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gr-qc/0009016
J. W. van Holten
A. Balakin, J.W. van Holten and R. Kerner
Motions and world-line deviations in Einstein-Maxwell theory
23 pages, no figures
Class.Quant.Grav.17:5009-5024,2000
10.1088/0264-9381/17/24/306
NIKHEF/00-023
gr-qc
null
We examine the motion of charged particles in gravitational and electro-magnetic background fields. We study in particular the deviation of world lines, describing the relative acceleration between particles on different space-time trajectories. Two special cases of background fields are considered in detail: (a) pp-waves, a combination of gravitational and electro-magnetic polarized plane waves travelling in the same direction; (b) the Reissner-Nordstr{\o}m solution. We perform a non-trivial check by computing the precession of the periastron for a charged particle in the Reissner-Nordstr{\o}m geometry both directly by solving the geodesic equation, and using the world-line deviation equation. The results agree to the order of approximation considered.
[ { "created": "Wed, 6 Sep 2000 11:26:54 GMT", "version": "v1" } ]
2008-11-26
[ [ "Balakin", "A.", "" ], [ "van Holten", "J. W.", "" ], [ "Kerner", "R.", "" ] ]
We examine the motion of charged particles in gravitational and electro-magnetic background fields. We study in particular the deviation of world lines, describing the relative acceleration between particles on different space-time trajectories. Two special cases of background fields are considered in detail: (a) pp-waves, a combination of gravitational and electro-magnetic polarized plane waves travelling in the same direction; (b) the Reissner-Nordstr{\o}m solution. We perform a non-trivial check by computing the precession of the periastron for a charged particle in the Reissner-Nordstr{\o}m geometry both directly by solving the geodesic equation, and using the world-line deviation equation. The results agree to the order of approximation considered.
2312.00121
Vladimir Strokov
Vladimir Strokov and Emanuele Berti
Quasimonochromatic LISA Sources in the Frequency Domain
14 pages, 9 figures; added references
null
null
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Among the binary sources of interest for LISA some are quasimonochromatic, in the sense that the change in the gravitational wave frequency $\Delta f\lesssim 1\;\mbox{yr}^{-1}$ during the observation time. For these sources, we revisit the stationary phase approximation (SPA) commonly used in Fisher matrix calculations in the frequency domain and show how it is modified by the Doppler shift induced by LISA's motion and by the LISA pattern functions. We compare our results with previous work in the time domain and discuss the transition from the quasimonochromatic case to the conventional SPA which applies when $\Delta f\gtrsim 1\;\mbox{yr}^{-1}$.
[ { "created": "Thu, 30 Nov 2023 19:00:01 GMT", "version": "v1" }, { "created": "Sat, 23 Dec 2023 20:07:25 GMT", "version": "v2" } ]
2023-12-27
[ [ "Strokov", "Vladimir", "" ], [ "Berti", "Emanuele", "" ] ]
Among the binary sources of interest for LISA some are quasimonochromatic, in the sense that the change in the gravitational wave frequency $\Delta f\lesssim 1\;\mbox{yr}^{-1}$ during the observation time. For these sources, we revisit the stationary phase approximation (SPA) commonly used in Fisher matrix calculations in the frequency domain and show how it is modified by the Doppler shift induced by LISA's motion and by the LISA pattern functions. We compare our results with previous work in the time domain and discuss the transition from the quasimonochromatic case to the conventional SPA which applies when $\Delta f\gtrsim 1\;\mbox{yr}^{-1}$.
2201.04071
Dr. Sudhaker Upadhyay
J. Sadeghi, B. Pourhassan, S. Noori Gashti and S. Upadhyay
Weak Gravity Conjecture, Black Branes and Violations of Universal Thermodynamic Relation
14 pages; 2 captioned figures
Annals of Physics 447 (2022) 169168
10.1016/j.aop.2022.169168
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
The universal thermodynamic relations between corrections to entropy and extremality for various black holes solutions have been studied. In this regard, we hereby consider a number of different black brane solutions in different structures for perturbative corrections to general relativity. These are, namely, black brane solution in Rastall AdS massive gravity, Einstein-Yang-Mills AdS black brane solution in massive gravity and general anisotropic black brane in Horava-Lifshitz gravity. We calculate both the entropy and extremality bound by introducing a small constant correction to the action. Remarkably, we find that black brane violates the universal thermodynamic relations. In other words, a universal relation between corrections to entropy and extremality are not valid in the black brane structure.
[ { "created": "Mon, 10 Jan 2022 16:18:34 GMT", "version": "v1" } ]
2022-11-22
[ [ "Sadeghi", "J.", "" ], [ "Pourhassan", "B.", "" ], [ "Gashti", "S. Noori", "" ], [ "Upadhyay", "S.", "" ] ]
The universal thermodynamic relations between corrections to entropy and extremality for various black holes solutions have been studied. In this regard, we hereby consider a number of different black brane solutions in different structures for perturbative corrections to general relativity. These are, namely, black brane solution in Rastall AdS massive gravity, Einstein-Yang-Mills AdS black brane solution in massive gravity and general anisotropic black brane in Horava-Lifshitz gravity. We calculate both the entropy and extremality bound by introducing a small constant correction to the action. Remarkably, we find that black brane violates the universal thermodynamic relations. In other words, a universal relation between corrections to entropy and extremality are not valid in the black brane structure.
gr-qc/9401012
null
J.H. Yoon
A Proposal of Positive-Definite Local Gravitational Energy Density in General Relativity
39p, SNUTP 93-78, RevTex 3.0
null
null
null
gr-qc
null
We propose a 4-dimensional Kaluza-Klein approach to general relativity in the (2,2)-splitting of space-time using the double null gauge. The associated Lagrangian is equivalent to the Einstein-Hilbert Lagrangian, since it yields the same field equations as the E-H Lagrangian does. It is describable as a (1+1)-dimensional Yang-Mills type gauge theory coupled to (1+1)-dimensional matter fields, where the minimal coupling associated with the diffeomorphism group of the 2-dimensional spacelike fibre space automatically appears. Written in the first-order formalism, our Lagrangian density directly yields a non-zero local Hamiltonian density, where the associated time function is the retarded time. From this Hamiltonian density, we obtain a positive-definite local gravitational energy density. In the asymptotically flat space-times, the volume integrals of the proposed local gravitational energy density over suitable 3-dimensional hypersurfaces correctly reproduce the Bondi and the ADM surface integral, at null and spatial infinity, respectively, supporting our proposal. We also obtain the Bondi mass-loss formula as a negative-definite flux integral of a bilinear in the gravitational currents at null infinity.
[ { "created": "Fri, 15 Jan 1993 13:49:52 GMT", "version": "v1" } ]
2007-05-23
[ [ "Yoon", "J. H.", "" ] ]
We propose a 4-dimensional Kaluza-Klein approach to general relativity in the (2,2)-splitting of space-time using the double null gauge. The associated Lagrangian is equivalent to the Einstein-Hilbert Lagrangian, since it yields the same field equations as the E-H Lagrangian does. It is describable as a (1+1)-dimensional Yang-Mills type gauge theory coupled to (1+1)-dimensional matter fields, where the minimal coupling associated with the diffeomorphism group of the 2-dimensional spacelike fibre space automatically appears. Written in the first-order formalism, our Lagrangian density directly yields a non-zero local Hamiltonian density, where the associated time function is the retarded time. From this Hamiltonian density, we obtain a positive-definite local gravitational energy density. In the asymptotically flat space-times, the volume integrals of the proposed local gravitational energy density over suitable 3-dimensional hypersurfaces correctly reproduce the Bondi and the ADM surface integral, at null and spatial infinity, respectively, supporting our proposal. We also obtain the Bondi mass-loss formula as a negative-definite flux integral of a bilinear in the gravitational currents at null infinity.
gr-qc/9511066
Pablo Labraga Lopez
A. Feinstein, J. Ib\'a\~nez and P. Labraga (Dpto. F\'isica Te\'orica, Universidad del Pa\'is Vasco, Bilbao, Spain)
Scalar Field Inhomogeneous Cosmologies
21 pages LaTeX, 3 figures appended as a uuencoded compressed tar file
J.Math.Phys. 36 (1995) 4962-4974
10.1063/1.530931
null
gr-qc
null
Some exact solutions for the Einstein field equations corresponding to inhomogeneous $G_2$ cosmologies with an exponential-potential scalar field which generalize solutions obtained previously are considered. Several particular cases are studied and the properties related to generalized inflation and asymptotic behaviour of the models are discussed.
[ { "created": "Fri, 24 Nov 1995 11:16:11 GMT", "version": "v1" } ]
2016-08-15
[ [ "Feinstein", "A.", "", "Dpto. Física Teórica,\n Universidad del País Vasco, Bilbao, Spain" ], [ "Ibáñez", "J.", "", "Dpto. Física Teórica,\n Universidad del País Vasco, Bilbao, Spain" ], [ "Labraga", "P.", "", "Dpto. Física Teórica,\n Universidad del País Vasco, Bilbao, Spain" ] ]
Some exact solutions for the Einstein field equations corresponding to inhomogeneous $G_2$ cosmologies with an exponential-potential scalar field which generalize solutions obtained previously are considered. Several particular cases are studied and the properties related to generalized inflation and asymptotic behaviour of the models are discussed.
2201.05908
Pierre-Henri Chavanis
Pierre-Henri Chavanis
A new logotropic model based on a complex scalar field with a logarithmic potential
null
null
10.1103/PhysRevD.106.063525
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a new logotropic model based on a complex scalar field with a logarithmic potential that unifies dark matter and dark energy. The scalar field satisfies a nonlinear wave equation generalizing the Klein-Gordon equation in the relativistic regime and the Schr\"odinger equation in the nonrelativistic regime. This model has an intrinsically quantum nature and returns the $\Lambda$CDM model in the classical limit $\hbar\rightarrow 0$. It involves a new fundamental constant of physics $A/c^2=2.10\times 10^{-26}\, {\rm g}\, {\rm m}^{-3}$ responsible for the late accelerating expansion of the Universe and superseding the Einstein cosmological constant $\Lambda$. The logotropic model is almost indistinguishable from the $\Lambda$CDM model at large (cosmological) scales but solves the CDM crisis at small (galactic) scales. It also solves the problems of the fuzzy dark matter model. Indeed, it leads to cored dark matter halos with a universal surface density $\Sigma_0^{\rm th}=5.85\,\left ({A}/{4\pi G}\right )^{1/2}=133\, M_{\odot}/{\rm pc}^2$. This universal surface density is predicted from the logotropic model without adjustable parameter and turns out to be close to the observed value $\Sigma_0^{\rm obs}=141_{-52}^{+83}\, M_{\odot}/{\rm pc}^2$. We also argue that the quantities $\Omega_{\rm dm,0}$ and $\Omega_{\rm de,0}$, which are usually interpreted as the present proportion of dark matter and dark energy in the $\Lambda$CDM model, are equal to $\Omega_{\rm dm,0}^{\rm th}=\frac{1}{1+e}(1-\Omega_{\rm b,0})=0.2559$ and $\Omega_{\rm de,0}^{\rm th}=\frac{e}{1+e}(1-\Omega_{\rm b,0})=0.6955$ in very good agreement with the measured values $\Omega_{\rm dm,0}^{\rm obs}=0.2589$ and $\Omega_{\rm de,0}^{\rm obs}=0.6911$ (their ratio $2.669$ is close to the pure number $e=2.71828...$).
[ { "created": "Sat, 15 Jan 2022 18:45:24 GMT", "version": "v1" } ]
2022-10-05
[ [ "Chavanis", "Pierre-Henri", "" ] ]
We introduce a new logotropic model based on a complex scalar field with a logarithmic potential that unifies dark matter and dark energy. The scalar field satisfies a nonlinear wave equation generalizing the Klein-Gordon equation in the relativistic regime and the Schr\"odinger equation in the nonrelativistic regime. This model has an intrinsically quantum nature and returns the $\Lambda$CDM model in the classical limit $\hbar\rightarrow 0$. It involves a new fundamental constant of physics $A/c^2=2.10\times 10^{-26}\, {\rm g}\, {\rm m}^{-3}$ responsible for the late accelerating expansion of the Universe and superseding the Einstein cosmological constant $\Lambda$. The logotropic model is almost indistinguishable from the $\Lambda$CDM model at large (cosmological) scales but solves the CDM crisis at small (galactic) scales. It also solves the problems of the fuzzy dark matter model. Indeed, it leads to cored dark matter halos with a universal surface density $\Sigma_0^{\rm th}=5.85\,\left ({A}/{4\pi G}\right )^{1/2}=133\, M_{\odot}/{\rm pc}^2$. This universal surface density is predicted from the logotropic model without adjustable parameter and turns out to be close to the observed value $\Sigma_0^{\rm obs}=141_{-52}^{+83}\, M_{\odot}/{\rm pc}^2$. We also argue that the quantities $\Omega_{\rm dm,0}$ and $\Omega_{\rm de,0}$, which are usually interpreted as the present proportion of dark matter and dark energy in the $\Lambda$CDM model, are equal to $\Omega_{\rm dm,0}^{\rm th}=\frac{1}{1+e}(1-\Omega_{\rm b,0})=0.2559$ and $\Omega_{\rm de,0}^{\rm th}=\frac{e}{1+e}(1-\Omega_{\rm b,0})=0.6955$ in very good agreement with the measured values $\Omega_{\rm dm,0}^{\rm obs}=0.2589$ and $\Omega_{\rm de,0}^{\rm obs}=0.6911$ (their ratio $2.669$ is close to the pure number $e=2.71828...$).
1601.00947
Agnes Fienga Dr.
A. Fienga, J. Laskar, H. Manche, M. Gastineau
Tests of GR with INPOP15a planetary ephemerides: estimations of possible supplementary advances of perihelia for Mercury and Saturn
Proceedings of the 14th Marcel Grossmann meeting
null
null
null
gr-qc astro-ph.EP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Planetary ephemerides are a good tool for studying general relativity at the scale of our solar system. We present here new evaluations of advances of perihelia for Mercury and Saturn.
[ { "created": "Tue, 5 Jan 2016 19:56:09 GMT", "version": "v1" } ]
2016-01-06
[ [ "Fienga", "A.", "" ], [ "Laskar", "J.", "" ], [ "Manche", "H.", "" ], [ "Gastineau", "M.", "" ] ]
Planetary ephemerides are a good tool for studying general relativity at the scale of our solar system. We present here new evaluations of advances of perihelia for Mercury and Saturn.
gr-qc/9812016
Jean-Pierre De Villiers
Jean-Pierre De Villiers and Valeri Frolov
Gravitational Scattering of Cosmic Strings by Non-Rotating Black Holes
31 pages, 11 figures. Paper revised with referee comments. To appear in Classical and Quantum Gravity
Class.Quant.Grav. 16 (1999) 2403-2425
10.1088/0264-9381/16/7/317
Alberta Thy 08-98
gr-qc
null
This paper discusses the gravitational scattering of a straight, infinitely long test cosmic string by a black hole. We present numerical results that probe the two-dimensional parameter space of impact parameter and initial velocity and compare them to approximate perturbative solutions derived previously. We analyze string scattering and loop formation in the ultra-relativistic regime and compare these results with analytical results for string scattering by a gravitational shock wave. Special attention is paid to regimes where the string approaches the black hole at near-critical impact parameters. The dynamics of string scattering in this case are highly sensitive to initial data and transient phenomena arise while portions of the string dwell in the strong gravitational field near the event horizon of the black hole. The role of string tension is also investigated by comparing the scattering of a cosmic string to the scattering of a tensionless "dust" string. Finally, the problem of string capture is revisited in light of these new results, and a capture curve covering the entire velocity range ($0 < v \le c$) is given.
[ { "created": "Fri, 4 Dec 1998 18:06:04 GMT", "version": "v1" }, { "created": "Sat, 12 Dec 1998 21:35:52 GMT", "version": "v2" }, { "created": "Tue, 27 Apr 1999 14:27:10 GMT", "version": "v3" }, { "created": "Wed, 28 Apr 1999 16:55:38 GMT", "version": "v4" } ]
2009-10-31
[ [ "De Villiers", "Jean-Pierre", "" ], [ "Frolov", "Valeri", "" ] ]
This paper discusses the gravitational scattering of a straight, infinitely long test cosmic string by a black hole. We present numerical results that probe the two-dimensional parameter space of impact parameter and initial velocity and compare them to approximate perturbative solutions derived previously. We analyze string scattering and loop formation in the ultra-relativistic regime and compare these results with analytical results for string scattering by a gravitational shock wave. Special attention is paid to regimes where the string approaches the black hole at near-critical impact parameters. The dynamics of string scattering in this case are highly sensitive to initial data and transient phenomena arise while portions of the string dwell in the strong gravitational field near the event horizon of the black hole. The role of string tension is also investigated by comparing the scattering of a cosmic string to the scattering of a tensionless "dust" string. Finally, the problem of string capture is revisited in light of these new results, and a capture curve covering the entire velocity range ($0 < v \le c$) is given.
1407.7791
Sunil Kumar Tripathy Mr.
