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1705.04743
Christopher Pilot
Christopher Pilot
Modeling Cosmic Expansion, and Possible Inflation, As a Thermodynamic Heat Engine
19 pages
Zeitschrift f. Naturforschung A (ZNA) Vol: 74 iss:01 (2019)
10.1515/zna-2018-0314
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Assuming a closed universe with slight positive curvature, cosmic expansion is modeled as a heat engine where the '"system'" is defined collectively as those regions of space within the observable universe which will later evolve into voids or empty space, and the '"surroundings'" are identified collectively as those...
[ { "created": "Fri, 12 May 2017 20:16:05 GMT", "version": "v1" }, { "created": "Wed, 21 Mar 2018 01:17:20 GMT", "version": "v2" } ]
2020-08-03
[ [ "Pilot", "Christopher", "" ] ]
Assuming a closed universe with slight positive curvature, cosmic expansion is modeled as a heat engine where the '"system'" is defined collectively as those regions of space within the observable universe which will later evolve into voids or empty space, and the '"surroundings'" are identified collectively as those p...
2210.07103
Viacheslav A. Emelyanov
Viacheslav A. Emelyanov
On free fall of fermions and antifermions
To be published in Eur. Phys. J. C
Eur. Phys. J. C 83 (2023) 632
10.1140/epjc/s10052-023-11788-1
null
gr-qc hep-th quant-ph
http://creativecommons.org/licenses/by/4.0/
We propose a model describing spin-half quantum particles in curved spacetime in the framework of quantum field theory. Our model is based on embodying Einstein's equivalence principle and general covariance in the definition of quantum-particle states. With this model at hand, we compute several observables which ch...
[ { "created": "Thu, 13 Oct 2022 15:35:36 GMT", "version": "v1" }, { "created": "Sat, 1 Jul 2023 08:38:28 GMT", "version": "v2" } ]
2023-07-26
[ [ "Emelyanov", "Viacheslav A.", "" ] ]
We propose a model describing spin-half quantum particles in curved spacetime in the framework of quantum field theory. Our model is based on embodying Einstein's equivalence principle and general covariance in the definition of quantum-particle states. With this model at hand, we compute several observables which char...
1506.03829
Yu Asato
Yu Asato
A note on cutting spin networks and the area spectrum in loop quantum gravity
7 pages with 2 figures; v2: added references; v3: added discussion of a sufficient condition, generalization, some clearer explanations, and more references
null
10.1088/0264-9381/33/11/117001
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, I show that if a spin network is cut by a surface separating space-time into two regions, the sum of spins of edges crossing the surface must be an integer. This gives a restriction on the area spectrum of such surfaces, including black hole horizons, in loop quantum gravity.
[ { "created": "Thu, 11 Jun 2015 20:36:44 GMT", "version": "v1" }, { "created": "Wed, 15 Jul 2015 01:25:53 GMT", "version": "v2" }, { "created": "Wed, 28 Oct 2015 04:39:46 GMT", "version": "v3" } ]
2016-05-25
[ [ "Asato", "Yu", "" ] ]
In this paper, I show that if a spin network is cut by a surface separating space-time into two regions, the sum of spins of edges crossing the surface must be an integer. This gives a restriction on the area spectrum of such surfaces, including black hole horizons, in loop quantum gravity.
1107.2910
M. D. Maia
M. D. Maia
The Poincare Conjecture and the Cosmological Constant
9 pages, Latex, presented at the 8th Friedmann Seminar, Rio de Janeiro, May-June 2011
null
10.1142/S2010194511001280
null
gr-qc astro-ph.CO hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The concept of deformation of Riemannian geometry is reviewed, with applications to gravitation and cosmology. Starting with an analysis of the cosmological constant problem, it is shown that space-times are deformable in the sense of local change of shape. These deformations leave an observable signature in the spac...
[ { "created": "Thu, 14 Jul 2011 19:49:52 GMT", "version": "v1" } ]
2015-05-28
[ [ "Maia", "M. D.", "" ] ]
The concept of deformation of Riemannian geometry is reviewed, with applications to gravitation and cosmology. Starting with an analysis of the cosmological constant problem, it is shown that space-times are deformable in the sense of local change of shape. These deformations leave an observable signature in the space-...
0905.2834
Peter Hogan
P. A. Hogan and S. O'Farrell
Generating Electromagnetic Waves from Gravity Waves in Cosmology
13 pages, Latex file, accepted for publication in Physical Review D
Phys.Rev.D79:104028,2009
10.1103/PhysRevD.79.104028
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Examples of test electromagnetic waves on a Friedmann-Lemaitre-Robertson-Walker(FLRW) background are constructed from explicit perturbations of the FLRW space-times describing gravitational waves propagating in the isotropic universes. A possible physical mechanism for the production of the test electromagnetic waves...
[ { "created": "Mon, 18 May 2009 09:02:50 GMT", "version": "v1" } ]
2009-07-30
[ [ "Hogan", "P. A.", "" ], [ "O'Farrell", "S.", "" ] ]
Examples of test electromagnetic waves on a Friedmann-Lemaitre-Robertson-Walker(FLRW) background are constructed from explicit perturbations of the FLRW space-times describing gravitational waves propagating in the isotropic universes. A possible physical mechanism for the production of the test electromagnetic waves i...
1506.03519
Piotr Bizon
Piotr Bizo\'n, Maciej Maliborski, Andrzej Rostworowski
Resonant dynamics and the instability of anti-de Sitter spacetime
5 pages, 7 figures
Phys. Rev. Lett. 115, 081103 (2015)
10.1103/PhysRevLett.115.081103
null
gr-qc hep-th math.AP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider spherically symmetric Einstein-massless-scalar field equations with negative cosmological constant in five dimensions and analyze evolution of small perturbations of anti-de Sitter spacetime using the recently proposed resonant approximation. We show that for typical initial data the solution of the reson...
[ { "created": "Thu, 11 Jun 2015 00:47:48 GMT", "version": "v1" } ]
2015-08-26
[ [ "Bizoń", "Piotr", "" ], [ "Maliborski", "Maciej", "" ], [ "Rostworowski", "Andrzej", "" ] ]
We consider spherically symmetric Einstein-massless-scalar field equations with negative cosmological constant in five dimensions and analyze evolution of small perturbations of anti-de Sitter spacetime using the recently proposed resonant approximation. We show that for typical initial data the solution of the resonan...
1007.4598
Oleg Zaslavskii
Oleg B. Zaslavskii
Acceleration of particles by nonrotating charged black holes
8 pages. Two new sections added. To appear in JETP Letters
JETP Lett.92:571-574,2010; Pisma Zh.Eksp.Teor.Fiz.92:635,2010
10.1134/S0021364010210010
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, in the series of works a new effect of acceleration of particles by black holes was found. Under certain conditions, the energy in the centre of mass frame can become infinitely large. The essential ingredient of such effect is the rotation of a black hole. In the present Letter, we argue that the similar e...
[ { "created": "Tue, 27 Jul 2010 00:51:51 GMT", "version": "v1" }, { "created": "Sun, 24 Oct 2010 15:53:13 GMT", "version": "v2" } ]
2011-03-28
[ [ "Zaslavskii", "Oleg B.", "" ] ]
Recently, in the series of works a new effect of acceleration of particles by black holes was found. Under certain conditions, the energy in the centre of mass frame can become infinitely large. The essential ingredient of such effect is the rotation of a black hole. In the present Letter, we argue that the similar eff...
1303.0399
Gergely Sz\'ekely
Judit X. Madar\'asz and Gergely Sz\'ekely
The Existence of Superluminal Particles is Consistent with Relativistic Dynamics
29 pages, 11 figures. arXiv admin note: text overlap with arXiv:1202.5790
Journal of Applied Logic 12:(4) pp. 477-500. (2014)
10.1016/j.jal.2014.07.003
null
gr-qc math-ph math.LO math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within an axiomatic framework, we prove that the existence of faster than light particles is consistent with (does not contradict) the dynamics of Einstein's special relativity.
[ { "created": "Sat, 2 Mar 2013 16:32:01 GMT", "version": "v1" }, { "created": "Thu, 24 Jul 2014 18:10:49 GMT", "version": "v2" } ]
2018-01-30
[ [ "Madarász", "Judit X.", "" ], [ "Székely", "Gergely", "" ] ]
Within an axiomatic framework, we prove that the existence of faster than light particles is consistent with (does not contradict) the dynamics of Einstein's special relativity.
1505.04162
Luis Cort\'es Barbado
Luis C. Barbado, Carlos Barcel\'o, Luis J. Garay
Quantum frictionless trajectories versus geodesics
5 pages, 3 figures
Phys. Rev. D 92, 084031 (2015)
10.1103/PhysRevD.92.084031
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Moving particles outside a star will generally experience quantum friction caused by the Unruh radiation reaction. There exist however radial trajectories that lack this effect (in the outgoing radiation sector, and ignoring backscattering). Along these trajectories, observers perceive just stellar emission, without ...
[ { "created": "Fri, 15 May 2015 19:02:27 GMT", "version": "v1" }, { "created": "Mon, 9 Nov 2015 14:04:32 GMT", "version": "v2" } ]
2015-11-10
[ [ "Barbado", "Luis C.", "" ], [ "Barceló", "Carlos", "" ], [ "Garay", "Luis J.", "" ] ]
Moving particles outside a star will generally experience quantum friction caused by the Unruh radiation reaction. There exist however radial trajectories that lack this effect (in the outgoing radiation sector, and ignoring backscattering). Along these trajectories, observers perceive just stellar emission, without fu...
gr-qc/0112002
Hendryk Pfeiffer
Hendryk Pfeiffer (Cambridge)
Dual variables and a connection picture for the Euclidean Barrett-Crane model
33 pages, LaTeX, combined PiCTeX/postscript figures, v2: note added, TeX error corrected
Class.Quant.Grav.19:1109-1138,2002
10.1088/0264-9381/19/6/306
DAMTP-2001-103
gr-qc
null
The partition function of the SO(4)- or Spin(4)-symmetric Euclidean Barrett-Crane model can be understood as a sum over all quantized geometries of a given triangulation of a four-manifold. In the original formulation, the variables of the model are balanced representations of SO(4) which describe the quantized areas...
[ { "created": "Tue, 4 Dec 2001 15:27:10 GMT", "version": "v1" }, { "created": "Wed, 30 Jan 2002 11:56:07 GMT", "version": "v2" } ]
2008-11-26
[ [ "Pfeiffer", "Hendryk", "", "Cambridge" ] ]
The partition function of the SO(4)- or Spin(4)-symmetric Euclidean Barrett-Crane model can be understood as a sum over all quantized geometries of a given triangulation of a four-manifold. In the original formulation, the variables of the model are balanced representations of SO(4) which describe the quantized areas o...
2407.19264
Marco Schreck MS
Carlos M. Reyes, C\'esar Riquelme, Marco Schreck, and Alex Soto
Reduced geometry and its role in explicit spacetime symmetry violation
6 pages, 1 figure
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The incompatibility of explicit diffeomorphism violation with Riemannian geometry within the gravitational Standard-Model Extension (SME) is revisited. We review two methods of how to deal with this problem. The first is based on an approach proposed originally by St\"{u}ckelberg and the latter is to restrict spaceti...
[ { "created": "Sat, 27 Jul 2024 14:12:45 GMT", "version": "v1" } ]
2024-07-30
[ [ "Reyes", "Carlos M.", "" ], [ "Riquelme", "César", "" ], [ "Schreck", "Marco", "" ], [ "Soto", "Alex", "" ] ]
The incompatibility of explicit diffeomorphism violation with Riemannian geometry within the gravitational Standard-Model Extension (SME) is revisited. We review two methods of how to deal with this problem. The first is based on an approach proposed originally by St\"{u}ckelberg and the latter is to restrict spacetime...
1209.3584
Hristu Culetu
Hristu Culetu
Comment on "Non-vacuum conformally flat space-times: dark energy"
5 pages, no figures, one reference updated, Accepted for publication in Astrophysics and Space Science
null
10.1007/s10509-012-1341-x
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ibohal, Ishwarchandra and Singh proposed a class of exact, non-vacuum and conformally flat solutions of Einstein's equations whose stress tensor $T_{ab}$ has negative pressure. We show that $T_{ab}$ corresponds to an anisotropic fluid and the equation of state parameter seems not to be $\omega = -1/2$. We consider th...
[ { "created": "Mon, 17 Sep 2012 08:38:22 GMT", "version": "v1" }, { "created": "Tue, 11 Dec 2012 10:46:22 GMT", "version": "v2" } ]
2015-06-11
[ [ "Culetu", "Hristu", "" ] ]
Ibohal, Ishwarchandra and Singh proposed a class of exact, non-vacuum and conformally flat solutions of Einstein's equations whose stress tensor $T_{ab}$ has negative pressure. We show that $T_{ab}$ corresponds to an anisotropic fluid and the equation of state parameter seems not to be $\omega = -1/2$. We consider the ...
2312.10443
Ricardo Escobedo PhD
Ricardo Escobedo, Roberto Santos-Silva, Rafael Hern\'andez-Jim\'enez, and Claudia Moreno
Quintom cosmology from an effective $BF$ theory
13 pages, 3 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article we analyze an effective action derived from a 7-dimensional $BF$ theory that, upon dimensional reduction, it transforms into an effective 4-dimensional action. Such resulting effective action involves a generic metric; however, we study a cosmological model described by a de Sitter universe, with a Hu...
[ { "created": "Sat, 16 Dec 2023 13:19:46 GMT", "version": "v1" }, { "created": "Tue, 28 May 2024 04:00:40 GMT", "version": "v2" } ]
2024-05-29
[ [ "Escobedo", "Ricardo", "" ], [ "Santos-Silva", "Roberto", "" ], [ "Hernández-Jiménez", "Rafael", "" ], [ "Moreno", "Claudia", "" ] ]
In this article we analyze an effective action derived from a 7-dimensional $BF$ theory that, upon dimensional reduction, it transforms into an effective 4-dimensional action. Such resulting effective action involves a generic metric; however, we study a cosmological model described by a de Sitter universe, with a Hubb...
