended to quantize gravity by using techniques of traditional quantum field theories. To avoid Ostrogradsky's ghosts, a problem that has been plaguing quantization of general relativity since the middle of 1970's, Ho\v{r}ava chose to break the Lorentz invariance by a...
1410.2581
Ilya Lvovich Shapiro
Ilya L. Shapiro (UFJF), Ana M. Pelinson (UFSC), Filipe de O. Salles (UFJF)
Gravitational Waves and Perspectives for Quantum Gravity
21 pages, 4 figures. LaTeX with WS style. Invited Brief Review published in Modern Physics Letters A
Modern Physics Letters. A29 No. 30 (2014) 1430034-1
10.1142/S0217732314300341
null
gr-qc hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Understanding the role of higher derivatives is probably one of the most relevant questions in quantum gravity theory. Already at the semiclassical level, when gravity is a classical background for quantum matter fields, the action of gravity should include fourth derivative terms to provide renormalizability in the ...
[ { "created": "Thu, 9 Oct 2014 19:18:32 GMT", "version": "v1" } ]
2014-10-10
[ [ "Shapiro", "Ilya L.", "", "UFJF" ], [ "Pelinson", "Ana M.", "", "UFSC" ], [ "Salles", "Filipe de O.", "", "UFJF" ] ]
Understanding the role of higher derivatives is probably one of the most relevant questions in quantum gravity theory. Already at the semiclassical level, when gravity is a classical background for quantum matter fields, the action of gravity should include fourth derivative terms to provide renormalizability in the va...
2201.00599
Yang Liu
Yang Liu
The effect of quantum correction on Hawking radiation for Schwarzschild black holes
null
null
null
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We investigate the effect of quantum correction on Hawking radiation for Schwarzschild black holes. We consider Hawking temperature and entropy to order G^2 and find that the area law of black holes should be modified. We think of Hawking radiation as tunneling and find that at certain frequency {\omega} the radiatio...
[ { "created": "Mon, 3 Jan 2022 12:02:32 GMT", "version": "v1" } ]
2022-01-04
[ [ "Liu", "Yang", "" ] ]
We investigate the effect of quantum correction on Hawking radiation for Schwarzschild black holes. We consider Hawking temperature and entropy to order G^2 and find that the area law of black holes should be modified. We think of Hawking radiation as tunneling and find that at certain frequency {\omega} the radiation ...
1105.2658
Jackson Levi Said
Jackson Levi Said, Kristian Zarb Adami
Rotating Charged Cylindrical Black Holes as Particle Accelerators
6 pages, 2 figures, Phys. Rev. D 83, 104047 (2011)
Phys.Rev.D83:104047,2011
10.1103/PhysRevD.83.104047
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has recently been pointed out that arbitrary center-of-mass energies may be obtained for particle collisions near the horizon of an extremal Kerr black hole. We investigate this mechanism in cylindrical topology. In particular we consider the center-of-mass energies of a cylindrical black hole with an extremal rot...
[ { "created": "Fri, 13 May 2011 08:40:54 GMT", "version": "v1" }, { "created": "Sat, 28 May 2011 13:07:49 GMT", "version": "v2" }, { "created": "Sun, 10 Jul 2011 21:27:01 GMT", "version": "v3" } ]
2015-03-19
[ [ "Said", "Jackson Levi", "" ], [ "Adami", "Kristian Zarb", "" ] ]
It has recently been pointed out that arbitrary center-of-mass energies may be obtained for particle collisions near the horizon of an extremal Kerr black hole. We investigate this mechanism in cylindrical topology. In particular we consider the center-of-mass energies of a cylindrical black hole with an extremal rotat...
2007.03211
Handhika Ramadhan
A S. Habibina and H.S. Ramadhan
Geodesic of nonlinear electrodynamics and stable photon orbits
30 pages, 19 figures
Phys.Rev. D101 (2020) no.12, 124036
10.1103/PhysRevD.101.124036
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the geodesics of charged black holes in polynomial Maxwell Lagrangians, a subclass of models within the nonlinear electrodynamics (NLED). Specifically, we consider black holes in Kruglov, power-law, and Ayon-Beato-Garcia models. Our exploration on the corresponding null bound states reveals that photon can o...