S. K. Tripathy
Late time Acceleration and Role of Skewness in Anisotropic models
15 pages, 4 figures, Astrophysics Space Science, 2014
Astrophys. Space Sci.(2014)350:367-374
10.1007/s10509-013-1727-4
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study cosmological models with anisotropy in expansion rates in the context of the recent observations predicting an accelerating universe. In the absence of any anisotropy in the cosmic fluid, it is shown that the role of skewness in directional Hubble rates is crucial in deciding the behavior of the model. We find that incorporation of skewness leads to a more evolving effective equation of state parameter.
[ { "created": "Sat, 26 Jul 2014 18:05:49 GMT", "version": "v1" } ]
2015-06-22
[ [ "Tripathy", "S. K.", "" ] ]
We study cosmological models with anisotropy in expansion rates in the context of the recent observations predicting an accelerating universe. In the absence of any anisotropy in the cosmic fluid, it is shown that the role of skewness in directional Hubble rates is crucial in deciding the behavior of the model. We find that incorporation of skewness leads to a more evolving effective equation of state parameter.
1602.07546
Sumanta Chakraborty
Krishnamohan Parattu, Sumanta Chakraborty and T. Padmanabhan
Variational Principle for Gravity with Null and Non-null boundaries: A Unified Boundary Counter-term
6 pages, no figures, accepted in Eur. Phys. J. C
Eur. Phys. J. C 76, 129 (2016)
10.1140/epjc/s10052-016-3979-y
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is common knowledge that the Einstein-Hilbert action does not furnish a well-posed variational principle. The usual solution to this problem is to add an extra boundary term to the action, called a counter-term, so that the variational principle becomes well-posed. When the boundary is spacelike or timelike, the Gibbons-Hawking-York counter-term is the most widely used. For null boundaries, we had proposed a counter-term in a previous paper. In this paper, we extend the previous analysis and propose a counter-term that can be used to eliminate variations of the "off-the-surface" derivatives of the metric on any boundary, regardless of its spacelike, timelike or null nature.
[ { "created": "Tue, 23 Feb 2016 06:53:41 GMT", "version": "v1" } ]
2016-07-15
[ [ "Parattu", "Krishnamohan", "" ], [ "Chakraborty", "Sumanta", "" ], [ "Padmanabhan", "T.", "" ] ]
It is common knowledge that the Einstein-Hilbert action does not furnish a well-posed variational principle. The usual solution to this problem is to add an extra boundary term to the action, called a counter-term, so that the variational principle becomes well-posed. When the boundary is spacelike or timelike, the Gibbons-Hawking-York counter-term is the most widely used. For null boundaries, we had proposed a counter-term in a previous paper. In this paper, we extend the previous analysis and propose a counter-term that can be used to eliminate variations of the "off-the-surface" derivatives of the metric on any boundary, regardless of its spacelike, timelike or null nature.
1809.07202
Sabrina D'Antonio
S. D'Antonio, C. Palomba, S. Frasca, G. Intini, I. La Rosa, P. Leaci, S. Mastrogiovanni, A. Miller, F. Muciaccia, O. J. Piccinni, A. Singhal
A semi-coherent analysis method to search for continuous gravitational waves emitted by ultra-light boson clouds around spinning black holes
13 pages, 13 figures
null
10.1103/PhysRevD.98.103017
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As a consequence of superradiant instability induced in Kerr black holes, ultra-light boson clouds can be a source of persistent gravitational waves, potentially detectable by current and future gravitational-wave detectors. These signals have been predicted to be nearly monochromatic, with a small steady frequency increase (spin-up), but given the several assumptions and simplifications done at theoretical level, it is wise to consider, from the data analysis point of view, a broader class of gravitational signals in which the phase (or the frequency) slightly wander in time. Also other types of sources, e.g. neutron stars in which a torque balance equilibrium exists between matter accretion and emission of persistent gravitational waves, would fit in this category. In this paper we present a robust and computationally cheap analysis pipeline devoted to the search of such kind of signals. We provide a full characterization of the method, through both a theoretical sensitivity estimation and through the analysis of syntethic data in which simulated signals have been injected. The search setup for both all-sky searches and higher sensitivity directed searches is discussed.
[ { "created": "Wed, 19 Sep 2018 14:09:32 GMT", "version": "v1" } ]
2018-12-05
[ [ "D'Antonio", "S.", "" ], [ "Palomba", "C.", "" ], [ "Frasca", "S.", "" ], [ "Intini", "G.", "" ], [ "La Rosa", "I.", "" ], [ "Leaci", "P.", "" ], [ "Mastrogiovanni", "S.", "" ], [ "Miller", "A.", "" ], [ "Muciaccia", "F.", "" ], [ "Piccinni", "O. J.", "" ], [ "Singhal", "A.", "" ] ]
As a consequence of superradiant instability induced in Kerr black holes, ultra-light boson clouds can be a source of persistent gravitational waves, potentially detectable by current and future gravitational-wave detectors. These signals have been predicted to be nearly monochromatic, with a small steady frequency increase (spin-up), but given the several assumptions and simplifications done at theoretical level, it is wise to consider, from the data analysis point of view, a broader class of gravitational signals in which the phase (or the frequency) slightly wander in time. Also other types of sources, e.g. neutron stars in which a torque balance equilibrium exists between matter accretion and emission of persistent gravitational waves, would fit in this category. In this paper we present a robust and computationally cheap analysis pipeline devoted to the search of such kind of signals. We provide a full characterization of the method, through both a theoretical sensitivity estimation and through the analysis of syntethic data in which simulated signals have been injected. The search setup for both all-sky searches and higher sensitivity directed searches is discussed.
2301.03590
Kimet Jusufi
Kimet Jusufi
Avoidance of singularity during the gravitational collapse with string T-duality effects
9 pages, no figures. Published in Universe https://www.mdpi.com/2218-1997/9/1/41
Universe 2023, 9(1), 41
10.3390/universe9010041
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we explore the gravitational collapse of matter (dust) under the effect of zero-point length $l_0$. During the gravitational collapse, we have neglected the backreaction effect of the pre-Hawking radiation (in the sense that it is small effect and cannot prevent the formation of apparent horizon), then we recast the internal metric of a collapsing star as a closed FRW universe for any spherically symmetric case and, finally, we obtain the minimal value for the scale factor meaning that the particles never hit the singularity. We argue that the object emerging at the end of the gravitational collapse can be interpreted as Planck stars (black hole core) hidden inside the event horizon of the black hole with radius proportional to $(GMl_0^{2}/c^2)^{1/3}$. Quite interestingly, we found the same result for radius of the Planck star using a free falling observer point of view. In addition, we pointed out a correspondence between the modified Friedmann's equations in loop quantum gravity and the modified Friedmann's equation in string T-duality. In the end, we discuss two possibilities regarding the final stage of the black hole. The first possibility is that we end up with a Planck-size black hole remnants. The second possibility is that the inner core can be unstable and, due to the quantum tunnelling effect, the spacetime can undergo a black hole-to-white hole transition (a bouncing Planck star).
[ { "created": "Mon, 9 Jan 2023 09:59:50 GMT", "version": "v1" }, { "created": "Thu, 19 Jan 2023 09:48:13 GMT", "version": "v2" } ]
2023-01-20
[ [ "Jusufi", "Kimet", "" ] ]
In this paper, we explore the gravitational collapse of matter (dust) under the effect of zero-point length $l_0$. During the gravitational collapse, we have neglected the backreaction effect of the pre-Hawking radiation (in the sense that it is small effect and cannot prevent the formation of apparent horizon), then we recast the internal metric of a collapsing star as a closed FRW universe for any spherically symmetric case and, finally, we obtain the minimal value for the scale factor meaning that the particles never hit the singularity. We argue that the object emerging at the end of the gravitational collapse can be interpreted as Planck stars (black hole core) hidden inside the event horizon of the black hole with radius proportional to $(GMl_0^{2}/c^2)^{1/3}$. Quite interestingly, we found the same result for radius of the Planck star using a free falling observer point of view. In addition, we pointed out a correspondence between the modified Friedmann's equations in loop quantum gravity and the modified Friedmann's equation in string T-duality. In the end, we discuss two possibilities regarding the final stage of the black hole. The first possibility is that we end up with a Planck-size black hole remnants. The second possibility is that the inner core can be unstable and, due to the quantum tunnelling effect, the spacetime can undergo a black hole-to-white hole transition (a bouncing Planck star).
2105.05325
Alice Boldrin
Alice Boldrin, Przemys{\l}aw Ma{\l}kiewicz
Dirac procedure and the Hamiltonian formalism for cosmological perturbations in a Bianchi I universe
Added references, corrected typos, clarified notation, improved discussions. Results unchanged
2022 Class. Quantum Grav. 39 025005
10.1088/1361-6382/ac3bda
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
We apply the Dirac procedure for constrained systems to the Arnowitt-Deser-Misner formalism linearized around the Bianchi I universe. We discuss and employ basic concepts such as Dirac observables, Dirac brackets, gauge-fixing conditions, reduced phase space, physical Hamiltonian, canonical isomorphism between different gauge-fixing surfaces and spacetime reconstruction. We relate this approach to the gauge-fixing procedure for non-perturbative canonical relativity. We discuss the issue of propagating a basis for the scalar-vector-tensor decomposition as, in an anisotropic universe, the wavefronts of plane waves undergo a nontrivial evolution. We show that the definition of a gravitational wave as a traceless-transverse mode of the metric perturbation needs to be revised. Moreover there exist coordinate systems in which a polarization mode of the gravitational wave is given entirely in terms of a scalar metric perturbation. We first develop the formalism for the universe with a single scalar field and then extend it to the multi-field case. The obtained fully canonical formalism will serve as a starting point for a complete quantization of the cosmological perturbations and the cosmological background.
[ { "created": "Tue, 11 May 2021 19:55:24 GMT", "version": "v1" }, { "created": "Fri, 22 Oct 2021 14:36:03 GMT", "version": "v2" }, { "created": "Tue, 14 Dec 2021 12:15:12 GMT", "version": "v3" } ]
2021-12-15
[ [ "Boldrin", "Alice", "" ], [ "Małkiewicz", "Przemysław", "" ] ]
We apply the Dirac procedure for constrained systems to the Arnowitt-Deser-Misner formalism linearized around the Bianchi I universe. We discuss and employ basic concepts such as Dirac observables, Dirac brackets, gauge-fixing conditions, reduced phase space, physical Hamiltonian, canonical isomorphism between different gauge-fixing surfaces and spacetime reconstruction. We relate this approach to the gauge-fixing procedure for non-perturbative canonical relativity. We discuss the issue of propagating a basis for the scalar-vector-tensor decomposition as, in an anisotropic universe, the wavefronts of plane waves undergo a nontrivial evolution. We show that the definition of a gravitational wave as a traceless-transverse mode of the metric perturbation needs to be revised. Moreover there exist coordinate systems in which a polarization mode of the gravitational wave is given entirely in terms of a scalar metric perturbation. We first develop the formalism for the universe with a single scalar field and then extend it to the multi-field case. The obtained fully canonical formalism will serve as a starting point for a complete quantization of the cosmological perturbations and the cosmological background.
0911.3967
Patrick Das Gupta
Patrick Das Gupta
On Chern-Simons corrections to magnetohydrodynamics equations
11 pages, to appear in Plasma Science and Technology (2010)
null
10.1080/10420150903500571
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the effect of a (3+1)-dimensional Chern-Simons electrodynamics on the equations governing the dynamics of magnetized plasma and fields. In this model, the Chern-Simons (CS) part consists of a dynamical pseudo-scalar field whose space-time derivatives couple with the electromagnetic field. We explore the CS corrections to the evolution equation for the magnetic field in a plasma with non-zero electrical resistivity. We revisit Cowling's theorem in this context and observe that the CS corrections lead to possibly small but non-zero source terms for axisymmetric magnetic field. The scalar product of electric and magnetic fields play the role of source of the pseudo-scalar field, and therefore, pulsars and magnetars are likely astrophysical candidates to generate propagating pseudo-scalar waves. Although aligned electric field gets shorted out by flowing charges in large parts of the magnetosphere, there are vacuum gaps in the vicinity of pulsars where strong $\vec E. \vec B$ is expected to be present. We derive a wave solution for the pseudo-scalar field generated by the time-varying $\vec E. \vec B$ associated with a pulsar.
[ { "created": "Fri, 20 Nov 2009 05:13:11 GMT", "version": "v1" } ]
2016-06-29
[ [ "Gupta", "Patrick Das", "" ] ]
We study the effect of a (3+1)-dimensional Chern-Simons electrodynamics on the equations governing the dynamics of magnetized plasma and fields. In this model, the Chern-Simons (CS) part consists of a dynamical pseudo-scalar field whose space-time derivatives couple with the electromagnetic field. We explore the CS corrections to the evolution equation for the magnetic field in a plasma with non-zero electrical resistivity. We revisit Cowling's theorem in this context and observe that the CS corrections lead to possibly small but non-zero source terms for axisymmetric magnetic field. The scalar product of electric and magnetic fields play the role of source of the pseudo-scalar field, and therefore, pulsars and magnetars are likely astrophysical candidates to generate propagating pseudo-scalar waves. Although aligned electric field gets shorted out by flowing charges in large parts of the magnetosphere, there are vacuum gaps in the vicinity of pulsars where strong $\vec E. \vec B$ is expected to be present. We derive a wave solution for the pseudo-scalar field generated by the time-varying $\vec E. \vec B$ associated with a pulsar.
2306.17471
Sven Zschocke
Sven Zschocke
Total light deflection in the gravitational field of an axisymmetric body at rest with full mass and spin multipole structure
56 pages, 1 figure, 3 tables
Physical Review D 107 (2023) 124055
10.1103/PhysRevD.107.124055
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
The tangent vector of the light trajectory at future infinity and the angle of total light deflection in the gravitational field of an isolated axisymmetric body at rest with full set of mass-multipoles and spin-multipoles is determined in harmonic coordinates in the 1PN and 1.5PN approximation of the post-Newtonian (PN) scheme. It is found that the evaluation of the tangent vector and of the angle of total light deflection caused by mass-multipoles and spin-multipoles leads directly and in a compelling way to Chebyshev polynomials of first and second kind, respectively. This fact allows to determine the upper limits of the total light deflection, which are strictly valid in the 1PN and 1.5PN approximation. They represent a criterion to identify those multipoles which contribute significantly to the total light deflection for a given astrometric accuracy. These upper limits are used to determine the total light deflection in the gravitational field of the Sun and giant planets of the solar system. It is found that the first few mass-multipoles with l \le 10 and the first few spin-multipoles with l \le 3 are sufficient for an accuracy on the nano-arcsecond level in astrometric angular measurements.
[ { "created": "Fri, 30 Jun 2023 08:37:01 GMT", "version": "v1" } ]
2023-07-12
[ [ "Zschocke", "Sven", "" ] ]
The tangent vector of the light trajectory at future infinity and the angle of total light deflection in the gravitational field of an isolated axisymmetric body at rest with full set of mass-multipoles and spin-multipoles is determined in harmonic coordinates in the 1PN and 1.5PN approximation of the post-Newtonian (PN) scheme. It is found that the evaluation of the tangent vector and of the angle of total light deflection caused by mass-multipoles and spin-multipoles leads directly and in a compelling way to Chebyshev polynomials of first and second kind, respectively. This fact allows to determine the upper limits of the total light deflection, which are strictly valid in the 1PN and 1.5PN approximation. They represent a criterion to identify those multipoles which contribute significantly to the total light deflection for a given astrometric accuracy. These upper limits are used to determine the total light deflection in the gravitational field of the Sun and giant planets of the solar system. It is found that the first few mass-multipoles with l \le 10 and the first few spin-multipoles with l \le 3 are sufficient for an accuracy on the nano-arcsecond level in astrometric angular measurements.
1808.05286
Evan McDonough
Stephon Alexander, Evan McDonough, Robert Sims and Nicolas Yunes
Hidden-Sector Modifications to Gravitational Waves From Binary Inspirals
18 pages, 6 figures, submitted to CQG. v2: matches published version
Class. Quant. Grav. 35, no. 23, 235012 (2018)
10.1088/1361-6382/aaeb5c
null
gr-qc hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gravitational wave astronomy has placed strong constraints on fundamental physics, and there is every expectation that future observations will continue to do so. In this work we quantify this expectation for future binary merger observations to constrain hidden sectors, such as scalar-tensor gravity or dark matter, which induce a Yukawa-type modification to the gravitational potential. We explicitly compute the gravitational waveform, and perform a Fisher information matrix analysis to estimate the sensitivity of next generation gravitational wave detectors to these modifications. We find an optimal sensitivity to the Yukawa interaction strength of $10^{-5}$ and to the associated dipole emission parameter of $10^{-7}$, with the best constraints arising from the Einstein Telescope. When applied to a minimal model of dark matter, this provides an exquisite probe of dark matter accumulation by neutron stars, and for sub-TeV dark matter gravitational waves are able to detect mass fractions $m_{DM}/m_{NS}$ less then 1 part in $10^{15}$.
