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0811.1600
Andrea Nerozzi Dr
Andrea Nerozzi, Oliver Elbracht
Using curvature invariants for wave extraction in numerical relativity
7 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new expression for the Weyl scalar Psi_4 that can be used in numerical relativity to extract the gravitational wave content of a spacetime. The formula relies upon the identification of transverse tetrads, namely the ones in which Psi_1=Psi_3=0. It is well known that tetrads with this property always exi...
[ { "created": "Mon, 10 Nov 2008 22:47:33 GMT", "version": "v1" } ]
2008-11-12
[ [ "Nerozzi", "Andrea", "" ], [ "Elbracht", "Oliver", "" ] ]
We present a new expression for the Weyl scalar Psi_4 that can be used in numerical relativity to extract the gravitational wave content of a spacetime. The formula relies upon the identification of transverse tetrads, namely the ones in which Psi_1=Psi_3=0. It is well known that tetrads with this property always exist...
1410.0114
Ebrahim Yusofi Ramneti
E. Yusofi, M. Mohsenzadeh and M.R. Tanhayi
Inflation in Non-de Sitter Background with Coherent States
typos corrected, refs revised, few comments added, no figure, to appear in Communications in Theoretical Physics (Vol. 65, No. 3, pp. 308--314, 2016)
Communications in Theoretical Physics, Vol. 65, No. 3, pp. 308--314, 2016
10.1088/0253-6102/65/3/308
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use the excited coherent states built over the initial non-de Sitter modes, to study the modification of spectra of primordial scalar fluctuation. Non-de Sitter modes are actually the asymptotic solution of the inflaton field equation[JHEP 09(2014) 020]. We build excited coherent states over the non-de Sitter mode...
[ { "created": "Wed, 1 Oct 2014 06:02:45 GMT", "version": "v1" }, { "created": "Mon, 6 Oct 2014 15:55:49 GMT", "version": "v2" }, { "created": "Tue, 15 Mar 2016 06:34:34 GMT", "version": "v3" } ]
2018-04-06
[ [ "Yusofi", "E.", "" ], [ "Mohsenzadeh", "M.", "" ], [ "Tanhayi", "M. R.", "" ] ]
We use the excited coherent states built over the initial non-de Sitter modes, to study the modification of spectra of primordial scalar fluctuation. Non-de Sitter modes are actually the asymptotic solution of the inflaton field equation[JHEP 09(2014) 020]. We build excited coherent states over the non-de Sitter modes ...
2109.07603
Casey McGrath
Casey McGrath
Gravitational Wave Timing Residual Models for Pulsar Timing Experiments
PhD dissertation. 241 pages, 37 figures. Published by ProQuest (Dissertations & Theses)
null
null
null
gr-qc astro-ph.CO astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
Pulsar timing experiments are currently searching for gravitational waves, and this dissertation focuses on the development and study of the pulsar timing residual models used for continuous wave searches. The first goal of this work is to re-present much of the fundamental physics and mathematics concepts behind the...
[ { "created": "Wed, 15 Sep 2021 22:33:17 GMT", "version": "v1" }, { "created": "Thu, 5 Jan 2023 20:18:37 GMT", "version": "v2" } ]
2023-01-09
[ [ "McGrath", "Casey", "" ] ]
Pulsar timing experiments are currently searching for gravitational waves, and this dissertation focuses on the development and study of the pulsar timing residual models used for continuous wave searches. The first goal of this work is to re-present much of the fundamental physics and mathematics concepts behind the c...
1401.3596
Amare Abebe
Amare Abebe
Anti-Newtonian cosmologies in f(R) gravity
14 pages, no figures, published version
Class. Quantum Grav. 31 (2014) 115011
10.1088/0264-9381/31/11/115011
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we investigate a class of perfect-fluid "anti-Newtonian" cosmological models in the context of f(R) gravity. In particular, we study the integrability conditions of such gravity models using covariant consistency analysis formalisms. We show that, unlike the results in General Relativity, anti-Newtonia...
[ { "created": "Wed, 15 Jan 2014 14:10:16 GMT", "version": "v1" }, { "created": "Sun, 19 Jan 2014 14:14:13 GMT", "version": "v2" }, { "created": "Tue, 20 May 2014 15:21:24 GMT", "version": "v3" } ]
2015-06-18
[ [ "Abebe", "Amare", "" ] ]
In this paper, we investigate a class of perfect-fluid "anti-Newtonian" cosmological models in the context of f(R) gravity. In particular, we study the integrability conditions of such gravity models using covariant consistency analysis formalisms. We show that, unlike the results in General Relativity, anti-Newtonian ...
1310.1513
Adam Pound
Adam Pound, Cesar Merlin, and Leor Barack
Gravitational self-force from radiation-gauge metric perturbations
46 pages, 1 figure, 1 table. Minor corrections. Final version to be published in Phys. Rev. D
Phys. Rev. D 89, 024009 (2014)
10.1103/PhysRevD.89.024009
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Calculations of the gravitational self-force (GSF) in curved spacetime require as input the metric perturbation in a sufficiently regular gauge. A basic challenge in the program to compute the GSF for orbits around a Kerr black hole is that the standard procedure for reconstructing the perturbation is formulated in a...
[ { "created": "Sat, 5 Oct 2013 20:05:37 GMT", "version": "v1" }, { "created": "Fri, 13 Dec 2013 00:32:04 GMT", "version": "v2" } ]
2014-01-21
[ [ "Pound", "Adam", "" ], [ "Merlin", "Cesar", "" ], [ "Barack", "Leor", "" ] ]
Calculations of the gravitational self-force (GSF) in curved spacetime require as input the metric perturbation in a sufficiently regular gauge. A basic challenge in the program to compute the GSF for orbits around a Kerr black hole is that the standard procedure for reconstructing the perturbation is formulated in a c...
2112.12523
Chao Niu
Wei Xiong, Peng Liu, Cheng-Yong Zhang and Chao Niu
Quasi-normal modes of the Einstein-Maxwell-aether Black Hole
25 pages. v2: Minor corrections and references added
null
10.1103/PhysRevD.106.064057
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the quasi-normal modes of the charged scalar perturbations in the background of the Einstein-Maxwell-aether black hole through three methods (WKB method, continued fraction method, generalized eigenvalue method). Then we propose the specific treatment for the generalized effective potential with $\omega$-dep...
[ { "created": "Thu, 23 Dec 2021 13:23:22 GMT", "version": "v1" }, { "created": "Fri, 11 Feb 2022 05:54:12 GMT", "version": "v2" } ]
2022-10-12
[ [ "Xiong", "Wei", "" ], [ "Liu", "Peng", "" ], [ "Zhang", "Cheng-Yong", "" ], [ "Niu", "Chao", "" ] ]
We study the quasi-normal modes of the charged scalar perturbations in the background of the Einstein-Maxwell-aether black hole through three methods (WKB method, continued fraction method, generalized eigenvalue method). Then we propose the specific treatment for the generalized effective potential with $\omega$-depen...
1810.04616
Cosimo Stornaiolo
Cosimo Stornaiolo
Tomographic analysis of the De Sitter model in quantum and classical cosmology
Submitted to International Journal of Geometric Methods in Modern Physics (IJGMMP)
null
10.1142/S0219887819500129
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The importance of the tomographic approach is that either in quantum mechanics as in classical mechanics the state of a physical system is expressed with the same family of functions, the tomograms. The extension of this procedure to quantum cosmology is straightforward. But instead of using the tomographic represent...
[ { "created": "Wed, 10 Oct 2018 16:19:57 GMT", "version": "v1" } ]
2019-01-30
[ [ "Stornaiolo", "Cosimo", "" ] ]
The importance of the tomographic approach is that either in quantum mechanics as in classical mechanics the state of a physical system is expressed with the same family of functions, the tomograms. The extension of this procedure to quantum cosmology is straightforward. But instead of using the tomographic representat...
1603.08459
Flavio Mercati
Flavio Mercati
On the fate of Birkhoff's theorem in Shape Dynamics
13 pages, 6 figures
null
10.1007/s10714-016-2134-2
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Spherically symmetric, asymptotically flat solutions of Shape Dynamics were previously studied assuming standard falloff conditions for the metric and the momenta. These ensure that the spacetime is asymptotically Minkowski, and that the falloff conditions are Poincar\'e-invariant. These requirements however are not ...
[ { "created": "Mon, 28 Mar 2016 17:48:01 GMT", "version": "v1" }, { "created": "Mon, 19 Sep 2016 20:14:36 GMT", "version": "v2" } ]
2016-09-21
[ [ "Mercati", "Flavio", "" ] ]
Spherically symmetric, asymptotically flat solutions of Shape Dynamics were previously studied assuming standard falloff conditions for the metric and the momenta. These ensure that the spacetime is asymptotically Minkowski, and that the falloff conditions are Poincar\'e-invariant. These requirements however are not le...
2205.11499
Justin Janquart
Justin Janquart, Anupreeta More, Chris Van Den Broeck
Ordering the confusion: A study of the impact of lens models on gravitational-wave lensing detection capabilities
21 pages, 10 figures
null
10.1093/mnras/stac3660
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
When traveling from their source to the observer, gravitational waves can get deflected by massive objects along their travel path. When the lens is massive enough and the source aligns closely with the line-of-sight to the lens, the wave undergoes strong lensing, leading to several images with the same frequency evo...
[ { "created": "Mon, 23 May 2022 17:54:43 GMT", "version": "v1" } ]
2022-12-28
[ [ "Janquart", "Justin", "" ], [ "More", "Anupreeta", "" ], [ "Broeck", "Chris Van Den", "" ] ]
When traveling from their source to the observer, gravitational waves can get deflected by massive objects along their travel path. When the lens is massive enough and the source aligns closely with the line-of-sight to the lens, the wave undergoes strong lensing, leading to several images with the same frequency evolu...
gr-qc/0206004
G. S. Asanov
D.G. Pavlov
Hypercomplex Numbers, Associated Metric Spaces, and Extension of Relativistic Hyperboloid
null
null
null
null
gr-qc
null
We undertake to develop a successful framework for commutative-associative hypercomplex numbers with the view to explicate and study associated geometric and generalized-relativistic concepts, basing on an interesting possibility to introduce appropriate multilinear metric forms in the treatment. The scalar polyprodu...
[ { "created": "Mon, 3 Jun 2002 12:34:28 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pavlov", "D. G.", "" ] ]
We undertake to develop a successful framework for commutative-associative hypercomplex numbers with the view to explicate and study associated geometric and generalized-relativistic concepts, basing on an interesting possibility to introduce appropriate multilinear metric forms in the treatment. The scalar polyproduct...
1903.08563
Martin Zofka
Martin Zofka
Bonnor-Melvin universe with a cosmological constant
3 pages
Phys. Rev. D 99, 044058 (2019)
10.1103/PhysRevD.99.044058
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We generalize the well-known Bonnor-Melvin solution of the Einstein-Maxwell equations to the case of a non-vanishing cosmological constant. The spacetime is again cylindrically symmetric and static but, unlike the original solution, it truly represents a homogeneous magnetic field.
[ { "created": "Wed, 20 Mar 2019 15:41:49 GMT", "version": "v1" } ]
2019-03-21
[ [ "Zofka", "Martin", "" ] ]
We generalize the well-known Bonnor-Melvin solution of the Einstein-Maxwell equations to the case of a non-vanishing cosmological constant. The spacetime is again cylindrically symmetric and static but, unlike the original solution, it truly represents a homogeneous magnetic field.
2406.10751
Bowen Zhao
Bowen Zhao, Lars Andersson and Shing-Tung Yau
Strong field behavior of Wang-Yau Quasi-local energy
null
null
null
null
gr-qc math-ph math.DG math.MP
http://creativecommons.org/publicdomain/zero/1.0/
We look at the strong field behavior of the Wang-Yau quasi-local energy. In particular, we examine the limit of the Wang-Yau quasi-local energy as the defining spacelike 2-surface {\Sigma} approaches an apparent horizon from outside. Assuming any smooth isometric embedding, we find that the Wang-Yau quasi-local energ...
[ { "created": "Sat, 15 Jun 2024 22:19:49 GMT", "version": "v1" } ]
2024-07-16
[ [ "Zhao", "Bowen", "" ], [ "Andersson", "Lars", "" ], [ "Yau", "Shing-Tung", "" ] ]
We look at the strong field behavior of the Wang-Yau quasi-local energy. In particular, we examine the limit of the Wang-Yau quasi-local energy as the defining spacelike 2-surface {\Sigma} approaches an apparent horizon from outside. Assuming any smooth isometric embedding, we find that the Wang-Yau quasi-local energy ...
1706.04521
Ahmet Baykal
Ahmet Baykal, Tekin Dereli
Impulsive gravitational waves in general massive 3D gravity
Published version
Phys. Rev. D 96, 084028 (2017)
10.1103/PhysRevD.96.084028
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Impulsive, non-diverging, Petrov-Segre type N gravitational wave solutions to a general massive three-dimensional gravity in the de Sitter, anti-de Sitter and flat Minkowski backgrounds are constructed in a unified manner by using the exterior algebra of differential forms.
[ { "created": "Wed, 14 Jun 2017 14:48:14 GMT", "version": "v1" }, { "created": "Mon, 14 Aug 2017 12:26:10 GMT", "version": "v2" }, { "created": "Sat, 14 Oct 2017 18:53:48 GMT", "version": "v3" } ]
2017-10-17
[ [ "Baykal", "Ahmet", "" ], [ "Dereli", "Tekin", "" ] ]
Impulsive, non-diverging, Petrov-Segre type N gravitational wave solutions to a general massive three-dimensional gravity in the de Sitter, anti-de Sitter and flat Minkowski backgrounds are constructed in a unified manner by using the exterior algebra of differential forms.
1306.4739
Marcus Khuri
Sergio Dain, Marcus Khuri, Gilbert Weinstein, Sumio Yamada
Lower Bounds for the Area of Black Holes in Terms of Mass, Charge, and Angular Momentum
12 pages; section 2 revised; to appear in Phys. Rev. D
Phys. Rev. D 88, 024048 (2013) [7 pages]
10.1103/PhysRevD.88.024048
null
gr-qc math-ph math.DG math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The most general formulation of Penrose's inequality yields a lower bound for ADM mass in terms of the area, charge, and angular momentum of black holes. This inequality is in turn equivalent to an upper and lower bound for the area in terms of the remaining quantities. In this note, we establish the lower bound for ...