1605.07611
Ines Godonou Salako
Ines G. Salako, M. J. S. Houndjo, Abdul Jawad
Generalized Mattig's relation in Brans-Dicke-Rastall gravity
20 pages, 4 figures
International Journal of Modern Physics D, Vol. 25, No. 7 (2016) 1650076 (20 pages)
10.1142/S0218271816500760
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Geodesic Deviation Equation is being studied in Brans-Dicke-Rastall gravity. We briefly discuss the Brans-Dicke-Rastall gravity and then construct GDE for FLRW metric. In this way, the obtained geodesic deviation equation will correspond to the Brans-Dicke-Rastall gravity. Eventually, we solve numerically the nul...
[ { "created": "Tue, 24 May 2016 15:47:25 GMT", "version": "v1" } ]
2016-05-26
[ [ "Salako", "Ines G.", "" ], [ "Houndjo", "M. J. S.", "" ], [ "Jawad", "Abdul", "" ] ]
The Geodesic Deviation Equation is being studied in Brans-Dicke-Rastall gravity. We briefly discuss the Brans-Dicke-Rastall gravity and then construct GDE for FLRW metric. In this way, the obtained geodesic deviation equation will correspond to the Brans-Dicke-Rastall gravity. Eventually, we solve numerically the null ...
1810.11713
Sergei Kopeikin
Sergei M. Kopeikin (University of Missouri, USA)
Covariant Equations of Motion of Extended Bodies with Arbitrary Mass and Spin Multipoles
121 pages, 1 figure, accepted to Phys. Rev. D
Phys. Rev. D 99, 084008 (2019)
10.1103/PhysRevD.99.084008
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper employs the post-Newtonian approximations of scalar-tensor theory of gravity along with the Cartesian STF tensors and the Blanchet-Damour multipole formalism to derive translational and rotational equations of motion of N extended bodies with arbitrary distribution of mass and velocity. We assume that spac...
[ { "created": "Sat, 27 Oct 2018 21:25:45 GMT", "version": "v1" }, { "created": "Sat, 23 Feb 2019 00:03:52 GMT", "version": "v2" }, { "created": "Sat, 6 Apr 2019 17:24:24 GMT", "version": "v3" } ]
2019-04-17
[ [ "Kopeikin", "Sergei M.", "", "University of Missouri, USA" ] ]
This paper employs the post-Newtonian approximations of scalar-tensor theory of gravity along with the Cartesian STF tensors and the Blanchet-Damour multipole formalism to derive translational and rotational equations of motion of N extended bodies with arbitrary distribution of mass and velocity. We assume that spacet...
1810.01960
Vasiliy P. Neznamov
V.P.Neznamov, I.I.Safronov, V.E.Shemarulin
Stationary solutions of second-order equations for fermions in Reissner-Nordstr\"{o}m space-time
42 pages, 10 figures, 8 tables
JETP Vol. 154 (4) 802 - 825 (2018); English transl. JETP Vol. 127 (4) 684 - 704 (2018)
10.1134/S0044451018100103; 10.1134/S1063776118100199
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Existence of degenerate stationary bound states with square integrable radial wave functions was proved when second-order equations are used with the effective potential of the Reissner-Nordstr\"{o}m (RN) field with two event horizons for charged and uncharged fermions. The fermions in such states are localized near ...
[ { "created": "Tue, 2 Oct 2018 17:11:04 GMT", "version": "v1" } ]
2018-12-06
[ [ "Neznamov", "V. P.", "" ], [ "Safronov", "I. I.", "" ], [ "Shemarulin", "V. E.", "" ] ]
Existence of degenerate stationary bound states with square integrable radial wave functions was proved when second-order equations are used with the effective potential of the Reissner-Nordstr\"{o}m (RN) field with two event horizons for charged and uncharged fermions. The fermions in such states are localized near ev...
2302.07044
Gui-Rong Liang
Jin Dai, Gui-Rong Liang
Graviton-Photon Conversion in Atoms and the Detection of Gravitons
null
null
null
null
gr-qc
http://creativecommons.org/licenses/by-nc-sa/4.0/
We study graviton-photon conversion in potential ground-based experiments. From graviton to photon transition, we calculate the cross section of graviton-atom interaction in the presence of spherical atomic electric fields; the obtained results hold for graviton energy around 100 keV to 1 GeV, and would be enhanced a...
[ { "created": "Tue, 14 Feb 2023 13:55:25 GMT", "version": "v1" }, { "created": "Thu, 23 Mar 2023 16:48:18 GMT", "version": "v2" }, { "created": "Thu, 18 May 2023 18:32:09 GMT", "version": "v3" } ]
2023-05-22
[ [ "Dai", "Jin", "" ], [ "Liang", "Gui-Rong", "" ] ]
We study graviton-photon conversion in potential ground-based experiments. From graviton to photon transition, we calculate the cross section of graviton-atom interaction in the presence of spherical atomic electric fields; the obtained results hold for graviton energy around 100 keV to 1 GeV, and would be enhanced alo...
2402.18915
Bivudutta Mishra Dr.
Rahul Bhagat, B.Mishra
Observational constrained Weyl type $f(Q,T)$ gravity cosmological model and the dynamical system analysis
17 pages, 7 figures, 4 tables. Suggestions and comments are welcome
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using the cosmological date sets, the cosmological parameters are constrained in this paper, with some well known form of Hubble parameter. To understand the dynamics of the Weyl type $f(Q,T)$, functional form $f(Q,T)$ has been introduced, where $Q$ and $T$ respectively represents the nonmetricity scalar and trace of...
[ { "created": "Thu, 29 Feb 2024 07:12:48 GMT", "version": "v1" } ]
2024-03-01
[ [ "Bhagat", "Rahul", "" ], [ "Mishra", "B.", "" ] ]
Using the cosmological date sets, the cosmological parameters are constrained in this paper, with some well known form of Hubble parameter. To understand the dynamics of the Weyl type $f(Q,T)$, functional form $f(Q,T)$ has been introduced, where $Q$ and $T$ respectively represents the nonmetricity scalar and trace of e...
gr-qc/0405129
Jiliang Jing
Qiyuan Pan and Jiliang Jing
Asymptotic tails of massive scalar fields in a stationary axisymmetric EMDA black hole geometry
6 pages
Chin.Phys.Lett. 21 (2004) 1873-1876
10.1088/0256-307X/21/10/002
null
gr-qc astro-ph hep-th
null
The late-time tail behavior of massive scalar fields is studied analytically in a stationary axisymmetric EMDA black hole geometry. It is shown that the asymptotic behavior of massive perturbations is dominated by the oscillatory inverse power-law decaying tail $ t^{-(l+3/2)}\sin(\mu t)$ at the intermediate late time...
[ { "created": "Wed, 26 May 2004 08:47:36 GMT", "version": "v1" }, { "created": "Sun, 30 May 2004 01:52:48 GMT", "version": "v2" } ]
2009-11-10
[ [ "Pan", "Qiyuan", "" ], [ "Jing", "Jiliang", "" ] ]
The late-time tail behavior of massive scalar fields is studied analytically in a stationary axisymmetric EMDA black hole geometry. It is shown that the asymptotic behavior of massive perturbations is dominated by the oscillatory inverse power-law decaying tail $ t^{-(l+3/2)}\sin(\mu t)$ at the intermediate late times,...
0809.3190
Igor Khavkine
Igor Khavkine
Evaluation of new spin foam vertex amplitudes
34 pages, 8 figures, amsrefs; v3: merged with 0810.1653, updated bibl., version submitted to CQG
Class.Quant.Grav.26:125012,2009
10.1088/0264-9381/26/12/125012
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Christensen-Egan algorithm is extended and generalized to efficiently evaluate new spin foam vertex amplitudes proposed by Engle, Pereira & Rovelli and Freidel & Krasnov, with or without (factored) boundary states. A concrete pragmatic proposal is made for comparing the different models using uniform methodologie...
[ { "created": "Thu, 18 Sep 2008 15:33:37 GMT", "version": "v1" }, { "created": "Thu, 9 Oct 2008 19:31:55 GMT", "version": "v2" }, { "created": "Fri, 31 Jul 2009 09:48:12 GMT", "version": "v3" } ]
2009-11-19
[ [ "Khavkine", "Igor", "" ] ]
The Christensen-Egan algorithm is extended and generalized to efficiently evaluate new spin foam vertex amplitudes proposed by Engle, Pereira & Rovelli and Freidel & Krasnov, with or without (factored) boundary states. A concrete pragmatic proposal is made for comparing the different models using uniform methodologies,...
2112.08365
Bivudutta Mishra Dr.
B.Mishra, A.S. Agrawal, S.K. Tripathy, S. Ray
Traversable wormhole models in $f(R)$ gravity
13 pages, 18 figures, Accepted version in IJMPA
International Journal of Modern Physics A, 37, 2250010, 2022
10.1142/S0217751X22500105
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we analyze the wormhole solutions in $f(R)$ gravity. Specifically we sought for wormhole geometry solutions for the following three shape functions: (i) $b(r)=r_{0}+\rho_{0}r_{0}^{3}\ln\left(\frac{r_{0}}{r}\right)$, (ii) $b(r)=r_{0}+\gamma r_{0}\left(1-\dfrac{r_{0}}{r}\right)$, and (iii) $b(r)=\alpha +\...
[ { "created": "Wed, 15 Dec 2021 05:11:11 GMT", "version": "v1" } ]
2022-04-22
[ [ "Mishra", "B.", "" ], [ "Agrawal", "A. S.", "" ], [ "Tripathy", "S. K.", "" ], [ "Ray", "S.", "" ] ]
In this work, we analyze the wormhole solutions in $f(R)$ gravity. Specifically we sought for wormhole geometry solutions for the following three shape functions: (i) $b(r)=r_{0}+\rho_{0}r_{0}^{3}\ln\left(\frac{r_{0}}{r}\right)$, (ii) $b(r)=r_{0}+\gamma r_{0}\left(1-\dfrac{r_{0}}{r}\right)$, and (iii) $b(r)=\alpha +\be...
2310.16250
Piero A. P. Molinari
Piero A. P. Molinari, Paola C. M. Delgado, Rodrigo F. Pinheiro, Nelson Pinto-Neto
Radiation-dominated bouncing model with slow contraction and inflation
14 pages, 5 figures
Phys. Rev. D 109, 043531 (2024)
10.1103/PhysRevD.109.043531
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A very simple non-singular inflationary model is presented where the unique matter content is a radiation fluid. The model slowly contracts from a very large, almost empty and flat spacetime and realizes a bounce. It is then launched to a quasi-de Sitter inflationary expansion with more than sixty e-folds, which smoo...
[ { "created": "Tue, 24 Oct 2023 23:49:40 GMT", "version": "v1" } ]
2024-03-08
[ [ "Molinari", "Piero A. P.", "" ], [ "Delgado", "Paola C. M.", "" ], [ "Pinheiro", "Rodrigo F.", "" ], [ "Pinto-Neto", "Nelson", "" ] ]
A very simple non-singular inflationary model is presented where the unique matter content is a radiation fluid. The model slowly contracts from a very large, almost empty and flat spacetime and realizes a bounce. It is then launched to a quasi-de Sitter inflationary expansion with more than sixty e-folds, which smooth...
1805.07312
Luca Bombelli
Mir Emad Aghili, Luca Bombelli, B.B. Pilgrim
Path length distribution in two-dimensional causal sets
9 pages, 5 figures
Eur. Phys. J. C (2018) 78: 744
10.1140/epjc/s10052-018-6229-7
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the distribution of maximal-chain lengths between two elements of a causal set and its relationship with the embeddability of the causal set in a region of flat spacetime. We start with causal sets obtained from uniformly distributed points in Minkowski space. After some general considerations we focus on th...
[ { "created": "Fri, 18 May 2018 16:23:15 GMT", "version": "v1" } ]
2018-09-18
[ [ "Aghili", "Mir Emad", "" ], [ "Bombelli", "Luca", "" ], [ "Pilgrim", "B. B.", "" ] ]
We study the distribution of maximal-chain lengths between two elements of a causal set and its relationship with the embeddability of the causal set in a region of flat spacetime. We start with causal sets obtained from uniformly distributed points in Minkowski space. After some general considerations we focus on the ...
gr-qc/0001077
Pedro Marronetti
P. Marronetti (1), M. Huq (2), P. Laguna (2), L. Lehner (1), R. Matzner (1), D. Shoemaker (2). ((1) The University of Texas at Austin, (2) Penn State University)
Approximate Analytical Solutions to the Initial Data Problem of Black Hole Binary Systems
6 pages, 5 postscript figures. Minor changes and some points clarified. Accepted for publication in Phys. Rev. D
Phys.Rev. D62 (2000) 024017
10.1103/PhysRevD.62.024017
null
gr-qc
null
We present approximate analytical solutions to the Hamiltonian and momentum constraint equations, corresponding to systems composed of two black holes with arbitrary linear and angular momentum. The analytical nature of these initial data solutions makes them easier to implement in numerical evolutions than the tradi...
[ { "created": "Mon, 24 Jan 2000 23:03:16 GMT", "version": "v1" }, { "created": "Mon, 10 Apr 2000 21:31:41 GMT", "version": "v2" } ]
2009-10-31
[ [ "Marronetti", "P.", "" ], [ "Huq", "M.", "" ], [ "Laguna", "P.", "" ], [ "Lehner", "L.", "" ], [ "Matzner", "R.", "" ], [ "Shoemaker", "D.", "" ], [ ".", "", "" ] ]
We present approximate analytical solutions to the Hamiltonian and momentum constraint equations, corresponding to systems composed of two black holes with arbitrary linear and angular momentum. The analytical nature of these initial data solutions makes them easier to implement in numerical evolutions than the traditi...
2208.00618
Reggie Pantig
Nikko John Leo S. Lobos, Reggie C. Pantig
Generalized Extended Uncertainty Principle Black Holes: Shadow and lensing in the macro- and microscopic realms
9 pages, 7 figures
Physics 2022, 4, 13181330
10.3390/physics4040084
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the recent work about the Extended Uncertainty Principle (EUP) black holes \cite{Mureika:2018gxl}, we present in this study its extension called the Generalized Extended Uncertainty Principle (GEUP) black holes. In particular, we investigated the GEUP effects on astrophysical and micro-black holes. First...