[ { "created": "Tue, 7 Jul 2020 05:46:41 GMT", "version": "v1" } ]
2020-07-08
[ [ "Habibina", "A S.", "" ], [ "Ramadhan", "H. S.", "" ] ]
We study the geodesics of charged black holes in polynomial Maxwell Lagrangians, a subclass of models within the nonlinear electrodynamics (NLED). Specifically, we consider black holes in Kruglov, power-law, and Ayon-Beato-Garcia models. Our exploration on the corresponding null bound states reveals that photon can orb...
gr-qc/9606022
Jorge Pullin
Carsten Gundlach and Jorge Pullin
Ill-posedness of a double null free evolution scheme for black hole spacetimes
5 pages, RevTeX, 1 figure, changes in introduction, title and conclusions, figure added, to appear in Classical and Quantum Gravity
Class.Quant.Grav. 14 (1997) 991
10.1088/0264-9381/14/4/014
CGPG-96/6-3, LAEFF-96/11
gr-qc
null
We suggest that ``free evolution'' integration schemes for the Einstein equations (that do not enforce constraints) may contain exponentially growing modes that render them useless in numerical integrations of black hole spacetimes, independently of how the equations are differenced. As an example we consider the evo...
[ { "created": "Tue, 11 Jun 1996 15:22:09 GMT", "version": "v1" }, { "created": "Wed, 29 Jan 1997 15:23:17 GMT", "version": "v2" } ]
2009-10-28
[ [ "Gundlach", "Carsten", "" ], [ "Pullin", "Jorge", "" ] ]
We suggest that ``free evolution'' integration schemes for the Einstein equations (that do not enforce constraints) may contain exponentially growing modes that render them useless in numerical integrations of black hole spacetimes, independently of how the equations are differenced. As an example we consider the evolu...
1705.01378
Peter Horvathy
P.-M. Zhang, C. Duval, G. W. Gibbons and P. A. Horvathy
Soft Gravitons & the Memory Effect for Plane Gravitational Waves
40 pages, many figures. Matches published version
Phys. Rev. D 96, 064013 (2017)
10.1103/PhysRevD.96.064013
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The "gravitational memory effect" due to an exact plane wave provides us with an elementary description of the diffeomorphisms associated with soft gravitons. It is explained how the presence of the latter may be detected by observing the motion of freely falling particles or other forms of gravitational wave detecti...
[ { "created": "Wed, 3 May 2017 12:13:07 GMT", "version": "v1" }, { "created": "Wed, 10 May 2017 14:52:46 GMT", "version": "v2" }, { "created": "Tue, 30 May 2017 06:06:09 GMT", "version": "v3" }, { "created": "Fri, 29 Sep 2017 16:53:54 GMT", "version": "v4" } ]
2017-10-02
[ [ "Zhang", "P. -M.", "" ], [ "Duval", "C.", "" ], [ "Gibbons", "G. W.", "" ], [ "Horvathy", "P. A.", "" ] ]
The "gravitational memory effect" due to an exact plane wave provides us with an elementary description of the diffeomorphisms associated with soft gravitons. It is explained how the presence of the latter may be detected by observing the motion of freely falling particles or other forms of gravitational wave detection...
0810.1120
Roberto A. Sussman
Roberto A. Sussman
Quasi-local variables and inhomogeneous cosmological sources with spherical symmetry
8 pages, 2 pdf figures. Provides a concise summary of some of the results of arXiv:0801.3324v4 [gr-qc]. Submitted to the AIP Conference Proceedings of the III International Meeting on Gravitation and Cosmology, Morelia, Mexico, May 26-30, 2008
AIP Conf.Proc.1083:228-235,2008
10.1063/1.3058574
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine a large class of inhomogeneous spherically symmetric spacetimes that generalize the Lemaitre-Tolman-Bondi dust solutions to nonzero pressure ("LTB spacetimes"). Local covariant LTB objects can be expressed as perturbations of covariant quasi-local (QL) scalars that satisfy evolution equations of equivalent...