[ { "created": "Thu, 20 Jun 2013 02:46:59 GMT", "version": "v1" }, { "created": "Fri, 5 Jul 2013 04:22:58 GMT", "version": "v2" } ]
2013-07-31
[ [ "Dain", "Sergio", "" ], [ "Khuri", "Marcus", "" ], [ "Weinstein", "Gilbert", "" ], [ "Yamada", "Sumio", "" ] ]
The most general formulation of Penrose's inequality yields a lower bound for ADM mass in terms of the area, charge, and angular momentum of black holes. This inequality is in turn equivalent to an upper and lower bound for the area in terms of the remaining quantities. In this note, we establish the lower bound for a ...
1910.01598
Ulrich Sperhake
U.Sperhake, R.Rosca-Mead, D.Gerosa, E.Berti
Amplification of superkicks in black-hole binaries through orbital eccentricity
9 pages, 4 figures, to match published version in Phys.Rev.D
Phys. Rev. D 101, 024044 (2020)
10.1103/PhysRevD.101.024044
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present new numerical-relativity simulations of eccentric merging black holes with initially antiparallel spins lying in the orbital plane (the so-called \emph{superkick} configuration). Binary eccentricity boosts the recoil of the merger remnant by up to $25\%$. The increase in the energy flux is much more modest...
[ { "created": "Thu, 3 Oct 2019 16:59:26 GMT", "version": "v1" }, { "created": "Thu, 23 Jan 2020 13:41:34 GMT", "version": "v2" } ]
2020-01-29
[ [ "Sperhake", "U.", "" ], [ "Rosca-Mead", "R.", "" ], [ "Gerosa", "D.", "" ], [ "Berti", "E.", "" ] ]
We present new numerical-relativity simulations of eccentric merging black holes with initially antiparallel spins lying in the orbital plane (the so-called \emph{superkick} configuration). Binary eccentricity boosts the recoil of the merger remnant by up to $25\%$. The increase in the energy flux is much more modest, ...
1301.2981
Anirban Saha Dr.
Sunandan Gangopadhyay, Anirban Saha, Swarup Saha
Trace of phase-space noncommutativity in the response of a free particle to linearized gravitational waves
9 pages, Latex, Published version, discussions and references added
Mod.Phys.Lett. A28 (2013) 35, 1350161
10.1142/S0217732313501617
null
gr-qc hep-ph hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Interaction of linearized gravitational waves with a otherwise free particle has been studied quantum mechanically in a noncommutative phase-space to examine whether the particle's response to the gravitational wave gets modified due to spatial and/or momentum noncommutativity. The result shows that momentum noncommu...
[ { "created": "Mon, 14 Jan 2013 14:08:52 GMT", "version": "v1" }, { "created": "Mon, 27 Jan 2014 06:09:03 GMT", "version": "v2" } ]
2014-01-28
[ [ "Gangopadhyay", "Sunandan", "" ], [ "Saha", "Anirban", "" ], [ "Saha", "Swarup", "" ] ]
Interaction of linearized gravitational waves with a otherwise free particle has been studied quantum mechanically in a noncommutative phase-space to examine whether the particle's response to the gravitational wave gets modified due to spatial and/or momentum noncommutativity. The result shows that momentum noncommuta...
2210.16366
Alejandra Gonzalez
Alejandra Gonzalez, Francesco Zappa, Matteo Breschi, Sebastiano Bernuzzi, David Radice, Ananya Adhikari, Alessandro Camilletti, Swami Vivekanandji Chaurasia, Georgios Doulis, Surendra Padamata, Alireza Rashti, Maximiliano Ujevic, Bernd Br\"ugmann, William Cook, Tim Dietrich, Albino Perego, Amit Poudel, Wolfgang...
Second release of the CoRe database of binary neutron star merger waveforms
33 pages, 14 figures
Class. Quantum Grav. 40 085011 (2023)
10.1088/1361-6382/acc231
null
gr-qc astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
We present the second data release of gravitational waveforms from binary neutron star merger simulations performed by the Computational Relativity (CoRe) collaboration. The current database consists of 254 different binary neutron star configurations and a total of 590 individual numerical-relativity simulations usi...
[ { "created": "Fri, 28 Oct 2022 19:01:58 GMT", "version": "v1" }, { "created": "Tue, 28 Mar 2023 12:40:25 GMT", "version": "v2" } ]
2023-03-29
[ [ "Gonzalez", "Alejandra", "" ], [ "Zappa", "Francesco", "" ], [ "Breschi", "Matteo", "" ], [ "Bernuzzi", "Sebastiano", "" ], [ "Radice", "David", "" ], [ "Adhikari", "Ananya", "" ], [ "Camilletti", "Alessandro",...
We present the second data release of gravitational waveforms from binary neutron star merger simulations performed by the Computational Relativity (CoRe) collaboration. The current database consists of 254 different binary neutron star configurations and a total of 590 individual numerical-relativity simulations using...
1801.05830
Marc Casals
Marc Casals and Peter Zimmerman
Perturbations of Extremal Kerr Spacetime: Analytic Framework and Late-time Tails
34 pages, 1 figure; in v3: version matching the published version
Phys. Rev. D 100, 124027 (2019)
10.1103/PhysRevD.100.124027
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a complete and systematic analytical approach to field perturbations of extremal Kerr spacetime based on the formalism of Mano, Suzuki and Takasugi (MST) for the Teukolsky equation. Analytical expressions for the radial solutions and frequency-domain Green function in terms of infinite series of special fu...
[ { "created": "Wed, 17 Jan 2018 19:14:48 GMT", "version": "v1" }, { "created": "Fri, 11 Oct 2019 14:49:19 GMT", "version": "v2" }, { "created": "Fri, 28 Feb 2020 17:19:17 GMT", "version": "v3" } ]
2020-03-02
[ [ "Casals", "Marc", "" ], [ "Zimmerman", "Peter", "" ] ]
We develop a complete and systematic analytical approach to field perturbations of extremal Kerr spacetime based on the formalism of Mano, Suzuki and Takasugi (MST) for the Teukolsky equation. Analytical expressions for the radial solutions and frequency-domain Green function in terms of infinite series of special func...
1401.4329
Silvije Domazet
Silvije Domazet and Tomislav Prokopec
A photon propagator on de Sitter in covariant gauges
15 pages
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct a de Sitter invariant photon propagator in general covariant gauges. Our result is a natural generalization of the Allen-Jacobson photon propagator in Feynman gauge. Our propagator reproduces the correct response to a point static charge and the one-loop electromagnetic stress-energy tensor, strongly sug...
[ { "created": "Fri, 17 Jan 2014 12:58:45 GMT", "version": "v1" } ]
2014-01-20
[ [ "Domazet", "Silvije", "" ], [ "Prokopec", "Tomislav", "" ] ]
We construct a de Sitter invariant photon propagator in general covariant gauges. Our result is a natural generalization of the Allen-Jacobson photon propagator in Feynman gauge. Our propagator reproduces the correct response to a point static charge and the one-loop electromagnetic stress-energy tensor, strongly sugge...
gr-qc/0003090
Remo Garattini
Remo Garattini
A Spacetime Foam approach to the cosmological constant and entropy
Uses RevTeX, 24 pages, Appendix deleted and some corrections inserted. Final results unchanged
Int.J.Mod.Phys.D4:635,2002
10.1142/S0218271802001445
null
gr-qc hep-th
null
A simple model of spacetime foam, made by $N$ wormholes in a semiclassical approximation, is taken under examination. The Casimir-like energy of the quantum fluctuation of such a model and its probability of being realized are computed. Implications on the Bekenstein-Hawking entropy and the cosmological constant are ...
[ { "created": "Wed, 22 Mar 2000 19:19:10 GMT", "version": "v1" }, { "created": "Tue, 4 Jun 2002 13:31:21 GMT", "version": "v2" } ]
2014-11-17
[ [ "Garattini", "Remo", "" ] ]
A simple model of spacetime foam, made by $N$ wormholes in a semiclassical approximation, is taken under examination. The Casimir-like energy of the quantum fluctuation of such a model and its probability of being realized are computed. Implications on the Bekenstein-Hawking entropy and the cosmological constant are co...
1011.5709
Hassan Amirhashchi
Hassan Amirhashchi
L.R.S. Bianchi type II Stiff Fluid cosmological model with Decaying Vacuum Energy Density $\Lambda$ in general relativity
null
Phys.Lett.B697:429-433,2011
10.1016/j.physletb.2011.02.046
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Locally rotationally symmetric (L.R.S.) Bianchi type II stiff fluid cosmological model is investigated. To get the deterministic model of the universe, we have assumed a condition $A=B^{m}$ between metric potentials $A,~B$ where $n$ is the constant. It is shown that the vacuum energy density $\Lambda$ is positive and...
[ { "created": "Fri, 26 Nov 2010 06:05:34 GMT", "version": "v1" } ]
2011-05-26
[ [ "Amirhashchi", "Hassan", "" ] ]
Locally rotationally symmetric (L.R.S.) Bianchi type II stiff fluid cosmological model is investigated. To get the deterministic model of the universe, we have assumed a condition $A=B^{m}$ between metric potentials $A,~B$ where $n$ is the constant. It is shown that the vacuum energy density $\Lambda$ is positive and p...
1506.08668
Jonathan R. Gair
Jonathan R. Gair, Joseph D. Romano and Stephen R. Taylor
Mapping gravitational-wave backgrounds in modified theories of gravity using pulsar timing arrays
35 pages, 8 figures, submitted to Phys. Rev. D
Phys. Rev. D 92, 102003 (2015)
10.1103/PhysRevD.92.102003
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend our previous work on applying CMB techniques to the mapping of gravitational-wave backgrounds to backgrounds which have non-GR polarisations. Our analysis and results are presented in the context of pulsar-timing array observations, but the overarching methods are general, and can be easily applied to LIGO ...
[ { "created": "Mon, 29 Jun 2015 15:01:00 GMT", "version": "v1" } ]
2015-12-02
[ [ "Gair", "Jonathan R.", "" ], [ "Romano", "Joseph D.", "" ], [ "Taylor", "Stephen R.", "" ] ]
We extend our previous work on applying CMB techniques to the mapping of gravitational-wave backgrounds to backgrounds which have non-GR polarisations. Our analysis and results are presented in the context of pulsar-timing array observations, but the overarching methods are general, and can be easily applied to LIGO or...
2004.14988
Daniela Pugliese Dr
D. Pugliese and G. Montani
Constraining LQG Graph with Light Surfaces: Properties of BH Thermodynamics for Mini-Super-Space, Semi-Classical Polymeric BH
34 pages; 16 figure multipanels; 2 tables
Entropy 2020, 22(4), 402;
10.3390/e22040402
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work discusses observational evidences of quantum effects on geometry in a black hole (BH) astrophysical context. We study properties of a family of loop quantum corrected regular BH solutions and their horizons, focusing on the geometry symmetries. We explore a recent model where the geometry is determined by a...
[ { "created": "Thu, 30 Apr 2020 17:33:13 GMT", "version": "v1" } ]
2020-05-01
[ [ "Pugliese", "D.", "" ], [ "Montani", "G.", "" ] ]
This work discusses observational evidences of quantum effects on geometry in a black hole (BH) astrophysical context. We study properties of a family of loop quantum corrected regular BH solutions and their horizons, focusing on the geometry symmetries. We explore a recent model where the geometry is determined by a m...
2204.02429
Aaron Held
Astrid Eichhorn, Aaron Held, Philipp-Vincent Johannsen
Universal signatures of singularity-resolving physics in photon rings of black holes and horizonless objects
26 pages + appendix; 12 figures
null
10.1088/1475-7516/2023/01/043
Imperial/TP/2022/AH/01
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within quantum-gravity approaches and beyond, different mechanisms for singularity resolution in black holes exist. Under a set of assumptions that we spell out in detail, these mechanisms leave their imprint in shadow images of spherically symmetric black holes. We find that even current EHT accuracy is sufficient t...
[ { "created": "Tue, 5 Apr 2022 18:10:49 GMT", "version": "v1" } ]
2023-02-01
[ [ "Eichhorn", "Astrid", "" ], [ "Held", "Aaron", "" ], [ "Johannsen", "Philipp-Vincent", "" ] ]
Within quantum-gravity approaches and beyond, different mechanisms for singularity resolution in black holes exist. Under a set of assumptions that we spell out in detail, these mechanisms leave their imprint in shadow images of spherically symmetric black holes. We find that even current EHT accuracy is sufficient to ...
gr-qc/0112028
Sergiu Vacaru
Sergiu Vacaru and Panayiotis Stavrinos
Spinors and Space-Time Anisotropy
Version 3 with new references, 301 pages, latex2e
Athens University Press, Athens, Greece, 2002
null
null
gr-qc hep-th math-ph math.DG math.MP
null
This is the first monograph on the geometry of anisotropic spinor spaces and its applications in modern physics. The main subjects are the theory of gravity and matter fields in spaces provided with off--diagonal metrics and associated anholonomic frames and nonlinear connection structures, the algebra and geometry o...
[ { "created": "Wed, 12 Dec 2001 21:08:58 GMT", "version": "v1" }, { "created": "Sat, 15 Dec 2001 13:33:57 GMT", "version": "v2" }, { "created": "Tue, 28 May 2002 20:57:17 GMT", "version": "v3" } ]
2007-05-23
[ [ "Vacaru", "Sergiu", "" ], [ "Stavrinos", "Panayiotis", "" ] ]
This is the first monograph on the geometry of anisotropic spinor spaces and its applications in modern physics. The main subjects are the theory of gravity and matter fields in spaces provided with off--diagonal metrics and associated anholonomic frames and nonlinear connection structures, the algebra and geometry of ...
2403.10377
Waleska de Medeiros Ma.
Waleska P. F. de Medeiros, Matheus J. Lazo, Daniel M\"uller and Dinalva A. Sales
Tilt in quadratic gravity
null
null
null
null
gr-qc astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
In this work, non perfect fluid, tilted source solutions in both Einstein-Hilbert General Relativity (GR) and Quadratic Gravity (QG) for the anisotropic Bianchi V model are addressed. Since the excellent CMBR match of Starobinsky's inflation with Planck's team measurements data, QG has acquired a prominent status in ...