[ { "created": "Mon, 1 Aug 2022 05:37:51 GMT", "version": "v1" }, { "created": "Thu, 7 Dec 2023 04:42:09 GMT", "version": "v2" } ]
2023-12-08
[ [ "Lobos", "Nikko John Leo S.", "" ], [ "Pantig", "Reggie C.", "" ] ]
Motivated by the recent work about the Extended Uncertainty Principle (EUP) black holes \cite{Mureika:2018gxl}, we present in this study its extension called the Generalized Extended Uncertainty Principle (GEUP) black holes. In particular, we investigated the GEUP effects on astrophysical and micro-black holes. First, ...
1201.5433
Carla Cederbaum
Carla Cederbaum
The Newtonian Limit of Geometrostatics
111 pages, 1 figure, dissertation
null
null
null
gr-qc math.AP math.DG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This thesis discusses the Newtonian limit of General Relativity for static isolated systems with compactly supported matter. We call these systems "geometrostatic" to underline their geometric nature. We introduce new quasi-local notions of mass and center of mass that can be read off locally in the vicinity of the m...
[ { "created": "Thu, 26 Jan 2012 02:53:48 GMT", "version": "v1" } ]
2012-01-27
[ [ "Cederbaum", "Carla", "" ] ]
This thesis discusses the Newtonian limit of General Relativity for static isolated systems with compactly supported matter. We call these systems "geometrostatic" to underline their geometric nature. We introduce new quasi-local notions of mass and center of mass that can be read off locally in the vicinity of the mat...
2402.17312
Ameek Malhotra
N. M. Jim\'enez Cruz, Ameek Malhotra, Gianmassimo Tasinato, Ivonne Zavala
Measuring kinematic anisotropies with pulsar timing arrays
29 pages, 6 figures. V2: corrected upper limit, updated forecasts
null
null
null
gr-qc astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Recent Pulsar Timing Array (PTA) collaborations show strong evidence for a stochastic gravitational wave background (SGWB) with the characteristic Hellings-Downs inter-pulsar correlations. The signal may stem from supermassive black hole binary mergers, or early universe phenomena. The former is expected to be strong...
[ { "created": "Tue, 27 Feb 2024 08:33:31 GMT", "version": "v1" }, { "created": "Fri, 7 Jun 2024 14:03:59 GMT", "version": "v2" } ]
2024-06-10
[ [ "Cruz", "N. M. Jiménez", "" ], [ "Malhotra", "Ameek", "" ], [ "Tasinato", "Gianmassimo", "" ], [ "Zavala", "Ivonne", "" ] ]
Recent Pulsar Timing Array (PTA) collaborations show strong evidence for a stochastic gravitational wave background (SGWB) with the characteristic Hellings-Downs inter-pulsar correlations. The signal may stem from supermassive black hole binary mergers, or early universe phenomena. The former is expected to be strongly...
2107.00620
Andronikos Paliathanasis
Andronikos Paliathanasis
$f(T)$ Cosmology with Nonzero Curvature
13 pages, no figures, reference list updated
null
10.1142/S0217732321502618
null
gr-qc math-ph math.MP
http://creativecommons.org/licenses/by/4.0/
We investigate exact and analytic solutions in $f\left( T\right) $ gravity within the context of a Friedmann--Lema\^{\i}tre--Robertson--Walker background space with nonzero spatial curvature. For the power law theory $f\left( T\right) =T^{n}$ we find that the field equations admit an exact solution with a linear scal...
[ { "created": "Thu, 1 Jul 2021 17:16:39 GMT", "version": "v1" }, { "created": "Sat, 3 Jul 2021 15:43:00 GMT", "version": "v2" } ]
2022-01-05
[ [ "Paliathanasis", "Andronikos", "" ] ]
We investigate exact and analytic solutions in $f\left( T\right) $ gravity within the context of a Friedmann--Lema\^{\i}tre--Robertson--Walker background space with nonzero spatial curvature. For the power law theory $f\left( T\right) =T^{n}$ we find that the field equations admit an exact solution with a linear scalar...
1205.4452
Paul Wesson
Paul S. Wesson
Particles, Waves and Vacuum in Five Dimensions: A Status Report
null
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Since the 5D canonical metric embeds all 4D vacuum solutions of Einstein's equations, I review its application to the cosmological 'constant', quantized particles, deBroglie waves, scalar fields and wave-particle duality. There are several ways to ra-tionalize these things using an extra dimension. A possible explana...
[ { "created": "Sun, 20 May 2012 19:56:07 GMT", "version": "v1" } ]
2012-05-22
[ [ "Wesson", "Paul S.", "" ] ]
Since the 5D canonical metric embeds all 4D vacuum solutions of Einstein's equations, I review its application to the cosmological 'constant', quantized particles, deBroglie waves, scalar fields and wave-particle duality. There are several ways to ra-tionalize these things using an extra dimension. A possible explanati...
1409.1018
C. Q. Geng
Chao-Qiang Geng, Chang Lai, Ling-Wei Luo, Huan-Hsin Tseng
Kaluza-Klein theory for teleparallel gravity
8 pages, no figure, Phys. Lett. B737 (2014) 248-250
Phys. Lett. B737 (2014) 248-250
10.1016/j.physletb.2014.08.055
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study teleparallel gravity in the \emph{original} Kaluza-Klein (KK) scenario. Our calculation of the KK reduction of teleparallel gravity indicates that the 5-dimensional torsion scalar $^{(5)}T$ generates the non-Brans-Dicke type effective Lagrangian in 4-dimension due to an additional coupling between the deriva...
[ { "created": "Wed, 3 Sep 2014 10:08:41 GMT", "version": "v1" } ]
2014-09-04
[ [ "Geng", "Chao-Qiang", "" ], [ "Lai", "Chang", "" ], [ "Luo", "Ling-Wei", "" ], [ "Tseng", "Huan-Hsin", "" ] ]
We study teleparallel gravity in the \emph{original} Kaluza-Klein (KK) scenario. Our calculation of the KK reduction of teleparallel gravity indicates that the 5-dimensional torsion scalar $^{(5)}T$ generates the non-Brans-Dicke type effective Lagrangian in 4-dimension due to an additional coupling between the derivati...
gr-qc/9410019
Peter Marzlin
Karl-Peter Marzlin
The Dipole Coupling of Atoms and Light in Gravitational Fields
10 pages, LaTeX
Phys.Rev. A51 (1995) 625
10.1103/PhysRevA.51.625
null
gr-qc
null
The dipole coupling term between a system of N particles with total charge zero and the electromagnetic field is derived in the presence of a weak gravitational field. It is shown that the form of the coupling remains the same as in flat space-time if it is written with respect to the proper time of the observer and ...
[ { "created": "Mon, 17 Oct 1994 11:50:28 GMT", "version": "v1" } ]
2009-10-22
[ [ "Marzlin", "Karl-Peter", "" ] ]
The dipole coupling term between a system of N particles with total charge zero and the electromagnetic field is derived in the presence of a weak gravitational field. It is shown that the form of the coupling remains the same as in flat space-time if it is written with respect to the proper time of the observer and to...
1205.5087
Shahar Hod
Shahar Hod
Quasinormal resonances of a charged scalar field in a charged Reissner-Nordstr\"om black hole spacetime: A WKB analysis
5 pages. arXiv admin note: text overlap with arXiv:1109.4080
Phys. Lett. B {\bf 710}, 349 (2012)
10.1016/j.physletb.2012.03.010
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The fundamental quasinormal resonances of charged Reissner-Nordstr\"om black holes due to charged scalar perturbations are derived {\it analytically}. In the WKB regime, $qQ\gg\hbar$, we obtain a simple expression for the fundamental quasinormal resonances: $\omega=qQ/r_+-i2\pi T_{\text{BH}}(n+{1 \over 2})$, where $T...
[ { "created": "Wed, 23 May 2012 03:57:16 GMT", "version": "v1" } ]
2015-06-05
[ [ "Hod", "Shahar", "" ] ]
The fundamental quasinormal resonances of charged Reissner-Nordstr\"om black holes due to charged scalar perturbations are derived {\it analytically}. In the WKB regime, $qQ\gg\hbar$, we obtain a simple expression for the fundamental quasinormal resonances: $\omega=qQ/r_+-i2\pi T_{\text{BH}}(n+{1 \over 2})$, where $T_{...
2106.03177
Vinod Bhardwaj Dr.
Vinod Kumar Bhardwaj, Anirudh Pradhan
Evaluation of cosmological models in $f(R, T)$ gravity in different dark energy scenario
20 pages, 16 figures
null
10.1016/j.newast.2021.101675
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In present paper, we search the existence of dark energy scalar field models within in $f(R, T)$ gravity theory established by Harko et al. (Phys. Rev. D 84, 024020, 2011) in a flat FRW universe. The correspondence between scalar field models have been examined by employing new generalized dynamical cosmological term...
[ { "created": "Sun, 6 Jun 2021 16:49:58 GMT", "version": "v1" } ]
2021-09-08
[ [ "Bhardwaj", "Vinod Kumar", "" ], [ "Pradhan", "Anirudh", "" ] ]
In present paper, we search the existence of dark energy scalar field models within in $f(R, T)$ gravity theory established by Harko et al. (Phys. Rev. D 84, 024020, 2011) in a flat FRW universe. The correspondence between scalar field models have been examined by employing new generalized dynamical cosmological term $...
2408.05417
Shaoyu Yin
Zibo Shen, Anzhong Wang, Shaoyu Yin
A Class of Analytical Models for Black holes Surrounded by Dark Matter Halos
5 pages, no figures
null
null
null
gr-qc astro-ph.CO hep-ph
http://creativecommons.org/licenses/by/4.0/
We present a class of analytic models for a dark matter halo surrounding a Schwarzschild black hole sitting at the center of a galaxy, with a variable inner radius $r_{\text{in}}$, at which the density profile of the dark matter halo vanishes. We examine in detail how the three energy conditions are satisfied in such...
[ { "created": "Sat, 10 Aug 2024 03:00:08 GMT", "version": "v1" } ]
2024-08-13
[ [ "Shen", "Zibo", "" ], [ "Wang", "Anzhong", "" ], [ "Yin", "Shaoyu", "" ] ]
We present a class of analytic models for a dark matter halo surrounding a Schwarzschild black hole sitting at the center of a galaxy, with a variable inner radius $r_{\text{in}}$, at which the density profile of the dark matter halo vanishes. We examine in detail how the three energy conditions are satisfied in such m...
1507.01153
Andrea Dapor
Emanuele Alesci, Andrea Dapor, Jerzy Lewandowski, Ilkka Makinen, Jan Sikorski
Coherent State Operators in Loop Quantum Gravity
34 pages, 4 figures (plus many pretty diagrams)
Phys. Rev. D 92, 104023 (2015)
10.1103/PhysRevD.92.104023
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new method for constructing operators in loop quantum gravity. The construction is an application of the general idea of "coherent state quantization", which allows one to associate a unique quantum operator to every function on a classical phase space. Using the heat kernel coherent states of Hall and T...
[ { "created": "Sat, 4 Jul 2015 23:07:28 GMT", "version": "v1" } ]
2015-11-18
[ [ "Alesci", "Emanuele", "" ], [ "Dapor", "Andrea", "" ], [ "Lewandowski", "Jerzy", "" ], [ "Makinen", "Ilkka", "" ], [ "Sikorski", "Jan", "" ] ]
We present a new method for constructing operators in loop quantum gravity. The construction is an application of the general idea of "coherent state quantization", which allows one to associate a unique quantum operator to every function on a classical phase space. Using the heat kernel coherent states of Hall and Thi...
2010.05945
Tanuman Ghosh
Tanuman Ghosh (RRI), Banibrata Mukhopadhyay (IISc)
Geometric phase for Dirac Hamiltonian under gravitational fields in the non-relativistic regime
15 pages including 1 figure, slightly modified title; version to appear in IJMPD
null
10.1142/S0218271821500905
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show the appearance of geometric phase in a Dirac particle traversing in non-relativistic limit in a time-independent gravitational field. This turns out to be similar to the one originally described as a geometric phase in magnetic fields. We explore the geometric phase in the Kerr and Schwarzschild geometries, w...
[ { "created": "Mon, 12 Oct 2020 18:08:45 GMT", "version": "v1" }, { "created": "Mon, 28 Jun 2021 15:17:21 GMT", "version": "v2" } ]
2021-10-27
[ [ "Ghosh", "Tanuman", "", "RRI" ], [ "Mukhopadhyay", "Banibrata", "", "IISc" ] ]
We show the appearance of geometric phase in a Dirac particle traversing in non-relativistic limit in a time-independent gravitational field. This turns out to be similar to the one originally described as a geometric phase in magnetic fields. We explore the geometric phase in the Kerr and Schwarzschild geometries, whi...
gr-qc/0606104
Frank L\"offler
Frank L\"offler, Luciano Rezzolla, Marcus Ansorg
Numerical evolutions of a black hole-neutron star system in full General Relativity: I. Head-on collision
16 pages, 12 figures
Phys. Rev. D 74, 104018 (2006)
10.1103/PhysRevD.74.104018
null
gr-qc
null
We present the first simulations in full General Relativity of the head-on collision between a neutron star and a black hole of comparable mass. These simulations are performed through the solution of the Einstein equations combined with an accurate solution of the relativistic hydrodynamics equations via high-resolu...
[ { "created": "Fri, 23 Jun 2006 15:21:10 GMT", "version": "v1" }, { "created": "Thu, 28 Jun 2007 07:56:06 GMT", "version": "v2" } ]
2009-11-11
[ [ "Löffler", "Frank", "" ], [ "Rezzolla", "Luciano", "" ], [ "Ansorg", "Marcus", "" ] ]
We present the first simulations in full General Relativity of the head-on collision between a neutron star and a black hole of comparable mass. These simulations are performed through the solution of the Einstein equations combined with an accurate solution of the relativistic hydrodynamics equations via high-resoluti...
1008.1776
Thomas-Paul Hack
Thomas-Paul Hack
On the Backreaction of Scalar and Spinor Quantum Fields in Curved Spacetimes - From the Basic Foundations to Cosmological Applications
Ph.D. thesis, 262 pages, 5 figures
null
null
DESY-THESIS-2010-042
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
First, the present work is concerned with generalising constructions and results in quantum field theory on curved spacetimes from the well-known case of the Klein-Gordon field to Dirac fields. To this end, the enlarged algebra of observables of the Dirac field is constructed in the algebraic framework. This algebra ...