[ { "created": "Tue, 7 Oct 2008 08:13:23 GMT", "version": "v1" } ]
2010-05-12
[ [ "Sussman", "Roberto A.", "" ] ]
We examine a large class of inhomogeneous spherically symmetric spacetimes that generalize the Lemaitre-Tolman-Bondi dust solutions to nonzero pressure ("LTB spacetimes"). Local covariant LTB objects can be expressed as perturbations of covariant quasi-local (QL) scalars that satisfy evolution equations of equivalent F...
gr-qc/0109033
Nashed Gamal Gergess Lamee
Gamal G.L. Nashed
Vacuum Non Singular Black Hole Solutions in Tetrad Theory of Gravitation
11 pages, LaTex, no figures, Submitted to GRG
Gen.Rel.Grav. 34 (2002) 1047-1058
10.1023/A:1016509920499
null
gr-qc
null
Starting from a spherically symmetric tetrad with three unknown functions of the radial coordinate, a general solution of M{\o}ller's field equations in case of spherical symmetry nonsingular black hole is derived. The previously obtained solutions are verified as special cases of the general solution. The general so...
[ { "created": "Mon, 10 Sep 2001 21:08:04 GMT", "version": "v1" } ]
2021-10-20
[ [ "Nashed", "Gamal G. L.", "" ] ]
Starting from a spherically symmetric tetrad with three unknown functions of the radial coordinate, a general solution of M{\o}ller's field equations in case of spherical symmetry nonsingular black hole is derived. The previously obtained solutions are verified as special cases of the general solution. The general solu...
2402.11343
Anele Ncube
Alan S. Cornell, Sheldon R. Herbst, Hajar Noshad, Anele M. Ncube
Solving the Regge-Wheeler and Teukolsky equations: supervised vs. unsupervised physics-informed neural networks
22 pages, 3 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Expanding on the research on physics-informed neural networks (PINNs) to solve the eigenvalue problems in black hole (BH) perturbation theory, the supervised learning approach was investigated to solve the Regge-Wheeler and Teukolsky equations governing gravitational perturbations of Schwarzschild and Kerr BHs. Previ...
[ { "created": "Sat, 17 Feb 2024 17:35:06 GMT", "version": "v1" } ]
2024-02-20
[ [ "Cornell", "Alan S.", "" ], [ "Herbst", "Sheldon R.", "" ], [ "Noshad", "Hajar", "" ], [ "Ncube", "Anele M.", "" ] ]
Expanding on the research on physics-informed neural networks (PINNs) to solve the eigenvalue problems in black hole (BH) perturbation theory, the supervised learning approach was investigated to solve the Regge-Wheeler and Teukolsky equations governing gravitational perturbations of Schwarzschild and Kerr BHs. Previou...
1612.03259
Michael Maziashvili
Michael Maziashvili
Light incoherence due to background space fluctuations
6 pages, accepted for publication in Phys. Rev. D
Phys. Rev. D 94, 124044 (2016)
10.1103/PhysRevD.94.124044
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Working by analogy, we use the description of light fluctuations due to random collisions of the radiating atoms to figure out why the reduction of the coherence for light propagating a cosmological distance in the fluctuating background space is negligibly small to be observed by the stellar interferometry.
[ { "created": "Sat, 10 Dec 2016 06:22:16 GMT", "version": "v1" } ]
2016-12-30
[ [ "Maziashvili", "Michael", "" ] ]
Working by analogy, we use the description of light fluctuations due to random collisions of the radiating atoms to figure out why the reduction of the coherence for light propagating a cosmological distance in the fluctuating background space is negligibly small to be observed by the stellar interferometry.