[ { "created": "Fri, 15 Mar 2024 15:07:18 GMT", "version": "v1" } ]
2024-03-18
[ [ "de Medeiros", "Waleska P. F.", "" ], [ "Lazo", "Matheus J.", "" ], [ "Müller", "Daniel", "" ], [ "Sales", "Dinalva A.", "" ] ]
In this work, non perfect fluid, tilted source solutions in both Einstein-Hilbert General Relativity (GR) and Quadratic Gravity (QG) for the anisotropic Bianchi V model are addressed. Since the excellent CMBR match of Starobinsky's inflation with Planck's team measurements data, QG has acquired a prominent status in th...
gr-qc/0009041
Antonio Bernal Navarro
A. N. Bernal, M. P. Lopez, M. Sanchez (Dpto. Geometria y Topologia, Granada, Spain)
Fundamental units of length and time
Part of the results of this article has been announced at the meeting ``XXIV International Workshop on the Fundamental Problems of High Energy Physics and Field Theory'' 27-29 June 2001, Protvino, Russia
Found.Phys.32:77-108,2002
10.1023/A:1013800914617
null
gr-qc
null
Ideal rods and clocks are defined as an infinitesimal symmetry of the spacetime. Since no a priori geometric structure is considered, all the possible models of spacetime are obtained.
[ { "created": "Wed, 13 Sep 2000 01:57:14 GMT", "version": "v1" }, { "created": "Thu, 14 Sep 2000 22:59:42 GMT", "version": "v2" }, { "created": "Mon, 7 Oct 2002 23:31:21 GMT", "version": "v3" } ]
2008-11-26
[ [ "Bernal", "A. N.", "", "Dpto. Geometria y Topologia,\n Granada, Spain" ], [ "Lopez", "M. P.", "", "Dpto. Geometria y Topologia,\n Granada, Spain" ], [ "Sanchez", "M.", "", "Dpto. Geometria y Topologia,\n Granada, Spain" ] ]
Ideal rods and clocks are defined as an infinitesimal symmetry of the spacetime. Since no a priori geometric structure is considered, all the possible models of spacetime are obtained.
2303.17296
Jo\~ao Lu\'is Rosa
Jo\~ao Lu\'is Rosa, Caio F. B. Macedo, Diego Rubiera-Garcia
Imaging compact boson stars with hot-spots and thin accretion disks
17 pages, 16 figures
Phys. Rev. D 108, 044021 (2023)
10.1103/PhysRevD.108.044021
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we consider the observational properties of compact boson stars with self-interactions orbited by isotropically emitting (hot-spot) sources and optically thin accretion disks. We consider two families of boson stars supported by quartic and sixth-order self-interaction potentials, and choose three sample...
[ { "created": "Thu, 30 Mar 2023 11:16:15 GMT", "version": "v1" } ]
2023-08-22
[ [ "Rosa", "João Luís", "" ], [ "Macedo", "Caio F. B.", "" ], [ "Rubiera-Garcia", "Diego", "" ] ]
In this work we consider the observational properties of compact boson stars with self-interactions orbited by isotropically emitting (hot-spot) sources and optically thin accretion disks. We consider two families of boson stars supported by quartic and sixth-order self-interaction potentials, and choose three samples ...
2306.00540
David Trestini
David Trestini
Gravitational waves in scalar-tensor theory to one-and-a-half post-Newtonian order
Contribution to the 2022 Gravitation session of the 56th Rencontres de Moriond. 4 pages
null
10.58027/1e1n-7973
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We compute the gravitational waves generated by compact binary systems in a class of massless scalar-tensor (ST) theories to the 1.5 post-Newtonian (1.5PN) order beyond the standard quadrupole radiation in general relativity (GR). Using and adapting to ST theories the multipolar-post-Minkowskian and post-Newtonian fo...
[ { "created": "Thu, 1 Jun 2023 10:50:21 GMT", "version": "v1" } ]
2023-06-02
[ [ "Trestini", "David", "" ] ]
We compute the gravitational waves generated by compact binary systems in a class of massless scalar-tensor (ST) theories to the 1.5 post-Newtonian (1.5PN) order beyond the standard quadrupole radiation in general relativity (GR). Using and adapting to ST theories the multipolar-post-Minkowskian and post-Newtonian form...
2111.04548
Ernesto F. Eiroa
Javier Bad\'ia, Ernesto F. Eiroa
Shadow of black holes with a plasma environment in 4D Einstein-Gauss-Bonnet gravity
9 pages, 2 figures; prepared for the Proceedings of the Sixteenth Marcel Grossmann Meeting - MG16
Proceedings of the Sixteenth Marcel Grossmann Meeting (MG16), pages 3856-3864 (World Scientific, Singapore, 2023)
10.1142/9789811269776_0320
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the shadow cast by rotating black holes surrounded by plasma in the context of the 4D Einstein-Gauss-Bonnet theory of gravity. The metric for these black holes results from applying the Newman-Janis algorithm to a spherically symmetric solution. We obtain the contour of the shadow for a plasma frequency mode...
[ { "created": "Mon, 8 Nov 2021 14:57:35 GMT", "version": "v1" } ]
2023-01-30
[ [ "Badía", "Javier", "" ], [ "Eiroa", "Ernesto F.", "" ] ]
We study the shadow cast by rotating black holes surrounded by plasma in the context of the 4D Einstein-Gauss-Bonnet theory of gravity. The metric for these black holes results from applying the Newman-Janis algorithm to a spherically symmetric solution. We obtain the contour of the shadow for a plasma frequency model ...
1712.04444
Yongwan Gim
Yongwan Gim, Hwajin Um, Wontae Kim
Black hole complementarity with the generalized uncertainty principle in gravity's rainbow
18 pages, 3 figures, version to appear in JCAP
JCAP, 02 (2018) 060
10.1088/1475-7516/2018/02/060
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
When gravitation is combined with quantum theory, the Heisenberg uncertainty principle could be extended to the generalized uncertainty principle accompanying a minimal length. To see how the generalized uncertainty principle works in the context of black hole complementarity, we calculate the required energy to dupl...
[ { "created": "Tue, 12 Dec 2017 05:42:36 GMT", "version": "v1" }, { "created": "Fri, 2 Mar 2018 02:17:16 GMT", "version": "v2" } ]
2018-03-05
[ [ "Gim", "Yongwan", "" ], [ "Um", "Hwajin", "" ], [ "Kim", "Wontae", "" ] ]
When gravitation is combined with quantum theory, the Heisenberg uncertainty principle could be extended to the generalized uncertainty principle accompanying a minimal length. To see how the generalized uncertainty principle works in the context of black hole complementarity, we calculate the required energy to duplic...
1010.1258
Antonino Marciano
Marco Valerio Battisti and Antonino Marciano
Big Bounce in Dipole Cosmology
5 pages
Phys.Rev.D82:124060,2010
10.1103/PhysRevD.82.124060
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the cosmological Big Bounce scenario from the dipole approximation of Loop Quantum Gravity. We show that a non-singular evolution takes place for any matter field and that, by considering a massless scalar field as a relational clock for the dynamics, the semi-classical proprieties of an initial state are p...
[ { "created": "Wed, 6 Oct 2010 20:06:04 GMT", "version": "v1" } ]
2011-01-24
[ [ "Battisti", "Marco Valerio", "" ], [ "Marciano", "Antonino", "" ] ]
We derive the cosmological Big Bounce scenario from the dipole approximation of Loop Quantum Gravity. We show that a non-singular evolution takes place for any matter field and that, by considering a massless scalar field as a relational clock for the dynamics, the semi-classical proprieties of an initial state are pre...
1105.4727
Luis Herrera
L. Herrera, A. Di Prisco and J. Iba\~nez
Tilted Lemaitre-Tolman-Bondi Spacetimes: Hydrodynamic and Thermodynamic Properties
11 pages Revtex. Some changes in the text, references updated. Published in Phys. Rev. D
Phys. Rev. D 84, 064036 (2011)
10.1103/PhysRevD.84.064036
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider Lemaitre-Tolman-Bondi spacetimes from the point of view of a tilted observer, i.e. one with respect to which the fluid is radially moving. The imperfect fluid and the congruence described by its four-velocity, as seen by the tilted observer is studied in detail. It is shown that from the point of view of ...
[ { "created": "Tue, 24 May 2011 10:32:38 GMT", "version": "v1" }, { "created": "Fri, 24 Jun 2011 08:19:56 GMT", "version": "v2" }, { "created": "Tue, 27 Sep 2011 08:36:14 GMT", "version": "v3" } ]
2015-05-28
[ [ "Herrera", "L.", "" ], [ "Di Prisco", "A.", "" ], [ "Ibañez", "J.", "" ] ]
We consider Lemaitre-Tolman-Bondi spacetimes from the point of view of a tilted observer, i.e. one with respect to which the fluid is radially moving. The imperfect fluid and the congruence described by its four-velocity, as seen by the tilted observer is studied in detail. It is shown that from the point of view of su...
gr-qc/0202089
David Langlois
Philippe Mounaix, David Langlois
Cosmological Equations for a Thick Brane
23 pages, Latex, 2 figures
Phys.Rev. D65 (2002) 103523
10.1103/PhysRevD.65.103523
null
gr-qc astro-ph hep-ph hep-th
null
Generalized Friedmann equations governing the cosmological evolution inside a thick brane embedded in a five-dimensional Anti-de Sitter spacetime are derived. These equations are written in terms of four-dimensional effective brane quantities obtained by integrating, along the fifth dimension, over the brane thicknes...
[ { "created": "Mon, 25 Feb 2002 15:08:35 GMT", "version": "v1" } ]
2009-11-07
[ [ "Mounaix", "Philippe", "" ], [ "Langlois", "David", "" ] ]
Generalized Friedmann equations governing the cosmological evolution inside a thick brane embedded in a five-dimensional Anti-de Sitter spacetime are derived. These equations are written in terms of four-dimensional effective brane quantities obtained by integrating, along the fifth dimension, over the brane thickness....
1705.06984
Daniela Doneva
Stoytcho S. Yazadjiev, Daniela D. Doneva, Kostas D. Kokkotas
Oscillation modes of rapidly rotating neutron stars in scalar-tensor theories of gravity
9 pages, 2 figures
Phys. Rev. D 96, 064002 (2017)
10.1103/PhysRevD.96.064002
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform the first study of the oscillation frequencies of rapidly rotating neutron stars in alternative theories of gravity, focusing mainly on the fundamental $f$-modes. We concentrated on a particular class of alternative theories - the (massive) scalar-tensor theories. The generalization to rapid rotation is im...
[ { "created": "Fri, 19 May 2017 13:39:34 GMT", "version": "v1" } ]
2017-09-13
[ [ "Yazadjiev", "Stoytcho S.", "" ], [ "Doneva", "Daniela D.", "" ], [ "Kokkotas", "Kostas D.", "" ] ]
We perform the first study of the oscillation frequencies of rapidly rotating neutron stars in alternative theories of gravity, focusing mainly on the fundamental $f$-modes. We concentrated on a particular class of alternative theories - the (massive) scalar-tensor theories. The generalization to rapid rotation is impo...
1911.06374
Gustavo Gutierrez-Cano
Alberto A. Garcia-Diaz and Gustavo Gutierrez-Cano
Regularity conditions for spherically symmetric solutions of Einstein-nonlinear electrodynamics equations; revised and improved version
43 pages, version-2: Sections and references added
Annals of Physics 2020
10.1016/j.aop.2020.168323
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this report, the regularity conditions at the center for static spherically symmetric (SSS) solutions of the Einstein equations coupled to nonlinear electrodynamics (NLE) with Lagrangian $\mathcal{L}= \mathcal{L}(\mathcal{F})$, depending on the electromagnetic invariant $\mathcal{F}=F_{\mu\nu}\,F^{\mu\nu}/4$, are ...
[ { "created": "Thu, 14 Nov 2019 20:33:49 GMT", "version": "v1" }, { "created": "Tue, 23 Jun 2020 18:48:35 GMT", "version": "v2" } ]
2020-11-05
[ [ "Garcia-Diaz", "Alberto A.", "" ], [ "Gutierrez-Cano", "Gustavo", "" ] ]
In this report, the regularity conditions at the center for static spherically symmetric (SSS) solutions of the Einstein equations coupled to nonlinear electrodynamics (NLE) with Lagrangian $\mathcal{L}= \mathcal{L}(\mathcal{F})$, depending on the electromagnetic invariant $\mathcal{F}=F_{\mu\nu}\,F^{\mu\nu}/4$, are es...
1707.02611
Joao Rafael Lucio Dos Santos
J. R. L. Santos, P. H. R. S. Moraes, D. A. Ferreira, D. C. Vilar Neta
Building analytical three-field cosmological models
11 pages, and 3 figures, updated version published in EPJC
The European Physical Journal C, 2018
10.1140/epjc/s10052-018-5614-6
null
gr-qc math.CA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A difficult task to deal with is the analytical treatment of models composed by three real scalar fields, once their equations of motion are in general coupled and hard to be integrated. In order to overcome this problem we introduce a methodology to construct three-field models based on the so-called "extension meth...
[ { "created": "Sun, 9 Jul 2017 18:08:13 GMT", "version": "v1" }, { "created": "Tue, 27 Feb 2018 02:20:29 GMT", "version": "v2" } ]
2018-02-28
[ [ "Santos", "J. R. L.", "" ], [ "Moraes", "P. H. R. S.", "" ], [ "Ferreira", "D. A.", "" ], [ "Neta", "D. C. Vilar", "" ] ]
A difficult task to deal with is the analytical treatment of models composed by three real scalar fields, once their equations of motion are in general coupled and hard to be integrated. In order to overcome this problem we introduce a methodology to construct three-field models based on the so-called "extension method...