[ { "created": "Wed, 15 Aug 2018 21:23:30 GMT", "version": "v1" }, { "created": "Mon, 12 Nov 2018 15:16:47 GMT", "version": "v2" } ]
2018-11-13
[ [ "Alexander", "Stephon", "" ], [ "McDonough", "Evan", "" ], [ "Sims", "Robert", "" ], [ "Yunes", "Nicolas", "" ] ]
Gravitational wave astronomy has placed strong constraints on fundamental physics, and there is every expectation that future observations will continue to do so. In this work we quantify this expectation for future binary merger observations to constrain hidden sectors, such as scalar-tensor gravity or dark matter, which induce a Yukawa-type modification to the gravitational potential. We explicitly compute the gravitational waveform, and perform a Fisher information matrix analysis to estimate the sensitivity of next generation gravitational wave detectors to these modifications. We find an optimal sensitivity to the Yukawa interaction strength of $10^{-5}$ and to the associated dipole emission parameter of $10^{-7}$, with the best constraints arising from the Einstein Telescope. When applied to a minimal model of dark matter, this provides an exquisite probe of dark matter accumulation by neutron stars, and for sub-TeV dark matter gravitational waves are able to detect mass fractions $m_{DM}/m_{NS}$ less then 1 part in $10^{15}$.
2306.15050
Kuantay Boshkayev
Yergali Kurmanov, Marco Muccino, Kuantay Boshkayev, Talgar Konysbayev, Orlando Luongo, Hernando Quevedo, Ainur Urazalina
Accretion disk in the Hartle-Thorne spacetime
15 pages, 11 figures
null
null
null
gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We consider the circular motion of test particles in the gravitational field of a rotating deformed object described by the Hartle-Thorne metric. This metric represents an approximate solution to the vacuum Einstein field equations, accurate to second order in the angular momentum $J$ and to first order in the mass quadrupole moment $Q$. We calculate the orbital parameters of neutral test particles on circular orbits (in accretion disks) such as angular velocity, $\Omega$, total energy, $E$, angular momentum, $L$, and radius of the innermost stable circular orbit, $R_{ISCO}$, as functions of the total mass, $M$, spin parameter, $j=J/M^2$ and quadrupole parameter, $q=Q/M^3$, of the source. We use the Novikov-Thorne-Page thin accretion disk model to investigate the characteristics of the disk. In particular, we analyze in detail the radiative flux, differential luminosity, and spectral luminosity of the accretion disk, which are the quantities that can be measured experimentally. We compare our results with those obtained in the literature for the Schwarzschild and Kerr metrics, and the $q$-metric. It turns out that the Hartle-Thorne metric and the Kerr metric lead to similar results for the predicted flux and the differential and spectral luminosities, whereas the q-metric predicts different values. We compare the predicted values of $M$, $j$, and $q$ with those of realistic neutron star models. Furthermore, we compare the values of $R_{ISCO}$ with the static and rotating radii of neutron stars.
[ { "created": "Mon, 26 Jun 2023 20:14:05 GMT", "version": "v1" } ]
2023-06-28
[ [ "Kurmanov", "Yergali", "" ], [ "Muccino", "Marco", "" ], [ "Boshkayev", "Kuantay", "" ], [ "Konysbayev", "Talgar", "" ], [ "Luongo", "Orlando", "" ], [ "Quevedo", "Hernando", "" ], [ "Urazalina", "Ainur", "" ] ]
We consider the circular motion of test particles in the gravitational field of a rotating deformed object described by the Hartle-Thorne metric. This metric represents an approximate solution to the vacuum Einstein field equations, accurate to second order in the angular momentum $J$ and to first order in the mass quadrupole moment $Q$. We calculate the orbital parameters of neutral test particles on circular orbits (in accretion disks) such as angular velocity, $\Omega$, total energy, $E$, angular momentum, $L$, and radius of the innermost stable circular orbit, $R_{ISCO}$, as functions of the total mass, $M$, spin parameter, $j=J/M^2$ and quadrupole parameter, $q=Q/M^3$, of the source. We use the Novikov-Thorne-Page thin accretion disk model to investigate the characteristics of the disk. In particular, we analyze in detail the radiative flux, differential luminosity, and spectral luminosity of the accretion disk, which are the quantities that can be measured experimentally. We compare our results with those obtained in the literature for the Schwarzschild and Kerr metrics, and the $q$-metric. It turns out that the Hartle-Thorne metric and the Kerr metric lead to similar results for the predicted flux and the differential and spectral luminosities, whereas the q-metric predicts different values. We compare the predicted values of $M$, $j$, and $q$ with those of realistic neutron star models. Furthermore, we compare the values of $R_{ISCO}$ with the static and rotating radii of neutron stars.
gr-qc/9409038
Ocariz Jose Humberto
J. Ocariz, H. Rago
The Gravitational and Electrostatic Fields Far from an Isolated Einstein-Maxwell Source
11 pages, revTeX
Gen.Rel.Grav. 26, 1249 (1994)
10.1007/BF02106716
ULA-TH-940901
gr-qc
null
The exterior solution for an arbitrary charged, massive source, is studied as a static deviation from the Reissner-Nordstr\o m metric. This is reduced to two coupled ordinary differential equations for the gravitational and electrostatic potential functions. The homogeneous equations are explicitly solved in the particular case $q^2=m^2$, obtaining a multipole expansion with radial hypergeometric dependence for both potentials. In the limiting case of a neutral source, the equations are shown to coincide with recent results by Bondi and Rindler.
[ { "created": "Sun, 18 Sep 1994 15:46:42 GMT", "version": "v1" }, { "created": "Fri, 17 Mar 2000 08:42:21 GMT", "version": "v2" } ]
2009-10-22
[ [ "Ocariz", "J.", "" ], [ "Rago", "H.", "" ] ]
The exterior solution for an arbitrary charged, massive source, is studied as a static deviation from the Reissner-Nordstr\o m metric. This is reduced to two coupled ordinary differential equations for the gravitational and electrostatic potential functions. The homogeneous equations are explicitly solved in the particular case $q^2=m^2$, obtaining a multipole expansion with radial hypergeometric dependence for both potentials. In the limiting case of a neutral source, the equations are shown to coincide with recent results by Bondi and Rindler.
1311.4436
Xiaolin Yang
Xiao-lin Yang and Jian-cheng Wang
ynogkm: A New Public Code For Calculating time-like Geodesics In The Kerr-Newmann Spacetime
14 pages,12 figures, 7 tables, and a public code ynogkm is presented. Accepted for publication by A&A. comments are welcome
null
10.1051/0004-6361/201322565
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present a new public code, named $ynogkm$, for the fast calculation of time-like geodesics in the Kerr-Newmann (K-N) spacetime, which is a direct extension of $ynogk$ calculating null geodesics in a Kerr spacetime. Following the strategies used in $ynogk$, we also solve the equations of motion analytically and semi-analytically by using Weierstrass' and Jacobi's elliptic functions and integrals, in which the Boyer-Lidquist (B-L) coordinates $r$, $\theta$, $\phi$, $t$ and the proper time $\sigma$ are expressed as functions of an independent variable $p$ (Mino time). All of the elliptic integrals are computed by Carlson's elliptic integral method, which guarantees the fast speed of the code. Finally the code is applied to a couple of toy problems.
[ { "created": "Mon, 18 Nov 2013 16:15:40 GMT", "version": "v1" } ]
2015-06-17
[ [ "Yang", "Xiao-lin", "" ], [ "Wang", "Jian-cheng", "" ] ]
In this paper we present a new public code, named $ynogkm$, for the fast calculation of time-like geodesics in the Kerr-Newmann (K-N) spacetime, which is a direct extension of $ynogk$ calculating null geodesics in a Kerr spacetime. Following the strategies used in $ynogk$, we also solve the equations of motion analytically and semi-analytically by using Weierstrass' and Jacobi's elliptic functions and integrals, in which the Boyer-Lidquist (B-L) coordinates $r$, $\theta$, $\phi$, $t$ and the proper time $\sigma$ are expressed as functions of an independent variable $p$ (Mino time). All of the elliptic integrals are computed by Carlson's elliptic integral method, which guarantees the fast speed of the code. Finally the code is applied to a couple of toy problems.
gr-qc/0701120
Mario Novello
M. Novello
A Spinor Theory of Gravity and the Cosmological Framework
null
JCAP 0706:018,2007
10.1088/1475-7516/2007/06/018
null
gr-qc astro-ph
null
Recently we have presented a new formulation of the theory of gravity based on an implementation of the Einstein Equivalence Principle distinct from General Relativity. The kinetic part of the theory - that describes how matter is affected by the modified geometry due to the gravitational field - is the same as in General Relativity. However, we do not consider the metric as an independent field. Instead, it is an effective one, constructed in terms of two fundamental spinor fields $\Psi$ and $\Upsilon$ and thus the metric does not have a dynamics of its own, but inherits its evolution through its relation with the fundamental spinors. In the first paper it was shown that the metric that describes the gravitational field generated by a compact static and spherically symmetric configuration is very similar to the Schwarzschild metric. In the present paper we describe the cosmological framework in the realm of the Spinor Theory of Gravity.
[ { "created": "Mon, 22 Jan 2007 12:10:22 GMT", "version": "v1" } ]
2010-10-27
[ [ "Novello", "M.", "" ] ]
Recently we have presented a new formulation of the theory of gravity based on an implementation of the Einstein Equivalence Principle distinct from General Relativity. The kinetic part of the theory - that describes how matter is affected by the modified geometry due to the gravitational field - is the same as in General Relativity. However, we do not consider the metric as an independent field. Instead, it is an effective one, constructed in terms of two fundamental spinor fields $\Psi$ and $\Upsilon$ and thus the metric does not have a dynamics of its own, but inherits its evolution through its relation with the fundamental spinors. In the first paper it was shown that the metric that describes the gravitational field generated by a compact static and spherically symmetric configuration is very similar to the Schwarzschild metric. In the present paper we describe the cosmological framework in the realm of the Spinor Theory of Gravity.
0810.5541
Nicolas Yunes
Nicolas Yunes and David N. Spergel
Double Binary Pulsar Test of Dynamical Chern-Simons Modified Gravity
Rewritten and extended for Phys. Rev. D. Replaced with accepted version
Phys.Rev.D80:042004,2009
10.1103/PhysRevD.80.042004
null
gr-qc astro-ph hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Chern-Simons modified gravity is a string-theory and loop-quantum-gravity inspired effective theory that modifies General Relativity by adding a parity-violating Pontryagin density to the Einstein-Hilbert action multiplied by a coupling scalar. We strongly constrain non-dynamical Chern-Simons modified gravity with a timelike Chern-Simons scalar through observations of the double binary pulsar PSR J0737-3039A/B. We first calculate Chern-Simons corrections to the orbital evolution of binary systems. We find that the ratio of the correction to periastron precession to the general relativistic prediction scales quadratically with the semi-major axis and inversely with the square of the object's radius. Binary pulsar systems are thus ideal to test this theory, since periastron precession can be measured with sub-degree accuracies and the semi-major axis is millions of times larger than the stellar radius. Using data from PSR J0737-3039A/B we dramatically constrain the non-dynamical Chern-Simons coupling to $M_{\CS} := 1/|\dot{\vartheta}| > 33 {\textrm{meV}}$, approximately a hundred billion times better than current Solar System tests.
[ { "created": "Thu, 30 Oct 2008 19:08:19 GMT", "version": "v1" }, { "created": "Wed, 5 Aug 2009 18:35:15 GMT", "version": "v2" } ]
2010-04-15
[ [ "Yunes", "Nicolas", "" ], [ "Spergel", "David N.", "" ] ]
Chern-Simons modified gravity is a string-theory and loop-quantum-gravity inspired effective theory that modifies General Relativity by adding a parity-violating Pontryagin density to the Einstein-Hilbert action multiplied by a coupling scalar. We strongly constrain non-dynamical Chern-Simons modified gravity with a timelike Chern-Simons scalar through observations of the double binary pulsar PSR J0737-3039A/B. We first calculate Chern-Simons corrections to the orbital evolution of binary systems. We find that the ratio of the correction to periastron precession to the general relativistic prediction scales quadratically with the semi-major axis and inversely with the square of the object's radius. Binary pulsar systems are thus ideal to test this theory, since periastron precession can be measured with sub-degree accuracies and the semi-major axis is millions of times larger than the stellar radius. Using data from PSR J0737-3039A/B we dramatically constrain the non-dynamical Chern-Simons coupling to $M_{\CS} := 1/|\dot{\vartheta}| > 33 {\textrm{meV}}$, approximately a hundred billion times better than current Solar System tests.
1302.2938
Lorenzo Fatibene
L. Fatibene, M. Francaviglia
Mathematical Equivalence vs. Physical Equivalence between Extended Theories of Gravitations
13 pages, 4 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We shall show that although Palatini f(R)-theories are equivalent to Brans-Dicke theories, still the first pass the Mercury precession of perihelia test, while the second do not. We argue that the two models are not physically equivalent due to a different assumptions about free fall. We shall also go through perihelia test without fixing a conformal gauge (clocks or rulers) in order to highlight what can be measured in a conformal invariant way and what cannot. We shall argue that the conformal gauge is broken by choosing a definition of clock, rulers or, equivalently, of masses.
[ { "created": "Tue, 12 Feb 2013 22:19:20 GMT", "version": "v1" } ]
2013-02-14
[ [ "Fatibene", "L.", "" ], [ "Francaviglia", "M.", "" ] ]
We shall show that although Palatini f(R)-theories are equivalent to Brans-Dicke theories, still the first pass the Mercury precession of perihelia test, while the second do not. We argue that the two models are not physically equivalent due to a different assumptions about free fall. We shall also go through perihelia test without fixing a conformal gauge (clocks or rulers) in order to highlight what can be measured in a conformal invariant way and what cannot. We shall argue that the conformal gauge is broken by choosing a definition of clock, rulers or, equivalently, of masses.
1702.06337
Branislav Nikolic
Branislav Nikolic
Treating the Einstein-Hilbert action as a higher derivative Lagrangian: revealing the missing information about conformal non-invariance
8 pages, Contribution to the DICE2016 Proceedings
null
10.1088/1742-6596/880/1/012027
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Hamiltonian formulation of conformally invariant Weyl-squared higher derivative theory teaches us that conformal symmetry is expressed through particular first class constraints related to the absence of the three-metric determinant and the trace of the extrinsic curvature from the theory. Any term depending on them which is added to this theory breaks conformal invariance and turns these constraints into second class ones. Such second class constraints are missing in the standard canonical formulation of the conformally non-invariant Einstein-Hilbert theory. It is demonstrated that such constraints do appear if the theory is treated as a higher derivative one --- if the extrinsic curvature is promoted to an independent variable, the apparently missing information about conformal behavior is revealed.
[ { "created": "Tue, 21 Feb 2017 11:35:40 GMT", "version": "v1" } ]
2017-09-13
[ [ "Nikolic", "Branislav", "" ] ]
The Hamiltonian formulation of conformally invariant Weyl-squared higher derivative theory teaches us that conformal symmetry is expressed through particular first class constraints related to the absence of the three-metric determinant and the trace of the extrinsic curvature from the theory. Any term depending on them which is added to this theory breaks conformal invariance and turns these constraints into second class ones. Such second class constraints are missing in the standard canonical formulation of the conformally non-invariant Einstein-Hilbert theory. It is demonstrated that such constraints do appear if the theory is treated as a higher derivative one --- if the extrinsic curvature is promoted to an independent variable, the apparently missing information about conformal behavior is revealed.
0804.4722
Vladimir Dzhunushaliev
Vladimir Dzhunushaliev
Yamabe flow, conformal gravity and spacetime foam
acknowledgment is added
null
null
null
gr-qc hep-th math.DG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that 3D part of a spherically symmetric solution in conformal Weyl gravity interacting with Maxwell electrodynamics is a Yamabe flow as well. The Yamabe flow describes the transition from a horn of an initial wormhole to a 3D Euclidean space both filled with a radial electric field. It is supposed that such transition may describe appearing/disappearing quantum wormholes in a spacetime foam.
[ { "created": "Wed, 30 Apr 2008 02:23:22 GMT", "version": "v1" }, { "created": "Wed, 7 May 2008 08:00:49 GMT", "version": "v2" }, { "created": "Tue, 27 May 2008 10:56:15 GMT", "version": "v3" }, { "created": "Tue, 30 Sep 2008 03:18:15 GMT", "version": "v4" }, { "created": "Thu, 23 Oct 2008 04:57:55 GMT", "version": "v5" } ]
2008-10-23
[ [ "Dzhunushaliev", "Vladimir", "" ] ]
It is shown that 3D part of a spherically symmetric solution in conformal Weyl gravity interacting with Maxwell electrodynamics is a Yamabe flow as well. The Yamabe flow describes the transition from a horn of an initial wormhole to a 3D Euclidean space both filled with a radial electric field. It is supposed that such transition may describe appearing/disappearing quantum wormholes in a spacetime foam.