1105.5830
J\"org Hennig
Gernot Neugebauer and J\"org Hennig
Stationary two-black-hole configurations: A non-existence proof
27 pages, 1 figure
J. Geom. Phys. 62, 613 (2012)
10.1016/j.geomphys.2011.05.008
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Based on the solution of a boundary problem for disconnected (Killing) horizons and the resulting violation of characteristic black hole properties, we present a non-existence proof for equilibrium configurations consisting of two aligned rotating black holes. Our discussion is principally aimed at developing the ide...
[ { "created": "Sun, 29 May 2011 21:31:43 GMT", "version": "v1" } ]
2012-01-17
[ [ "Neugebauer", "Gernot", "" ], [ "Hennig", "Jörg", "" ] ]
Based on the solution of a boundary problem for disconnected (Killing) horizons and the resulting violation of characteristic black hole properties, we present a non-existence proof for equilibrium configurations consisting of two aligned rotating black holes. Our discussion is principally aimed at developing the ideas...
1608.07511
Klaus Kassner
Klaus Kassner
Why ghosts don't touch: a tale of two adventurers falling one after another into a black hole
Submitted to European Journal of Physics, 1 figure with 2 panels
European Journal of Physics 38.1 (2016): 015605
10.1088/0143-0807/38/1/015605
null
gr-qc physics.ed-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The case for the utility of Kruskal-Szekeres coordinates in classroom made by Augousti et al. in this journal (Eur. J. Phys. 33:1--11, 2012) is strengthened by extending their discussion beyond the event horizon of the black hole. Observations made by two adventurers following one another into a Schwarzschild black h...
[ { "created": "Fri, 26 Aug 2016 16:34:21 GMT", "version": "v1" } ]
2017-03-13
[ [ "Kassner", "Klaus", "" ] ]
The case for the utility of Kruskal-Szekeres coordinates in classroom made by Augousti et al. in this journal (Eur. J. Phys. 33:1--11, 2012) is strengthened by extending their discussion beyond the event horizon of the black hole. Observations made by two adventurers following one another into a Schwarzschild black hol...
1303.1308
Tatyana P. Shestakova
T. P. Shestakova
Hamiltonian dynamics in extended phase space for gravity and its consistency with Lagrangian formalism: a generalized spherically symmetric model as an example
4 pages, talk presented at the XIII Marcel Grossmann Meeting, Stockholm, Sweden, July 2012
Proceedings of the Thirteenth Marcel Grossmann Meeting on General Relativity (Stockholm, Sweden, 2012), eds. by R. T Jantzen, K. Rosquist and R. Ruffini, World Scientific, Singapore (2015), P. 1880 - 1882
10.1142/9789814623995_0305
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Among theoretical issues in General Relativity the problem of constructing its Hamiltonian formulation is still of interest. The most of attempts to quantize Gravity are based upon Dirac generalization of Hamiltonian dynamics for system with constraints. At the same time there exists another way to formulate Hamilton...
[ { "created": "Wed, 6 Mar 2013 12:09:29 GMT", "version": "v1" } ]
2015-04-09
[ [ "Shestakova", "T. P.", "" ] ]
Among theoretical issues in General Relativity the problem of constructing its Hamiltonian formulation is still of interest. The most of attempts to quantize Gravity are based upon Dirac generalization of Hamiltonian dynamics for system with constraints. At the same time there exists another way to formulate Hamiltonia...
2110.02242
Parampreet Singh
Jorge Pullin, Parampreet Singh
Report on the session Loop Quantum Gravity: Cosmology and Black Holes of the 16th Marcel Grossmann Meeting
5 pages
null
null
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We summarize the main results of 19 talks presented at the QG3 session (loop quantum gravity: cosmology and black holes) of the 16th Marcel Grossmann Meeting held online from July $5^{\mathrm{th}}$-10$^{\mathrm{th}}$, 2021.