1901.09173
Andronikos Paliathanasis
John D. Barrow and Andronikos Paliathanasis
Cyclic Szekeres Universes
10 pages, 7 figures, accepted for publication in EPJC
Eur. Phys. J. C (2019) 79: 379
10.1140/epjc/s10052-019-6890-5
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the Szekeres universe with an inhomogeneous dust fluid and a homogeneous and isotropic ghost matter source with equation of state $p_{g}=\left( \gamma-1\right) \rho_{g},$ where $\gamma$ is a constant. The field equations determine two families of spacetimes which describe homogeneous Kantowski-Sachs unive...
[ { "created": "Sat, 26 Jan 2019 08:10:29 GMT", "version": "v1" }, { "created": "Thu, 18 Apr 2019 13:39:04 GMT", "version": "v2" } ]
2020-01-17
[ [ "Barrow", "John D.", "" ], [ "Paliathanasis", "Andronikos", "" ] ]
We consider the Szekeres universe with an inhomogeneous dust fluid and a homogeneous and isotropic ghost matter source with equation of state $p_{g}=\left( \gamma-1\right) \rho_{g},$ where $\gamma$ is a constant. The field equations determine two families of spacetimes which describe homogeneous Kantowski-Sachs univers...
1104.3723
Ritabrata Biswas
Ritabrata Biswas, Subenoy Chakraborty
A Study of Phase Transition in Black Hole Thermodynamics
16 figures
Astrophys.Space Sci.332:171,2011
10.1007/s10509-010-0488-6
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper deals with five-dimensional black hole solutions in (a) Einstein-Maxwell-Gauss-Bonnet theory with a cosmological constant and (b)Einstein-Yang-Mills-Gauss-Bonnet theory for spherically symmetric space time. In both the cases the possibility of phase transition is examined and it is analyzed whether the pha...
[ { "created": "Tue, 19 Apr 2011 12:16:31 GMT", "version": "v1" } ]
2011-05-23
[ [ "Biswas", "Ritabrata", "" ], [ "Chakraborty", "Subenoy", "" ] ]
This paper deals with five-dimensional black hole solutions in (a) Einstein-Maxwell-Gauss-Bonnet theory with a cosmological constant and (b)Einstein-Yang-Mills-Gauss-Bonnet theory for spherically symmetric space time. In both the cases the possibility of phase transition is examined and it is analyzed whether the phase...
1603.09655
Bayram Tekin
Metin Gurses, Tahsin Cagri Sisman, Bayram Tekin
From Smooth Curves to Universal Metrics
10 pages, 1 figure. Discussions extended
Phys. Rev. D 94, 044042 (2016)
10.1103/PhysRevD.94.044042
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A special class of metrics, called universal metrics, solve all gravity theories defined by covariant field equations purely based on the metric tensor. Since we currently lack the knowledge of what the full of quantum-corrected field equations of gravity are at a given microscopic length scale, these metrics are par...
[ { "created": "Thu, 31 Mar 2016 16:04:02 GMT", "version": "v1" }, { "created": "Wed, 10 Aug 2016 15:50:13 GMT", "version": "v2" } ]
2016-08-24
[ [ "Gurses", "Metin", "" ], [ "Sisman", "Tahsin Cagri", "" ], [ "Tekin", "Bayram", "" ] ]
A special class of metrics, called universal metrics, solve all gravity theories defined by covariant field equations purely based on the metric tensor. Since we currently lack the knowledge of what the full of quantum-corrected field equations of gravity are at a given microscopic length scale, these metrics are parti...
gr-qc/9903063
Elisa Di Pietro
Elisa Di Pietro, Jacques Demaret
Scale-factor duality in string Bianchi cosmologies
18 pages, no figures
Int.J.Mod.Phys. D8 (1999) 349-361
10.1142/S0218271899000262
null
gr-qc
null
We apply the scale factor duality transformations introduced in the context of the effective string theory to the anisotropic Bianchi-type models. We find dual models for all the Bianchi-types [except for types $VIII$ and $IX$] and construct for each of them its explicit form starting from the exact original solution...
[ { "created": "Wed, 17 Mar 1999 10:01:10 GMT", "version": "v1" }, { "created": "Tue, 13 Jul 1999 09:11:36 GMT", "version": "v2" } ]
2016-08-31
[ [ "Di Pietro", "Elisa", "" ], [ "Demaret", "Jacques", "" ] ]
We apply the scale factor duality transformations introduced in the context of the effective string theory to the anisotropic Bianchi-type models. We find dual models for all the Bianchi-types [except for types $VIII$ and $IX$] and construct for each of them its explicit form starting from the exact original solution o...
1611.00430
Sergio Ulhoa
S.C. Ulhoa, R.G.G. Amorim, Abra\~ao J. S. Capistrano
On Quasinormal Modes for Scalar Perturbations of Static Spherically Symmetric Black Holes in Nash Embedding Framework
null
Advances in High Energy Physics Volume 2017 (2017), Article ID 9891231
10.1155/2017/9891231
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we investigate scalar perturbations of black holes embedded in a five dimensional bulk space. It is calculated the quasinormal frequencies of a such black holes using the third order of Wentzel, Kramers, Brillouin (WKB) approximation for scalar perturbations. The results are presented in tables along th...
[ { "created": "Wed, 2 Nov 2016 00:30:29 GMT", "version": "v1" } ]
2017-11-30
[ [ "Ulhoa", "S. C.", "" ], [ "Amorim", "R. G. G.", "" ], [ "Capistrano", "Abraão J. S.", "" ] ]
In this paper we investigate scalar perturbations of black holes embedded in a five dimensional bulk space. It is calculated the quasinormal frequencies of a such black holes using the third order of Wentzel, Kramers, Brillouin (WKB) approximation for scalar perturbations. The results are presented in tables along the ...
1403.8116
Surajit Chattopadhyay
Surajit Chattopadhyay
QCD ghost reconstruction of f(T) gravity in flat FRW universe
13 pages, 8 figures, Accepted for publication in European Physical Journal Plus
Eur. Phys. J. Plus (2014) 129: 82
10.1140/epjp/i2014-14082-6
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The present work reports a reconstruction scheme for f(T) gravity based on QCD ghost dark energy. Two models of f(T) have been generated and the pressure and density contributions due to torsion have been reconstructed. Two realistic models have been obtained and the effective equations of state have been studied. Al...
[ { "created": "Fri, 28 Mar 2014 04:30:35 GMT", "version": "v1" } ]
2014-05-14
[ [ "Chattopadhyay", "Surajit", "" ] ]
The present work reports a reconstruction scheme for f(T) gravity based on QCD ghost dark energy. Two models of f(T) have been generated and the pressure and density contributions due to torsion have been reconstructed. Two realistic models have been obtained and the effective equations of state have been studied. Also...
1501.00974
Gamal G.L. Nashed
G.G.L. Nashed
Schwarzschild solution in extended teleparallel gravity
8 pages Latex
EPL Vol. 105 (2014), 10001
10.1209/0295-5075/105/10001
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Tetrad field, with two unknown functions of radial coordinate and an angle $\Phi$ which is the polar angle $\phi$ times a function of the redial coordinate, is applied to the field equation of modified theory of gravity. Exact vacuum solution is derived whose scalar torsion, $T ={T^\alpha}_{\mu \nu} {S_\alpha}^{\mu \...
[ { "created": "Mon, 5 Jan 2015 08:14:21 GMT", "version": "v1" } ]
2015-01-07
[ [ "Nashed", "G. G. L.", "" ] ]
Tetrad field, with two unknown functions of radial coordinate and an angle $\Phi$ which is the polar angle $\phi$ times a function of the redial coordinate, is applied to the field equation of modified theory of gravity. Exact vacuum solution is derived whose scalar torsion, $T ={T^\alpha}_{\mu \nu} {S_\alpha}^{\mu \nu...
1306.0908
Richard Brito
Richard Brito, Vitor Cardoso, Paolo Pani
Partially massless gravitons do not destroy general relativity black holes
5 pages, 1 figure; v2: matched to published version; v3: references added
Phys.Rev.D87:124024,2013
10.1103/PhysRevD.87.124024
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent nonlinear completions of Fierz-Pauli theory for a massive spin-2 field include nonlinear massive gravity and bimetric theories. The spectrum of black-hole solutions in these theories is rich, and comprises the same vacuum solutions of Einstein's gravity enlarged to include a cosmological constant. It was recen...
[ { "created": "Tue, 4 Jun 2013 20:00:16 GMT", "version": "v1" }, { "created": "Fri, 21 Jun 2013 12:51:25 GMT", "version": "v2" }, { "created": "Thu, 22 Aug 2013 22:13:54 GMT", "version": "v3" } ]
2013-08-26
[ [ "Brito", "Richard", "" ], [ "Cardoso", "Vitor", "" ], [ "Pani", "Paolo", "" ] ]
Recent nonlinear completions of Fierz-Pauli theory for a massive spin-2 field include nonlinear massive gravity and bimetric theories. The spectrum of black-hole solutions in these theories is rich, and comprises the same vacuum solutions of Einstein's gravity enlarged to include a cosmological constant. It was recentl...
1707.07586
Carlos Alex Souza da Silva Dr
C. A. S. Silva
Loop quantum cosmology on a brane via holography
6 pages. New results added
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this letter, we demonstrate that Loop Quantum Cosmology equations, with a near vanishing late time cosmological constant, can be induced on a brane in a Randall-Sundrum II scenario, corresponding to the holographic dual of a strongly coupled string regime in the bulk. Such results can establish a possible connecti...
[ { "created": "Thu, 20 Jul 2017 21:08:24 GMT", "version": "v1" }, { "created": "Thu, 7 Mar 2019 01:24:27 GMT", "version": "v2" } ]
2019-03-08
[ [ "Silva", "C. A. S.", "" ] ]
In this letter, we demonstrate that Loop Quantum Cosmology equations, with a near vanishing late time cosmological constant, can be induced on a brane in a Randall-Sundrum II scenario, corresponding to the holographic dual of a strongly coupled string regime in the bulk. Such results can establish a possible connection...
2008.07837
Luciano Gabbanelli
Luciano Gabbanelli and Silvia De Bianchi
Cosmological implications of the hydrodynamical phase of group field theory
34 pages
General Relativity and Gravitation 53(66), 2021
10.1007/s10714-021-02833-z
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this review we focus on the main cosmological implications of the Group Field Theory approach, according to which an effective continuum macroscopic dynamics can be extracted from the underlying formalism for quantum gravity. Within this picture what counts is the collective behaviour of a large number of quanta o...
[ { "created": "Tue, 18 Aug 2020 10:18:52 GMT", "version": "v1" }, { "created": "Tue, 1 Jun 2021 10:36:55 GMT", "version": "v2" } ]
2022-04-27
[ [ "Gabbanelli", "Luciano", "" ], [ "De Bianchi", "Silvia", "" ] ]
In this review we focus on the main cosmological implications of the Group Field Theory approach, according to which an effective continuum macroscopic dynamics can be extracted from the underlying formalism for quantum gravity. Within this picture what counts is the collective behaviour of a large number of quanta of ...
1207.5318
Yongwan Kim
Wontae Kim and Yongwan Kim
Phase transition of quantum corrected Schwarzschild black hole
12 pages, 4 figures, added : version accepted for publication in PLB
Phys.Lett.B 718:687-691,2012
10.1016/j.physletb.2012.11.017
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the thermodynamic phase transition of a quantum-corrected Schwarzschild black hole. The modified metric affects the critical temperature which is slightly less than the conventional one. The space without black holes is not the hot flat space but the hot curved space due to vacuum fluctuations so that there ...
[ { "created": "Mon, 23 Jul 2012 08:43:23 GMT", "version": "v1" }, { "created": "Wed, 7 Nov 2012 08:26:54 GMT", "version": "v2" } ]
2013-02-15
[ [ "Kim", "Wontae", "" ], [ "Kim", "Yongwan", "" ] ]
We study the thermodynamic phase transition of a quantum-corrected Schwarzschild black hole. The modified metric affects the critical temperature which is slightly less than the conventional one. The space without black holes is not the hot flat space but the hot curved space due to vacuum fluctuations so that there ap...
1606.00207
Alessandro Nagar
Alessandro Nagar, Abhay G. Shah
iResum: a new paradigm for resumming gravitational wave amplitudes
6 pages, 7 figures. Improved discussion for the comparable-mass case
Phys. Rev. D 94, 104017 (2016)
10.1103/PhysRevD.94.104017
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a new, resummed, analytical form of the post-Newtonian (PN), factorized, multipolar amplitude corrections $f_{\ell m}$ of the effective-one-body (EOB) gravitational waveform of spinning, nonprecessing, circularized, coalescing black hole binaries (BBHs). This stems from the following two-step paradigm: (...
[ { "created": "Wed, 1 Jun 2016 10:20:27 GMT", "version": "v1" }, { "created": "Wed, 28 Sep 2016 10:25:36 GMT", "version": "v2" } ]
2016-11-15
[ [ "Nagar", "Alessandro", "" ], [ "Shah", "Abhay G.", "" ] ]
We introduce a new, resummed, analytical form of the post-Newtonian (PN), factorized, multipolar amplitude corrections $f_{\ell m}$ of the effective-one-body (EOB) gravitational waveform of spinning, nonprecessing, circularized, coalescing black hole binaries (BBHs). This stems from the following two-step paradigm: (i)...
1412.8111
Sunil Maharaj
G. Z. Abebe, S. D. Maharaj, K. S. Govinder
Geodesic models generated by Lie symmetries
16 pages, Submitted for publication
Gen. Relativ. Gravit. 46, 1650 (2014)
10.1007/s10714-013-1650-6
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the junction condition relating the pressure to the heat flux at the boundary of a shearing and expanding spherically symmetric radiating star when the fluid particles are travelling in geodesic motion. The Lie symmetry generators that leave the junction condition invariant are identified and the optimal sys...
[ { "created": "Sun, 28 Dec 2014 05:11:08 GMT", "version": "v1" } ]
2015-06-23
[ [ "Abebe", "G. Z.", "" ], [ "Maharaj", "S. D.", "" ], [ "Govinder", "K. S.", "" ] ]
We study the junction condition relating the pressure to the heat flux at the boundary of a shearing and expanding spherically symmetric radiating star when the fluid particles are travelling in geodesic motion. The Lie symmetry generators that leave the junction condition invariant are identified and the optimal syste...