[ { "created": "Tue, 10 Aug 2010 19:21:24 GMT", "version": "v1" } ]
2010-10-22
[ [ "Hack", "Thomas-Paul", "" ] ]
First, the present work is concerned with generalising constructions and results in quantum field theory on curved spacetimes from the well-known case of the Klein-Gordon field to Dirac fields. To this end, the enlarged algebra of observables of the Dirac field is constructed in the algebraic framework. This algebra co...
2103.01249
Mariam Bouhmadi-Lopez
Che-Yu Chen, Mariam Bouhmadi-L\'opez, Pisin Chen
Lessons from black hole quasinormal modes in modified gravity
12 pages, 8 figures
Eur. Phys. J. Plus 136, (2021) no.2, 253
10.1140/epjp/s13360-021-01227-z
null
gr-qc astro-ph.GA hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quasinormal modes of perturbed black holes have recently gained much interest because of their tight relations with the gravitational wave signals emitted during the post-merger phase of a binary black hole coalescence. One of the intriguing features of these modes is that they respect the no-hair theorem, and hence,...
[ { "created": "Mon, 1 Mar 2021 19:02:11 GMT", "version": "v1" } ]
2021-03-03
[ [ "Chen", "Che-Yu", "" ], [ "Bouhmadi-López", "Mariam", "" ], [ "Chen", "Pisin", "" ] ]
Quasinormal modes of perturbed black holes have recently gained much interest because of their tight relations with the gravitational wave signals emitted during the post-merger phase of a binary black hole coalescence. One of the intriguing features of these modes is that they respect the no-hair theorem, and hence, t...
0901.2063
Romeo Brunetti
Romeo Brunetti, Klaus Fredenhagen
Quantum Field Theory on Curved Backgrounds
19 pages, submitted for the Proceedings of the Kompaktkurs "Quantenfeldtheorie auf gekruemmten Raumzeiten" held at Universitaet Potsdam, Germany, in 8.-12.10.2007, organized by C. Baer and K. Fredenhagen
null
10.1007/978-3-642-02780-2_5
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the status of (scalar) quantum field theory on curved spacetimes using a novel formulation in terms of non linear functionals over the smooth configuration fields. In particular, this entails also a new foundation of locally covariant classical field theory. For all that, methods from microlocal analysis co...
[ { "created": "Wed, 14 Jan 2009 16:52:38 GMT", "version": "v1" } ]
2015-05-13
[ [ "Brunetti", "Romeo", "" ], [ "Fredenhagen", "Klaus", "" ] ]
We review the status of (scalar) quantum field theory on curved spacetimes using a novel formulation in terms of non linear functionals over the smooth configuration fields. In particular, this entails also a new foundation of locally covariant classical field theory. For all that, methods from microlocal analysis comb...
gr-qc/9312003
Piotr Koc
Janusz Karkowski, Piotr Koc, Zdobyslaw Swierczynski
Penrose Inequality for Gravitational Waves
5 pages, emTeX Version 3.0 [3a]. Submited to Class. and Quantum Grav
Class.Quant.Grav.11:1535-1538,1994
10.1088/0264-9381/11/6/017
null
gr-qc
null
We investigate axially symmetric asymptotically flat vacuum self-gravitating system. A class of initial data with apparent horizon was numerically constructed. The examined solutions satisfy the Penrose inequality. The prior analysis of a massive system and the present results suggest that either massive or sourcefre...
[ { "created": "Thu, 2 Dec 1993 10:55:09 GMT", "version": "v1" } ]
2010-04-06
[ [ "Karkowski", "Janusz", "" ], [ "Koc", "Piotr", "" ], [ "Swierczynski", "Zdobyslaw", "" ] ]
We investigate axially symmetric asymptotically flat vacuum self-gravitating system. A class of initial data with apparent horizon was numerically constructed. The examined solutions satisfy the Penrose inequality. The prior analysis of a massive system and the present results suggest that either massive or sourcefree ...
2301.00025
Jahed Abedi
Jahed Abedi
Search for echoes on the edge of quantum black holes
6 pages, 4 figures
null
null
null
gr-qc astro-ph.CO astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I perform an unprecedented template-based search for stimulated emission of Hawking radiation (or Boltzmann echoes) by combining the gravitational wave data from 65 binary black hole merger events observed by the LIGO/Virgo collaboration. With a careful Bayesian inference approach, I found no statistically significan...
[ { "created": "Fri, 30 Dec 2022 19:00:05 GMT", "version": "v1" } ]
2023-01-03
[ [ "Abedi", "Jahed", "" ] ]
I perform an unprecedented template-based search for stimulated emission of Hawking radiation (or Boltzmann echoes) by combining the gravitational wave data from 65 binary black hole merger events observed by the LIGO/Virgo collaboration. With a careful Bayesian inference approach, I found no statistically significant ...
1811.05778
Tanmoy Paul
Tanmoy Paul and Soumitra SenGupta
Scalaron tunneling and the fate of antisymmetric tensor fields in $F(R)$ gravity
12 pages, 4 figures, additional calculations, figures and references. CQG accepted
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The work provides a possible explanation of a well motivated question - why the present universe is practically free from any noticeable footmarks of higher rank antisymmetric tensor fields, despite having the signatures of scalar, vector, fermion as well as symmetric rank 2 tensor field in the form of gravity ? The ...
[ { "created": "Tue, 13 Nov 2018 05:01:13 GMT", "version": "v1" }, { "created": "Wed, 16 Sep 2020 15:24:25 GMT", "version": "v2" } ]
2020-09-17
[ [ "Paul", "Tanmoy", "" ], [ "SenGupta", "Soumitra", "" ] ]
The work provides a possible explanation of a well motivated question - why the present universe is practically free from any noticeable footmarks of higher rank antisymmetric tensor fields, despite having the signatures of scalar, vector, fermion as well as symmetric rank 2 tensor field in the form of gravity ? The ex...
1404.5371
P. A. Gonzalez
P. A. Gonzalez and Yerko Vasquez
Dirac Quasinormal Modes of New Type Black Holes in New Massive Gravity
improved version. arXiv admin note: text overlap with arXiv:1306.5974, arXiv:1404.3172
null
10.1140/epjc/s10052-014-2969-1
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study new type black holes in three-dimensional New Massive Gravity and we calculate analytically the quasinormal modes for fermionic perturbations for some special cases. Then, we show that for these cases the new type black holes are stable under fermionic field perturbations.
[ { "created": "Tue, 22 Apr 2014 02:45:38 GMT", "version": "v1" }, { "created": "Mon, 28 Apr 2014 15:37:00 GMT", "version": "v2" } ]
2015-06-19
[ [ "Gonzalez", "P. A.", "" ], [ "Vasquez", "Yerko", "" ] ]
We study new type black holes in three-dimensional New Massive Gravity and we calculate analytically the quasinormal modes for fermionic perturbations for some special cases. Then, we show that for these cases the new type black holes are stable under fermionic field perturbations.
2401.15134
Ahmad Al-Badawi
Ahmad Al-Badawi and M.Q. Owaidat
Particle dynamics and shadow of a regular non-minimal magnetic black hole
null
General Relativity and Gravitation, (2023) 55:131
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study the dynamics of a test particle around a regular black hole (BH) in a non-minimal Einstein Yang Mills (EYM) theory and examine the BH shadow. The EYM theory is a non-minimally coupled theory in which curvature couples to non-Abelian gauge fields. We investigate particle motion with parameters ...
[ { "created": "Fri, 26 Jan 2024 17:05:40 GMT", "version": "v1" } ]
2024-01-30
[ [ "Al-Badawi", "Ahmad", "" ], [ "Owaidat", "M. Q.", "" ] ]
In this paper, we study the dynamics of a test particle around a regular black hole (BH) in a non-minimal Einstein Yang Mills (EYM) theory and examine the BH shadow. The EYM theory is a non-minimally coupled theory in which curvature couples to non-Abelian gauge fields. We investigate particle motion with parameters in...
2007.09413
Oleg Zaslavskii
O. B. Zaslavskii
Can a nonextremal black hole be a particle accelerator?
19 pages. Typose corrected. Matches published version
Phys. Rev. D 102, 104004 (2020)
10.1103/PhysRevD.102.104004
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider particle collisions in the background of a nonextremal black hole. Two particles fall from infinity, particle 1 is fine-tuned (critical), collision occurs in its turning point. The first example is the Reissner-Nordstr\"{o}m (RN) one. If the energy at infinity $E_{1}$ is big enough, the turning point is c...
[ { "created": "Sat, 18 Jul 2020 11:46:45 GMT", "version": "v1" }, { "created": "Thu, 1 Oct 2020 15:25:34 GMT", "version": "v2" }, { "created": "Sat, 7 Nov 2020 12:17:27 GMT", "version": "v3" } ]
2020-11-11
[ [ "Zaslavskii", "O. B.", "" ] ]
We consider particle collisions in the background of a nonextremal black hole. Two particles fall from infinity, particle 1 is fine-tuned (critical), collision occurs in its turning point. The first example is the Reissner-Nordstr\"{o}m (RN) one. If the energy at infinity $E_{1}$ is big enough, the turning point is clo...
2002.00377
Lunchakorn Tannukij
Lunchakorn Tannukij, Pitayuth Wongjun, Ekapong Hirunsirisawat, Tanapat Deesuwan, Chatchai Promsiri
Thermodynamics and Phase Transition of Spherically Symmetric Black Hole in de Sitter Space from R\'enyi Statistics
19 pages, 7 figures
Eur. Phys. J. Plus 135, 500 (2020)
10.1140/epjp/s13360-020-00517-2
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Schwarzschild black holes in a de Sitter background were studied in terms of their thermodynamics based on the R\'enyi statistics. This led to thermodynamically stable black hole configurations for some certain range of black hole radii; namely within this range the corresponding black holes have positive heat capaci...
[ { "created": "Sun, 2 Feb 2020 12:22:50 GMT", "version": "v1" } ]
2020-07-10
[ [ "Tannukij", "Lunchakorn", "" ], [ "Wongjun", "Pitayuth", "" ], [ "Hirunsirisawat", "Ekapong", "" ], [ "Deesuwan", "Tanapat", "" ], [ "Promsiri", "Chatchai", "" ] ]
Schwarzschild black holes in a de Sitter background were studied in terms of their thermodynamics based on the R\'enyi statistics. This led to thermodynamically stable black hole configurations for some certain range of black hole radii; namely within this range the corresponding black holes have positive heat capacity...
2307.01903
Marius Adrian Oancea
Marius A. Oancea, Richard Stiskalek, Miguel Zumalac\'arregui
Probing general relativistic spin-orbit coupling with gravitational waves from hierarchical triple systems
null
null
null
null
gr-qc astro-ph.GA astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Wave packets propagating in inhomogeneous media experience a coupling between internal and external degrees of freedom and, as a consequence, follow spin-dependent trajectories. These are known as spin Hall effects, which are well known in optics and condensed matter physics. Similarly, the gravitational spin Hall ef...
[ { "created": "Tue, 4 Jul 2023 20:18:09 GMT", "version": "v1" } ]
2023-07-06
[ [ "Oancea", "Marius A.", "" ], [ "Stiskalek", "Richard", "" ], [ "Zumalacárregui", "Miguel", "" ] ]
Wave packets propagating in inhomogeneous media experience a coupling between internal and external degrees of freedom and, as a consequence, follow spin-dependent trajectories. These are known as spin Hall effects, which are well known in optics and condensed matter physics. Similarly, the gravitational spin Hall effe...
gr-qc/0407020
Alberto Saa
Alberto Saa
On the viability of local criteria for chaos
10 pages
Annals Phys. 314 (2004) 508-516
10.1016/j.aop.2004.08.008
null
gr-qc
null
We consider here a recently proposed geometrical criterion for local instability based on the geodesic deviation equation. Although such a criterion can be useful in some cases, we show here that, in general, it is neither necessary nor sufficient for the occurrence of chaos. To this purpose, we introduce a class of ...
[ { "created": "Tue, 6 Jul 2004 01:29:49 GMT", "version": "v1" } ]
2009-11-10
[ [ "Saa", "Alberto", "" ] ]
We consider here a recently proposed geometrical criterion for local instability based on the geodesic deviation equation. Although such a criterion can be useful in some cases, we show here that, in general, it is neither necessary nor sufficient for the occurrence of chaos. To this purpose, we introduce a class of ch...
gr-qc/9706065
Janna Levin
John D. Barrow and Janna Levin
Chaos in the Einstein-Yang-Mills Equations
3 pages LaTeX + 3 pages of figures
Phys.Rev.Lett. 80 (1998) 656-659
10.1103/PhysRevLett.80.656
null
gr-qc hep-th
null
Yang-Mills color fields evolve chaotically in an anisotropically expanding universe. The chaotic behaviour differs from that found in anisotropic Mixmaster universes. The universe isotropizes at late times, approaching the mean expansion rate of a radiation-dominated universe. However, small chaotic oscillations of t...
[ { "created": "Fri, 20 Jun 1997 19:30:27 GMT", "version": "v1" } ]
2009-10-30
[ [ "Barrow", "John D.", "" ], [ "Levin", "Janna", "" ] ]
Yang-Mills color fields evolve chaotically in an anisotropically expanding universe. The chaotic behaviour differs from that found in anisotropic Mixmaster universes. The universe isotropizes at late times, approaching the mean expansion rate of a radiation-dominated universe. However, small chaotic oscillations of the...
2404.06986
Shahram Jalalzadeh
R. Jalalzadeh, S. Jalalzadeh, A. Sayahian Jahromi, and H. Moradpour
Friedmann equations of the fractal apparent horizon
9 pages, 6 figures, to appear in Physics of the Dark Universe
null
null
null
gr-qc astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
From a fractal perspective, the entropy bound of gravitational systems undergoes changes. Furthermore, in the cosmological setting, the conservation law of a perfect fluid is also altered in such systems, affecting spatial elements like volume, area, and radius. By applying the first law of thermodynamics and derivin...