[ { "created": "Tue, 5 Oct 2021 18:00:14 GMT", "version": "v1" } ]
2021-10-07
[ [ "Pullin", "Jorge", "" ], [ "Singh", "Parampreet", "" ] ]
We summarize the main results of 19 talks presented at the QG3 session (loop quantum gravity: cosmology and black holes) of the 16th Marcel Grossmann Meeting held online from July $5^{\mathrm{th}}$-10$^{\mathrm{th}}$, 2021.
1909.13272
Jing-Bo Wang
Jingbo Wang
Hawking Radiation from Boundary Scalar Field
7 pages;v2, add the discussion about the impact on the information loss paradox,
Universe 2023, 9, 154
10.3390/universe9030154
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hawking radiation is one essential property of quantum black hole. It results in the information loss paradox, and give important clue to the unification of quantum mechanics and general relativity. In the previous works, the boundary scalar field on the horizon of black holes were used to give the microstates of BTZ...
[ { "created": "Sun, 29 Sep 2019 12:51:09 GMT", "version": "v1" }, { "created": "Tue, 31 Dec 2019 08:30:45 GMT", "version": "v2" } ]
2023-03-24
[ [ "Wang", "Jingbo", "" ] ]
Hawking radiation is one essential property of quantum black hole. It results in the information loss paradox, and give important clue to the unification of quantum mechanics and general relativity. In the previous works, the boundary scalar field on the horizon of black holes were used to give the microstates of BTZ b...
0911.5560
Ryosuke Mizuno
Ryosuke Mizuno, Seiju Ohashi, Tetsuya Shiromizu
Static black hole uniqueness and Penrose inequality
6 pages
null
10.1103/PhysRevD.81.044030
null
gr-qc astro-ph.CO hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Under certain conditions, we give a new way to prove the uniqueness of static black hole in higher dimensional asymptotically flat spacetimes. In the proof, the Penrose inequality plays a key role in higher dimensions as well as four dimensions.
[ { "created": "Mon, 30 Nov 2009 07:34:37 GMT", "version": "v1" } ]
2013-05-29
[ [ "Mizuno", "Ryosuke", "" ], [ "Ohashi", "Seiju", "" ], [ "Shiromizu", "Tetsuya", "" ] ]
Under certain conditions, we give a new way to prove the uniqueness of static black hole in higher dimensional asymptotically flat spacetimes. In the proof, the Penrose inequality plays a key role in higher dimensions as well as four dimensions.
2407.18790
Rubens R. S. Oliveira
R. R. S. Oliveira
Comment on "Exact massless spinor quasibound states of Schwarzschild black hole"
3 pages. Comment on "Exact massless spinor quasibound states of Schwarzschild black hole'' (DOI: 10.1016/j.physletb.2024.138714)
Phys. Lett. B 856 (2024) 138888
10.1016/j.physletb.2024.138888
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this comment, we point out a series of errors made by Senjaya in your paper (2024) \cite{Senjaya}. In particular, these errors involved the Dirac equation in the 3+1 dimensional Schwarzschild spacetime, tetrad field, curved gamma matrices, and the time-independent Dirac equation written in terms of the inner/scala...
[ { "created": "Fri, 26 Jul 2024 14:52:40 GMT", "version": "v1" } ]
2024-07-29
[ [ "Oliveira", "R. R. S.", "" ] ]
In this comment, we point out a series of errors made by Senjaya in your paper (2024) \cite{Senjaya}. In particular, these errors involved the Dirac equation in the 3+1 dimensional Schwarzschild spacetime, tetrad field, curved gamma matrices, and the time-independent Dirac equation written in terms of the inner/scalar ...
gr-qc/9412021
Harald Mueller
Harald F. Muller and Christoph Schmid
Energy Density Fluctuations in Inflationary Cosmology
20 pages, uses AMSTex, 7 figures (not included)
null
null
ETH-TH/94-25
gr-qc astro-ph
null
We analyze the energy density fluctuations contributed by scalar fields $\Phi$ with vanishing expectation values, $\langle\Phi\rangle=0$, which are present in addition to the inflaton field. For simplicity we take $\Phi$ to be non--interacting and minimally coupled to gravity. We use normal ordering to define the ren...