2311.11661
Moreshwar Tayde
Moreshwar Tayde, Zinnat Hassan and P.K. Sahoo
Conformally symmetric wormhole solutions supported by non-commutative geometries in the context of $f(Q,T)$ gravity
Chinese Journal of Physics accepted version
Chinese Journal of Physics, 89 (2024) 195-209
10.1016/j.cjph.2024.02.003
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
This paper examines wormhole geometries in the context of $f(Q,T)$ gravity under the background of non-commutative distributions. We discuss the analytical solutions assuming spherical symmetry and the presence of conformal Killing vectors, which provides a systematic approach for seeking exact wormhole solutions. Sp...
[ { "created": "Mon, 20 Nov 2023 10:52:24 GMT", "version": "v1" }, { "created": "Wed, 6 Dec 2023 08:30:04 GMT", "version": "v2" }, { "created": "Sun, 4 Feb 2024 09:21:16 GMT", "version": "v3" }, { "created": "Wed, 28 Feb 2024 04:00:38 GMT", "version": "v4" } ]
2024-03-22
[ [ "Tayde", "Moreshwar", "" ], [ "Hassan", "Zinnat", "" ], [ "Sahoo", "P. K.", "" ] ]
This paper examines wormhole geometries in the context of $f(Q,T)$ gravity under the background of non-commutative distributions. We discuss the analytical solutions assuming spherical symmetry and the presence of conformal Killing vectors, which provides a systematic approach for seeking exact wormhole solutions. Spec...
1512.04411
Tomonori Totani
Tomonori Totani (UTokyo)
Initial Conditions of Inhomogeneous Universe and the Cosmological Constant Problem
11 pages, no figure, matches the published version in JCAP. This is the first appearance in the gr-qc daily mailings because of the primary category change made by arXiv
JCAP 06 (2016) 003
10.1088/1475-7516/2016/06/003
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deriving the Einstein field equations (EFE) with matter fluid from the action principle is not straightforward, because mass conservation must be added as an additional constraint to make rest-frame mass density variable in reaction to metric variation. This can be avoided by introducing a constraint $\delta(\sqrt{-g...
[ { "created": "Wed, 25 Nov 2015 03:47:39 GMT", "version": "v1" }, { "created": "Fri, 26 Feb 2016 06:08:30 GMT", "version": "v2" }, { "created": "Tue, 24 May 2016 17:10:01 GMT", "version": "v3" }, { "created": "Fri, 10 Jun 2016 02:52:36 GMT", "version": "v4" } ]
2016-06-13
[ [ "Totani", "Tomonori", "", "UTokyo" ] ]
Deriving the Einstein field equations (EFE) with matter fluid from the action principle is not straightforward, because mass conservation must be added as an additional constraint to make rest-frame mass density variable in reaction to metric variation. This can be avoided by introducing a constraint $\delta(\sqrt{-g})...
1704.05681
Leandros Perivolaropoulos
L. Perivolaropoulos
Cosmological Horizons, Uncertainty Principle and Maximum Length Quantum Mechanics
11 pages, 7 Figures. The Mathematica file that was used for the production of the Figures may be downloaded from http://leandros.physics.uoi.gr/maxlenqm/
Phys. Rev. D 95, 103523 (2017)
10.1103/PhysRevD.95.103523
null
gr-qc astro-ph.CO hep-ph hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The cosmological particle horizon is the maximum measurable length in the Universe. The existence of such a maximum observable length scale implies a modification of the quantum uncertainty principle. Thus due to non-locality of quantum mechanics, the global properties of the Universe could produce a signature on the...
[ { "created": "Wed, 19 Apr 2017 10:39:50 GMT", "version": "v1" } ]
2017-06-07
[ [ "Perivolaropoulos", "L.", "" ] ]
The cosmological particle horizon is the maximum measurable length in the Universe. The existence of such a maximum observable length scale implies a modification of the quantum uncertainty principle. Thus due to non-locality of quantum mechanics, the global properties of the Universe could produce a signature on the b...
1912.10533
Karan Jani
Richard Udall, Karan Jani, Jacob Lange, Richard O'Shaughnessy, James Clark, Laura Cadonati, Deirdre Shoemaker, Kelly Holley-Bockelmann
Inferring Parameters of GW170502: The Loudest Intermediate-mass Black Hole Trigger in LIGO's O1/O2 data
6 pages, 4 figures, 3 tables; Accepted for publication in the Astrophysical Journal
ApJ, vol. 900, issue 1, article 80 (2020)
10.3847/1538-4357/abab9d
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gravitational wave (GW) measurements provide the most robust constraints of the mass of astrophysical black holes. Using state-of-the-art GW signal models and a unique parameter estimation technique, we infer the source parameters of the loudest marginal trigger, GW170502, found by LIGO from 2015 to 2017. If this tri...
[ { "created": "Sun, 22 Dec 2019 21:01:34 GMT", "version": "v1" }, { "created": "Mon, 31 Aug 2020 18:01:11 GMT", "version": "v2" } ]
2020-09-02
[ [ "Udall", "Richard", "" ], [ "Jani", "Karan", "" ], [ "Lange", "Jacob", "" ], [ "O'Shaughnessy", "Richard", "" ], [ "Clark", "James", "" ], [ "Cadonati", "Laura", "" ], [ "Shoemaker", "Deirdre", "" ], [ ...
Gravitational wave (GW) measurements provide the most robust constraints of the mass of astrophysical black holes. Using state-of-the-art GW signal models and a unique parameter estimation technique, we infer the source parameters of the loudest marginal trigger, GW170502, found by LIGO from 2015 to 2017. If this trigg...
1403.2885
Juan A. Valiente-Kroon
C. L\"ubbe and J. A. Valiente Kroon
Spherically symmetric Anti-de Sitter-like Einstein-Yang-Mills spacetimes
31 pages, 2 figures. Analysis extended to include a Yang-Mills fields with non-vanishing magnetic part
null
10.1103/PhysRevD.90.024021
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The conformal field equations are used to discuss the local existence of spherically symmetric solutions to the Einstein-Yang-Mills system which behave asymptotically like the anti-de Sitter spacetime. By using a gauge based on conformally privileged curves we obtain a formulation of the problem in terms of an initia...
[ { "created": "Wed, 12 Mar 2014 11:11:51 GMT", "version": "v1" }, { "created": "Sun, 1 Jun 2014 19:16:58 GMT", "version": "v2" } ]
2015-06-19
[ [ "Lübbe", "C.", "" ], [ "Kroon", "J. A. Valiente", "" ] ]
The conformal field equations are used to discuss the local existence of spherically symmetric solutions to the Einstein-Yang-Mills system which behave asymptotically like the anti-de Sitter spacetime. By using a gauge based on conformally privileged curves we obtain a formulation of the problem in terms of an initial ...
1506.03517
Edward Anderson
Edward Anderson
Problem of Time: Temporal Relationalism Compatibility of Other Local Classical Facets Completed
28 pages including 13 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Temporal Relationalism (TR) is that there is no time for the universe as a whole at the primary level. Time emerges rather at a secondary level; one compelling idea for this is Mach's `time is to be abstracted from change'. TR leads to, and better explains, the well-known Frozen Formalism Problem encountered in GR at...
[ { "created": "Thu, 11 Jun 2015 00:37:59 GMT", "version": "v1" } ]
2015-06-12
[ [ "Anderson", "Edward", "" ] ]
Temporal Relationalism (TR) is that there is no time for the universe as a whole at the primary level. Time emerges rather at a secondary level; one compelling idea for this is Mach's `time is to be abstracted from change'. TR leads to, and better explains, the well-known Frozen Formalism Problem encountered in GR at t...
2311.16893
Tiberiu Harko
Maria Cr\u{a}ciun, Tiberiu Harko
Testing Weyl geometric gravity with the SPARC galactic rotation curves database
23 pages, 21 figures
null
null
null
gr-qc astro-ph.GA hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a detailed investigation of the properties of the galactic rotation curves in the Weyl geometric gravity model, in which the gravitational action is constructed from the square of the Weyl curvature scalar, and of the strength of the Weyl vector. The theory admits a scalar-vector tensor representation, obt...
[ { "created": "Tue, 28 Nov 2023 15:44:44 GMT", "version": "v1" } ]
2023-11-29
[ [ "Crăciun", "Maria", "" ], [ "Harko", "Tiberiu", "" ] ]
We present a detailed investigation of the properties of the galactic rotation curves in the Weyl geometric gravity model, in which the gravitational action is constructed from the square of the Weyl curvature scalar, and of the strength of the Weyl vector. The theory admits a scalar-vector tensor representation, obtai...
gr-qc/9803077
Hisaaki Shinkai
Gen Yoneda (Waseda U.) and Hisa-aki Shinkai (Washington U., St.Louis)
Symmetric hyperbolic system in the Ashtekar formulation
4 pages, RevTeX, to appear in Phys. Rev. Lett., Comments added, refs updated
Phys.Rev.Lett. 82 (1999) 263-266
10.1103/PhysRevLett.82.263
null
gr-qc math-ph math.MP
null
We present a first-order symmetric hyperbolic system in the Ashtekar formulation of general relativity for vacuum spacetime. We add terms from constraint equations to the evolution equations with appropriate combinations, which is the same technique used by Iriondo, Leguizam\'on and Reula [Phys. Rev. Lett. 79, 4732 (...
[ { "created": "Tue, 24 Mar 1998 10:35:54 GMT", "version": "v1" }, { "created": "Sat, 5 Dec 1998 00:14:53 GMT", "version": "v2" } ]
2009-10-31
[ [ "Yoneda", "Gen", "", "Waseda U." ], [ "Shinkai", "Hisa-aki", "", "Washington U., St.Louis" ] ]
We present a first-order symmetric hyperbolic system in the Ashtekar formulation of general relativity for vacuum spacetime. We add terms from constraint equations to the evolution equations with appropriate combinations, which is the same technique used by Iriondo, Leguizam\'on and Reula [Phys. Rev. Lett. 79, 4732 (19...
1808.08962
Vitor Cardoso
Vitor Cardoso, Masashi Kimura, Andrea Maselli, Leonardo Senatore
Black holes in an Effective Field Theory extension of GR
8 pages, RevTex4. v2: Minor edits. v3: Typo in Eq. (16) corrected. Published in Physical Review Letters
Phys. Rev. Lett. 121, 251105 (2018)
10.1103/PhysRevLett.121.251105
null
gr-qc astro-ph.HE hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Effective field theory methods suggest that some rather-general extensions of General Relativity include, or are mimicked by, certain higher-order curvature corrections, with coupling constants expected to be small but otherwise arbitrary. Thus, the tantalizing prospect to test the fundamental nature of gravity with ...
[ { "created": "Mon, 27 Aug 2018 18:00:02 GMT", "version": "v1" }, { "created": "Mon, 19 Nov 2018 19:00:09 GMT", "version": "v2" }, { "created": "Mon, 28 Aug 2023 17:36:38 GMT", "version": "v3" } ]
2023-08-29
[ [ "Cardoso", "Vitor", "" ], [ "Kimura", "Masashi", "" ], [ "Maselli", "Andrea", "" ], [ "Senatore", "Leonardo", "" ] ]
Effective field theory methods suggest that some rather-general extensions of General Relativity include, or are mimicked by, certain higher-order curvature corrections, with coupling constants expected to be small but otherwise arbitrary. Thus, the tantalizing prospect to test the fundamental nature of gravity with gr...
0710.4153
Craig J. Hogan
Craig J. Hogan
Quantum Indeterminacy of Emergent Spacetime
null
null
null
null
gr-qc astro-ph hep-th
null
It is shown that nearly-flat 3+1D spacetime emerging from a dual quantum field theory in 2+1D displays quantum fluctuations from classical Euclidean geometry on macroscopic scales. A covariant holographic mapping is assumed, where plane wave states with wavevector k on a 2D surface map onto classical null trajectorie...
[ { "created": "Mon, 22 Oct 2007 21:13:28 GMT", "version": "v1" }, { "created": "Sun, 28 Oct 2007 12:43:50 GMT", "version": "v2" } ]
2007-10-28
[ [ "Hogan", "Craig J.", "" ] ]
It is shown that nearly-flat 3+1D spacetime emerging from a dual quantum field theory in 2+1D displays quantum fluctuations from classical Euclidean geometry on macroscopic scales. A covariant holographic mapping is assumed, where plane wave states with wavevector k on a 2D surface map onto classical null trajectories ...
1512.00856
Shahar Hod
Shahar Hod
Ten shades of black
5 pages. This essay received an Honorable Mention from the Gravity Research Foundation 2015
International Journal of Modern Physics D 24, No. 12, 1544007 (2015)
10.1142/S0218271815440071
null
gr-qc astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The holographic principle has taught us that, as far as their entropy content is concerned, black holes in $(3+1)$-dimensional curved spacetimes behave as ordinary thermodynamic systems in flat $(2+1)$-dimensional spacetimes. In this essay we point out that the opposite behavior can also be observed in black-hole phy...
[ { "created": "Wed, 2 Dec 2015 21:00:05 GMT", "version": "v1" } ]
2015-12-09
[ [ "Hod", "Shahar", "" ] ]
The holographic principle has taught us that, as far as their entropy content is concerned, black holes in $(3+1)$-dimensional curved spacetimes behave as ordinary thermodynamic systems in flat $(2+1)$-dimensional spacetimes. In this essay we point out that the opposite behavior can also be observed in black-hole physi...
1212.5677
Daniel Mart\'in-de Blas
Laura Castell\'o Gomar, Jer\'onimo Cortez, Daniel Mart\'in-de Blas, Guillermo A. Mena Marug\'an, Jos\'e. M. Velhinho
Unitary evolution and uniqueness of the Fock quantization in flat cosmologies with compact spatial sections
23 pages. New section 4.2. Added references. Published in EJTP
EJTP 11 (2014) 43-64
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the Fock quantization of scalar fields with a time dependent mass in cosmological scenarios with flat compact spatial sections. This framework describes physically interesting situations like, e.g., cosmological perturbations in flat Friedmann-Robertson-Walker spacetimes, generally including a suitable scali...