[ { "created": "Wed, 10 Apr 2024 13:01:52 GMT", "version": "v1" } ]
2024-04-11
[ [ "Jalalzadeh", "R.", "" ], [ "Jalalzadeh", "S.", "" ], [ "Jahromi", "A. Sayahian", "" ], [ "Moradpour", "H.", "" ] ]
From a fractal perspective, the entropy bound of gravitational systems undergoes changes. Furthermore, in the cosmological setting, the conservation law of a perfect fluid is also altered in such systems, affecting spatial elements like volume, area, and radius. By applying the first law of thermodynamics and deriving ...
1807.01157
Ritika Nagpal
J. K. Singh, Kazuharu Bamba, Ritika Nagpal, S. K. J. Pacif
Bouncing cosmology in $f(R,T)$ gravity
null
Phys.Rev. D97 (2018) no.12, 123536
10.1103/PhysRevD.97.123536
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A cosmological model with a specific form of the Hubble parameter is constructed in a flat homogeneous, and isotropic background in the framework of $f(R, T)$ gravity, where $R$ is the scalar curvature and $T$ is the trace of the stress-energy-momentum tensor. The proposed functional form of the Hubble parameter is t...
[ { "created": "Sat, 30 Jun 2018 16:32:37 GMT", "version": "v1" } ]
2018-07-04
[ [ "Singh", "J. K.", "" ], [ "Bamba", "Kazuharu", "" ], [ "Nagpal", "Ritika", "" ], [ "Pacif", "S. K. J.", "" ] ]
A cosmological model with a specific form of the Hubble parameter is constructed in a flat homogeneous, and isotropic background in the framework of $f(R, T)$ gravity, where $R$ is the scalar curvature and $T$ is the trace of the stress-energy-momentum tensor. The proposed functional form of the Hubble parameter is tak...
1006.5272
Lau Loi So
Lau Loi So
An unique alternative non-negative gravitational energy tensor to the Bel-Robinson tensor in the quasilocal small sphere limit
13 pages, a major revision of arXiv:0901.4828
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Bel-Robinson tensor $B_{\alpha\beta\mu\nu}$ gives a positive definite gravitational energy in the quasilocal small sphere limit approximation. However, there is an alternative tensor $V_{\alpha\beta\mu\nu}$ that was proposed recently that offers the same positivity as $B_{\alpha\beta\mu\nu}$ does. We have found t...
[ { "created": "Mon, 28 Jun 2010 06:37:27 GMT", "version": "v1" } ]
2010-06-29
[ [ "So", "Lau Loi", "" ] ]
The Bel-Robinson tensor $B_{\alpha\beta\mu\nu}$ gives a positive definite gravitational energy in the quasilocal small sphere limit approximation. However, there is an alternative tensor $V_{\alpha\beta\mu\nu}$ that was proposed recently that offers the same positivity as $B_{\alpha\beta\mu\nu}$ does. We have found tha...
1304.5627
Muxin Han
Muxin Han
On Spinfoam Models in Large Spin Regime
20 pages, no figure, presentation improved, published version
Class. Quantum Grav. 31 (2014) 015004
10.1088/0264-9381/31/1/015004
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the semiclassical behavior of Lorentzian Engle-Pereira-Rovelli-Livine (EPRL) spinfoam model, by taking into account the sum over spins in the large spin regime. We also employ the method of stationary phase analysis with parameters and the so called, almost-analytic machinery, in order to find the asymptotic...
[ { "created": "Sat, 20 Apr 2013 12:34:57 GMT", "version": "v1" }, { "created": "Wed, 21 Aug 2013 16:50:27 GMT", "version": "v2" }, { "created": "Fri, 15 Nov 2013 11:55:08 GMT", "version": "v3" } ]
2013-11-18
[ [ "Han", "Muxin", "" ] ]
We study the semiclassical behavior of Lorentzian Engle-Pereira-Rovelli-Livine (EPRL) spinfoam model, by taking into account the sum over spins in the large spin regime. We also employ the method of stationary phase analysis with parameters and the so called, almost-analytic machinery, in order to find the asymptotic b...
1306.6087
Joseph Keir
Joe Keir
Stability, Instability, Canonical Energy and Charged Black Holes
31 pages
null
10.1088/0264-9381/31/3/035014
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use the canonical energy method of Hollands and Wald to study the stability properties of asymptotically flat, stationary solutions to a very general class of theories, consisting of a set of coupled scalar fields and p-form gauge fields, minimally coupled to gravity. We find that, provided certain very weak assum...
[ { "created": "Tue, 25 Jun 2013 20:41:57 GMT", "version": "v1" } ]
2015-06-16
[ [ "Keir", "Joe", "" ] ]
We use the canonical energy method of Hollands and Wald to study the stability properties of asymptotically flat, stationary solutions to a very general class of theories, consisting of a set of coupled scalar fields and p-form gauge fields, minimally coupled to gravity. We find that, provided certain very weak assumpt...
gr-qc/0307108
Pavel Krtous
Jiri Podolsky, Marcello Ortaggio, and Pavel Krtous
Radiation from accelerated black holes in an anti-de Sitter universe
19 pages, 11 colour figures, submitted to Phys. Rev. D [Low quality figures are included in this version because of arXive size restrictions. The version with the standard quality figures is available at http://utf.mff.cuni.cz/~podolsky/jppubl.htm.]
Phys.Rev. D68 (2003) 124004
10.1103/PhysRevD.68.124004
null
gr-qc hep-th
null
We study gravitational and electromagnetic radiation generated by uniformly accelerated charged black holes in anti-de Sitter spacetime. This is described by the C-metric exact solution of the Einstein-Maxwell equations with a negative cosmological constant Lambda. We explicitly find and interpret the pattern of radi...
[ { "created": "Fri, 25 Jul 2003 16:37:06 GMT", "version": "v1" }, { "created": "Tue, 2 Dec 2003 15:05:04 GMT", "version": "v2" } ]
2007-05-23
[ [ "Podolsky", "Jiri", "" ], [ "Ortaggio", "Marcello", "" ], [ "Krtous", "Pavel", "" ] ]
We study gravitational and electromagnetic radiation generated by uniformly accelerated charged black holes in anti-de Sitter spacetime. This is described by the C-metric exact solution of the Einstein-Maxwell equations with a negative cosmological constant Lambda. We explicitly find and interpret the pattern of radiat...
2203.03536
Federico De Lillo
Federico De Lillo, Jishnu Suresh, Andrew L. Miller
Stochastic gravitational-wave background searches and constraints on neutron-star ellipticity
10 pages, 6 figures, 2 tables
null
10.1093/mnras/stac984
LIGO-P2200050
gr-qc astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Rotating neutron stars (NSs) are promising sources of gravitational waves (GWs) in the frequency band of ground-based detectors. They are expected to emit quasi-monochromatic, long-duration GW signals, called continuous waves (CWs), due to their deviations from spherical symmetry. The degree of such deformations, and...
[ { "created": "Mon, 7 Mar 2022 17:41:09 GMT", "version": "v1" } ]
2022-04-20
[ [ "De Lillo", "Federico", "" ], [ "Suresh", "Jishnu", "" ], [ "Miller", "Andrew L.", "" ] ]
Rotating neutron stars (NSs) are promising sources of gravitational waves (GWs) in the frequency band of ground-based detectors. They are expected to emit quasi-monochromatic, long-duration GW signals, called continuous waves (CWs), due to their deviations from spherical symmetry. The degree of such deformations, and h...
2209.04348
Pardyumn Kumar Sahoo
Gaurav N. Gadbail, Simran Arora, Praveen Kumar, P.K. Sahoo
Interaction of divergence-free deceleration parameter in Weyl-type $f(Q,T)$ gravity
Chinese Journal of Physics published version
Chinese Journal of Physics, 79 (2022) 246-255
10.1016/j.cjph.2022.09.005
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We study an extension of symmetric teleparallel gravity i.e. Weyl-type $f(Q,T)$ gravity and the divergence-free parametrization of the deceleration parameter $q(z) = q_{0}+q_{1}\frac{z(1+z)}{1+z^2}$ ($q_{0}$ and $q_{1}$ are free constants) to explore the evolution of the universe. By considering the above parametric ...
[ { "created": "Thu, 8 Sep 2022 00:50:22 GMT", "version": "v1" } ]
2022-09-20
[ [ "Gadbail", "Gaurav N.", "" ], [ "Arora", "Simran", "" ], [ "Kumar", "Praveen", "" ], [ "Sahoo", "P. K.", "" ] ]
We study an extension of symmetric teleparallel gravity i.e. Weyl-type $f(Q,T)$ gravity and the divergence-free parametrization of the deceleration parameter $q(z) = q_{0}+q_{1}\frac{z(1+z)}{1+z^2}$ ($q_{0}$ and $q_{1}$ are free constants) to explore the evolution of the universe. By considering the above parametric fo...
2111.06990
David Reitze
Vicky Kalogera, B.S. Sathyaprakash, Matthew Bailes, Marie-Anne Bizouard, Alessandra Buonanno, Adam Burrows, Monica Colpi, Matt Evans, Stephen Fairhurst, Stefan Hild, Mansi M. Kasliwal, Luis Lehner, Ilya Mandel, Vuk Mandic, Samaya Nissanke, Maria Alessandra Papa, Sanjay Reddy, Stephan Rosswog, Chris Van Den Broe...
The Next Generation Global Gravitational Wave Observatory: The Science Book
69 pages, 18 figures
null
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
The next generation of ground-based gravitational-wave detectors will observe coalescences of black holes and neutron stars throughout the cosmos, thousands of them with exceptional fidelity. The Science Book is the result of a 3-year effort to study the science capabilities of networks of next generation detectors. ...
[ { "created": "Fri, 12 Nov 2021 23:46:10 GMT", "version": "v1" } ]
2021-11-16
[ [ "Kalogera", "Vicky", "" ], [ "Sathyaprakash", "B. S.", "" ], [ "Bailes", "Matthew", "" ], [ "Bizouard", "Marie-Anne", "" ], [ "Buonanno", "Alessandra", "" ], [ "Burrows", "Adam", "" ], [ "Colpi", "Monica", ...
The next generation of ground-based gravitational-wave detectors will observe coalescences of black holes and neutron stars throughout the cosmos, thousands of them with exceptional fidelity. The Science Book is the result of a 3-year effort to study the science capabilities of networks of next generation detectors. Su...
2402.09312
N. Rieger
N. E. Rieger
Topologies of maximally extended non-Hausdorff Misner Space
null
null
null
null
gr-qc math-ph math.DG math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Misner (1967) space is a portion of 2-dimensional Minkowski spacetime, identified under a boost $\mathcal B$. It is well known that the maximal analytic extension of Misner space that is Hausdorff consists of one half of Minkowski spacetime, identified under $\mathcal B$; and Hawking and Ellis (1973) have shown that ...
[ { "created": "Wed, 14 Feb 2024 16:59:06 GMT", "version": "v1" }, { "created": "Tue, 25 Jun 2024 21:52:49 GMT", "version": "v2" } ]
2024-06-27
[ [ "Rieger", "N. E.", "" ] ]
Misner (1967) space is a portion of 2-dimensional Minkowski spacetime, identified under a boost $\mathcal B$. It is well known that the maximal analytic extension of Misner space that is Hausdorff consists of one half of Minkowski spacetime, identified under $\mathcal B$; and Hawking and Ellis (1973) have shown that th...
0905.2742
Douglas A. Singleton
Emil T. Akhmedov, P. V. Buividovich, Douglas A. Singleton
De Sitter space and perpetuum mobile
11 pages revtex, no figures. Added discussion to strengthen conclusion
null
10.1134/S1063778812040023
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We give general arguments that any interacting non--conformal {\it classical} field theory in de Sitter space leads to the possibility of constructing a perpetuum mobile. The arguments are based on the observation that massive free falling particles can radiate other massive particles on the classical level as seen b...
[ { "created": "Sun, 17 May 2009 14:44:22 GMT", "version": "v1" }, { "created": "Fri, 1 Jan 2010 20:21:34 GMT", "version": "v2" }, { "created": "Sun, 14 Feb 2010 22:46:20 GMT", "version": "v3" } ]
2015-05-13
[ [ "Akhmedov", "Emil T.", "" ], [ "Buividovich", "P. V.", "" ], [ "Singleton", "Douglas A.", "" ] ]
We give general arguments that any interacting non--conformal {\it classical} field theory in de Sitter space leads to the possibility of constructing a perpetuum mobile. The arguments are based on the observation that massive free falling particles can radiate other massive particles on the classical level as seen by ...
0804.4326
Babak Vakili
B. Vakili, N. Khosravi and H. R. Sepangi
Thermodynamics of noncommutative de Sitter spacetime
11 pages, no figures, accepted for publication in IJMPD
Int.J.Mod.Phys.D18:159-171,2009
10.1142/S0218271809014297
null
gr-qc hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the effects of noncommutativity of spacetime geometry on the thermodynamical properties of the de Sitter horizon. We show that noncommutativity results in modifications in temperature, entropy and vacuum energy and that these modifications are of order of the Planck scale, suggesting that the size of the non...
[ { "created": "Mon, 28 Apr 2008 06:12:14 GMT", "version": "v1" } ]
2009-03-24
[ [ "Vakili", "B.", "" ], [ "Khosravi", "N.", "" ], [ "Sepangi", "H. R.", "" ] ]
We study the effects of noncommutativity of spacetime geometry on the thermodynamical properties of the de Sitter horizon. We show that noncommutativity results in modifications in temperature, entropy and vacuum energy and that these modifications are of order of the Planck scale, suggesting that the size of the nonco...
0902.4081
Sachie Shiomi
Sachie Shiomi
Testing gravitational physics with superconducting gravimeters
Proceedings for VIII Asia-Pacific International Conference on Gravitation and Astrophysics (ICGA8)
Progress of Theoretical Physics Supplement No. 172, 2008
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Superconducting gravimeters are the most sensitive instruments to measure surface gravity changes at low frequencies. Currently, about twenty five superconducting gravimeters are operating in the world and their global network has been developed. We investigate possible applications of the superconducting gravimeters...
[ { "created": "Tue, 24 Feb 2009 07:48:24 GMT", "version": "v1" } ]
2009-09-30
[ [ "Shiomi", "Sachie", "" ] ]
Superconducting gravimeters are the most sensitive instruments to measure surface gravity changes at low frequencies. Currently, about twenty five superconducting gravimeters are operating in the world and their global network has been developed. We investigate possible applications of the superconducting gravimeters t...