[ { "created": "Wed, 7 Dec 1994 15:27:22 GMT", "version": "v1" } ]
2009-09-25
[ [ "Muller", "Harald F.", "" ], [ "Schmid", "Christoph", "" ] ]
We analyze the energy density fluctuations contributed by scalar fields $\Phi$ with vanishing expectation values, $\langle\Phi\rangle=0$, which are present in addition to the inflaton field. For simplicity we take $\Phi$ to be non--interacting and minimally coupled to gravity. We use normal ordering to define the renor...
1407.1188
Yusuf Kucukakca
Yusuf Kucukakca
Teleparallel dark energy model with a fermionic field via Noether symmetry
7 pages, no figure, the version accepted for publication in The European Physical Journal C
null
10.1140/epjc/s10052-014-3086-x
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the present work, we consider a model with a fermionic field that is non-minimally coupled to gravity in the framework of teleparallel gravity. In order to determine forms of the coupling and potential function of fermionic field for the considered model, we use Noether symmetry approach. By applying this approach...
[ { "created": "Fri, 4 Jul 2014 10:54:37 GMT", "version": "v1" }, { "created": "Wed, 17 Sep 2014 07:23:35 GMT", "version": "v2" } ]
2015-06-22
[ [ "Kucukakca", "Yusuf", "" ] ]
In the present work, we consider a model with a fermionic field that is non-minimally coupled to gravity in the framework of teleparallel gravity. In order to determine forms of the coupling and potential function of fermionic field for the considered model, we use Noether symmetry approach. By applying this approach, ...
2402.14265
Wen-Di Guo
Wen-Di Guo and Qin Tan
Quasinormal modes of a charged black hole with scalar hair
10 pages, 4 figures, and 3 tables
Universe 9, 97, 320 (2023)
10.3390/universe9070320
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
From a five-dimensional Einstein-Maxwell theory, Bah et al. constructed a singularity free topology star/black hole [Phys. Rev. Lett. 126, 151101 (2021)]. After the Klein-Kluza reduction, i.e., integrating the extra space dimension, it can obtain an effective four-dimensional static spherical charged black hole with ...
[ { "created": "Thu, 22 Feb 2024 04:03:38 GMT", "version": "v1" } ]
2024-02-23
[ [ "Guo", "Wen-Di", "" ], [ "Tan", "Qin", "" ] ]
From a five-dimensional Einstein-Maxwell theory, Bah et al. constructed a singularity free topology star/black hole [Phys. Rev. Lett. 126, 151101 (2021)]. After the Klein-Kluza reduction, i.e., integrating the extra space dimension, it can obtain an effective four-dimensional static spherical charged black hole with sc...
gr-qc/9512036
Bernd Bruegmann
Bernd Bruegmann
On the constraint algebra of quantum gravity in the loop representation
17 pages, LaTeX, 2 figures included with epsf
Nucl.Phys.B474:249-268,1996
10.1016/0550-3213(96)00241-6
null
gr-qc
null
Although an important issue in canonical quantization, the problem of representing the constraint algebra in the loop representation of quantum gravity has received little attention. The only explicit computation was performed by Gambini, Garat and Pullin for a formal point-splitting regularization of the diffeomorph...
[ { "created": "Wed, 20 Dec 1995 16:15:50 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bruegmann", "Bernd", "" ] ]
Although an important issue in canonical quantization, the problem of representing the constraint algebra in the loop representation of quantum gravity has received little attention. The only explicit computation was performed by Gambini, Garat and Pullin for a formal point-splitting regularization of the diffeomorphis...
0707.1202
Emanuele Berti
Emanuele Berti, Jaime Cardoso, Vitor Cardoso, Marco Cavaglia
Matched-filtering and parameter estimation of ringdown waveforms
19 pages, 9 figures, matches version in press in PRD
Phys.Rev.D76:104044,2007
10.1103/PhysRevD.76.104044
null
gr-qc astro-ph
null
Using recent results from numerical relativity simulations of non-spinning binary black hole mergers we revisit the problem of detecting ringdown waveforms and of estimating the source parameters, considering both LISA and Earth-based interferometers. We find that Advanced LIGO and EGO could detect intermediate-mass ...