[ { "created": "Sat, 22 Dec 2012 10:28:57 GMT", "version": "v1" }, { "created": "Mon, 6 Oct 2014 16:24:18 GMT", "version": "v2" } ]
2014-10-07
[ [ "Gomar", "Laura Castelló", "" ], [ "Cortez", "Jerónimo", "" ], [ "Blas", "Daniel Martín-de", "" ], [ "Marugán", "Guillermo A. Mena", "" ], [ "Velhinho", "José. M.", "" ] ]
We study the Fock quantization of scalar fields with a time dependent mass in cosmological scenarios with flat compact spatial sections. This framework describes physically interesting situations like, e.g., cosmological perturbations in flat Friedmann-Robertson-Walker spacetimes, generally including a suitable scaling...
gr-qc/9606068
Alexander L. Gromov
Alexander Gromov (St-Petersburg State Thechnical University, Russia)
The Analysis of Initial Conditions for the LTB Model
LaTeX,9 pages,Invited talk at the Cosmion'96 Int. Conf. 1996; submitted to Gravitation and Astrophysics
null
null
IRB-StP-GR-120696
gr-qc
null
The Caushy problem in the LTB model is formulated. The rules of calculating three undetermined functions which defined a solution in the LTB model are presented. One example of exact nonhomogeneous model is studied. The limit transformation to the FRW model is shown.
[ { "created": "Mon, 24 Jun 1996 09:59:32 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gromov", "Alexander", "", "St-Petersburg State Thechnical University, Russia" ] ]
The Caushy problem in the LTB model is formulated. The rules of calculating three undetermined functions which defined a solution in the LTB model are presented. One example of exact nonhomogeneous model is studied. The limit transformation to the FRW model is shown.
1701.02340
Edgar Leon
E. A. Le\'on, J. A. Nieto, E. R\'ios
Hyperbolic trajectories around Black Holes
13 pages, 2 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyse test particle's trajectories around the geometry of a Schwarzschild black hole. In order to resemble sections of jets in the neighborhood of a black hole, we consider the conserved quantities corresponding to constraints imposed on the trajectories of the test particles, namely conic and hyperboloidic traj...
[ { "created": "Mon, 9 Jan 2017 20:30:51 GMT", "version": "v1" } ]
2017-01-11
[ [ "León", "E. A.", "" ], [ "Nieto", "J. A.", "" ], [ "Ríos", "E.", "" ] ]
We analyse test particle's trajectories around the geometry of a Schwarzschild black hole. In order to resemble sections of jets in the neighborhood of a black hole, we consider the conserved quantities corresponding to constraints imposed on the trajectories of the test particles, namely conic and hyperboloidic trajec...
2209.09462
Yu Nakayama
Yu Nakayama
Geometrical Trinity of Unimodular Gravity
16 pages
null
10.1088/1361-6382/acd100
RUP-22-19
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct a Weyl transverse diffeomorphism invariant theory of teleparallel gravity by employing the Weyl compensator formalism. The low-energy dynamics has a single spin two gravition without a scalar degree of freedom. By construction, it is equivalent to unimodular gravity (as well as Einstein's general relativ...
[ { "created": "Tue, 20 Sep 2022 04:40:17 GMT", "version": "v1" } ]
2023-05-31
[ [ "Nakayama", "Yu", "" ] ]
We construct a Weyl transverse diffeomorphism invariant theory of teleparallel gravity by employing the Weyl compensator formalism. The low-energy dynamics has a single spin two gravition without a scalar degree of freedom. By construction, it is equivalent to unimodular gravity (as well as Einstein's general relativit...
2206.05799
Sashwat Tanay Dr.
Sashwat Tanay
Integrability and action-angle-based solution of the post-Newtonian BBH system (lecture notes)
Pedagogical lecture notes based on Refs. arXiv:2110.15351, 2012.06586, 1908.02927, 2210.01605. Accompanied by Mathematica package at https://github.com/sashwattanay/BBH-PN-Toolkit. For the most updated version of these notes (with typos fixed), see https://github.com/sashwattanay/lectures_integrability_action-a...
null
null
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
These lecture notes are based on Refs. arXiv:2110.15351, arXiv:2012.06586, and arXiv:1908.02927, which aim to give closed-form solutions to the spinning, eccentric binary black hole dynamics at 1.5PN via two different equivalent ways: (1) the standard way of integrating Hamilton's equations and (2) using action-angle...
[ { "created": "Sun, 12 Jun 2022 17:33:32 GMT", "version": "v1" }, { "created": "Thu, 20 Oct 2022 14:57:48 GMT", "version": "v2" }, { "created": "Tue, 23 May 2023 19:57:06 GMT", "version": "v3" } ]
2023-05-25
[ [ "Tanay", "Sashwat", "" ] ]
These lecture notes are based on Refs. arXiv:2110.15351, arXiv:2012.06586, and arXiv:1908.02927, which aim to give closed-form solutions to the spinning, eccentric binary black hole dynamics at 1.5PN via two different equivalent ways: (1) the standard way of integrating Hamilton's equations and (2) using action-angle v...
0907.2798
Subenoy Chakraborty
Nairwita Mazumder, Subenoy Chakraborty
Thermodynamics of the Universe Filled with Perfect Fluid Having Variable Equation of State
14 figures
Astrophys.Space Sci.330:137-144,2010
10.1007/s10509-010-0365-3
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the thermodynamics of the universe containing perfect fluid with equation of state $p=\omega\rho,\omega$ is variable. Here we choose $\omega$ to be a function of the red shift variable $z$ and four different choices of $\omega$ has been investigated. Also the laws of thermodynamics are examined considering t...
[ { "created": "Thu, 16 Jul 2009 09:45:34 GMT", "version": "v1" } ]
2014-11-20
[ [ "Mazumder", "Nairwita", "" ], [ "Chakraborty", "Subenoy", "" ] ]
We study the thermodynamics of the universe containing perfect fluid with equation of state $p=\omega\rho,\omega$ is variable. Here we choose $\omega$ to be a function of the red shift variable $z$ and four different choices of $\omega$ has been investigated. Also the laws of thermodynamics are examined considering the...
1803.04605
James B. Hartle
Murray Gell-Mann and James B. Hartle
Quantum Mechanics in the Light of Quantum Cosmology
29 pages, 4 figures, pdf, an older paper posted for accessibility
null
null
null
gr-qc quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We sketch a quantum mechanical framework for the universe as a whole. Within that framework we propose a program for describing the ultimate origin in quantum cosmology of the quasiclassical domain of familiar experience and for characterizing the process of measurement. Predictions in quantum mechanics are made from...
[ { "created": "Tue, 13 Mar 2018 03:31:55 GMT", "version": "v1" } ]
2018-03-14
[ [ "Gell-Mann", "Murray", "" ], [ "Hartle", "James B.", "" ] ]
We sketch a quantum mechanical framework for the universe as a whole. Within that framework we propose a program for describing the ultimate origin in quantum cosmology of the quasiclassical domain of familiar experience and for characterizing the process of measurement. Predictions in quantum mechanics are made from p...
1904.08027
Cosimo Bambi
Honghui Liu, Askar B. Abdikamalov, Dimitry Ayzenberg, Cosimo Bambi, Thomas Dauser, Javier A. Garcia, Sourabh Nampalliwar
Testing the Kerr hypothesis using X-ray reflection spectroscopy with NuSTAR data of Cygnus X-1 in the soft state
15 pages, 8 figures. v2: refereed version
Phys. Rev. D 99, 123007 (2019)
10.1103/PhysRevD.99.123007
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We continue exploring the constraining capabilities of X-ray reflection spectroscopy to test the Kerr-nature of astrophysical black holes and we present the results of our analysis of two NuSTAR observations of Cygnus X-1 in the soft state. We find that the final measurement can strongly depend on the assumption of t...
[ { "created": "Wed, 17 Apr 2019 00:19:21 GMT", "version": "v1" }, { "created": "Tue, 11 Jun 2019 14:54:11 GMT", "version": "v2" } ]
2019-06-12
[ [ "Liu", "Honghui", "" ], [ "Abdikamalov", "Askar B.", "" ], [ "Ayzenberg", "Dimitry", "" ], [ "Bambi", "Cosimo", "" ], [ "Dauser", "Thomas", "" ], [ "Garcia", "Javier A.", "" ], [ "Nampalliwar", "Sourabh", "...
We continue exploring the constraining capabilities of X-ray reflection spectroscopy to test the Kerr-nature of astrophysical black holes and we present the results of our analysis of two NuSTAR observations of Cygnus X-1 in the soft state. We find that the final measurement can strongly depend on the assumption of the...
1711.09922
Eric Linder
Michael R.R. Good, Eric V. Linder
Eternal and Evanescent Black Holes: It's All Done With Mirrors
13 pages, 11 figures
Phys. Rev. D 97, 065006 (2018)
10.1103/PhysRevD.97.065006
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The analogy between black hole radiation and accelerating mirror radiation (the dynamical Casimir effect) is particularly strong for mirror trajectories giving rise to a constant thermal flux of particles. We present new ways to achieve such thermal plateaus, and customize their finite, semi-infinite, and eternal pre...
[ { "created": "Mon, 27 Nov 2017 19:00:15 GMT", "version": "v1" } ]
2018-03-14
[ [ "Good", "Michael R. R.", "" ], [ "Linder", "Eric V.", "" ] ]
The analogy between black hole radiation and accelerating mirror radiation (the dynamical Casimir effect) is particularly strong for mirror trajectories giving rise to a constant thermal flux of particles. We present new ways to achieve such thermal plateaus, and customize their finite, semi-infinite, and eternal prese...
gr-qc/9407013
Daksh Lohiya
Daksh Lohia
Gravity Balls
Normal TeX, 6 pages, 1 figure available from author
null
null
null
gr-qc
null
The existence of non trivial, non topological solutions in a class of induced, effective gravity models arising out of a non minimally coupled scalar field is established. We shall call such solutions ``Gravity Balls'' as the effective gravitational constant inside the soliton differs from its effective value outside...
[ { "created": "Wed, 13 Jul 1994 09:16:10 GMT", "version": "v1" } ]
2009-09-25
[ [ "Lohia", "Daksh", "" ] ]
The existence of non trivial, non topological solutions in a class of induced, effective gravity models arising out of a non minimally coupled scalar field is established. We shall call such solutions ``Gravity Balls'' as the effective gravitational constant inside the soliton differs from its effective value outside.
2210.05687
Daniel Mayerson
Daniel R. Mayerson
Gravitational Multipoles in General Stationary Spacetimes
22 pages + appendices; v2: SciPost published version; significant improvements and extensions (most notably a new section 3.3 and additions in section 2.1)
SciPost Phys. 15, 154 (2023)
10.21468/SciPostPhys.15.4.154
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Geroch-Hansen and Thorne (ACMC) formalisms give rigorous and equivalent definitions for gravitational multipoles in stationary vacuum spacetimes. However, despite their ubiquitous use in gravitational physics, it has not been shown that these formalisms can be generalized to non-vacuum stationary solutions, excep...
[ { "created": "Tue, 11 Oct 2022 18:00:03 GMT", "version": "v1" }, { "created": "Thu, 12 Oct 2023 07:58:47 GMT", "version": "v2" } ]
2023-10-13
[ [ "Mayerson", "Daniel R.", "" ] ]
The Geroch-Hansen and Thorne (ACMC) formalisms give rigorous and equivalent definitions for gravitational multipoles in stationary vacuum spacetimes. However, despite their ubiquitous use in gravitational physics, it has not been shown that these formalisms can be generalized to non-vacuum stationary solutions, except ...
1401.6343
Alexey Golovnev
Alexey Golovnev
On non-perturbative analysis of massive and bimetric gravity
5 pages; prepared for the Proceedings of II Russian-Spanish Congress on Particle and Nuclear Physics at all Scales and Cosmology
AIP Conference Proceedings 1606, 299 (2014)
10.1063/1.4891145
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is my contribution to Proceedings of II Russian-Spanish Congress on Particle and Nuclear Physics at all Scales and Cosmology, Saint Petersburg, Russia, October 1 - 4, 2013. We give a brief overview of the ghost-free massive and bimetric gravity emphasising its non-perturbative aspects and ADM approach to calcula...
[ { "created": "Fri, 24 Jan 2014 14:15:51 GMT", "version": "v1" } ]
2014-08-20
[ [ "Golovnev", "Alexey", "" ] ]
This is my contribution to Proceedings of II Russian-Spanish Congress on Particle and Nuclear Physics at all Scales and Cosmology, Saint Petersburg, Russia, October 1 - 4, 2013. We give a brief overview of the ghost-free massive and bimetric gravity emphasising its non-perturbative aspects and ADM approach to calculati...
1806.10238
Costantino Pacilio
Costantino Pacilio
Scalar charge of black holes in Einstein-Maxwell-dilaton theory
v2: 6 pages, corrected typos, references added
Phys. Rev. D 98, 064055 (2018)
10.1103/PhysRevD.98.064055
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the monopole scalar charge of black holes in Einstein--Maxwell--dilaton theory is proportional to the electric potential at the event horizon, with a proportionality factor given by (minus) the scalar coupling constant. We also show that the scalar charge, in the weak electric charge limit, does not depe...
[ { "created": "Tue, 26 Jun 2018 22:58:22 GMT", "version": "v1" }, { "created": "Sun, 15 Jul 2018 11:08:59 GMT", "version": "v2" } ]
2018-10-03
[ [ "Pacilio", "Costantino", "" ] ]
We show that the monopole scalar charge of black holes in Einstein--Maxwell--dilaton theory is proportional to the electric potential at the event horizon, with a proportionality factor given by (minus) the scalar coupling constant. We also show that the scalar charge, in the weak electric charge limit, does not depend...
0704.1058
Pilar Ruiz-Lapuente
Pilar Ruiz-Lapuente
Dark energy, gravitation and supernovae
Invited Topical Review (Class. Quan. Grav) 27 pages Journal link: http://stacks.iop.org/0264-9381/24/R91
Class.Quant.Grav.24:R91-R111,2007
10.1088/0264-9381/24/11/R01
null
gr-qc astro-ph hep-ph
null
The discovery of the acceleration of the rate of expansion of the Universe fosters new explorations of the behavior of gravitation theories in the cosmological context. Either the GR framework is valid but a cosmic component with a negative equation of state is dominating the energy--matter contents or the Universe i...