1706.03541
Jerzy Kr\'ol
Michael Heller and Jerzy Kr\'ol
Gravity in the smallest
19 pages
null
null
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Synthetic Differential Geometry (SDG) is a categorical version of differential geometry based on enriching the real line with infinitesimals and weakening of classical logic to intuitionistic logic. We show that SDG provides an effective mathematical tool to formulate general relativity in infinitesimally small domai...
[ { "created": "Mon, 12 Jun 2017 09:58:59 GMT", "version": "v1" } ]
2017-06-13
[ [ "Heller", "Michael", "" ], [ "Król", "Jerzy", "" ] ]
Synthetic Differential Geometry (SDG) is a categorical version of differential geometry based on enriching the real line with infinitesimals and weakening of classical logic to intuitionistic logic. We show that SDG provides an effective mathematical tool to formulate general relativity in infinitesimally small domains...
1212.0138
Xuefeng Zhang PhD
Xuefeng Zhang and Daniel Finley
Interpretation of twisting type N vacuum solutions with cosmological constant
12 pages
Class. Quantum Grav. 30 (2013) 075021
10.1088/0264-9381/30/7/075021
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate a new class of twisting type N vacuum solutions with nonzero (positive) cosmological constant Lambda by studying the equations of geodesic deviations along the privileged radial timelike geodesics, generalizing J. Bicak and J. Podolsky's results on non-twisting type N solutions. It is shown that these ...
[ { "created": "Sat, 1 Dec 2012 17:41:33 GMT", "version": "v1" }, { "created": "Thu, 14 Mar 2013 17:29:06 GMT", "version": "v2" } ]
2013-03-15
[ [ "Zhang", "Xuefeng", "" ], [ "Finley", "Daniel", "" ] ]
We investigate a new class of twisting type N vacuum solutions with nonzero (positive) cosmological constant Lambda by studying the equations of geodesic deviations along the privileged radial timelike geodesics, generalizing J. Bicak and J. Podolsky's results on non-twisting type N solutions. It is shown that these tw...
gr-qc/9812041
John T. Whelan
John T. Whelan (Uni. Bern) and Joseph D. Romano (U Texas-Brownsville)
Quasistationary binary inspiral. I. Einstein equations for the two Killing vector spacetime
37 pages, REVTeX, one PostScript Figure included with epsfig; minor formatting changes and copyright notice added for journal publication
Phys. Rev. D 60, 084009 (1999)
10.1103/PhysRevD.60.084009
null
gr-qc
null
The geometry of two infinitely long lines of mass moving in a fixed circular orbit is considered as a toy model for the inspiral of a binary system of compact objects due to gravitational radiation. The two Killing fields in the toy model are used, according to a formalism introduced by Geroch, to describe the geomet...
[ { "created": "Sat, 12 Dec 1998 07:28:26 GMT", "version": "v1" }, { "created": "Tue, 13 Apr 1999 21:31:03 GMT", "version": "v2" }, { "created": "Fri, 17 Sep 1999 12:41:15 GMT", "version": "v3" } ]
2016-08-25
[ [ "Whelan", "John T.", "", "Uni. Bern" ], [ "Romano", "Joseph D.", "", "U Texas-Brownsville" ] ]
The geometry of two infinitely long lines of mass moving in a fixed circular orbit is considered as a toy model for the inspiral of a binary system of compact objects due to gravitational radiation. The two Killing fields in the toy model are used, according to a formalism introduced by Geroch, to describe the geometry...
1605.00496
Giacomo Rosati
Giovanni Amelino-Camelia, Leonardo Barcaroli, Giacomo D'Amico, Niccol\'o Loret, Giacomo Rosati
IceCube and GRB neutrinos propagating in quantum spacetime
In V2 the possible helicity dependence of the effects (only mentioned in a footnote of V1) is discussed in the main text, and we give an estimate of possible values the parameters could take in order to produce the feature found in the data
Phys.Lett. B761 (2016) 318-325
10.1016/j.physletb.2016.07.075
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Two recent publications have reported intriguing analyses, tentatively suggesting that some aspects of IceCube data might be manifestations of quantum-gravity-modified laws of propagation for neutrinos. We here propose a strategy of data analysis which has the advantage of being applicable to several alternative poss...
[ { "created": "Mon, 2 May 2016 14:10:55 GMT", "version": "v1" }, { "created": "Thu, 12 May 2016 21:24:46 GMT", "version": "v2" } ]
2017-06-13
[ [ "Amelino-Camelia", "Giovanni", "" ], [ "Barcaroli", "Leonardo", "" ], [ "D'Amico", "Giacomo", "" ], [ "Loret", "Niccoló", "" ], [ "Rosati", "Giacomo", "" ] ]
Two recent publications have reported intriguing analyses, tentatively suggesting that some aspects of IceCube data might be manifestations of quantum-gravity-modified laws of propagation for neutrinos. We here propose a strategy of data analysis which has the advantage of being applicable to several alternative possib...
2010.14437
Asier Alonso-Bardaji
Asier Alonso-Bardaji, David Brizuela
Holonomy and inverse-triad corrections in spherical models coupled to matter
null
Eur. Phys. J. C 81, 283 (2021)
10.1140/epjc/s10052-021-09075-y
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Loop quantum gravity introduces two characteristic modifications in the classical constraints of general relativity: the holonomy and inverse-triad corrections. In this paper, a systematic construction of anomaly-free effective constraints encoding such corrections is developed for spherically symmetric spacetimes. T...
[ { "created": "Tue, 27 Oct 2020 16:51:21 GMT", "version": "v1" }, { "created": "Thu, 11 Aug 2022 13:25:55 GMT", "version": "v2" } ]
2022-08-12
[ [ "Alonso-Bardaji", "Asier", "" ], [ "Brizuela", "David", "" ] ]
Loop quantum gravity introduces two characteristic modifications in the classical constraints of general relativity: the holonomy and inverse-triad corrections. In this paper, a systematic construction of anomaly-free effective constraints encoding such corrections is developed for spherically symmetric spacetimes. The...
1402.1055
Betti Hartmann
Yves Brihaye (Universit\'e de Mons, Belgium), Valeria Diemer (Uni Oldenburg, Germany) and Betti Hartmann (JUB, Germany & UFES, Brazil)
Charged Q-balls and boson stars and dynamics of charged test particles
23 pages including 15 figures; v2: references added, comments on limits on model parameters added, discussion on stability with respect to pair production added; matched version accepted for publication in Phys. Rev. D
Phys. Rev. D 89, 084048 (2014)
10.1103/PhysRevD.89.084048
null
gr-qc hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct electrically charged Q-balls and boson stars in a model with a scalar self-interaction potential resulting from gauge mediated supersymmetry breaking. We discuss the properties of these solutions in detail and emphasize the differences to the uncharged case. We observe that Q-balls can only be constructe...
[ { "created": "Wed, 5 Feb 2014 14:32:40 GMT", "version": "v1" }, { "created": "Thu, 27 Mar 2014 13:25:28 GMT", "version": "v2" } ]
2014-04-23
[ [ "Brihaye", "Yves", "", "Université de Mons, Belgium" ], [ "Diemer", "Valeria", "", "Uni\n Oldenburg, Germany" ], [ "Hartmann", "Betti", "", "JUB, Germany & UFES, Brazil" ] ]
We construct electrically charged Q-balls and boson stars in a model with a scalar self-interaction potential resulting from gauge mediated supersymmetry breaking. We discuss the properties of these solutions in detail and emphasize the differences to the uncharged case. We observe that Q-balls can only be constructed ...
1908.03700
Alexander Tsirulev
I. M. Potashov, Ju. V. Tchemarina, A. N. Tsirulev
Bound orbits near scalar field naked singularities
9 pages, 6 figures
Eur. Phys. J. C (2019) 79: 709
10.1140/epjc/s10052-019-7192-7
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study bound orbits near the centres of static, spherically symmetric, asymptotically flat configurations of a self-gravitating scalar field minimally coupled to gravity. In our approach, a nonlinear scalar field is considered as an idealized model of dark matter, and the main examples that we have in mind are the ...
[ { "created": "Sat, 10 Aug 2019 06:43:03 GMT", "version": "v1" } ]
2019-08-29
[ [ "Potashov", "I. M.", "" ], [ "Tchemarina", "Ju. V.", "" ], [ "Tsirulev", "A. N.", "" ] ]
We study bound orbits near the centres of static, spherically symmetric, asymptotically flat configurations of a self-gravitating scalar field minimally coupled to gravity. In our approach, a nonlinear scalar field is considered as an idealized model of dark matter, and the main examples that we have in mind are the ce...
2309.01638
Wei-Hsiang Shao
Tin-Long Chau, Pei-Ming Ho, Hikaru Kawai, Wei-Hsiang Shao, Cheng-Tsung Wang
Hawking Radiation Under Generalized Uncertainty Principle
23 pages, 1 figure; v2: references added; v3: published version with more references and added clarifications
Eur. Phys. J. C (2023) 83:1118
10.1140/epjc/s10052-023-12302-3
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The generalized uncertainty relation is expected to be an essential element in a theory of quantum gravity. In this work, we examine its effect on the Hawking radiation of a Schwarzschild black hole formed from collapse by incorporating a minimal uncertainty length scale into the radial coordinate of the background. ...
[ { "created": "Mon, 4 Sep 2023 14:46:32 GMT", "version": "v1" }, { "created": "Mon, 11 Sep 2023 14:28:48 GMT", "version": "v2" }, { "created": "Tue, 2 Jan 2024 09:31:59 GMT", "version": "v3" } ]
2024-01-03
[ [ "Chau", "Tin-Long", "" ], [ "Ho", "Pei-Ming", "" ], [ "Kawai", "Hikaru", "" ], [ "Shao", "Wei-Hsiang", "" ], [ "Wang", "Cheng-Tsung", "" ] ]
The generalized uncertainty relation is expected to be an essential element in a theory of quantum gravity. In this work, we examine its effect on the Hawking radiation of a Schwarzschild black hole formed from collapse by incorporating a minimal uncertainty length scale into the radial coordinate of the background. Th...
2405.03607
Angela Borchers
Angela Borchers, Frank Ohme, Jannik Mielke and Shrobana Ghosh
Observability of spin precession in the presence of a black-hole remnant kick
24 pages, 22 figures
Phys. Rev. D 110, 024037 (2024)
10.1103/PhysRevD.110.024037
LIGO-P2400159
gr-qc
http://creativecommons.org/licenses/by-nc-sa/4.0/
Remnants of binary black-hole mergers can gain significant recoil or kick velocities when the binaries are asymmetric. The kick is the consequence of anisotropic emission of gravitational waves, which may leave a characteristic imprint in the observed signal. So far, only one gravitational-wave event supports a non-z...
[ { "created": "Mon, 6 May 2024 16:17:53 GMT", "version": "v1" }, { "created": "Wed, 17 Jul 2024 10:32:17 GMT", "version": "v2" } ]
2024-07-18
[ [ "Borchers", "Angela", "" ], [ "Ohme", "Frank", "" ], [ "Mielke", "Jannik", "" ], [ "Ghosh", "Shrobana", "" ] ]
Remnants of binary black-hole mergers can gain significant recoil or kick velocities when the binaries are asymmetric. The kick is the consequence of anisotropic emission of gravitational waves, which may leave a characteristic imprint in the observed signal. So far, only one gravitational-wave event supports a non-zer...
gr-qc/0409123
Edward Anderson
E. Anderson
Geometrodynamics: Spacetime or Space ?
Thesis, University of London, Examined in June by Prof Chris Isham and Prof James Vickers. 226 pages including 21 figures
null
null
null
gr-qc
null
This thesis concerns the split of Einstein's field equations (EFE's) with respect to nowhere null hypersurfaces. Areas covered include A) the foundations of relativity, deriving geometrodynamics from relational first principles and showing that this form accommodates a sufficient set of fundamental matter fields to b...
[ { "created": "Thu, 30 Sep 2004 17:18:39 GMT", "version": "v1" } ]
2007-05-23
[ [ "Anderson", "E.", "" ] ]
This thesis concerns the split of Einstein's field equations (EFE's) with respect to nowhere null hypersurfaces. Areas covered include A) the foundations of relativity, deriving geometrodynamics from relational first principles and showing that this form accommodates a sufficient set of fundamental matter fields to be ...
gr-qc/0408046
Elizabeth Winstanley
Elizabeth Winstanley
Classical and thermodynamical aspects of black holes with conformally coupled scalar field hair
19 pages, 8 figures, talk given at the `Workshop on Dynamics and Thermodynamics of Black Holes and Naked Singularities', Milan, May 2004
null
null
null
gr-qc
null
We discuss the existence, stability and classical thermodynamics of four-dimensional, spherically symmetric black hole solutions of the Einstein equations with a conformally coupled scalar field. We review the solutions existing in the literature with zero, positive and negative cosmological constant. We also outline...
[ { "created": "Mon, 16 Aug 2004 14:06:10 GMT", "version": "v1" } ]
2007-05-23
[ [ "Winstanley", "Elizabeth", "" ] ]
We discuss the existence, stability and classical thermodynamics of four-dimensional, spherically symmetric black hole solutions of the Einstein equations with a conformally coupled scalar field. We review the solutions existing in the literature with zero, positive and negative cosmological constant. We also outline n...
2009.06531
Partha Sarathi DEBNATH
Partha Sarathi Debnath
Causal cosmology with braneworld gravity including Gauss Bonnet coupling
8 figures
Modern Physics Letters A, Vol. 35, No. 26 (2020) 2050216
10.1142/S0217732320502168
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Causal cosmological evolutions in Randall Sundrum type II (RS) braneworld gravity with Gauss Bonnet coupling and dissipative effects are discussed here. Causal theory of dissipative effects are illustrated by Full Israel Stewart theory are implemented. We consider the numerical solutions of evolutions and analytic so...