[ { "created": "Mon, 9 Jul 2007 09:10:13 GMT", "version": "v1" }, { "created": "Sun, 18 Nov 2007 03:25:22 GMT", "version": "v2" } ]
2008-11-26
[ [ "Berti", "Emanuele", "" ], [ "Cardoso", "Jaime", "" ], [ "Cardoso", "Vitor", "" ], [ "Cavaglia", "Marco", "" ] ]
Using recent results from numerical relativity simulations of non-spinning binary black hole mergers we revisit the problem of detecting ringdown waveforms and of estimating the source parameters, considering both LISA and Earth-based interferometers. We find that Advanced LIGO and EGO could detect intermediate-mass bl...
2108.04146
Mengjie Wang
Yunhe Lei, Mengjie Wang, Jiliang Jing
Maxwell perturbations in a cavity with Robin boundary conditions: two branches of modes with spectrum bifurcation on Schwarzschild black holes
11 pages, 5 figures, published in EPJC
null
10.1140/epjc/s10052-021-09942-8
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a systematic study of the Maxwell quasinormal spectrum in a mirror-like cavity following the generic Robin type vanishing energy flux principle, by starting with the Schwarzschild black holes in this paper. It is shown that, for black holes in a cavity, the vanishing energy flux principle leads to \textit{...
[ { "created": "Mon, 9 Aug 2021 16:15:09 GMT", "version": "v1" }, { "created": "Fri, 24 Dec 2021 09:50:29 GMT", "version": "v2" } ]
2021-12-28
[ [ "Lei", "Yunhe", "" ], [ "Wang", "Mengjie", "" ], [ "Jing", "Jiliang", "" ] ]
We perform a systematic study of the Maxwell quasinormal spectrum in a mirror-like cavity following the generic Robin type vanishing energy flux principle, by starting with the Schwarzschild black holes in this paper. It is shown that, for black holes in a cavity, the vanishing energy flux principle leads to \textit{tw...
2307.13041
Marcelo E. Rubio
Marcelo E. Rubio, \'Aron D. Kov\'acs, M. Herrero-Valea, Miguel Bezares, Enrico Barausse
Well-posed evolution of field theories with anisotropic scaling: the Lifshitz scalar field in a black hole space-time
28 pages, 11 figures, 1 table. Accepted for publication in JCAP
JCAP11(2023)001
10.1088/1475-7516/2023/11/001
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
Partial differential equations exhibiting an anisotropic scaling between space and time -- such as those of Horava-Lifshitz gravity -- have a dispersive nature. They contain higher-order spatial derivatives, but remain second order in time. This is inconvenient for performing long-time numerical evolutions, as standa...
[ { "created": "Mon, 24 Jul 2023 18:00:08 GMT", "version": "v1" }, { "created": "Mon, 25 Sep 2023 09:26:50 GMT", "version": "v2" } ]
2023-11-23
[ [ "Rubio", "Marcelo E.", "" ], [ "Kovács", "Áron D.", "" ], [ "Herrero-Valea", "M.", "" ], [ "Bezares", "Miguel", "" ], [ "Barausse", "Enrico", "" ] ]
Partial differential equations exhibiting an anisotropic scaling between space and time -- such as those of Horava-Lifshitz gravity -- have a dispersive nature. They contain higher-order spatial derivatives, but remain second order in time. This is inconvenient for performing long-time numerical evolutions, as standard...
0911.0593
Sandipan Sengupta
Sandipan Sengupta
Quantum realizations of Hilbert-Palatini second-class constraints
Published version
Class.Quant.Grav.27:145008,2010
10.1088/0264-9381/27/14/145008
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a classical theory of gravity, the Barbero-Immirzi parameter ($\eta$) appears as a topological coupling constant through the Lagrangian density containing the Hilbert-Palatini term and the Nieh-Yan invariant. In a quantum framework, the topological interpretation of $\eta$ can be captured through a rescaling of th...