[ { "created": "Mon, 9 Apr 2007 03:10:51 GMT", "version": "v1" }, { "created": "Tue, 26 Jun 2007 23:57:24 GMT", "version": "v2" } ]
2010-11-02
[ [ "Ruiz-Lapuente", "Pilar", "" ] ]
The discovery of the acceleration of the rate of expansion of the Universe fosters new explorations of the behavior of gravitation theories in the cosmological context. Either the GR framework is valid but a cosmic component with a negative equation of state is dominating the energy--matter contents or the Universe is ...
0902.1718
Valentino Lacquaniti
Valentino Lacquaniti, Giovanni Montani
Dynamics of Matter in a Compactified Kaluza-Klein Model
21 pages, to appear on IJMPD
Int.J.Mod.Phys.D18:929-946,2009
10.1142/S0218271809014844
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A longstanding problem in Kaluza-Klein models is the description of matter dynamics. Within the 5D model, the dimensional reduction of the geodesic motion for a 5D free test particle formally restores electrodynamics, but the reduced 4D particle shows a charge-mass ratio that is upper bounded, such that it cannot fit...
[ { "created": "Tue, 10 Feb 2009 18:18:48 GMT", "version": "v1" } ]
2009-07-22
[ [ "Lacquaniti", "Valentino", "" ], [ "Montani", "Giovanni", "" ] ]
A longstanding problem in Kaluza-Klein models is the description of matter dynamics. Within the 5D model, the dimensional reduction of the geodesic motion for a 5D free test particle formally restores electrodynamics, but the reduced 4D particle shows a charge-mass ratio that is upper bounded, such that it cannot fit t...
gr-qc/9805100
Viqar Husain
Viqar Husain
Initial data for gravity coupled to scalar, electromagnetic and Yang-Mills fields
16 pages, RevTeX, references added, presentational changes, version to appear in Phys Rev. D
Phys.Rev. D59 (1999) 044004
10.1103/PhysRevD.59.044004
UBCTH
gr-qc hep-th
null
We give ansatze for solving classically the initial value constraints of general relativity minimally coupled to a scalar field, electromagnetism or Yang-Mills theory. The results include both time-symmetric and asymmetric data. The time-asymmetric examples are used to test Penrose's cosmic censorship inequality. We ...
[ { "created": "Fri, 29 May 1998 00:27:26 GMT", "version": "v1" }, { "created": "Mon, 2 Nov 1998 23:56:34 GMT", "version": "v2" } ]
2016-08-31
[ [ "Husain", "Viqar", "" ] ]
We give ansatze for solving classically the initial value constraints of general relativity minimally coupled to a scalar field, electromagnetism or Yang-Mills theory. The results include both time-symmetric and asymmetric data. The time-asymmetric examples are used to test Penrose's cosmic censorship inequality. We fi...
2311.07063
Yuki Kawasaki
Yuki Kawasaki, Shoki Iwaguchi, Tomohiro Ishikawa, Atsushi Nishizawa, Masaaki Kitaguchi, Yutaka Yamagata, Yanbei Chen, Bin Wu, Ryuma Shimizu, Kurumi Umemura, Kenji Tsuji, Hirohiko Shimizu, Yuta Michimura, Kazuhiro Kobayashi, Takafumi Onishi, and Seiji Kawamura
Sagnac-type neutron displacement-noise-free interferometeric gravitational-wave detector
17 pages, 6figures
null
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
The detection of low-frequency gravitational waves on Earth requires the reduction of displacement noise, which dominates the low-frequency band. One method to cancel test mass displacement noise is a neutron displacement-noise-free interferometer (DFI). This paper proposes a new neutron DFI configuration, a Sagnac-t...
[ { "created": "Mon, 13 Nov 2023 04:06:03 GMT", "version": "v1" }, { "created": "Sat, 13 Jan 2024 02:17:12 GMT", "version": "v2" }, { "created": "Mon, 25 Mar 2024 05:39:14 GMT", "version": "v3" } ]
2024-03-26
[ [ "Kawasaki", "Yuki", "" ], [ "Iwaguchi", "Shoki", "" ], [ "Ishikawa", "Tomohiro", "" ], [ "Nishizawa", "Atsushi", "" ], [ "Kitaguchi", "Masaaki", "" ], [ "Yamagata", "Yutaka", "" ], [ "Chen", "Yanbei", "" ...
The detection of low-frequency gravitational waves on Earth requires the reduction of displacement noise, which dominates the low-frequency band. One method to cancel test mass displacement noise is a neutron displacement-noise-free interferometer (DFI). This paper proposes a new neutron DFI configuration, a Sagnac-typ...
1605.05866
Piyabut Burikham
Piyabut Burikham, Rujikorn Dhanawittayapol, Taum Wuthicharn
A new mass scale, implications on black hole evaporation and holography
17 pages, 3 figures
null
10.1142/S0217751X16500895
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a new mass scale $M_{T}=(\hbar^{2}\sqrt{\Lambda}/G)^{1/3}$ constructed from dimensional analysis by using $G$, $\hbar$ and $\Lambda$ and discuss its physical interpretation. Based on the Generalized Uncertainty Relation, a black hole with age comparable to the universe would stop radiating when the mass r...
[ { "created": "Thu, 19 May 2016 09:37:33 GMT", "version": "v1" } ]
2016-06-22
[ [ "Burikham", "Piyabut", "" ], [ "Dhanawittayapol", "Rujikorn", "" ], [ "Wuthicharn", "Taum", "" ] ]
We consider a new mass scale $M_{T}=(\hbar^{2}\sqrt{\Lambda}/G)^{1/3}$ constructed from dimensional analysis by using $G$, $\hbar$ and $\Lambda$ and discuss its physical interpretation. Based on the Generalized Uncertainty Relation, a black hole with age comparable to the universe would stop radiating when the mass rea...
2307.12585
Lorenzo Speri
Lorenzo Speri, Michael L. Katz, Alvin J. K. Chua, Scott A. Hughes, Niels Warburton, Jonathan E. Thompson, Christian E. A. Chapman-Bird, Jonathan R. Gair
Fast and Fourier: Extreme Mass Ratio Inspiral Waveforms in the Frequency Domain
23 pages, 6 figures
Front. Appl. Math. Stat. 9 (2023)
10.3389/fams.2023.1266739
null
gr-qc astro-ph.HE astro-ph.IM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Extreme Mass Ratio Inspirals (EMRIs) are one of the key sources for future space-based gravitational wave interferometers. Measurements of EMRI gravitational waves are expected to determine the characteristics of their sources with sub-percent precision. However, their waveform generation is challenging due to the lo...
[ { "created": "Mon, 24 Jul 2023 07:56:07 GMT", "version": "v1" }, { "created": "Mon, 15 Jan 2024 15:10:17 GMT", "version": "v2" } ]
2024-01-17
[ [ "Speri", "Lorenzo", "" ], [ "Katz", "Michael L.", "" ], [ "Chua", "Alvin J. K.", "" ], [ "Hughes", "Scott A.", "" ], [ "Warburton", "Niels", "" ], [ "Thompson", "Jonathan E.", "" ], [ "Chapman-Bird", "Christian...
Extreme Mass Ratio Inspirals (EMRIs) are one of the key sources for future space-based gravitational wave interferometers. Measurements of EMRI gravitational waves are expected to determine the characteristics of their sources with sub-percent precision. However, their waveform generation is challenging due to the long...
0807.2066
Roman Sverdlov
Roman Sverdlov
Gauge Fields in Causal Set Theory
11 pages, no figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is the second paper in a series on the dynamics of matter fields in the causal set approach to quantum gravity. We start with the usual expression for the Lagrangian of a charged scalar field coupled to a SU(n) Yang-Mills field, in which the gauge field is represented by a connection form, and show how to write ...
[ { "created": "Sun, 13 Jul 2008 23:07:58 GMT", "version": "v1" } ]
2008-07-15
[ [ "Sverdlov", "Roman", "" ] ]
This is the second paper in a series on the dynamics of matter fields in the causal set approach to quantum gravity. We start with the usual expression for the Lagrangian of a charged scalar field coupled to a SU(n) Yang-Mills field, in which the gauge field is represented by a connection form, and show how to write it...
2401.12368
Eduardo Guendelman I
Eduardo Guendelman and Jacov Portnoy
Bubble Universe from Flat Spaces
final version, published in European Physics Journal C, 10 pages
European Physics Journal C, 84, article number 418, (2024)
10.1140/epjc/s10052-024-12750-5
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We show by matching two flat spaces one in Minkowski coordinates ( empty space) and the other in Minkowski coordinates after a special conformal transformation (also empty space) through a bubble with positive and constant surface tension, that the motion of the bubble is hyperbolic. If the surface tension is very bi...
[ { "created": "Mon, 22 Jan 2024 21:39:17 GMT", "version": "v1" }, { "created": "Tue, 23 Apr 2024 12:26:27 GMT", "version": "v2" } ]
2024-04-24
[ [ "Guendelman", "Eduardo", "" ], [ "Portnoy", "Jacov", "" ] ]
We show by matching two flat spaces one in Minkowski coordinates ( empty space) and the other in Minkowski coordinates after a special conformal transformation (also empty space) through a bubble with positive and constant surface tension, that the motion of the bubble is hyperbolic. If the surface tension is very big ...
gr-qc/0411080
Bijan Saha
Bijan Saha
Anisotropic cosmological models with a perfect fluid and a $\Lambda$ term
8 pages, 8 Figures
Astrophys.Space Sci. 302 (2006) 83-91
10.1007/s10509-005-9008-5
null
gr-qc
null
We consider a self-consistent system of Bianchi type-I (BI) gravitational field and a binary mixture of perfect fluid and dark energy given by a cosmological constant. The perfect fluid is chosen to be the one obeying either the usual equation of state, i.e., $p = \zeta \ve$, with $\zeta \in [0, 1]$ or a van der Waal...
[ { "created": "Tue, 16 Nov 2004 12:35:42 GMT", "version": "v1" } ]
2015-05-01
[ [ "Saha", "Bijan", "" ] ]
We consider a self-consistent system of Bianchi type-I (BI) gravitational field and a binary mixture of perfect fluid and dark energy given by a cosmological constant. The perfect fluid is chosen to be the one obeying either the usual equation of state, i.e., $p = \zeta \ve$, with $\zeta \in [0, 1]$ or a van der Waals ...
1102.0487
Karel Van Acoleyen
Karel Van Acoleyen and Jos Van Doorsselaere
Galileons from Lovelock actions
15 pages, some extra references
null
10.1103/PhysRevD.83.084025
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We demonstrate how, for an arbitrary number of dimensions, the Galileon actions and their covariant generalizations can be obtained through a standard Kaluza-Klein compactification of higher-dimensional Lovelock gravity. In this setup, the dilaton takes on the role of the Galileon. In addition, such compactifications...
[ { "created": "Wed, 2 Feb 2011 16:53:48 GMT", "version": "v1" }, { "created": "Thu, 10 Feb 2011 15:15:53 GMT", "version": "v2" } ]
2013-05-29
[ [ "Van Acoleyen", "Karel", "" ], [ "Van Doorsselaere", "Jos", "" ] ]
We demonstrate how, for an arbitrary number of dimensions, the Galileon actions and their covariant generalizations can be obtained through a standard Kaluza-Klein compactification of higher-dimensional Lovelock gravity. In this setup, the dilaton takes on the role of the Galileon. In addition, such compactifications u...
gr-qc/0006001
Warner A. Miller
Warner A. Miller and Arkady Kheyfets
Time in Quantum Geometrodynamics
17 pages, 0 figures, formatted with LaTex, IJMP-A in press
Int.J.Mod.Phys. A15 (2000) 4125-4140
10.1142/S0217751X00001361
null
gr-qc
null
We revisit the issue of time in quantum geometrodynamics and suggest a quantization procedure on the space of true dynamic variables. This procedure separates the issue of quantization from enforcing the constraints caused by the general covariance symmetries. The resulting theory, unlike the standard approach, takes...
[ { "created": "Wed, 31 May 2000 23:31:28 GMT", "version": "v1" } ]
2016-12-21
[ [ "Miller", "Warner A.", "" ], [ "Kheyfets", "Arkady", "" ] ]
We revisit the issue of time in quantum geometrodynamics and suggest a quantization procedure on the space of true dynamic variables. This procedure separates the issue of quantization from enforcing the constraints caused by the general covariance symmetries. The resulting theory, unlike the standard approach, takes i...
1102.1683
Ernesto F. Eiroa
Ernesto F. Eiroa, Claudio Simeone
Stability of charged thin shells
8 pages, 2 figures. v2: Improved version, new references added
Phys.Rev.D83:104009,2011
10.1103/PhysRevD.83.104009
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article we study the mechanical stability of spherically symmetric thin shells with charge, in Einstein-Maxwell and Einstein-Born-Infeld theories. We analyze linearized perturbations preserving the symmetry, for shells around vacuum and shells surrounding non charged black holes.
[ { "created": "Tue, 8 Feb 2011 18:43:48 GMT", "version": "v1" }, { "created": "Wed, 4 May 2011 17:45:28 GMT", "version": "v2" } ]
2011-05-05
[ [ "Eiroa", "Ernesto F.", "" ], [ "Simeone", "Claudio", "" ] ]
In this article we study the mechanical stability of spherically symmetric thin shells with charge, in Einstein-Maxwell and Einstein-Born-Infeld theories. We analyze linearized perturbations preserving the symmetry, for shells around vacuum and shells surrounding non charged black holes.
0709.3276
Ricardo E. Gamboa Saravi
Ricardo E. Gamboa Saravi
Infinite slabs and other weird plane symmetric space-times with constant positive density
8 pages
Gen.Rel.Grav.41:1459-1473,2009
10.1007/s10714-008-0714-5
null
gr-qc
null
We present the exact solution of Einstein's equation corresponding to a static and plane symmetric distribution of matter with constant positive density located below $z=0$. This solution depends essentially on two constants: the density $\rho$ and a parameter $\kappa$. We show that this space-time finishes down belo...