2111.13315
Joshua Foo
Joshua Foo, Cemile Senem Arabaci, Magdalena Zych, Robert B. Mann
Quantum signatures of black hole mass superpositions
Close to published version. Supplemental materials found on publisher's website
Phys. Rev. Lett. 129, 181301 (2022)
10.1103/PhysRevLett.129.181301
null
gr-qc hep-th quant-ph
http://creativecommons.org/licenses/by/4.0/
We present a new operational framework for studying ``superpositions of spacetimes'', which are of fundamental interest in the development of a theory of quantum gravity. Our approach capitalizes on nonlocal correlations in curved spacetime quantum field theory, allowing us to formulate a metric for spacetime superpositions as well as characterizing the coupling of particle detectors to a quantum field. We apply our approach to analyze the dynamics of a detector (using the Unruh-deWitt model) in a spacetime generated by a BTZ black hole in a superposition of masses. We find that the detector exhibits signatures of quantum-gravitational effects corroborating and extending Bekenstein's seminal conjecture concerning the quantized mass spectrum of black holes in quantum gravity. Crucially, this result follows directly from the approach, without any additional assumptions about the black hole mass properties.
[ { "created": "Fri, 26 Nov 2021 05:20:25 GMT", "version": "v1" }, { "created": "Tue, 1 Nov 2022 03:27:14 GMT", "version": "v2" } ]
2022-11-02
[ [ "Foo", "Joshua", "" ], [ "Arabaci", "Cemile Senem", "" ], [ "Zych", "Magdalena", "" ], [ "Mann", "Robert B.", "" ] ]
We present a new operational framework for studying ``superpositions of spacetimes'', which are of fundamental interest in the development of a theory of quantum gravity. Our approach capitalizes on nonlocal correlations in curved spacetime quantum field theory, allowing us to formulate a metric for spacetime superpositions as well as characterizing the coupling of particle detectors to a quantum field. We apply our approach to analyze the dynamics of a detector (using the Unruh-deWitt model) in a spacetime generated by a BTZ black hole in a superposition of masses. We find that the detector exhibits signatures of quantum-gravitational effects corroborating and extending Bekenstein's seminal conjecture concerning the quantized mass spectrum of black holes in quantum gravity. Crucially, this result follows directly from the approach, without any additional assumptions about the black hole mass properties.
2307.01796
Roberto Giamb\`o
Roberto Giamb\`o
Gravitational collapse of a spherical scalar field
Invited chapter for the edited book New Frontiers in Gravitational Collapse and Spacetime Singularities (Eds. P. Joshi and D. Malafarina, Springer Singapore, expected in 2023)
null
10.1007/978-981-97-1172-7_6
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Examining the relativistic collapse of a spherical spacetime where gravity is coupled with a scalar field, this review provides a thorough analysis of some of the most relevant studies from both analytical and numerical perspectives. The discussion includes achievements made in this field, with a focus on those related to cosmic censorship, as well as recent perspectives on the topic.
[ { "created": "Tue, 4 Jul 2023 16:04:28 GMT", "version": "v1" } ]
2024-05-09
[ [ "Giambò", "Roberto", "" ] ]
Examining the relativistic collapse of a spherical spacetime where gravity is coupled with a scalar field, this review provides a thorough analysis of some of the most relevant studies from both analytical and numerical perspectives. The discussion includes achievements made in this field, with a focus on those related to cosmic censorship, as well as recent perspectives on the topic.
1710.08413
Ratbay Myrzakulov
Shynaray Myrzakul, Kairat Myrzakulov, Sabit Bekov, Tolkynay Myrzakul and Ratbay Myrzakulov
Starobinsky model with f-essence
6 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we consider a cosmological model of the flat and homogeneous universe for the Starobinsky model $F(R)=\alpha R + \beta R^{2}$, which is non-minimally coupled with f-essence. For this model we obtained the field equations and considered particular solutions of the coupling and fermionic field functions. It is shown that the fermionic field can describe a nature of the universe.
[ { "created": "Mon, 23 Oct 2017 17:26:05 GMT", "version": "v1" } ]
2017-10-25
[ [ "Myrzakul", "Shynaray", "" ], [ "Myrzakulov", "Kairat", "" ], [ "Bekov", "Sabit", "" ], [ "Myrzakul", "Tolkynay", "" ], [ "Myrzakulov", "Ratbay", "" ] ]
In this paper, we consider a cosmological model of the flat and homogeneous universe for the Starobinsky model $F(R)=\alpha R + \beta R^{2}$, which is non-minimally coupled with f-essence. For this model we obtained the field equations and considered particular solutions of the coupling and fermionic field functions. It is shown that the fermionic field can describe a nature of the universe.
1710.01371
Merced Montesinos
Bogar Diaz, Merced Montesinos
Geometric Lagrangian approach to the physical degree of freedom count in field theory
It matches published version
J.Math.Phys.59:052901,2018
10.1063/1.5008740
null
gr-qc hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
To circumvent some technical difficulties faced by the geometric Lagrangian approach to the physical degree of freedom count presented in the work of Diaz, Higuita, and Montesinos, J. Math. Phys. 55, 122901 (2014) that prevent its direct implementation to field theory, in this paper, we slightly modify the geometric Lagrangian approach in such a way that its resulting version works perfectly for field theory (and for particle systems, of course). As in previous work, the current approach also allows us to directly get the Lagrangian constraints, a new Lagrangian formula for the counting of the number of physical degrees of freedom, the gauge transformations, and the number of first- and second-class constraints for any action principle based on a Lagrangian depending on the fields and their first derivatives without performing any Dirac's canonical analysis. An advantage of this approach over the previous work is that it also allows us to handle the reducibility of the constraints and to get the off-shell gauge transformations. The theoretical framework is illustrated in 3-dimensional generalized general relativity (Palatini and Witten's exotic actions), Chern-Simons theory, $4$-dimensional BF theory, and $4$-dimensional general relativity given by Palatini's action with cosmological constant.
[ { "created": "Tue, 3 Oct 2017 20:13:15 GMT", "version": "v1" }, { "created": "Thu, 17 May 2018 18:41:32 GMT", "version": "v2" } ]
2018-05-21
[ [ "Diaz", "Bogar", "" ], [ "Montesinos", "Merced", "" ] ]
To circumvent some technical difficulties faced by the geometric Lagrangian approach to the physical degree of freedom count presented in the work of Diaz, Higuita, and Montesinos, J. Math. Phys. 55, 122901 (2014) that prevent its direct implementation to field theory, in this paper, we slightly modify the geometric Lagrangian approach in such a way that its resulting version works perfectly for field theory (and for particle systems, of course). As in previous work, the current approach also allows us to directly get the Lagrangian constraints, a new Lagrangian formula for the counting of the number of physical degrees of freedom, the gauge transformations, and the number of first- and second-class constraints for any action principle based on a Lagrangian depending on the fields and their first derivatives without performing any Dirac's canonical analysis. An advantage of this approach over the previous work is that it also allows us to handle the reducibility of the constraints and to get the off-shell gauge transformations. The theoretical framework is illustrated in 3-dimensional generalized general relativity (Palatini and Witten's exotic actions), Chern-Simons theory, $4$-dimensional BF theory, and $4$-dimensional general relativity given by Palatini's action with cosmological constant.
gr-qc/9802067
A. Mikovic
J. Cruz, A. Mikovic and J. Navarro-Salas
Free Field Realization of Cylindrically Symmetric Einstein Gravity
8 pages, no figures, discussions on the dual metric and on the free-field expansion are added
Phys.Lett.B437:273-278,1998
10.1016/S0370-2693(98)00904-6
FTUV/98-21, IFIC/98-21
gr-qc hep-th
null
Cylindrically reduced Einstein gravity can be regarded as an $SL(2,R)/SO(2)$ sigma model coupled to 2D dilaton gravity. By using the corresponding 2D diffeomorphism algebra of constraints and the asymptotic behaviour of the Ernst equation we show that the theory can be mapped by a canonical transformation into a set of free fields with a Minkowskian target space. We briefly discuss the quantization in terms of these free-field variables, which is considerably simpler than in the other approaches.
[ { "created": "Fri, 27 Feb 1998 13:50:33 GMT", "version": "v1" }, { "created": "Mon, 2 Mar 1998 12:08:29 GMT", "version": "v2" }, { "created": "Fri, 29 May 1998 10:43:17 GMT", "version": "v3" } ]
2009-01-16
[ [ "Cruz", "J.", "" ], [ "Mikovic", "A.", "" ], [ "Navarro-Salas", "J.", "" ] ]
Cylindrically reduced Einstein gravity can be regarded as an $SL(2,R)/SO(2)$ sigma model coupled to 2D dilaton gravity. By using the corresponding 2D diffeomorphism algebra of constraints and the asymptotic behaviour of the Ernst equation we show that the theory can be mapped by a canonical transformation into a set of free fields with a Minkowskian target space. We briefly discuss the quantization in terms of these free-field variables, which is considerably simpler than in the other approaches.
gr-qc/9606025
Robert Mann
R.B. Mann and G. Papadopoulos
Killing spinors, the adS black hole and I(ISO(2,1)) gravity
12 pages, uses phyzzx
Phys.Rev.D55:2119-2123,1997
10.1103/PhysRevD.55.2119
DAMTP-96-29
gr-qc
null
We construct a supersymmetric extension of the $I\big(ISO(2,1)\big)$ Chern-Simons gravity and show that certain particle-like solutions and the adS black-hole solution of this theory are supersymmetric.
[ { "created": "Wed, 12 Jun 1996 21:14:15 GMT", "version": "v1" } ]
2009-06-09
[ [ "Mann", "R. B.", "" ], [ "Papadopoulos", "G.", "" ] ]
We construct a supersymmetric extension of the $I\big(ISO(2,1)\big)$ Chern-Simons gravity and show that certain particle-like solutions and the adS black-hole solution of this theory are supersymmetric.
gr-qc/9911076
Martin Rainer
Martin Rainer
Algebraic Quantum Theory on Manifolds: A Haag-Kastler Setting for Quantum Geometry
15 pages, Latex; v2: several corrections, in particular in def. 1 and in sec. 6
Class.Quant.Grav. 17 (2000) 1935-1947
10.1088/0264-9381/17/9/305
null
gr-qc
null
Motivated by the invariance of current representations of quantum gravity under diffeomorphisms much more general than isometries, the Haag-Kastler setting is extended to manifolds without metric background structure. First, the causal structure on a differentiable manifold M of arbitrary dimension (d+1>2) can be defined in purely topological terms, via cones (C-causality). Then, the general structure of a net of C*-algebras on a manifold M and its causal properties required for an algebraic quantum field theory can be described as an extension of the Haag-Kastler axiomatic framework. An important application is given with quantum geometry on a spatial slice within the causally exterior region of a topological horizon H, resulting in a net of Weyl algebras for states with an infinite number of intersection points of edges and transversal (d-1)-faces within any neighbourhood of the spatial boundary S^2.
[ { "created": "Fri, 19 Nov 1999 19:39:46 GMT", "version": "v1" }, { "created": "Wed, 16 Feb 2000 13:51:52 GMT", "version": "v2" }, { "created": "Tue, 14 Mar 2000 20:41:39 GMT", "version": "v3" } ]
2009-10-31
[ [ "Rainer", "Martin", "" ] ]
Motivated by the invariance of current representations of quantum gravity under diffeomorphisms much more general than isometries, the Haag-Kastler setting is extended to manifolds without metric background structure. First, the causal structure on a differentiable manifold M of arbitrary dimension (d+1>2) can be defined in purely topological terms, via cones (C-causality). Then, the general structure of a net of C*-algebras on a manifold M and its causal properties required for an algebraic quantum field theory can be described as an extension of the Haag-Kastler axiomatic framework. An important application is given with quantum geometry on a spatial slice within the causally exterior region of a topological horizon H, resulting in a net of Weyl algebras for states with an infinite number of intersection points of edges and transversal (d-1)-faces within any neighbourhood of the spatial boundary S^2.
1607.03478
Sergio Vitorino Borba Gon\c{c}alves
F. G. Alvarenga, R. Fracalossi, R. C. Freitas and S. V. B. Gon\c{c}alves
Classical and quantum cosmology with two perfect fluids: stiff matter and radiation
17 pages and 21 figures
null
10.1007/s10714-017-2301-0
null
gr-qc astro-ph.CO hep-th
http://creativecommons.org/publicdomain/zero/1.0/
In this work the homogeneous and isotropic Universe of Friedmann-Robertson-Walker is studied in the presence of two fluids: stiff matter and radiation described by the Schutz's formalism. We obtain to the classic case the behaviour of the scale factor of the universe. For the quantum case the wave packets are constructed and the wave function of the universe is found.
[ { "created": "Tue, 12 Jul 2016 19:47:13 GMT", "version": "v1" } ]
2017-10-18
[ [ "Alvarenga", "F. G.", "" ], [ "Fracalossi", "R.", "" ], [ "Freitas", "R. C.", "" ], [ "Gonçalves", "S. V. B.", "" ] ]
In this work the homogeneous and isotropic Universe of Friedmann-Robertson-Walker is studied in the presence of two fluids: stiff matter and radiation described by the Schutz's formalism. We obtain to the classic case the behaviour of the scale factor of the universe. For the quantum case the wave packets are constructed and the wave function of the universe is found.
1002.2056
Peter Dunsby
Anne Marie Nzioki, Peter K. S. Dunsby, Rituparno Goswami and Sante Carloni
A Geometrical Approach to Strong Gravitational Lensing in f(R) Gravity
9 pages
Phys.Rev.D83:024030,2011
10.1103/PhysRevD.83.024030
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a framework for the study of lensing in spherically symmetric spacetimes within the context of f(R) gravity. Equations for the propagation of null geodesics, together with an expression for the bending angle are derived for any f(R) theory and then applied to an exact spherically symmetric solution of R^n gravity. We find that for this case more bending is expected for R^n gravity theories in comparison to GR and is dependent on the value of n and the value of distance of closest approach of the incident null geodesic.
[ { "created": "Wed, 10 Feb 2010 10:11:16 GMT", "version": "v1" } ]
2011-02-25
[ [ "Nzioki", "Anne Marie", "" ], [ "Dunsby", "Peter K. S.", "" ], [ "Goswami", "Rituparno", "" ], [ "Carloni", "Sante", "" ] ]
We present a framework for the study of lensing in spherically symmetric spacetimes within the context of f(R) gravity. Equations for the propagation of null geodesics, together with an expression for the bending angle are derived for any f(R) theory and then applied to an exact spherically symmetric solution of R^n gravity. We find that for this case more bending is expected for R^n gravity theories in comparison to GR and is dependent on the value of n and the value of distance of closest approach of the incident null geodesic.
gr-qc/9908029
Matt Visser
Carlos Barcelo (Washington University) and Matt Visser (Washington University)
Traversable wormholes from massless conformally coupled scalar fields
11 Pages, plain LaTeX2e, uses graphics.sty, three *.eps figures
Phys.Lett.B466:127-134,1999
10.1016/S0370-2693(99)01117-X
null
gr-qc hep-th
null
The massless conformally coupled scalar field is characterized by the so-called "new improved stress-energy tensor", which is capable of classically violating the null energy condition. When coupled to Einstein gravity we find a three-parameter class of exact solutions. These exact solutions include the Schwarzschild geometry, assorted naked singularities, and a large class of traversable wormholes.
[ { "created": "Mon, 9 Aug 1999 18:04:19 GMT", "version": "v1" } ]
2008-11-26
[ [ "Barcelo", "Carlos", "", "Washington University" ], [ "Visser", "Matt", "", "Washington\n University" ] ]
The massless conformally coupled scalar field is characterized by the so-called "new improved stress-energy tensor", which is capable of classically violating the null energy condition. When coupled to Einstein gravity we find a three-parameter class of exact solutions. These exact solutions include the Schwarzschild geometry, assorted naked singularities, and a large class of traversable wormholes.
2108.07454
Ayan Banerjee
Juan M. Z. Pretel, Ayan Banerjee and Anirudh Pradhan
Electrically Charged Quark Stars in $4D$ Einstein-Gauss-Bonnet Gravity
10 pages, 5 figures, 2 tables, accepted for publication in European Physical Journal C
Eur. Phys. J. C 82 (2022) 180
10.1140/epjc/s10052-022-10123-4
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we study the properties of compact spheres made of a charged perfect fluid with a MIT bag model EoS for quark matter. Considering static spherically symmetric spacetime we derive the hydrostatic equilibrium equations in the recently formulated four dimensional Einstein-Gauss-Bonnet ($4D$ EGB) gravity theory. In this setting, the modified TOV equations are solved numerically with the aim to investigate the impact of electric charge on the stellar structure. A nice feature of $4D$ EGB theory is that the Gauss-Bonnet term has a non-vanishing contribution to the gravitational dynamics in $4D$ spacetime. We therefore analyse the effects of Gauss-Bonnet coupling constant $\alpha$ and the charge fraction $\beta$ on the mass-radius ($M-R$) diagram and also the mass-central density $(M-\rho_c)$ relation of quark stars. Finally, we conclude that depending on the choice of coupling constant one could have larger mass and radius compared with GR and can also be relevant for more massive compact objects due to the effect of the repulsive Coulomb force.