[ { "created": "Tue, 3 Nov 2009 15:35:26 GMT", "version": "v1" }, { "created": "Sat, 29 May 2010 03:27:24 GMT", "version": "v2" } ]
2014-11-20
[ [ "Sengupta", "Sandipan", "" ] ]
In a classical theory of gravity, the Barbero-Immirzi parameter ($\eta$) appears as a topological coupling constant through the Lagrangian density containing the Hilbert-Palatini term and the Nieh-Yan invariant. In a quantum framework, the topological interpretation of $\eta$ can be captured through a rescaling of the ...
2009.02928
Naoki Seto
Naoki Seto
Measuring Parity Asymmetry of Gravitational Wave Backgrounds with a Heliocentric Detector Network in the mHz Band
6 pages, 4 figures, to appear in PRL
Phys. Rev. Lett. 125, 251101 (2020)
10.1103/PhysRevLett.125.251101
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss exploration for isotropic gravitational wave backgrounds around 1 mHz by correlation analysis, targeting both parity odd and even polarization modes. Even though the space interferometer LISA alone cannot probe the two modes due to cancellations, the outlook is being changed drastically by the strong devel...
[ { "created": "Mon, 7 Sep 2020 08:00:14 GMT", "version": "v1" }, { "created": "Fri, 20 Nov 2020 03:35:46 GMT", "version": "v2" } ]
2021-01-04
[ [ "Seto", "Naoki", "" ] ]
We discuss exploration for isotropic gravitational wave backgrounds around 1 mHz by correlation analysis, targeting both parity odd and even polarization modes. Even though the space interferometer LISA alone cannot probe the two modes due to cancellations, the outlook is being changed drastically by the strong develop...
1803.10947
Song Ming Du
Song Ming Du and Yanbei Chen
Searching for near-horizon quantum structures in the binary black-hole stochastic gravitational-wave background
5 pages, 5 figures
Phys. Rev. Lett. 121, 051105 (2018)
10.1103/PhysRevLett.121.051105
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been speculated that quantum gravity corrections may lead to modifications to space-time geometry near black hole horizons. Such structures may cause reflections to gravitational waves, causing {\it echoes} that follow the main gravitational waves from binary black hole coalescence. We show that such echoes, i...
[ { "created": "Thu, 29 Mar 2018 07:49:25 GMT", "version": "v1" }, { "created": "Sat, 4 Aug 2018 21:18:14 GMT", "version": "v2" } ]
2018-08-07
[ [ "Du", "Song Ming", "" ], [ "Chen", "Yanbei", "" ] ]
It has been speculated that quantum gravity corrections may lead to modifications to space-time geometry near black hole horizons. Such structures may cause reflections to gravitational waves, causing {\it echoes} that follow the main gravitational waves from binary black hole coalescence. We show that such echoes, if ...
1901.09808
B. S. Ratanpal
B. S. Ratanpal
Cracking and Stability of Non-Rotating Relativistic Spheres with Anisotropic Internal Stresses
null
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The stability of static uncharged spheres with anisotropic internal stresses is studied in general relativity. It has been noticed that pressure anisotropy plays an important role for stability of stellar structure. It is shown that radial profile of the stress anisotropy can be considered to decide potentially stabl...
[ { "created": "Wed, 23 Jan 2019 05:50:10 GMT", "version": "v1" }, { "created": "Fri, 26 Jun 2020 08:42:47 GMT", "version": "v2" } ]
2020-06-29
[ [ "Ratanpal", "B. S.", "" ] ]
The stability of static uncharged spheres with anisotropic internal stresses is studied in general relativity. It has been noticed that pressure anisotropy plays an important role for stability of stellar structure. It is shown that radial profile of the stress anisotropy can be considered to decide potentially stable/...