[ { "created": "Thu, 20 Sep 2007 19:00:35 GMT", "version": "v1" } ]
2009-07-22
[ [ "Saravi", "Ricardo E. Gamboa", "" ] ]
We present the exact solution of Einstein's equation corresponding to a static and plane symmetric distribution of matter with constant positive density located below $z=0$. This solution depends essentially on two constants: the density $\rho$ and a parameter $\kappa$. We show that this space-time finishes down below ...
gr-qc/0102023
Yoshiyuki Morisawa
Daisuke Ida and Yoshiyuki Morisawa
Hidden symmetry of the three-dimensional Einstein-Maxwell equations
5 pages
Phys.Rev. D63 (2001) 104019
10.1103/PhysRevD.63.104019
KUNS-1706,YITP-01-8
gr-qc
null
It is shown how to generate three-dimensional Einstein-Maxwell fields from known ones in the presence of a hypersurface-orthogonal non-null Killing vector field. The continuous symmetry group is isomorphic to the Heisenberg group including the Harrison-type transformation. The symmetry of the Einstein-Maxwell-dilaton...
[ { "created": "Tue, 6 Feb 2001 13:57:34 GMT", "version": "v1" } ]
2009-11-07
[ [ "Ida", "Daisuke", "" ], [ "Morisawa", "Yoshiyuki", "" ] ]
It is shown how to generate three-dimensional Einstein-Maxwell fields from known ones in the presence of a hypersurface-orthogonal non-null Killing vector field. The continuous symmetry group is isomorphic to the Heisenberg group including the Harrison-type transformation. The symmetry of the Einstein-Maxwell-dilaton s...
1808.01489
Paolo Marcoccia
P. Marcoccia and G. Montani
Weakly Inhomogeneous models for the Low-Redshift Universe
12 pages, 6 figures
null
null
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze two different algorithms for constructing weakly inhomogeneous models for the low-redshift Universe, in order to provide a tool for testing the geodesic dynamics, within the sphere of validity for the Universe acceleration. We first implement the so-called quasi-isotropic solution in the late Universe, whe...
[ { "created": "Sat, 4 Aug 2018 14:55:57 GMT", "version": "v1" }, { "created": "Tue, 26 Feb 2019 14:48:38 GMT", "version": "v2" }, { "created": "Mon, 13 Jul 2020 10:29:01 GMT", "version": "v3" } ]
2020-07-14
[ [ "Marcoccia", "P.", "" ], [ "Montani", "G.", "" ] ]
We analyze two different algorithms for constructing weakly inhomogeneous models for the low-redshift Universe, in order to provide a tool for testing the geodesic dynamics, within the sphere of validity for the Universe acceleration. We first implement the so-called quasi-isotropic solution in the late Universe, when ...
2001.00154
Seiga Sato
Seiga Sato, Kei-ichi Maeda
Stability of Hybrid Higgs Inflation
9 pages, 9 figures
Phys. Rev. D 101, 103520 (2020)
10.1103/PhysRevD.101.103520
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hybrid Higgs inflation model is a hybrid type of the so-called Higgs inflation model with the conventional non-minimal $\xi$ coupling to a scalar curvature $R$ and new Higgs inflation model with the derivative coupling to the Einstein curvature tensor $G_{\mu\nu}$. This model can explain all possible value of the ten...
[ { "created": "Wed, 1 Jan 2020 07:27:47 GMT", "version": "v1" } ]
2020-05-20
[ [ "Sato", "Seiga", "" ], [ "Maeda", "Kei-ichi", "" ] ]
Hybrid Higgs inflation model is a hybrid type of the so-called Higgs inflation model with the conventional non-minimal $\xi$ coupling to a scalar curvature $R$ and new Higgs inflation model with the derivative coupling to the Einstein curvature tensor $G_{\mu\nu}$. This model can explain all possible value of the tenso...
2203.13933
Filipe Mena
Rodrigo D. B. Fontana and Filipe C. Mena
Quasinormal modes and stability of boosted Reissner-Nordstr\"om AdS black holes
23 pages, 3 figures
null
10.1007/JHEP10(2022)047
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We investigate the numerical stability of accelerated AdS black holes against linear scalar perturbations. In particular, we study the evolution of a probe non-minimally coupled scalar field on Schwarzschild and Reissner-Nordstr\"om AdS black holes with small accelerations by computing the quasinormal modes of the pe...
[ { "created": "Fri, 25 Mar 2022 22:50:14 GMT", "version": "v1" } ]
2022-10-26
[ [ "Fontana", "Rodrigo D. B.", "" ], [ "Mena", "Filipe C.", "" ] ]
We investigate the numerical stability of accelerated AdS black holes against linear scalar perturbations. In particular, we study the evolution of a probe non-minimally coupled scalar field on Schwarzschild and Reissner-Nordstr\"om AdS black holes with small accelerations by computing the quasinormal modes of the pert...
0803.4200
Anzhong Wang
P. Rocha, A.Y. Miguelote, R. Chan, M.F. da Silva, N.O. Santos, and Anzhong Wang
Bounded excursion stable gravastars and black holes
Revtex4, 12 figures. Version published in JCAP, 06 (2008) 025
JCAP 0806:025,2008
10.1088/1475-7516/2008/06/025
null
gr-qc astro-ph hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dynamical models of prototype gravastars were constructed in order to study their stability. The models are the Visser-Wiltshire three-layer gravastars, in which an infinitely thin spherical shell of stiff fluid divides the whole spacetime into two regions, where the internal region is de Sitter, and the external is ...
[ { "created": "Fri, 28 Mar 2008 20:07:52 GMT", "version": "v1" }, { "created": "Wed, 21 May 2008 12:15:37 GMT", "version": "v2" }, { "created": "Sun, 18 Jul 2010 16:18:22 GMT", "version": "v3" } ]
2011-03-28
[ [ "Rocha", "P.", "" ], [ "Miguelote", "A. Y.", "" ], [ "Chan", "R.", "" ], [ "da Silva", "M. F.", "" ], [ "Santos", "N. O.", "" ], [ "Wang", "Anzhong", "" ] ]
Dynamical models of prototype gravastars were constructed in order to study their stability. The models are the Visser-Wiltshire three-layer gravastars, in which an infinitely thin spherical shell of stiff fluid divides the whole spacetime into two regions, where the internal region is de Sitter, and the external is Sc...
2306.00030
Hamidreza Simchi
Hamidreza Simchi
Topos Many-Node Theory: Roots, Foundations and Predictions
null
null
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
Assuming that the first creatures of creation create a network, it is shown that how the network can be mapped to a topos discrete quantum manifold which is equipped with both the discrete calculus and the Alexandrov's algebra. We assign a locale to each nodes of the space-time network and show that in general, invar...
[ { "created": "Wed, 31 May 2023 06:29:25 GMT", "version": "v1" } ]
2023-06-02
[ [ "Simchi", "Hamidreza", "" ] ]
Assuming that the first creatures of creation create a network, it is shown that how the network can be mapped to a topos discrete quantum manifold which is equipped with both the discrete calculus and the Alexandrov's algebra. We assign a locale to each nodes of the space-time network and show that in general, invaria...
gr-qc/0205020
Sayan Kar
Sayan Kar (Physics and CTS, IIT Kharagpur, India)
Asymmetrically warped R=0 braneworlds
10 pages, no figures, title changed, new results added and an error corrected
null
null
null
gr-qc hep-th
null
A new family of five dimensional, R=0 braneworlds with asymmetric warp factors is proposed. Beginning with the invariance of the Ricci scalar for the general class of asymmetrically warped spacetimes we, subsequently specialise to the R=0 case. Solutions are obtained by choosing a particular relation (involving a par...
[ { "created": "Mon, 6 May 2002 09:19:12 GMT", "version": "v1" }, { "created": "Sat, 28 Sep 2002 09:50:37 GMT", "version": "v2" } ]
2007-05-23
[ [ "Kar", "Sayan", "", "Physics and CTS, IIT Kharagpur, India" ] ]
A new family of five dimensional, R=0 braneworlds with asymmetric warp factors is proposed. Beginning with the invariance of the Ricci scalar for the general class of asymmetrically warped spacetimes we, subsequently specialise to the R=0 case. Solutions are obtained by choosing a particular relation (involving a param...
1202.3324
Matteo Smerlak
Matteo Smerlak
On the inertia of heat
3 pages
Eur. Phys. J. Plus (2012), 127: 72
10.1140/epjp/i2012-12072-4
null
gr-qc cond-mat.stat-mech
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Does heat have inertia? This question is at the core of a long-standing controversy on Eckart's dissipative relativistic hydrodynamics. Here I show that the troublesome inertial term in Eckart's heat flux arises only if one insists on defining thermal diffusivity as a spacetime constant. I argue that this is the most...
[ { "created": "Wed, 15 Feb 2012 14:44:40 GMT", "version": "v1" } ]
2012-08-24
[ [ "Smerlak", "Matteo", "" ] ]
Does heat have inertia? This question is at the core of a long-standing controversy on Eckart's dissipative relativistic hydrodynamics. Here I show that the troublesome inertial term in Eckart's heat flux arises only if one insists on defining thermal diffusivity as a spacetime constant. I argue that this is the most n...
0905.1506
Luca Bombelli
Roman Sverdlov, Luca Bombelli
Dynamics for causal sets with matter fields: A Lagrangian-based approach
25 pages, no figures. Contribution to the Proceedings of DICE2008, From Quantum Mechanics through Complexity to Space-time: The role of emergent dynamical structures (Castiglioncello, Italy, Sept. 2008)
J.Phys.Conf.Ser.174:012019,2009
10.1088/1742-6596/174/1/012019
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a framework for the dynamics of causal sets and coupled matter fields, which is a simplification and generalization of an approach we recently proposed. Given a set of fields including the gravitational one, the main step in implementing our proposal consists in writing their continuum-based action using a...
[ { "created": "Sun, 10 May 2009 20:56:29 GMT", "version": "v1" } ]
2009-07-28
[ [ "Sverdlov", "Roman", "" ], [ "Bombelli", "Luca", "" ] ]
We present a framework for the dynamics of causal sets and coupled matter fields, which is a simplification and generalization of an approach we recently proposed. Given a set of fields including the gravitational one, the main step in implementing our proposal consists in writing their continuum-based action using as ...
2006.08724
Roman Sverdlov
Roman Sverdlov
Continuous measurement on a causal set with and without a boundary
27 pages, no figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The purpose of this paper is two-fold. First, we would like to get rid of common assumption that causal set is bounded and attempt to model its scalar field action under the assumption that it isn't. Secondly, we would like to propose continuous measurement model in this context.
[ { "created": "Mon, 15 Jun 2020 19:46:54 GMT", "version": "v1" }, { "created": "Wed, 17 Jun 2020 08:03:43 GMT", "version": "v2" } ]
2020-06-18
[ [ "Sverdlov", "Roman", "" ] ]
The purpose of this paper is two-fold. First, we would like to get rid of common assumption that causal set is bounded and attempt to model its scalar field action under the assumption that it isn't. Secondly, we would like to propose continuous measurement model in this context.
1510.06930
David Langlois
David Langlois, Karim Noui
Degenerate higher derivative theories beyond Horndeski: evading the Ostrogradski instability
19 pages, no figure
JCAP 1602 (2016) 02, 034
10.1088/1475-7516/2016/02/034
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Theories with higher order time derivatives generically suffer from ghost-like instabilities, known as Ostrogradski instabilities. This fate can be avoided by considering "degenerate" Lagrangians, whose kinetic matrix cannot be inverted, thus leading to constraints between canonical variables and a reduced number of ...
[ { "created": "Fri, 23 Oct 2015 13:29:17 GMT", "version": "v1" }, { "created": "Fri, 4 Mar 2016 12:06:12 GMT", "version": "v2" } ]
2016-03-07
[ [ "Langlois", "David", "" ], [ "Noui", "Karim", "" ] ]
Theories with higher order time derivatives generically suffer from ghost-like instabilities, known as Ostrogradski instabilities. This fate can be avoided by considering "degenerate" Lagrangians, whose kinetic matrix cannot be inverted, thus leading to constraints between canonical variables and a reduced number of ph...
1903.05402
T. P. Singh
Tejinder P. Singh
Proposal for a new quantum theory of gravity
v2: 32 pages, 1 figure, Section I borrows some text (overview of trace dynamics) from arXiv:1701.09132v1 [quant-ph], revised in response to reviewer comments: list of revisions appended after bibliography; accepted for publication in Zeitschrift fur Naturforschung
Z. Naturforsch. A 74 (2019) 617
10.1515/zna-2019-0079
null
gr-qc hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We recall a classical theory of torsion gravity with an asymmetric metric, sourced by a Nambu-Goto + Kalb-Ramond string . We explain why this is a significant gravitational theory, and in what sense classical general relativity is an approximation to it. We propose that a non-commutative generalisation of this theory...
[ { "created": "Wed, 13 Mar 2019 10:30:08 GMT", "version": "v1" }, { "created": "Tue, 9 Apr 2019 12:27:31 GMT", "version": "v2" } ]
2019-07-01
[ [ "Singh", "Tejinder P.", "" ] ]
We recall a classical theory of torsion gravity with an asymmetric metric, sourced by a Nambu-Goto + Kalb-Ramond string . We explain why this is a significant gravitational theory, and in what sense classical general relativity is an approximation to it. We propose that a non-commutative generalisation of this theory (...
1506.01786
Ahmad Sheykhi
A. Sheykhi and A. Kazemi
Higher dimensional dilaton black holes in the presence of exponential nonlinear electrodynamics
16 pages, 12 figs. arXiv admin note: substantial text overlap with arXiv:1504.04009
Phys. Rev. D 90 (2014) 044028
10.1103/PhysRevD.90.044028
null
gr-qc
http://creativecommons.org/licenses/by/3.0/
We examine the higher dimensional action in which gravity is coupled to the exponential nonlinear electrodynamic and a scalar dilaton field. We construct a new class of $n$-dimensional static and spherically symmetric black hole solutions of this theory in the presence of the dilaton potential with two Liouville-type...
[ { "created": "Fri, 5 Jun 2015 05:53:43 GMT", "version": "v1" } ]
2015-06-08
[ [ "Sheykhi", "A.", "" ], [ "Kazemi", "A.", "" ] ]
We examine the higher dimensional action in which gravity is coupled to the exponential nonlinear electrodynamic and a scalar dilaton field. We construct a new class of $n$-dimensional static and spherically symmetric black hole solutions of this theory in the presence of the dilaton potential with two Liouville-type t...