[ { "created": "Tue, 17 Aug 2021 06:09:24 GMT", "version": "v1" }, { "created": "Wed, 25 Aug 2021 06:21:50 GMT", "version": "v2" }, { "created": "Sun, 13 Feb 2022 16:25:00 GMT", "version": "v3" } ]
2022-03-01
[ [ "Pretel", "Juan M. Z.", "" ], [ "Banerjee", "Ayan", "" ], [ "Pradhan", "Anirudh", "" ] ]
In this work we study the properties of compact spheres made of a charged perfect fluid with a MIT bag model EoS for quark matter. Considering static spherically symmetric spacetime we derive the hydrostatic equilibrium equations in the recently formulated four dimensional Einstein-Gauss-Bonnet ($4D$ EGB) gravity theory. In this setting, the modified TOV equations are solved numerically with the aim to investigate the impact of electric charge on the stellar structure. A nice feature of $4D$ EGB theory is that the Gauss-Bonnet term has a non-vanishing contribution to the gravitational dynamics in $4D$ spacetime. We therefore analyse the effects of Gauss-Bonnet coupling constant $\alpha$ and the charge fraction $\beta$ on the mass-radius ($M-R$) diagram and also the mass-central density $(M-\rho_c)$ relation of quark stars. Finally, we conclude that depending on the choice of coupling constant one could have larger mass and radius compared with GR and can also be relevant for more massive compact objects due to the effect of the repulsive Coulomb force.
1508.06786
Boris Bolliet
Susanne Schander, Aur\'elien Barrau, Boris Bolliet, Julien Grain, Linda Linsefors, Jakub Mielczarek
Primordial scalar power spectrum from the Euclidean Big Bounce
13 pages, 4 figures
Phys. Rev. D 93, 023531 (2016)
10.1103/PhysRevD.93.023531
null
gr-qc astro-ph.CO hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In effective models of loop quantum cosmology, the holonomy corrections are associated with deformations of space-time symmetries. The most evident manifestation of the deformations is the emergence of an Euclidean phase accompanying the non-singular bouncing dynamics of the scale factor. In this article, we compute the power spectrum of scalar perturbations generated in this model, with a massive scalar field as the matter content. Instantaneous and adiabatic vacuum-type initial conditions for scalar perturbations are imposed in the contracting phase. The evolution through the Euclidean region is calculated based on the extrapolation of the time direction pointed by the vectors normal to the Cauchy hypersurface in the Lorentzian domains. The obtained power spectrum is characterized by a suppression in the IR regime and oscillations in the intermediate energy range. Furthermore, the speculative extension of the analysis in the UV reveals a specific rise of the power.
[ { "created": "Thu, 27 Aug 2015 10:00:11 GMT", "version": "v1" }, { "created": "Wed, 7 Oct 2015 07:20:18 GMT", "version": "v2" }, { "created": "Fri, 15 Jan 2016 11:54:53 GMT", "version": "v3" } ]
2016-02-03
[ [ "Schander", "Susanne", "" ], [ "Barrau", "Aurélien", "" ], [ "Bolliet", "Boris", "" ], [ "Grain", "Julien", "" ], [ "Linsefors", "Linda", "" ], [ "Mielczarek", "Jakub", "" ] ]
In effective models of loop quantum cosmology, the holonomy corrections are associated with deformations of space-time symmetries. The most evident manifestation of the deformations is the emergence of an Euclidean phase accompanying the non-singular bouncing dynamics of the scale factor. In this article, we compute the power spectrum of scalar perturbations generated in this model, with a massive scalar field as the matter content. Instantaneous and adiabatic vacuum-type initial conditions for scalar perturbations are imposed in the contracting phase. The evolution through the Euclidean region is calculated based on the extrapolation of the time direction pointed by the vectors normal to the Cauchy hypersurface in the Lorentzian domains. The obtained power spectrum is characterized by a suppression in the IR regime and oscillations in the intermediate energy range. Furthermore, the speculative extension of the analysis in the UV reveals a specific rise of the power.
1812.11291
Arun Mathew
Arun Mathew and Malay K. Nandy
Prospect of Chandrasekhar's limit against modified dispersion relation
null
null
10.1007/s10714-020-02686-y
null
gr-qc astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Newtonian gravity predicts the existence of white dwarfs with masses far exceeding the Chandrasekhar limit when the equation of state of the degenerate electron gas incorporates the effect of quantum spacetime fluctuations (via a modified dispersion relation) even when the strength of the fluctuations is taken to be very small. In this paper, we show that this Newtonian "super-stability" does not hold true when the gravity is treated in the general relativistic framework. Employing dynamical instability analysis, we find that the Chandrasekhar limit can be reassured even for a range of high strengths of quantum spacetime fluctuations with the onset density for gravitational collapse practically remaining unaffected.
[ { "created": "Sat, 29 Dec 2018 05:44:43 GMT", "version": "v1" }, { "created": "Wed, 9 Jan 2019 04:39:12 GMT", "version": "v2" }, { "created": "Thu, 8 Aug 2019 12:08:47 GMT", "version": "v3" } ]
2020-04-23
[ [ "Mathew", "Arun", "" ], [ "Nandy", "Malay K.", "" ] ]
Newtonian gravity predicts the existence of white dwarfs with masses far exceeding the Chandrasekhar limit when the equation of state of the degenerate electron gas incorporates the effect of quantum spacetime fluctuations (via a modified dispersion relation) even when the strength of the fluctuations is taken to be very small. In this paper, we show that this Newtonian "super-stability" does not hold true when the gravity is treated in the general relativistic framework. Employing dynamical instability analysis, we find that the Chandrasekhar limit can be reassured even for a range of high strengths of quantum spacetime fluctuations with the onset density for gravitational collapse practically remaining unaffected.
gr-qc/9701051
Dorje C. Brody
Dorje C. Brody (ADMTP) and Lane P. Hughston (Merrill Lynch)
Statistical Geometry in Quantum Mechanics
32 pages, LaTex file, Extended version to include quantum measurement theory
null
10.1098/rspa.1998.0266
null
gr-qc
null
A statistical model M is a family of probability distributions, characterised by a set of continuous parameters known as the parameter space. This possesses natural geometrical properties induced by the embedding of the family of probability distributions into the Hilbert space H. By consideration of the square-root density function we can regard M as a submanifold of the unit sphere in H. Therefore, H embodies the `state space' of the probability distributions, and the geometry of M can be described in terms of the embedding of in H. The geometry in question is characterised by a natural Riemannian metric (the Fisher-Rao metric), thus allowing us to formulate the principles of classical statistical inference in a natural geometric setting. In particular, we focus attention on the variance lower bounds for statistical estimation, and establish generalisations of the classical Cramer-Rao and Bhattacharyya inequalities. The statistical model M is then specialised to the case of a submanifold of the state space of a quantum mechanical system. This is pursued by introducing a compatible complex structure on the underlying real Hilbert space, which allows the operations of ordinary quantum mechanics to be reinterpreted in the language of real Hilbert space geometry. The application of generalised variance bounds in the case of quantum statistical estimation leads to a set of higher order corrections to the Heisenberg uncertainty relations for canonically conjugate observables.
[ { "created": "Thu, 23 Jan 1997 15:01:43 GMT", "version": "v1" }, { "created": "Wed, 22 Oct 1997 16:12:18 GMT", "version": "v2" } ]
2009-10-30
[ [ "Brody", "Dorje C.", "", "ADMTP" ], [ "Hughston", "Lane P.", "", "Merrill Lynch" ] ]
A statistical model M is a family of probability distributions, characterised by a set of continuous parameters known as the parameter space. This possesses natural geometrical properties induced by the embedding of the family of probability distributions into the Hilbert space H. By consideration of the square-root density function we can regard M as a submanifold of the unit sphere in H. Therefore, H embodies the `state space' of the probability distributions, and the geometry of M can be described in terms of the embedding of in H. The geometry in question is characterised by a natural Riemannian metric (the Fisher-Rao metric), thus allowing us to formulate the principles of classical statistical inference in a natural geometric setting. In particular, we focus attention on the variance lower bounds for statistical estimation, and establish generalisations of the classical Cramer-Rao and Bhattacharyya inequalities. The statistical model M is then specialised to the case of a submanifold of the state space of a quantum mechanical system. This is pursued by introducing a compatible complex structure on the underlying real Hilbert space, which allows the operations of ordinary quantum mechanics to be reinterpreted in the language of real Hilbert space geometry. The application of generalised variance bounds in the case of quantum statistical estimation leads to a set of higher order corrections to the Heisenberg uncertainty relations for canonically conjugate observables.
1007.1917
Arturo Stabile
A. Stabile
The most general fourth order theory of Gravity at low energy
7 pages, 2 figures
Phys.Rev.D82:124026,2010
10.1103/PhysRevD.82.124026
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Newtonian limit of the most general fourth order gravity is performed with metric approach in the Jordan frame with no gauge condition. The most general theory with fourth order differential equations is obtained by generalizing the $f(R)$ term in the action with a generic function containing other two curvature invariants: \emph{Ricci square} ($R_{\alpha\beta}R^{\alpha\beta}$) and \emph{Riemann square} ($R_{\alpha\beta\gamma\delta}R^{\alpha\beta\gamma\delta}$). The spherically symmetric solutions of metric tensor yet present Yukawa-like spatial behavior, but now one has two characteristic lengths. At Newtonian order any function of curvature invariants gives us the same outcome like the so-called \emph{Quadratic Lagrangian} of Gravity. From Gauss - Bonnet invariant one have the complete interpretation of solutions and the absence of a possible third characteristic length linked to Riemann square contribution. From analysis of metric potentials, generated by point-like source, one has a constraint condition on the derivatives of $f$ with respect to scalar invariants.
[ { "created": "Mon, 12 Jul 2010 14:44:14 GMT", "version": "v1" } ]
2010-12-28
[ [ "Stabile", "A.", "" ] ]
The Newtonian limit of the most general fourth order gravity is performed with metric approach in the Jordan frame with no gauge condition. The most general theory with fourth order differential equations is obtained by generalizing the $f(R)$ term in the action with a generic function containing other two curvature invariants: \emph{Ricci square} ($R_{\alpha\beta}R^{\alpha\beta}$) and \emph{Riemann square} ($R_{\alpha\beta\gamma\delta}R^{\alpha\beta\gamma\delta}$). The spherically symmetric solutions of metric tensor yet present Yukawa-like spatial behavior, but now one has two characteristic lengths. At Newtonian order any function of curvature invariants gives us the same outcome like the so-called \emph{Quadratic Lagrangian} of Gravity. From Gauss - Bonnet invariant one have the complete interpretation of solutions and the absence of a possible third characteristic length linked to Riemann square contribution. From analysis of metric potentials, generated by point-like source, one has a constraint condition on the derivatives of $f$ with respect to scalar invariants.
2101.12126
Marcel Ignacio Y\'a\~nez Reyes
Marco Rivera-Tapia and Marcel I. Y\'a\~nez Reyes and A. Delgado and G. Rubilar
Outperforming classical estimation of Post-Newtonian parameters of Earth's gravitational field using quantum metrology
25 pages, 14 Figures
null
null
null
gr-qc quant-ph
http://creativecommons.org/licenses/by/4.0/
The Hong-Ou-Mandel (HOM) effect is analyzed for photons in a modified Mach-Zehnder setup with two particles experiencing different gravitational potentials, which are later recombined using a beam-splitter. It is found that the HOM effect depends directly on the relativistic time dilation between the arms of the setup. This temporal dilation can be used to estimate the $\gamma$ and $\beta$ parameters of the parameterized post-Newtonian formalism. The uncertainty in the parameters $\gamma$ and $\beta$ are of the order $ 10^{-8}-10^{-12}$, depending on the quantum state employed.
[ { "created": "Thu, 28 Jan 2021 17:16:26 GMT", "version": "v1" } ]
2021-01-29
[ [ "Rivera-Tapia", "Marco", "" ], [ "Reyes", "Marcel I. Yáñez", "" ], [ "Delgado", "A.", "" ], [ "Rubilar", "G.", "" ] ]
The Hong-Ou-Mandel (HOM) effect is analyzed for photons in a modified Mach-Zehnder setup with two particles experiencing different gravitational potentials, which are later recombined using a beam-splitter. It is found that the HOM effect depends directly on the relativistic time dilation between the arms of the setup. This temporal dilation can be used to estimate the $\gamma$ and $\beta$ parameters of the parameterized post-Newtonian formalism. The uncertainty in the parameters $\gamma$ and $\beta$ are of the order $ 10^{-8}-10^{-12}$, depending on the quantum state employed.
0803.1629
Orchidea Maria Lecian
O.M. Lecian, G. Montani
Fundamental Symmetries of the extended Spacetime
4 pages, to appear in Proceedings of the II Stueckelberg Workshop - Int. J. Mod. Phys. A
Int.J.Mod.Phys.A23:1266-1269,2008
10.1142/S0217751X08040196
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
On the basis of Fourier duality and Stone-von Neumann theorem, we will examine polymer-quantization techniques and modified uncertainty relations as possible 1-extraD compactification schemes for a phenomenological truncation of the extraD tower.
[ { "created": "Tue, 11 Mar 2008 16:34:30 GMT", "version": "v1" } ]
2008-11-26
[ [ "Lecian", "O. M.", "" ], [ "Montani", "G.", "" ] ]
On the basis of Fourier duality and Stone-von Neumann theorem, we will examine polymer-quantization techniques and modified uncertainty relations as possible 1-extraD compactification schemes for a phenomenological truncation of the extraD tower.
0711.0150
Slava G. Turyshev
S.G. Turyshev, U.E. Israelsson, M. Shao, N. Yu, A. Kusenko, E.L. Wright, C.W.F. Everitt, M.A. Kasevich, J.A. Lipa, J.C. Mester, R.D. Reasenberg, R.L. Walsworth, N. Ashby, H. Gould, H.-J.Paik
Space-based research in fundamental physics and quantum technologies
a white paper, revtex, 27 pages, updated bibliography
Int.J.Mod.Phys.D16:1879-1925,2008
10.1142/S0218271807011760
null
gr-qc astro-ph hep-ph physics.space-ph
null
Space-based experiments today can uniquely address important questions related to the fundamental laws of Nature. In particular, high-accuracy physics experiments in space can test relativistic gravity and probe the physics beyond the Standard Model; they can perform direct detection of gravitational waves and are naturally suited for precision investigations in cosmology and astroparticle physics. In addition, atomic physics has recently shown substantial progress in the development of optical clocks and atom interferometers. If placed in space, these instruments could turn into powerful high-resolution quantum sensors greatly benefiting fundamental physics. We discuss the current status of space-based research in fundamental physics, its discovery potential, and its importance for modern science. We offer a set of recommendations to be considered by the upcoming National Academy of Sciences' Decadal Survey in Astronomy and Astrophysics. In our opinion, the Decadal Survey should include space-based research in fundamental physics as one of its focus areas. We recommend establishing an Astronomy and Astrophysics Advisory Committee's interagency ``Fundamental Physics Task Force'' to assess the status of both ground- and space-based efforts in the field, to identify the most important objectives, and to suggest the best ways to organize the work of several federal agencies involved. We also recommend establishing a new NASA-led interagency program in fundamental physics that will consolidate new technologies, prepare key instruments for future space missions, and build a strong scientific and engineering community. Our goal is to expand NASA's science objectives in space by including ``laboratory research in fundamental physics'' as an element in agency's ongoing space research efforts.
[ { "created": "Thu, 1 Nov 2007 19:34:10 GMT", "version": "v1" }, { "created": "Mon, 10 Dec 2007 21:18:30 GMT", "version": "v2" }, { "created": "Tue, 4 Mar 2008 02:22:48 GMT", "version": "v3" } ]
2011-04-11
[ [ "Turyshev", "S. G.", "" ], [ "Israelsson", "U. E.", "" ], [ "Shao", "M.", "" ], [ "Yu", "N.", "" ], [ "Kusenko", "A.", "" ], [ "Wright", "E. L.", "" ], [ "Everitt", "C. W. F.", "" ], [ "Kasevich", "M. A.", "" ], [ "Lipa", "J. A.", "" ], [ "Mester", "J. C.", "" ], [ "Reasenberg", "R. D.", "" ], [ "Walsworth", "R. L.", "" ], [ "Ashby", "N.", "" ], [ "Gould", "H.", "" ], [ "Paik", "H. -J.", "" ] ]
Space-based experiments today can uniquely address important questions related to the fundamental laws of Nature. In particular, high-accuracy physics experiments in space can test relativistic gravity and probe the physics beyond the Standard Model; they can perform direct detection of gravitational waves and are naturally suited for precision investigations in cosmology and astroparticle physics. In addition, atomic physics has recently shown substantial progress in the development of optical clocks and atom interferometers. If placed in space, these instruments could turn into powerful high-resolution quantum sensors greatly benefiting fundamental physics. We discuss the current status of space-based research in fundamental physics, its discovery potential, and its importance for modern science. We offer a set of recommendations to be considered by the upcoming National Academy of Sciences' Decadal Survey in Astronomy and Astrophysics. In our opinion, the Decadal Survey should include space-based research in fundamental physics as one of its focus areas. We recommend establishing an Astronomy and Astrophysics Advisory Committee's interagency ``Fundamental Physics Task Force'' to assess the status of both ground- and space-based efforts in the field, to identify the most important objectives, and to suggest the best ways to organize the work of several federal agencies involved. We also recommend establishing a new NASA-led interagency program in fundamental physics that will consolidate new technologies, prepare key instruments for future space missions, and build a strong scientific and engineering community. Our goal is to expand NASA's science objectives in space by including ``laboratory research in fundamental physics'' as an element in agency's ongoing space research efforts.
gr-qc/0105060
null
Sergei M. Kopeikin (Department of Physics and Astronomy, University of Missouri-Columbia)
Testing Relativistic Effect of Propagation of Gravity by Very-Long Baseline Interferometry
11 pages, accepted to ApJ Letters
Astrophys.J.556:L1-L6,2001
10.1086/322872
null
gr-qc astro-ph hep-ph hep-th physics.space-ph
null
It is shown that the finite speed of gravity affects very-long baseline interferometric observations of quasars during the time of their line-of-sight close angular encounter with Jupiter. The next such event will take place in 2002, September 8. The present Letter suggests a new experimental test of general relativity in which the effect of propagation of gravity can be directly measured by very-long baseline interferometry as an excess time delay in addition to the logarithmic Shapiro time delay (Shapiro, I. I., 1964, Phys. Rev. Lett., 13, 789).