[ { "created": "Mon, 14 Sep 2020 15:52:41 GMT", "version": "v1" } ]
2020-09-15
[ [ "Debnath", "Partha Sarathi", "" ] ]
Causal cosmological evolutions in Randall Sundrum type II (RS) braneworld gravity with Gauss Bonnet coupling and dissipative effects are discussed here. Causal theory of dissipative effects are illustrated by Full Israel Stewart theory are implemented. We consider the numerical solutions of evolutions and analytic solu...
1401.3384
Marcus Khuri
Ye Sle Cha, Marcus A. Khuri
Deformations of Axially Symmetric Initial Data and the Mass-Angular Momentum Inequality
47 pages; final version
Ann. Henri Poincare, 16 (2015), no. 3, 841-896
null
null
gr-qc math-ph math.DG math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show how to reduce the general formulation of the mass-angular momentum inequality, for axisymmetric initial data of the Einstein equations, to the known maximal case whenever a geometrically motivated system of equations admits a solution. This procedure is based on a certain deformation of the initial data which...
[ { "created": "Tue, 14 Jan 2014 23:18:55 GMT", "version": "v1" }, { "created": "Sat, 14 Feb 2015 01:03:42 GMT", "version": "v2" } ]
2015-02-17
[ [ "Cha", "Ye Sle", "" ], [ "Khuri", "Marcus A.", "" ] ]
We show how to reduce the general formulation of the mass-angular momentum inequality, for axisymmetric initial data of the Einstein equations, to the known maximal case whenever a geometrically motivated system of equations admits a solution. This procedure is based on a certain deformation of the initial data which p...
1403.5490
Peter K.F. Kuhfittig
Peter K.F. Kuhfittig
A simple argument for dark matter as an effect of slightly modified gravity
6 pages, 1 figure
Adv. Studies Theor. Phys., Vol. 8, pp. 349-355, 2014
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This note presents a simple argument showing that dark matter is an effect of $f(R)$ gravity based on the definition of slightly modified gravitational theories previously proposed by the author.
[ { "created": "Fri, 21 Mar 2014 15:17:24 GMT", "version": "v1" }, { "created": "Fri, 12 Sep 2014 15:22:51 GMT", "version": "v2" } ]
2014-09-15
[ [ "Kuhfittig", "Peter K. F.", "" ] ]
This note presents a simple argument showing that dark matter is an effect of $f(R)$ gravity based on the definition of slightly modified gravitational theories previously proposed by the author.
2312.17712
Philippe G. LeFloch
Philippe G. LeFloch and Yue Ma
The Euclidean-hyperboloidal foliation method. Application to f(R) modified gravity
46 pages
null
null
null
gr-qc math.AP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper is a part of a series devoted to the Euclidean-hyperboloidal foliation method introduced by the authors for investigating the global existence problem associated with nonlinear systems of coupled wave-Klein-Gordon equations with small data. This method was developed especially for investigating the initial...
[ { "created": "Fri, 29 Dec 2023 18:03:49 GMT", "version": "v1" }, { "created": "Sun, 14 Jan 2024 16:49:03 GMT", "version": "v2" }, { "created": "Tue, 7 May 2024 08:06:55 GMT", "version": "v3" } ]
2024-05-08
[ [ "LeFloch", "Philippe G.", "" ], [ "Ma", "Yue", "" ] ]
This paper is a part of a series devoted to the Euclidean-hyperboloidal foliation method introduced by the authors for investigating the global existence problem associated with nonlinear systems of coupled wave-Klein-Gordon equations with small data. This method was developed especially for investigating the initial v...
1603.03175
Kazuharu Bamba
Z. Yousaf, Kazuharu Bamba and M. Zaeem ul Haq Bhatti
The Influence of Modification of Gravity on the Dynamics of Radiating Spherical Fluids
25 pages, no figure, version accepted for publication in Physical Review D
Phys. Rev. D 93, 064059 (2016)
10.1103/PhysRevD.93.064059
FU-PCG-08
gr-qc astro-ph.CO hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the evolutionary behaviors of compact objects in a modified gravitational theory with the help of structure scalars. Particularly, we consider the spherical geometry coupled with heat and radiation emitting shearing viscous matter configurations. We construct structure scalars by splitting the Riemann tens...
[ { "created": "Thu, 10 Mar 2016 08:01:26 GMT", "version": "v1" } ]
2016-04-12
[ [ "Yousaf", "Z.", "" ], [ "Bamba", "Kazuharu", "" ], [ "Bhatti", "M. Zaeem ul Haq", "" ] ]
We explore the evolutionary behaviors of compact objects in a modified gravitational theory with the help of structure scalars. Particularly, we consider the spherical geometry coupled with heat and radiation emitting shearing viscous matter configurations. We construct structure scalars by splitting the Riemann tensor...
1803.09089
Carlos A. R. Herdeiro
Yves Brihaye, Thomas Delplace, Carlos Herdeiro, Eugen Radu
An analytic effective model for hairy black holes
16 pages, 5 figures
null
10.1016/j.physletb.2018.05.018
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hairy black holes (BHs) have macroscopic degrees of freedom which are not associated with a Gauss law. As such, these degrees of freedom are not manifest as quasi-local quantities computed at the horizon. This suggests conceiving hairy BHs as an interacting system with two components: a "bald" horizon coupled to a "h...
[ { "created": "Sat, 24 Mar 2018 10:49:20 GMT", "version": "v1" } ]
2018-08-01
[ [ "Brihaye", "Yves", "" ], [ "Delplace", "Thomas", "" ], [ "Herdeiro", "Carlos", "" ], [ "Radu", "Eugen", "" ] ]
Hairy black holes (BHs) have macroscopic degrees of freedom which are not associated with a Gauss law. As such, these degrees of freedom are not manifest as quasi-local quantities computed at the horizon. This suggests conceiving hairy BHs as an interacting system with two components: a "bald" horizon coupled to a "hai...
2201.05263
Caitlin Rose
Caitlin A. Rose, Vinaya Valsan, Patrick R. Brady, Sinead Walsh, Chris Pankow
Supplementing rapid Bayesian parameter estimation schemes with adaptive grids
null
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the age of multi-messenger astrophysics, low-latency parameter estimation of gravitational-wave signals is essential for electromagnetic follow-up observations. In this paper, we present a new edition of the Bayesian parameter estimation scheme for compact binaries known as Rapid PE. Rapid PE parallelizes paramete...
[ { "created": "Fri, 14 Jan 2022 00:47:49 GMT", "version": "v1" } ]
2022-01-17
[ [ "Rose", "Caitlin A.", "" ], [ "Valsan", "Vinaya", "" ], [ "Brady", "Patrick R.", "" ], [ "Walsh", "Sinead", "" ], [ "Pankow", "Chris", "" ] ]
In the age of multi-messenger astrophysics, low-latency parameter estimation of gravitational-wave signals is essential for electromagnetic follow-up observations. In this paper, we present a new edition of the Bayesian parameter estimation scheme for compact binaries known as Rapid PE. Rapid PE parallelizes parameter ...
2106.01234
Vasilis Oikonomou
A.V. Astashenok, S. Capozziello, S.D. Odintsov, V.K. Oikonomou
Novel Stellar Astrophysics from Extended Gravity
EPL Accepted
null
10.1209/0295-5075/134/59001
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Novel implications on neutron stars come from extended gravity. Specifically, the GW190814 event indicated the probability of having large mass stars in the mass-gap region $2.5-5\, M_{\odot}$. If the secondary component of GW190814 is a neutron star, such large masses are marginally supported by General Relativity (...
[ { "created": "Wed, 2 Jun 2021 15:31:02 GMT", "version": "v1" } ]
2021-09-01
[ [ "Astashenok", "A. V.", "" ], [ "Capozziello", "S.", "" ], [ "Odintsov", "S. D.", "" ], [ "Oikonomou", "V. K.", "" ] ]
Novel implications on neutron stars come from extended gravity. Specifically, the GW190814 event indicated the probability of having large mass stars in the mass-gap region $2.5-5\, M_{\odot}$. If the secondary component of GW190814 is a neutron star, such large masses are marginally supported by General Relativity (GR...
1003.1886
Winston Fairbairn
John W. Barrett, Richard J. Dowdall, Winston J. Fairbairn, Henrique Gomes, Frank Hellmann, Roberto Pereira
Asymptotics of 4d spin foam models
10 pages, Proceedings for the 2nd Corfu summer school and workshop on quantum gravity and quantum geometry, talk given by Winston J. Fairbairn
null
10.1007/s10714-010-0983-7
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the asymptotic properties of four-simplex amplitudes for various four-dimensional spin foam models. We investigate the semi-classical limit of the Ooguri, Euclidean and Lorentzian EPRL models using coherent states for the boundary data. For some classes of geometrical boundary data, the asymptotic formulae a...
[ { "created": "Tue, 9 Mar 2010 14:50:24 GMT", "version": "v1" } ]
2015-05-18
[ [ "Barrett", "John W.", "" ], [ "Dowdall", "Richard J.", "" ], [ "Fairbairn", "Winston J.", "" ], [ "Gomes", "Henrique", "" ], [ "Hellmann", "Frank", "" ], [ "Pereira", "Roberto", "" ] ]
We study the asymptotic properties of four-simplex amplitudes for various four-dimensional spin foam models. We investigate the semi-classical limit of the Ooguri, Euclidean and Lorentzian EPRL models using coherent states for the boundary data. For some classes of geometrical boundary data, the asymptotic formulae are...
1201.5601
Julio Oliva
Julio Oliva, Sourya Ray
Birkhoff's Theorem in Higher Derivative Theories of Gravity II: Asymptotically Lifshitz Black Holes
10 pages, no figures. v2: minor corrections. Rejected by CQG. v3: Final version, to appear in PRD with the title "Birkhoff's Theorem in Higher Derivative Theories of Gravity II"
null
10.1103/PhysRevD.86.084014
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As a continuation of a previous work, here we examine the admittance of Birkhoff's theorem in a class of higher derivative theories of gravity. This class is contained in a larger class of theories which are characterized by the property that the trace of the field equations are of second order in the metric. The act...
[ { "created": "Thu, 26 Jan 2012 18:50:31 GMT", "version": "v1" }, { "created": "Fri, 18 May 2012 04:28:17 GMT", "version": "v2" }, { "created": "Mon, 17 Sep 2012 22:00:42 GMT", "version": "v3" } ]
2013-05-30
[ [ "Oliva", "Julio", "" ], [ "Ray", "Sourya", "" ] ]
As a continuation of a previous work, here we examine the admittance of Birkhoff's theorem in a class of higher derivative theories of gravity. This class is contained in a larger class of theories which are characterized by the property that the trace of the field equations are of second order in the metric. The actio...
1405.5503
Ahmed Alhamzawi
Ahmed Alhamzawi and Rahim Alhamzawi
Extensions of GR using Projective-Invariance
Dear arxiv, We would like to withdraw this article because we have discovered some incomplete assumptions at the begining of the paper which may result in some instability in the rest of the theory presented in the paper. Currenctly, We have not reached a viable way to correct these assumptions so we think it i...
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the unification of electromagnetism and gravity into a single geometrical entity can be beautifully accomplished in a theory with non-symmetric affine connection (${\Gamma}_{\mu\nu}^{\lambda}\neq{\Gamma}_{\nu\mu}^{\lambda}$), and the unifying symmetry being projective symmetry. In addition, we show that ...
[ { "created": "Wed, 21 May 2014 18:16:22 GMT", "version": "v1" }, { "created": "Thu, 4 Jun 2020 20:39:06 GMT", "version": "v2" } ]
2020-06-08
[ [ "Alhamzawi", "Ahmed", "" ], [ "Alhamzawi", "Rahim", "" ] ]
We show that the unification of electromagnetism and gravity into a single geometrical entity can be beautifully accomplished in a theory with non-symmetric affine connection (${\Gamma}_{\mu\nu}^{\lambda}\neq{\Gamma}_{\nu\mu}^{\lambda}$), and the unifying symmetry being projective symmetry. In addition, we show that in...
2102.05693
Nolene Naidu
Nolene F. Naidu, Sante Carloni and Peter Dunsby
Two-fluid stellar objects in General Relativity: the covariant formulation
19 pages, 14 figures
Phys. Rev. D 104, 044014 (2021)
10.1103/PhysRevD.104.044014
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We apply the 1+1+2 covariant approach to describe a general static and spherically symmetric relativistic stellar object which contains two interacting fluids. We then use the 1+1+2 equations to derive the corresponding Tolman-Oppenheimer-Volkoff (TOV) equations in covariant form in the isotropic, non-interacting cas...
[ { "created": "Wed, 10 Feb 2021 19:08:19 GMT", "version": "v1" }, { "created": "Wed, 26 May 2021 13:16:01 GMT", "version": "v2" } ]
2021-08-11
[ [ "Naidu", "Nolene F.", "" ], [ "Carloni", "Sante", "" ], [ "Dunsby", "Peter", "" ] ]
We apply the 1+1+2 covariant approach to describe a general static and spherically symmetric relativistic stellar object which contains two interacting fluids. We then use the 1+1+2 equations to derive the corresponding Tolman-Oppenheimer-Volkoff (TOV) equations in covariant form in the isotropic, non-interacting case....
2007.03524
Askold Duviryak
Askold Duviryak
Solvable two-particle systems with time-asymmetric interactions in de Sitter space
22 pages
null
null
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The two-particle models in de Sitter space-time with time-asymmetric retarded-advanced interactions are constructed. Particular cases of the field-type electromagnetic and scalar interactions are considered. The manifestly covariant descriptions of the models within the Lagrangian and Hamiltonian formalisms with cons...
[ { "created": "Mon, 6 Jul 2020 11:53:00 GMT", "version": "v1" } ]
2020-07-08
[ [ "Duviryak", "Askold", "" ] ]
The two-particle models in de Sitter space-time with time-asymmetric retarded-advanced interactions are constructed. Particular cases of the field-type electromagnetic and scalar interactions are considered. The manifestly covariant descriptions of the models within the Lagrangian and Hamiltonian formalisms with constr...
2009.05520
Li Li
Rong-Gen Cai, Li Li, Run-Qiu Yang
No Inner-Horizon Theorem for Black Holes with Charged Scalar Hairs
v4: typos fixed, published version
JHEP 03 (2021) 263
10.1007/JHEP03(2021)263
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We establish a no inner-horizon theorem for black holes with charged scalar hairs. Considering a general gravitational theory with a charged scalar field, we prove that there exists no inner Cauchy horizon for both spherical and planar black holes with non-trivial scalar hair. The hairy black holes approach to a spac...