[ { "created": "Thu, 17 May 2001 16:07:36 GMT", "version": "v1" }, { "created": "Thu, 7 Jun 2001 23:16:47 GMT", "version": "v2" } ]
2014-11-17
[ [ "Kopeikin", "Sergei M.", "", "Department of Physics and Astronomy, University of\n Missouri-Columbia" ] ]
It is shown that the finite speed of gravity affects very-long baseline interferometric observations of quasars during the time of their line-of-sight close angular encounter with Jupiter. The next such event will take place in 2002, September 8. The present Letter suggests a new experimental test of general relativity in which the effect of propagation of gravity can be directly measured by very-long baseline interferometry as an excess time delay in addition to the logarithmic Shapiro time delay (Shapiro, I. I., 1964, Phys. Rev. Lett., 13, 789).
1211.7026
Subenoy Chakraborty
Subenoy Chakraborty
Generalized Bekenstein-Hawking system: Logarithmic Correction
10 pages
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The present work is a generalization of the recent work [arXiv: 1206.1420] on the modified Hawking temperature on the event horizon. Here the Hawking temperature is generalized by multiplying the modified Hawking temperature by a variable parameter \alpha representing the ratio of the growth rate of the apparent horizon to the event horizon. It is found that both the first and the generalized second law of thermodynamics are valid on the event horizon for any fluid distribution. Subsequently, Bekenstein entropy is modified on the event horizon and thermodynamical laws are examined. Finally, interpretation of the parameters involved has been presented.
[ { "created": "Mon, 26 Nov 2012 12:32:20 GMT", "version": "v1" }, { "created": "Wed, 23 Apr 2014 12:25:20 GMT", "version": "v2" } ]
2014-04-24
[ [ "Chakraborty", "Subenoy", "" ] ]
The present work is a generalization of the recent work [arXiv: 1206.1420] on the modified Hawking temperature on the event horizon. Here the Hawking temperature is generalized by multiplying the modified Hawking temperature by a variable parameter \alpha representing the ratio of the growth rate of the apparent horizon to the event horizon. It is found that both the first and the generalized second law of thermodynamics are valid on the event horizon for any fluid distribution. Subsequently, Bekenstein entropy is modified on the event horizon and thermodynamical laws are examined. Finally, interpretation of the parameters involved has been presented.
2305.19819
Yongqiang Wang
Peng-Bo Ding, Tian-Xiang Ma, Yong-Qiang Wang
Study of Boson Stars with Wormhole
23 pages, 17 figures
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we reconsider the mixed system of BSs with wormholes at their center which performed by complex scalar field and phantom field and study a whole new condition about the potential. Both the symmetric and asymmetric solutions in the two asymptotically flat regions are obtained by using numerical method and we mainly explore the change of the results by varying the parameters of throats and potential. In ground state, we find there are multiple solutions at certain setting of parameters and with the increase of $\eta_0$ or decrease of $c$, the results gradually become single-valued functions and these two variables have similar influence to the curve shape of mass $M$ and charge $Q$, furthermore, the asymmetric solutions can turn into the solutions of symmetry at some frequency $\omega$ in certain $\eta_0$ and $c$. However, when it comes to excited state, the properties of solutions of symmetry is similar to the ground state while asymmetrical results exhibit altered characteristics. We also present the geometries of wormhole to investigate the property of this model.
[ { "created": "Wed, 31 May 2023 13:02:09 GMT", "version": "v1" } ]
2023-06-01
[ [ "Ding", "Peng-Bo", "" ], [ "Ma", "Tian-Xiang", "" ], [ "Wang", "Yong-Qiang", "" ] ]
In this paper, we reconsider the mixed system of BSs with wormholes at their center which performed by complex scalar field and phantom field and study a whole new condition about the potential. Both the symmetric and asymmetric solutions in the two asymptotically flat regions are obtained by using numerical method and we mainly explore the change of the results by varying the parameters of throats and potential. In ground state, we find there are multiple solutions at certain setting of parameters and with the increase of $\eta_0$ or decrease of $c$, the results gradually become single-valued functions and these two variables have similar influence to the curve shape of mass $M$ and charge $Q$, furthermore, the asymmetric solutions can turn into the solutions of symmetry at some frequency $\omega$ in certain $\eta_0$ and $c$. However, when it comes to excited state, the properties of solutions of symmetry is similar to the ground state while asymmetrical results exhibit altered characteristics. We also present the geometries of wormhole to investigate the property of this model.
2110.07411
Jaroslav Vrba
Zden\v{e}k Stuchl\'ik and Jaroslav Vrba
Supermassive black holes surrounded by dark matter modeled as anisotropic fluid: epicyclic oscillations and their fitting to observed QPOs
19 pages, 9 figures, 2 tables
null
10.1088/1475-7516/2021/11/059
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently introduced exact solution of the Einstein gravity coupled minimally to an anisotropic fluid representing dark matter can well represent supermassive black holes in galactic nuclei with realistic distribution of dark matter around the black hole, given by the Hernquist-like density distribution. For these fluid-hairy black hole spacetimes, properties of the gravitational radiation, quasinormal ringing, and optical phenomena were studied, giving interesting results. Here, using the range of physical parameters of these spacetimes allowing for their relevance in astrophysics, we study the epicyclic oscillatory motion of test particles in these spacetimes. The frequencies of the orbital and epicyclic motion are applied in the epicyclic resonance variant of the geodesic model of quasiperiodic oscillations (QPOs) observed in active galactic nuclei to demonstrate the possibility to solve the cases where the standard vacuum black hole spacetimes are not allowing for explanation of the observed data. We demonstrate that the geodesic model can explain the QPOs observed in most of the active galactic nuclei for the fluid-hairy black holes with reasonable halo parameters.
[ { "created": "Thu, 14 Oct 2021 14:42:43 GMT", "version": "v1" } ]
2021-12-08
[ [ "Stuchlík", "Zdeněk", "" ], [ "Vrba", "Jaroslav", "" ] ]
Recently introduced exact solution of the Einstein gravity coupled minimally to an anisotropic fluid representing dark matter can well represent supermassive black holes in galactic nuclei with realistic distribution of dark matter around the black hole, given by the Hernquist-like density distribution. For these fluid-hairy black hole spacetimes, properties of the gravitational radiation, quasinormal ringing, and optical phenomena were studied, giving interesting results. Here, using the range of physical parameters of these spacetimes allowing for their relevance in astrophysics, we study the epicyclic oscillatory motion of test particles in these spacetimes. The frequencies of the orbital and epicyclic motion are applied in the epicyclic resonance variant of the geodesic model of quasiperiodic oscillations (QPOs) observed in active galactic nuclei to demonstrate the possibility to solve the cases where the standard vacuum black hole spacetimes are not allowing for explanation of the observed data. We demonstrate that the geodesic model can explain the QPOs observed in most of the active galactic nuclei for the fluid-hairy black holes with reasonable halo parameters.
2307.04444
Yu Zhang
Qian Li, Yu Zhang, Zhi-Wen Lin, Qi-Quan Li, Qi Sun
Weak gravitational lensing by an ESTGB black hole in the presence of a plasma
24 pages, 15 figures
Modern Physics Letters A Vol. 38, No. 04, 2350025 (2023)
10.1142/S0217732323500256
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper is devoted to studying the weak-field gravitational lensing properties of a 4D ESTGB black hole, which is surrounded by the plasma medium. The effects of the magnetic charges and the three plasma distribution models in the deflection of light around a 4D ESTGB black hole are investigated in detail. We find that the uniform plasma leads to a larger deflection of light rays in comparison with the singular isothermal sphere (SIS), the non-singular isothermal sphere (NSIS) models. Moreover, the deflection angle increases slightly as the absolute value of the magnetic charge decreases. Finally, we analyze the total magnification of image due to weak gravitational lensing around the black hole. The result shows that the presence of a uniform plasma medium remarkably enhances the total magnification whereas the non-uniform plasma reduces the total magnification.
[ { "created": "Mon, 10 Jul 2023 09:53:13 GMT", "version": "v1" } ]
2023-07-11
[ [ "Li", "Qian", "" ], [ "Zhang", "Yu", "" ], [ "Lin", "Zhi-Wen", "" ], [ "Li", "Qi-Quan", "" ], [ "Sun", "Qi", "" ] ]
This paper is devoted to studying the weak-field gravitational lensing properties of a 4D ESTGB black hole, which is surrounded by the plasma medium. The effects of the magnetic charges and the three plasma distribution models in the deflection of light around a 4D ESTGB black hole are investigated in detail. We find that the uniform plasma leads to a larger deflection of light rays in comparison with the singular isothermal sphere (SIS), the non-singular isothermal sphere (NSIS) models. Moreover, the deflection angle increases slightly as the absolute value of the magnetic charge decreases. Finally, we analyze the total magnification of image due to weak gravitational lensing around the black hole. The result shows that the presence of a uniform plasma medium remarkably enhances the total magnification whereas the non-uniform plasma reduces the total magnification.
1903.11066
T. P. Singh
Shounak De, Tejinder P. Singh, Abhinav Varma
Quantum gravity as an emergent phenomenon
8 pages, 1 figure, Essay written for the Gravity Research Foundation 2019 Awards for Essays on Gravitation. arXiv admin note: substantial text overlap with arXiv:1903.05402; v2: this essay is a significantly condensed version of arXiv:1903.05402, Ref. 2 updated, Honorable Mention, to appear in Int. J. Mod. Phys
null
10.1142/S0218271819440036
null
gr-qc hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
There ought to exist a reformulation of quantum theory which does not depend on classical time. To achieve such a reformulation, we introduce the concept of an atom of space-time-matter (STM). An STM atom is a classical non-commutative geometry, based on an asymmetric metric, and sourced by a closed string. Different such atoms interact via entanglement. The statistical thermodynamics of a large number of such atoms gives rise, at equilibrium, to a theory of quantum gravity. Far from equilibrium, where statistical fluctuations are large, the emergent theory reduces to classical general relativity. In this theory, classical black holes are far-from-equilibrium low entropy states, and their Hawking evaporation represents an attempt to return to the (maximum entropy) equilibrium quantum gravitational state.
[ { "created": "Tue, 26 Mar 2019 16:42:22 GMT", "version": "v1" }, { "created": "Wed, 22 May 2019 04:29:23 GMT", "version": "v2" } ]
2019-07-17
[ [ "De", "Shounak", "" ], [ "Singh", "Tejinder P.", "" ], [ "Varma", "Abhinav", "" ] ]
There ought to exist a reformulation of quantum theory which does not depend on classical time. To achieve such a reformulation, we introduce the concept of an atom of space-time-matter (STM). An STM atom is a classical non-commutative geometry, based on an asymmetric metric, and sourced by a closed string. Different such atoms interact via entanglement. The statistical thermodynamics of a large number of such atoms gives rise, at equilibrium, to a theory of quantum gravity. Far from equilibrium, where statistical fluctuations are large, the emergent theory reduces to classical general relativity. In this theory, classical black holes are far-from-equilibrium low entropy states, and their Hawking evaporation represents an attempt to return to the (maximum entropy) equilibrium quantum gravitational state.
2303.06115
William Barker Dr
A. N. Lasenby and M. P. Hobson and W. E. V. Barker
Gravitomagnetism and galaxy rotation curves: a cautionary tale
Minor textual changes
null
null
null
gr-qc astro-ph.GA
http://creativecommons.org/licenses/by/4.0/
We investigate recent claims that gravitomagnetic effects in linearised general relativity can explain flat and rising rotation curves, such as those observed in galaxies, without the need for dark matter. If one models a galaxy as an axisymmetric, stationary, rotating, non-relativistic and pressureless 'dust' of stars in the gravitoelectromagnetic (GEM) formalism, we show that GEM effects on the circular velocity $v$ of a star are $O(10^{-6})$ smaller than the standard Newtonian (gravitoelectric) effects. Moreover, we find that gravitomagnetic effects are $O(10^{-6})$ too small to provide the vertical support necessary to maintain the dynamical equilibrium assumed. These issues are obscured if one constructs a single equation for $v$, as considered previously. We nevertheless solve this equation for a galaxy having a Miyamoto--Nagai density profile. We show that for the values of the mass, $M$, and semi-major and semi-minor axes, $a$ and $b$, typical for a dwarf galaxy, the rotation curve depends only very weakly on $M$. Moreover, for aspect ratios $a/b > 2$, the rotation curves are concave over their entire range, which does not match observations in any galaxy. Most importantly, we show that for the poloidal gravitomagnetic flux $\psi$ to provide the necessary vertical support, it must become singular at the origin. This originates from the unwitting, but forbidden, inclusion of free-space solutions of the Poisson-like equation that determines $\psi$, hence ruling out the methodology as a means of explaining flat galaxy rotation curves. We further show that recent deliberate attempts to leverage such free-space solutions against the rotation curve problem yield no deterministic modification outside the thin disk approximation, and that, in any case, the homogeneous contributions to $\psi$ are ruled out by the boundary value problem posed by any physical axisymmetric galaxy.
[ { "created": "Fri, 10 Mar 2023 18:04:36 GMT", "version": "v1" }, { "created": "Tue, 11 Apr 2023 20:44:30 GMT", "version": "v2" } ]
2023-04-13
[ [ "Lasenby", "A. N.", "" ], [ "Hobson", "M. P.", "" ], [ "Barker", "W. E. V.", "" ] ]
We investigate recent claims that gravitomagnetic effects in linearised general relativity can explain flat and rising rotation curves, such as those observed in galaxies, without the need for dark matter. If one models a galaxy as an axisymmetric, stationary, rotating, non-relativistic and pressureless 'dust' of stars in the gravitoelectromagnetic (GEM) formalism, we show that GEM effects on the circular velocity $v$ of a star are $O(10^{-6})$ smaller than the standard Newtonian (gravitoelectric) effects. Moreover, we find that gravitomagnetic effects are $O(10^{-6})$ too small to provide the vertical support necessary to maintain the dynamical equilibrium assumed. These issues are obscured if one constructs a single equation for $v$, as considered previously. We nevertheless solve this equation for a galaxy having a Miyamoto--Nagai density profile. We show that for the values of the mass, $M$, and semi-major and semi-minor axes, $a$ and $b$, typical for a dwarf galaxy, the rotation curve depends only very weakly on $M$. Moreover, for aspect ratios $a/b > 2$, the rotation curves are concave over their entire range, which does not match observations in any galaxy. Most importantly, we show that for the poloidal gravitomagnetic flux $\psi$ to provide the necessary vertical support, it must become singular at the origin. This originates from the unwitting, but forbidden, inclusion of free-space solutions of the Poisson-like equation that determines $\psi$, hence ruling out the methodology as a means of explaining flat galaxy rotation curves. We further show that recent deliberate attempts to leverage such free-space solutions against the rotation curve problem yield no deterministic modification outside the thin disk approximation, and that, in any case, the homogeneous contributions to $\psi$ are ruled out by the boundary value problem posed by any physical axisymmetric galaxy.
2112.13860
Kristina Giesel
Kristina Giesel, Bao-Fei Li, Parampreet Singh, Stefan Andreas Weigl
On consistent gauge fixing conditions in polymerized gravitational systems
Minor correction of the third assumption in Corollaries 1 and 2 from published version in PRD, 31 pages
Phys. Rev. D 105, 066023 2022
10.1103/PhysRevD.105.066023
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For classical gravitational systems the lapse function and the shift vector are usually determined by imposing appropriate gauge fixing conditions and then demanding their preservation with respect to the dynamics generated by a canonical Hamiltonian. Effective descriptions encoding quantum geometric effects motivated by loop quantum gravity for symmetry reduced models are often captured by polymerization of connection (or related) variables in gauge fixing conditions as well as constraints. Usually, one chooses the same form of polymerization in both cases. A pertinent question is if the dynamical stability of the effective gauge fixing conditions under the effective dynamics generated by the polymerized canonical Hamiltonian is provided by the lapse function and the shift vector obtained from the polymerization of their classical counterparts. If this is the case, then we say that gauge fixing and polymerization commute. In this manuscript we investigate these issues and obtain consistency conditions for the commutativity of gauge fixing and polymerization. Our analysis shows that such a commutativity occurs in rather special situations and reveals pitfalls in making seemingly well motivated choices which turn out to be inconsistent with the effective dynamics. We illustrate these findings via examples of symmetry reduced models in the loop quantization of the Schwarzschild interior and Lema\^{\i}tre-Tolman-Bondi (LTB) spacetimes and report the non-commutativity of gauge fixing and polymerization, and inherent limitations of some choices made in the literature with a consistent effective dynamics.
[ { "created": "Mon, 27 Dec 2021 19:00:06 GMT", "version": "v1" }, { "created": "Fri, 8 Apr 2022 09:29:44 GMT", "version": "v2" } ]
2022-04-11
[ [ "Giesel", "Kristina", "" ], [ "Li", "Bao-Fei", "" ], [ "Singh", "Parampreet", "" ], [ "Weigl", "Stefan Andreas", "" ] ]
For classical gravitational systems the lapse function and the shift vector are usually determined by imposing appropriate gauge fixing conditions and then demanding their preservation with respect to the dynamics generated by a canonical Hamiltonian. Effective descriptions encoding quantum geometric effects motivated by loop quantum gravity for symmetry reduced models are often captured by polymerization of connection (or related) variables in gauge fixing conditions as well as constraints. Usually, one chooses the same form of polymerization in both cases. A pertinent question is if the dynamical stability of the effective gauge fixing conditions under the effective dynamics generated by the polymerized canonical Hamiltonian is provided by the lapse function and the shift vector obtained from the polymerization of their classical counterparts. If this is the case, then we say that gauge fixing and polymerization commute. In this manuscript we investigate these issues and obtain consistency conditions for the commutativity of gauge fixing and polymerization. Our analysis shows that such a commutativity occurs in rather special situations and reveals pitfalls in making seemingly well motivated choices which turn out to be inconsistent with the effective dynamics. We illustrate these findings via examples of symmetry reduced models in the loop quantization of the Schwarzschild interior and Lema\^{\i}tre-Tolman-Bondi (LTB) spacetimes and report the non-commutativity of gauge fixing and polymerization, and inherent limitations of some choices made in the literature with a consistent effective dynamics.
2304.08835
Bahram Mashhoon
Bahram Mashhoon, Masoud Molaei, and Yuri N. Obukhov
Spin-Gravity Coupling in a Rotating Universe
37 pages; v2: presentation improved, invited contribution to appear in Symmetry
Symmetry 15, 1518 (2023)
10.3390/sym15081518
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
The coupling of intrinsic spin with the nonlinear gravitomagnetic fields of Goedel-type spacetimes is studied. We work with Goedel-type universes in order to show that the main features of spin-gravity coupling are independent of causality problems of the Goedel universe. The connection between the spin-gravitomagnetic field coupling and Mathisson's spin-curvature force is demonstrated in the Goedel-type universe. That is, the gravitomagnetic Stern--Gerlach force due to the coupling of spin with the gravitomagnetic field reduces in the appropriate correspondence limit to the classical Mathisson spin-curvature force.
[ { "created": "Tue, 18 Apr 2023 09:04:22 GMT", "version": "v1" }, { "created": "Thu, 3 Aug 2023 14:05:35 GMT", "version": "v2" } ]
2023-08-07
[ [ "Mashhoon", "Bahram", "" ], [ "Molaei", "Masoud", "" ], [ "Obukhov", "Yuri N.", "" ] ]
The coupling of intrinsic spin with the nonlinear gravitomagnetic fields of Goedel-type spacetimes is studied. We work with Goedel-type universes in order to show that the main features of spin-gravity coupling are independent of causality problems of the Goedel universe. The connection between the spin-gravitomagnetic field coupling and Mathisson's spin-curvature force is demonstrated in the Goedel-type universe. That is, the gravitomagnetic Stern--Gerlach force due to the coupling of spin with the gravitomagnetic field reduces in the appropriate correspondence limit to the classical Mathisson spin-curvature force.
1912.05569
Liang Ma
Liang Ma and H. Lu
Bounds on Photon Spheres and Shadows of Charged Black Holes in Einstein-Gauss-Bonnet-Maxwell Gravity
Latex, 11 pages
null
10.1016/j.physletb.2020.135535
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider spherically symmetric and static charged black holes in Einstein-Gauss-Bonnet-Maxwell gravities in general $D\ge 5$ dimensions and study their photon spheres and black hole shadows. We show that they all satisfy the sequence of inequalities recently proposed relating a black hole's horizon, photon sphere, shadow and its mass.
[ { "created": "Wed, 11 Dec 2019 19:00:44 GMT", "version": "v1" } ]
2020-06-10
[ [ "Ma", "Liang", "" ], [ "Lu", "H.", "" ] ]
We consider spherically symmetric and static charged black holes in Einstein-Gauss-Bonnet-Maxwell gravities in general $D\ge 5$ dimensions and study their photon spheres and black hole shadows. We show that they all satisfy the sequence of inequalities recently proposed relating a black hole's horizon, photon sphere, shadow and its mass.
0911.0258
Maria E. Gabach-Clement
Mar\'ia E. Gabach Clement
Conformally flat black hole initial data, with one cylindrical end
Minor changes and formula (21) revised according to the published version in Class. Quantum Grav. (2010). Results unchanged
Class.Quant.Grav.27:125010,2010
10.1088/0264-9381/27/12/125010
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We give a complete analytical proof of existence and uniqueness of extreme-like black hole initial data for Einstein equations, which possess a cilindrical end, analogous to extreme Kerr, extreme Reissner Nordstrom, and extreme Bowen-York's initial data. This extends and refines a previous result \cite{dain-gabach09} to a general case of conformally flat, maximal initial data with angular momentum, linear momentum and matter.
[ { "created": "Mon, 2 Nov 2009 19:22:13 GMT", "version": "v1" }, { "created": "Thu, 16 Aug 2012 11:41:44 GMT", "version": "v2" } ]
2012-08-17
[ [ "Clement", "María E. Gabach", "" ] ]
We give a complete analytical proof of existence and uniqueness of extreme-like black hole initial data for Einstein equations, which possess a cilindrical end, analogous to extreme Kerr, extreme Reissner Nordstrom, and extreme Bowen-York's initial data. This extends and refines a previous result \cite{dain-gabach09} to a general case of conformally flat, maximal initial data with angular momentum, linear momentum and matter.
0802.2431
Zurab Silagadze
O.I. Chashchina, Z.K. Silagadze
Remark on orbital precession due to central-force perturbations
3 pages, ReVTeX4, title changed to match the version to be published in Phys. Rev. D, one new reference added, minor corrections in the text
Phys.Rev.D77:107502,2008
10.1103/PhysRevD.77.107502
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is a comment on the recent paper by G. S. Adkins and J. McDonnell ``Orbital precession due to central-force perturbations'' published in Phys. Rev. D75 (2007), 082001 [arXiv:gr-qc/0702015]. We show that the main result of this paper, the formula for the precession of Keplerian orbits induced by central-force perturbations, can be obtained very simply by the use of Hamilton's vector.
[ { "created": "Mon, 18 Feb 2008 10:19:22 GMT", "version": "v1" }, { "created": "Mon, 31 Mar 2008 04:58:32 GMT", "version": "v2" } ]
2008-11-26
[ [ "Chashchina", "O. I.", "" ], [ "Silagadze", "Z. K.", "" ] ]
This is a comment on the recent paper by G. S. Adkins and J. McDonnell ``Orbital precession due to central-force perturbations'' published in Phys. Rev. D75 (2007), 082001 [arXiv:gr-qc/0702015]. We show that the main result of this paper, the formula for the precession of Keplerian orbits induced by central-force perturbations, can be obtained very simply by the use of Hamilton's vector.
2407.03702
Rog\'erio Capobianco
Rog\'erio Capobianco, Betti Hartmann and Jutta Kunz
Motion of charged particles in an electromagnetic swirling universe: The complete set of solutions
14 pages, 3 figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the motion of electrically and magnetically charged particles in the electromagnetic swirling universe. We show that the equations of motion can be decoupled in the Hamilton-Jacobi formalism, revealing the existence of a fourth constant of motion. The equations of motion can be analytically integrated. The solutions are presented in terms of elementary and elliptic functions. In addition, we discuss the possible orbits for both uncharged particles (in which case the motion is geodesic) and charged particles, respectively. A typical orbit is bounded in the radial direction and escapes to infinity in the $z-$ direction. However, the presence of the electromagnetic fields also leads to the existence of planar orbits.
[ { "created": "Thu, 4 Jul 2024 07:43:04 GMT", "version": "v1" } ]
2024-07-08
[ [ "Capobianco", "Rogério", "" ], [ "Hartmann", "Betti", "" ], [ "Kunz", "Jutta", "" ] ]
We discuss the motion of electrically and magnetically charged particles in the electromagnetic swirling universe. We show that the equations of motion can be decoupled in the Hamilton-Jacobi formalism, revealing the existence of a fourth constant of motion. The equations of motion can be analytically integrated. The solutions are presented in terms of elementary and elliptic functions. In addition, we discuss the possible orbits for both uncharged particles (in which case the motion is geodesic) and charged particles, respectively. A typical orbit is bounded in the radial direction and escapes to infinity in the $z-$ direction. However, the presence of the electromagnetic fields also leads to the existence of planar orbits.
1205.3112
John T. Whelan
John T. Whelan, Emma L. Robinson, Joseph D. Romano, and Eric H. Thrane
Treatment of Calibration Uncertainty in Multi-Baseline Cross-Correlation Searches for Gravitational Waves
4 pages; submitted to the Proceedings of the International Conference on Gravitation and Cosmology (ICGC 2011), Goa, India, December 2011
J. Phys.: Conf. Ser. 484 (2014) 012027
10.1088/1742-6596/484/1/012027
LIGO-P1200051-v4
gr-qc astro-ph.IM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Uncertainty in the calibration of gravitational-wave (GW) detector data leads to systematic errors which must be accounted for in setting limits on the strength of GW signals. When cross-correlation measurements are made using data from a pair of instruments, as in searches for a stochastic GW background, the calibration uncertainties of the individual instruments can be combined into an uncertainty associated with the pair. With the advent of multi-baseline GW observation (e.g., networks consisting of multiple detectors such as the LIGO observatories and Virgo), a more sophisticated treatment is called for. We describe how the correlations between calibration factors associated with different pairs can be taken into account by marginalizing over the uncertainty associated with each instrument.
[ { "created": "Mon, 14 May 2012 17:30:38 GMT", "version": "v1" }, { "created": "Sun, 24 Jun 2012 21:46:27 GMT", "version": "v2" }, { "created": "Fri, 3 Aug 2012 18:53:22 GMT", "version": "v3" } ]
2014-03-07
[ [ "Whelan", "John T.", "" ], [ "Robinson", "Emma L.", "" ], [ "Romano", "Joseph D.", "" ], [ "Thrane", "Eric H.", "" ] ]
Uncertainty in the calibration of gravitational-wave (GW) detector data leads to systematic errors which must be accounted for in setting limits on the strength of GW signals. When cross-correlation measurements are made using data from a pair of instruments, as in searches for a stochastic GW background, the calibration uncertainties of the individual instruments can be combined into an uncertainty associated with the pair. With the advent of multi-baseline GW observation (e.g., networks consisting of multiple detectors such as the LIGO observatories and Virgo), a more sophisticated treatment is called for. We describe how the correlations between calibration factors associated with different pairs can be taken into account by marginalizing over the uncertainty associated with each instrument.
1506.05065
P.C.E. Stamp
P.C.E. Stamp
Rationale for a Correlated Worldline Theory of Quantum Gravity
26 pages, 15 figures; intended for broad audience. New Journal of Physics, 2015 (in press)
null
null
null
gr-qc cond-mat.other quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is argued that gravity should cause a breakdown of quantum mechanics, at low energies, accessible to table-top experiments. It is then shown that one can formulate a theory of quantum gravity in which gravitational correlations exist between worldline or worldsheet paths, for the particle or field of interest. Using a generalized equivalence principle, one can give a unique form for the correlators, yielding a theory with no adjustable parameters. A key feature of the theory is the "bunching" of quantum trajectories caused by the gravitational correlations - this is {\it not} a decoherence or a "collapse" mechanism. This bunching causes a breakdown of the superposition principle for large masses, with a very rapid crossover to classical behaviour at an energy scale which depends on the physical structure of the object. Formal details, and applications of the theory, are kept to a minimum in this paper; but we show how physical quantities can be calculated, and give a detailed discussion of the dynamics of a single particle.
[ { "created": "Tue, 16 Jun 2015 18:43:19 GMT", "version": "v1" } ]
2015-06-17
[ [ "Stamp", "P. C. E.", "" ] ]
It is argued that gravity should cause a breakdown of quantum mechanics, at low energies, accessible to table-top experiments. It is then shown that one can formulate a theory of quantum gravity in which gravitational correlations exist between worldline or worldsheet paths, for the particle or field of interest. Using a generalized equivalence principle, one can give a unique form for the correlators, yielding a theory with no adjustable parameters. A key feature of the theory is the "bunching" of quantum trajectories caused by the gravitational correlations - this is {\it not} a decoherence or a "collapse" mechanism. This bunching causes a breakdown of the superposition principle for large masses, with a very rapid crossover to classical behaviour at an energy scale which depends on the physical structure of the object. Formal details, and applications of the theory, are kept to a minimum in this paper; but we show how physical quantities can be calculated, and give a detailed discussion of the dynamics of a single particle.
1903.08211
Rajibul Shaikh
Rajibul Shaikh, Pritam Banerjee, Suvankar Paul, Tapobrata Sarkar
Analytical approach to strong gravitational lensing from ultracompact objects
17 pages, 3 figures, minor corrections, published in PRD
Phys. Rev. D 99, 104040 (2019)
10.1103/PhysRevD.99.104040
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Strong gravitational lensing from black holes results in the formation of relativistic images, in particular, relativistic Einstein rings. For objects with event horizons, the radius of the unstable light ring (photon sphere) is the lowest radius at which a relativistic image might be formed. For horizonless ultracompact objects, additional relativistic images and rings can form inside this radius. In this paper, we provide an analytical approach to deal with strong gravitational lensing from such ultracompact objects, which is substantially different from the black hole cases, first reported by Bozza. Here, our analysis indicates that the angular separations and magnifications of relativistic images inside the unstable light ring (photon sphere) might be several orders of magnitude higher compared to the ones outside it. This indicates fundamental differences in the nature of strong gravitational lensing from black holes and ultracompact objects.
[ { "created": "Tue, 19 Mar 2019 18:45:06 GMT", "version": "v1" }, { "created": "Sat, 18 May 2019 11:16:44 GMT", "version": "v2" } ]
2019-05-21
[ [ "Shaikh", "Rajibul", "" ], [ "Banerjee", "Pritam", "" ], [ "Paul", "Suvankar", "" ], [ "Sarkar", "Tapobrata", "" ] ]
Strong gravitational lensing from black holes results in the formation of relativistic images, in particular, relativistic Einstein rings. For objects with event horizons, the radius of the unstable light ring (photon sphere) is the lowest radius at which a relativistic image might be formed. For horizonless ultracompact objects, additional relativistic images and rings can form inside this radius. In this paper, we provide an analytical approach to deal with strong gravitational lensing from such ultracompact objects, which is substantially different from the black hole cases, first reported by Bozza. Here, our analysis indicates that the angular separations and magnifications of relativistic images inside the unstable light ring (photon sphere) might be several orders of magnitude higher compared to the ones outside it. This indicates fundamental differences in the nature of strong gravitational lensing from black holes and ultracompact objects.
1711.04245
Shaun Inglis Ph.D. (Phys. Sci.)
Shaun Inglis, Peter Jarvis
The self-coupled Einstein-Cartan-Dirac equations in terms of Dirac bilinears
21 pages, updated version accepted for publication
null
10.1088/1751-8121/aaf4e0
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article we present the algebraic rearrangement, or matrix inversion of the Dirac equation in a curved Riemann-Cartan spacetime with torsion, the presence of non-vanishing torsion is implied by the intrinsic spin-1/2 of the Dirac field. We then demonstrate how the inversion leads to a reformulation of the fully non-linear and self-interactive Einstein-Cartan-Dirac field equations in terms of Dirac bilinears. It has been known for some decades that the Dirac equation for charged fermions interacting with an electromagnetic field can be algebraically inverted, so as to obtain an explicit rational expression of the four-vector potential of the gauge field in terms of the spinors. Substitution of this expression into Maxwell's equations yields the bilinear form of the self-interactive Maxwell-Dirac equations. In the present (purely gravitational) case, the inversion process yields \emph{two} rational four-vector expressions in terms of Dirac bilinears, which act as gravitational analogues of the electromagnetic vector potential. These "potentials" also appear as irreducible summand components of the connection, along with a traceless residual term of mixed symmetry. When taking the torsion field equation into account, the residual term can be written as a function of the object of anholonomity. Using the local tetrad frame associated with observers co-moving with the Dirac matter, a generic vierbein frame can described in terms of four Dirac bilinear vector fields, normalized by a scalar and pseudoscalar field. A corollary of this is that in regions where the Dirac field is non-vanishing, the self-coupled Einstein-Cartan-Dirac equations can in principle be expressed in terms of Dirac bilinears only.