[ { "created": "Fri, 11 Sep 2020 16:45:22 GMT", "version": "v1" }, { "created": "Tue, 15 Sep 2020 14:02:05 GMT", "version": "v2" }, { "created": "Thu, 25 Feb 2021 05:40:14 GMT", "version": "v3" }, { "created": "Mon, 5 Apr 2021 01:20:54 GMT", "version": "v4" } ]
2021-04-06
[ [ "Cai", "Rong-Gen", "" ], [ "Li", "Li", "" ], [ "Yang", "Run-Qiu", "" ] ]
We establish a no inner-horizon theorem for black holes with charged scalar hairs. Considering a general gravitational theory with a charged scalar field, we prove that there exists no inner Cauchy horizon for both spherical and planar black holes with non-trivial scalar hair. The hairy black holes approach to a spacel...
2206.14819
Shahar Hod
Shahar Hod
How short can stationary charged scalar hair be?
8 pages
Physical Review D 105, 024061 (2022)
10.1103/PhysRevD.105.024061
null
gr-qc astro-ph.HE hep-th
http://creativecommons.org/licenses/by/4.0/
It is by now well established that charged rotating Kerr-Newman black holes can support bound-state charged matter configurations which are made of minimally coupled massive scalar fields. We here prove that the externally supported stationary charged scalar configurations {\it cannot} be arbitrarily compact. In part...
[ { "created": "Wed, 29 Jun 2022 18:00:01 GMT", "version": "v1" } ]
2022-07-06
[ [ "Hod", "Shahar", "" ] ]
It is by now well established that charged rotating Kerr-Newman black holes can support bound-state charged matter configurations which are made of minimally coupled massive scalar fields. We here prove that the externally supported stationary charged scalar configurations {\it cannot} be arbitrarily compact. In partic...
1412.7783
Sumanta Chakraborty
Sumanta Chakraborty and Soumitra SenGupta
Solutions on a brane in a bulk spacetime with Kalb-Ramond field
26 pages, no figures, title changed, matches published version
Annals of Physics 367, 258 (2016)
10.1016/j.aop.2016.01.023
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Effective gravitational field equations on a brane have been derived, when the bulk spacetime is endowed with the second rank antisymmetric Kalb-Ramond field. Since both the graviton and the Kalb-Ramond field are closed string excitations, they can propagate in the bulk. After deriving the effective gravitational fie...
[ { "created": "Thu, 25 Dec 2014 04:09:12 GMT", "version": "v1" }, { "created": "Mon, 29 Feb 2016 03:55:08 GMT", "version": "v2" } ]
2016-03-01
[ [ "Chakraborty", "Sumanta", "" ], [ "SenGupta", "Soumitra", "" ] ]
Effective gravitational field equations on a brane have been derived, when the bulk spacetime is endowed with the second rank antisymmetric Kalb-Ramond field. Since both the graviton and the Kalb-Ramond field are closed string excitations, they can propagate in the bulk. After deriving the effective gravitational field...
1101.3164
Ion I. Cotaescu
Ion I. Cotaescu
The free Dirac spinors of the spin basis on the de Sitter expanding universe
8 pages no figures
Mod.Phys.Lett.A26:1613-1619,2011
10.1142/S0217732311036048
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that on the de Sitter space-time the global behavior of the free Dirac spinors in momentum representation is determined by several phases factors which are functions of momentum with special properties. Such suitable phase functions can be chosen for writing down the free Dirac quantum modes of the spin b...
[ { "created": "Mon, 17 Jan 2011 10:03:28 GMT", "version": "v1" }, { "created": "Wed, 9 Mar 2011 09:57:48 GMT", "version": "v2" }, { "created": "Mon, 2 May 2011 07:31:03 GMT", "version": "v3" }, { "created": "Fri, 23 Nov 2012 12:23:03 GMT", "version": "v4" } ]
2012-11-26
[ [ "Cotaescu", "Ion I.", "" ] ]
It is shown that on the de Sitter space-time the global behavior of the free Dirac spinors in momentum representation is determined by several phases factors which are functions of momentum with special properties. Such suitable phase functions can be chosen for writing down the free Dirac quantum modes of the spin bas...
gr-qc/0404113
Luis F. Urrutia
Jorge Alfaro, Marat Reyes, Hugo A. Morales-Tecotl and L. F. Urrutia
On alternative approaches to Lorentz violation in loop quantum gravity inspired models
4 pages, revtex4, no figures, references added
Phys.Rev. D70 (2004) 084002
10.1103/PhysRevD.70.084002
null
gr-qc
null
Recent claims point out that possible violations of Lorentz symmetry appearing in some semiclassical models of extended matter dynamics motivated by loop quantum gravity can be removed by a different choice of canonically conjugated variables. In this note we show that such alternative is inconsistent with the choice...
[ { "created": "Tue, 27 Apr 2004 21:26:53 GMT", "version": "v1" }, { "created": "Wed, 5 May 2004 16:44:30 GMT", "version": "v2" } ]
2009-11-10
[ [ "Alfaro", "Jorge", "" ], [ "Reyes", "Marat", "" ], [ "Morales-Tecotl", "Hugo A.", "" ], [ "Urrutia", "L. F.", "" ] ]
Recent claims point out that possible violations of Lorentz symmetry appearing in some semiclassical models of extended matter dynamics motivated by loop quantum gravity can be removed by a different choice of canonically conjugated variables. In this note we show that such alternative is inconsistent with the choice o...
1410.2252
Shahar Hod
Shahar Hod
A short remark (with a long title) on the universality of the quasinormal spectrum of near-extremal Kerr-Newman black holes
2 pages
The European Physical Journal C (Letter) 75, 272 (2015) [A slightly extended version]
null
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a recent paper (arXiv:1410.0694) Zilh\~ao, Cardoso, Herdeiro, Lehner, and Sperhake have studied the nonlinear stability of Kerr-Newman black holes. We show that their numerical results for the time evolutions of the spacetime deformations of near-extremal Kerr-Newman black holes are described extremely well by a {...
[ { "created": "Wed, 8 Oct 2014 20:00:17 GMT", "version": "v1" } ]
2015-06-25
[ [ "Hod", "Shahar", "" ] ]
In a recent paper (arXiv:1410.0694) Zilh\~ao, Cardoso, Herdeiro, Lehner, and Sperhake have studied the nonlinear stability of Kerr-Newman black holes. We show that their numerical results for the time evolutions of the spacetime deformations of near-extremal Kerr-Newman black holes are described extremely well by a {\i...
0707.0942
Leszek Soko{\l}owski
Leszek M. Sokolowski
Metric gravity theories and cosmology:II. Stability of a ground state in f(R) theories
A modified and expanded version of a second part of the paper which previously appeared as gr-qc/0702097v1. The first, modified part is now published as gr-qc/0702097v2 and as a separate paper in Class. Qu. Grav. The present paper matches the published version
Class.Quant.Grav.24:3713-3734,2007
10.1088/0264-9381/24/14/011
null
gr-qc
null
A fundamental criterion of viability of any gravity theory is existence of a stable ground-state solution being either Minkowski, dS or AdS space. Stability of the ground state is independent of which frame is physical. In general, a given theory has multiple ground states and splits into independent physical sectors...
[ { "created": "Fri, 6 Jul 2007 10:31:59 GMT", "version": "v1" } ]
2008-11-26
[ [ "Sokolowski", "Leszek M.", "" ] ]
A fundamental criterion of viability of any gravity theory is existence of a stable ground-state solution being either Minkowski, dS or AdS space. Stability of the ground state is independent of which frame is physical. In general, a given theory has multiple ground states and splits into independent physical sectors. ...
gr-qc/0305052
Abel Camacho Quintana
Abel Camacho (Physics Department, Universidad Autonoma Metropolitana-Iztapalapa)
Some Consequences of a Generalization to Heisenberg Algebra in Quantum Electrodynamics
Awarded with an Honorable Mention in the 2003 Essay Competition by the Gravity Research Foundation
Int.J.Mod.Phys. D12 (2003) 1687-1692
10.1142/S0218271803004341
null
gr-qc quant-ph
null
In this essay it will be shown that the introduction of a modification to Heisenberg algebra (here this feature means the existence of a minimal obserlvable length), as a fundamental part of the quantization process of the electrodynamical field, renders states in which the uncertainties in the two quadrature compone...
[ { "created": "Tue, 13 May 2003 18:57:13 GMT", "version": "v1" } ]
2009-11-10
[ [ "Camacho", "Abel", "", "Physics Department, Universidad Autonoma\n Metropolitana-Iztapalapa" ] ]
In this essay it will be shown that the introduction of a modification to Heisenberg algebra (here this feature means the existence of a minimal obserlvable length), as a fundamental part of the quantization process of the electrodynamical field, renders states in which the uncertainties in the two quadrature component...
2203.03936
Alejandro Jim\'enez-Cano
Alejandro Jim\'enez-Cano
Review of gravitational wave solutions in quadratic metric-affine gravity
31 pages, 1 figure, contribution to the Special Issue of the International Journal of Geometric Methods in Modern Physics dedicated to the conference Geometric Foundations of Gravity in Tartu 2021
null
10.1142/S0219887822400047
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this review we consider the quadratic Metric-Affine Gauge gravity Lagrangian, which contains all the algebraic invariants up to quadratic order in torsion, nonmetricity and curvature. The goal will be to collect the known exact solutions for this theory that describe the propagation of a gravitational wave and som...
[ { "created": "Tue, 8 Mar 2022 09:01:27 GMT", "version": "v1" } ]
2022-11-09
[ [ "Jiménez-Cano", "Alejandro", "" ] ]
In this review we consider the quadratic Metric-Affine Gauge gravity Lagrangian, which contains all the algebraic invariants up to quadratic order in torsion, nonmetricity and curvature. The goal will be to collect the known exact solutions for this theory that describe the propagation of a gravitational wave and some ...
0910.0350
Charles Hellaby
Charles Hellaby
Modelling Inhomogeneity in the Universe
LaTeX, PoS class, 50 pages. See http://fisica.ufmt.br/school2/ and http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=81
PoS ISFTG:005,2009
null
uct-cosmology-2009-10-02
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An overview of some recent developments in inhomogeneous models is presented. As the volume and precision of cosmological data improves, it will become more and more essential to understand the non-linear behaviour of the Einstein field equations. This requires the study of exact inhomogeneous solutions, including th...
[ { "created": "Fri, 2 Oct 2009 09:58:01 GMT", "version": "v1" } ]
2010-01-06
[ [ "Hellaby", "Charles", "" ] ]
An overview of some recent developments in inhomogeneous models is presented. As the volume and precision of cosmological data improves, it will become more and more essential to understand the non-linear behaviour of the Einstein field equations. This requires the study of exact inhomogeneous solutions, including thei...
1605.01316
Jorma Louko
Christopher J. Fewster, Benito A. Ju\'arez-Aubry, Jorma Louko
Waiting for Unruh
29 pages. v2: minor clarifications, references added, typos corrected
Class. Quantum Grav. 33 (2016) 165003
10.1088/0264-9381/33/16/165003
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
How long does a uniformly accelerated observer need to interact with a quantum field in order to record thermality in the Unruh temperature? We address this question for a pointlike Unruh-DeWitt detector, coupled linearly to a real Klein-Gordon field of mass $m\ge0$ and treated within first order perturbation theory,...
[ { "created": "Wed, 4 May 2016 15:31:39 GMT", "version": "v1" }, { "created": "Tue, 19 Jul 2016 15:29:53 GMT", "version": "v2" } ]
2016-07-20
[ [ "Fewster", "Christopher J.", "" ], [ "Juárez-Aubry", "Benito A.", "" ], [ "Louko", "Jorma", "" ] ]
How long does a uniformly accelerated observer need to interact with a quantum field in order to record thermality in the Unruh temperature? We address this question for a pointlike Unruh-DeWitt detector, coupled linearly to a real Klein-Gordon field of mass $m\ge0$ and treated within first order perturbation theory, i...
2309.07790
Yao Guo
Yao Guo, Wenjie Zhong, Yiqiu Ma, Daiqin Su
Mass transfer and boson cloud depletion in a binary black hole system
null
null
null
null
gr-qc astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
Ultralight boson is one of the potential candidates for dark matter. If exists, it can be generated by a rapidly rotating black hole via superradiance, extracting the energy and angular momentum of the black hole and forming a boson cloud. The boson cloud can be affected by the presence of a companion star, generatin...
[ { "created": "Thu, 14 Sep 2023 15:25:43 GMT", "version": "v1" } ]
2023-09-15
[ [ "Guo", "Yao", "" ], [ "Zhong", "Wenjie", "" ], [ "Ma", "Yiqiu", "" ], [ "Su", "Daiqin", "" ] ]
Ultralight boson is one of the potential candidates for dark matter. If exists, it can be generated by a rapidly rotating black hole via superradiance, extracting the energy and angular momentum of the black hole and forming a boson cloud. The boson cloud can be affected by the presence of a companion star, generating ...
0909.0531
Jorge I. Ovalle A.
J Ovalle
Braneworld Stars: Anisotropy Minimally Projected Onto the Brane
15 pages, 1 figure. Schwarzschild's solution removed. References added. Based on the contributed lecture given at the IX Asia-Pacific International Conference on Gravitation and Astrophysics (ICGA9), June 28-July 2, 2009, Wuhan, China
null
10.1142/9789814307673_0017
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the context of the Randall-Sundrum braneworld, an exhaustive and detailed description of the approach based in the minimal anisotropic consequence onto the brane, which has been successfully used to generate exact interior solutions to Einstein's field equations for static and non-uniform braneworld stars with loc...
[ { "created": "Wed, 2 Sep 2009 21:08:02 GMT", "version": "v1" }, { "created": "Mon, 30 Aug 2010 20:45:23 GMT", "version": "v2" } ]
2017-08-23
[ [ "Ovalle", "J", "" ] ]
In the context of the Randall-Sundrum braneworld, an exhaustive and detailed description of the approach based in the minimal anisotropic consequence onto the brane, which has been successfully used to generate exact interior solutions to Einstein's field equations for static and non-uniform braneworld stars with local...