[ { "created": "Sun, 12 Nov 2017 07:11:32 GMT", "version": "v1" }, { "created": "Sun, 16 Dec 2018 00:53:03 GMT", "version": "v2" } ]
2018-12-18
[ [ "Inglis", "Shaun", "" ], [ "Jarvis", "Peter", "" ] ]
In this article we present the algebraic rearrangement, or matrix inversion of the Dirac equation in a curved Riemann-Cartan spacetime with torsion, the presence of non-vanishing torsion is implied by the intrinsic spin-1/2 of the Dirac field. We then demonstrate how the inversion leads to a reformulation of the fully non-linear and self-interactive Einstein-Cartan-Dirac field equations in terms of Dirac bilinears. It has been known for some decades that the Dirac equation for charged fermions interacting with an electromagnetic field can be algebraically inverted, so as to obtain an explicit rational expression of the four-vector potential of the gauge field in terms of the spinors. Substitution of this expression into Maxwell's equations yields the bilinear form of the self-interactive Maxwell-Dirac equations. In the present (purely gravitational) case, the inversion process yields \emph{two} rational four-vector expressions in terms of Dirac bilinears, which act as gravitational analogues of the electromagnetic vector potential. These "potentials" also appear as irreducible summand components of the connection, along with a traceless residual term of mixed symmetry. When taking the torsion field equation into account, the residual term can be written as a function of the object of anholonomity. Using the local tetrad frame associated with observers co-moving with the Dirac matter, a generic vierbein frame can described in terms of four Dirac bilinear vector fields, normalized by a scalar and pseudoscalar field. A corollary of this is that in regions where the Dirac field is non-vanishing, the self-coupled Einstein-Cartan-Dirac equations can in principle be expressed in terms of Dirac bilinears only.
0802.4305
Daniel M\"uller
Daniel Muller
Geodesic Motion on Closed Spaces: Two Numerical Examples
version accepted for publication
Physics Letters A, 376, 221-226 (2012)
10.1016/j.physleta.2011.11.041
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The geodesic structure is very closely related to the trace of the Laplace operator, involved in the calculation of the expectation value of the energy momentum tensor in Universes with non trivial topology. The purpose of this work is to provide concrete numerical examples of geodesic flows. Two manifolds with genus $g=0$ are given. In one the chaotic regions, form sets of negligible or zero measure. In the second example the geodesic flow, shows the presence of measurable chaotic regions. The approach is "experimental", numerical, and there is no attempt to an analytical calculation.
[ { "created": "Thu, 28 Feb 2008 22:51:46 GMT", "version": "v1" }, { "created": "Wed, 12 Mar 2008 02:35:58 GMT", "version": "v2" }, { "created": "Mon, 30 Jan 2012 13:52:19 GMT", "version": "v3" } ]
2015-05-13
[ [ "Muller", "Daniel", "" ] ]
The geodesic structure is very closely related to the trace of the Laplace operator, involved in the calculation of the expectation value of the energy momentum tensor in Universes with non trivial topology. The purpose of this work is to provide concrete numerical examples of geodesic flows. Two manifolds with genus $g=0$ are given. In one the chaotic regions, form sets of negligible or zero measure. In the second example the geodesic flow, shows the presence of measurable chaotic regions. The approach is "experimental", numerical, and there is no attempt to an analytical calculation.
1905.01088
Bobir Toshmatov
Bobir Toshmatov, Daniele Malafarina, Naresh Dadhich
Harmonic oscillations of neutral particles in the $\gamma$-metric
11 pages, 5 figures
Phys. Rev. D 100, 044001 (2019)
10.1103/PhysRevD.100.044001
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a well-known static, axially symmetric, vacuum solution of Einstein equations belonging to Weyl's class and determine the fundamental frequencies of small harmonic oscillations of test particles around stable circular orbits in the equatorial plane. We discuss the radial profiles of frequencies of the radial, latitudinal (vertical), and azimuthal (Keplerian) harmonic oscillations relative to the comoving and distant observers and compare with the corresponding ones in the Schwarzschild and Kerr geometries. We show that there exist latitudinal and radial frequencies of harmonic oscillations of particles moving along the circular orbits for which it is impossible to determine whether the central gravitating object is described by the slowly rotating Kerr solution or by a slightly deformed static space-time.
[ { "created": "Fri, 3 May 2019 09:30:24 GMT", "version": "v1" }, { "created": "Fri, 2 Aug 2019 05:27:34 GMT", "version": "v2" } ]
2019-08-05
[ [ "Toshmatov", "Bobir", "" ], [ "Malafarina", "Daniele", "" ], [ "Dadhich", "Naresh", "" ] ]
We consider a well-known static, axially symmetric, vacuum solution of Einstein equations belonging to Weyl's class and determine the fundamental frequencies of small harmonic oscillations of test particles around stable circular orbits in the equatorial plane. We discuss the radial profiles of frequencies of the radial, latitudinal (vertical), and azimuthal (Keplerian) harmonic oscillations relative to the comoving and distant observers and compare with the corresponding ones in the Schwarzschild and Kerr geometries. We show that there exist latitudinal and radial frequencies of harmonic oscillations of particles moving along the circular orbits for which it is impossible to determine whether the central gravitating object is described by the slowly rotating Kerr solution or by a slightly deformed static space-time.
2204.03322
Andr\'e Gro{\ss}ardt
Andr\'e Gro{\ss}ardt
Gravitational entanglement and the mass contribution of internal energy in nonrelativistic quantum systems
Essay written for the Gravity Research Foundation 2022 Awards for Essays on Gravitation
Int. J, Mod. Phys. D 31, 2242017 (2022)
10.1142/S0218271822420172
null
gr-qc quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, interest has increased in the entanglement of remote quantum particles through the Newtonian gravitational interaction, both from a fundamental perspective and as a test case for the quantization of gravity. Likewise, post-Newtonian gravitational effects in composite nonrelativistic quantum systems have been discussed, where the internal energy contributes to the mass, promoting the mass to a Hilbert space operator. Employing a modified version of a previously considered thought experiment, it can be shown that both concepts, when combined, result in inconsistencies, reinforcing the arguments for the necessity of a rigorous derivation of the nonrelativistic limit of gravitating quantum matter from first principles.
[ { "created": "Thu, 7 Apr 2022 09:39:07 GMT", "version": "v1" } ]
2022-12-29
[ [ "Großardt", "André", "" ] ]
Recently, interest has increased in the entanglement of remote quantum particles through the Newtonian gravitational interaction, both from a fundamental perspective and as a test case for the quantization of gravity. Likewise, post-Newtonian gravitational effects in composite nonrelativistic quantum systems have been discussed, where the internal energy contributes to the mass, promoting the mass to a Hilbert space operator. Employing a modified version of a previously considered thought experiment, it can be shown that both concepts, when combined, result in inconsistencies, reinforcing the arguments for the necessity of a rigorous derivation of the nonrelativistic limit of gravitating quantum matter from first principles.
1310.4531
Gustavo Joaquin Turiaci
Gustavo Joaquin Turiaci and Matias Zaldarriaga
Non-Gaussianities in Dissipative EFT of Inflation Coupled to a Fluid
42 pages, 9 figures
null
null
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We studied models of inflation with a preferred clock specifying the end of inflation and giving the curvature perturbations, coupled with another non-equivalent clock that at late times defines the same frame and do not contribute to the density perturbations. This can happen in the framework of dissipative EFT of inflation where the additional degrees of freedom include a fluid developing sound waves propagating with sound speed $c_{sr}$. The fluid defines a preferred frame comoving with it. The paradigmatic example of this is the warm inflation scenario. We studied the dynamics of this systems during inflation and the three-point function. We saw that in the strong dissipation regime the nonlinear parameter induced by the new terms is $|f_{\rm NL}| \sim 1/c_{sr}^2$, not enhanced by the dissipation parameter which enters the two-point function. We checked that the squeezed limit of the three-point function still satisfies the consistency condition with corrections of order $\mathcal{O}(k_L^2/k_S^2)$. We computed the Planck constraints for the case of warm inflation obtaining a bound of $\gamma\lesssim 10^5 H$ for the clock coupled to radiation. For decreasing sound speed the bound decreases. We also checked that the shape of the three-point function corresponding to the model studied here is a mixture between equilateral and orthogonal with a small local component, which is more consistent with Planck's results.
[ { "created": "Wed, 16 Oct 2013 22:00:34 GMT", "version": "v1" } ]
2013-10-18
[ [ "Turiaci", "Gustavo Joaquin", "" ], [ "Zaldarriaga", "Matias", "" ] ]
We studied models of inflation with a preferred clock specifying the end of inflation and giving the curvature perturbations, coupled with another non-equivalent clock that at late times defines the same frame and do not contribute to the density perturbations. This can happen in the framework of dissipative EFT of inflation where the additional degrees of freedom include a fluid developing sound waves propagating with sound speed $c_{sr}$. The fluid defines a preferred frame comoving with it. The paradigmatic example of this is the warm inflation scenario. We studied the dynamics of this systems during inflation and the three-point function. We saw that in the strong dissipation regime the nonlinear parameter induced by the new terms is $|f_{\rm NL}| \sim 1/c_{sr}^2$, not enhanced by the dissipation parameter which enters the two-point function. We checked that the squeezed limit of the three-point function still satisfies the consistency condition with corrections of order $\mathcal{O}(k_L^2/k_S^2)$. We computed the Planck constraints for the case of warm inflation obtaining a bound of $\gamma\lesssim 10^5 H$ for the clock coupled to radiation. For decreasing sound speed the bound decreases. We also checked that the shape of the three-point function corresponding to the model studied here is a mixture between equilateral and orthogonal with a small local component, which is more consistent with Planck's results.
1212.2307
Edwin J. Son
Edwin J. Son, Wontae Kim
Two critical phenomena in the exactly soluble quantized Schwarzschild black hole
v2. improved version published in JHEP; 11 pages, 3 figures, clarifications and references added
J. High Energy Phys. 03 (2013) 060
10.1007/JHEP03(2013)060
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study thermodynamic quantities and phase transitions of a spherically symmetric Schwarzschild black hole by taking into account the back reaction through the conformal anomaly of matter fields, and show that there exists an additional phase transition to the conventional Hawking-Page phase transition. The small black hole is more probable than the hot flat space above a second critical temperature, while it is less probable than the hot flat space in the classical Schwarzschild black hole. However, the unstable small black hole eventually should decay into the stable large black hole because the conformal anomaly does not change its thermodynamic stability.
[ { "created": "Tue, 11 Dec 2012 06:01:13 GMT", "version": "v1" }, { "created": "Sat, 16 Mar 2013 07:38:47 GMT", "version": "v2" } ]
2013-03-19
[ [ "Son", "Edwin J.", "" ], [ "Kim", "Wontae", "" ] ]
We study thermodynamic quantities and phase transitions of a spherically symmetric Schwarzschild black hole by taking into account the back reaction through the conformal anomaly of matter fields, and show that there exists an additional phase transition to the conventional Hawking-Page phase transition. The small black hole is more probable than the hot flat space above a second critical temperature, while it is less probable than the hot flat space in the classical Schwarzschild black hole. However, the unstable small black hole eventually should decay into the stable large black hole because the conformal anomaly does not change its thermodynamic stability.
2301.12666
Rui Xu
Rui Xu
A Four-Parameter Black-Hole Solution in the Bumblebee Gravity Model
Presented at the Ninth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, May 17-26, 2022
null
null
null
gr-qc hep-ph
http://creativecommons.org/licenses/by-sa/4.0/
The bumblebee gravity model includes a class of vector-tensor theories of gravitation where the vector field couples to the Ricci tensor quadratically. We obtain an analytical spherical black-hole solution in this model. The solution has four parameters, expanding the two-parameter solution family known in the literature. Special choices of the parameters are pointed out and discussed.
[ { "created": "Mon, 30 Jan 2023 05:02:17 GMT", "version": "v1" } ]
2023-01-31
[ [ "Xu", "Rui", "" ] ]
The bumblebee gravity model includes a class of vector-tensor theories of gravitation where the vector field couples to the Ricci tensor quadratically. We obtain an analytical spherical black-hole solution in this model. The solution has four parameters, expanding the two-parameter solution family known in the literature. Special choices of the parameters are pointed out and discussed.
gr-qc/9402041
Charles R. Evans
Charles R. Evans and Jason S. Coleman
Observation of critical phenomena and self-similarity in the gravitational collapse of radiation fluid
10 pages (LaTeX) (to appear in Phys. Rev. Lett.), TAR-039-UNC
Phys.Rev.Lett. 72 (1994) 1782-1785
10.1103/PhysRevLett.72.1782
null
gr-qc
null
We observe critical phenomena in spherical collapse of radiation fluid. A sequence of spacetimes $\cal{S}[\eta]$ is numerically computed, containing models ($\eta\ll 1$) that adiabatically disperse and models ($\eta\gg 1$) that form a black hole. Near the critical point ($\eta_c$), evolutions develop a self-similar region within which collapse is balanced by a strong, inward-moving rarefaction wave that holds $m(r)/r$ constant as a function of a self-similar coordinate $\xi$. The self-similar solution is known and we show near-critical evolutions asymptotically approaching it. A critical exponent $\beta \simeq 0.36$ is found for supercritical ($\eta>\eta_c$) models.
[ { "created": "Wed, 23 Feb 1994 04:59:49 GMT", "version": "v1" } ]
2009-10-22
[ [ "Evans", "Charles R.", "" ], [ "Coleman", "Jason S.", "" ] ]
We observe critical phenomena in spherical collapse of radiation fluid. A sequence of spacetimes $\cal{S}[\eta]$ is numerically computed, containing models ($\eta\ll 1$) that adiabatically disperse and models ($\eta\gg 1$) that form a black hole. Near the critical point ($\eta_c$), evolutions develop a self-similar region within which collapse is balanced by a strong, inward-moving rarefaction wave that holds $m(r)/r$ constant as a function of a self-similar coordinate $\xi$. The self-similar solution is known and we show near-critical evolutions asymptotically approaching it. A critical exponent $\beta \simeq 0.36$ is found for supercritical ($\eta>\eta_c$) models.
1004.1714
Sebastiano Sonego
Sebastiano Sonego
Ultrastatic spacetimes
13 pages
J.Math.Phys.51:092502,2010
10.1063/1.3485599
null
gr-qc math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Several calculations in conformally static spacetimes rely on the introduction of an ultrastatic background. I describe the general properties of ultrastatic spacetimes, and then focus on the problem of whether a given spacetime can be ultrastatic, or conformally ultrastatic, in more than one way. I show that the first possibility arises iff the spacetime is a product containing a Minkowskian factor, and that the second arises iff the spatial sections are conformal to a product space.
[ { "created": "Sat, 10 Apr 2010 14:27:25 GMT", "version": "v1" }, { "created": "Wed, 6 Oct 2010 07:50:23 GMT", "version": "v2" } ]
2011-04-07
[ [ "Sonego", "Sebastiano", "" ] ]
Several calculations in conformally static spacetimes rely on the introduction of an ultrastatic background. I describe the general properties of ultrastatic spacetimes, and then focus on the problem of whether a given spacetime can be ultrastatic, or conformally ultrastatic, in more than one way. I show that the first possibility arises iff the spacetime is a product containing a Minkowskian factor, and that the second arises iff the spatial sections are conformal to a product space.
2101.03115
Madhavan Varadarajan
Madhavan Varadarajan
Euclidean LQG Dynamics: An Electric Shift in Perspective
37 pages, 7 figures
null
10.1088/1361-6382/abfc2d
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Loop Quantum Gravity (LQG) is a non-perturbative attempt at quantization of a classical phase space description of gravity in terms of $SU(2)$ connections and electric fields. As emphasized recently [1], on this phase space, classical gravitational evolution in $time$ can be understood in terms of certain gauge covariant generalizations of Lie derivatives with respect to a $spatial$ $SU(2)$ Lie algebra valued vector field called the Electric Shift. We present a derivation of a quantum dynamics for Euclidean LQG which is informed by this understanding. In addition to the physically motivated nature of the action of the Euclidean Hamiltonian constraint so derived, the derivation implies that the spin labels of regulating holonomies are determined by corresponding labels of the spin network state being acted upon thus eliminating the `spin $j$-ambiguity' pointed out by Perez. By virtue of Thiemann's seminal work, the Euclidean quantum dynamics plays a crucial role in the construction of the Lorentzian quantum dynamics so that our considerations also have application to Lorentzian LQG.
[ { "created": "Fri, 8 Jan 2021 17:15:27 GMT", "version": "v1" } ]
2021-07-07
[ [ "Varadarajan", "Madhavan", "" ] ]
Loop Quantum Gravity (LQG) is a non-perturbative attempt at quantization of a classical phase space description of gravity in terms of $SU(2)$ connections and electric fields. As emphasized recently [1], on this phase space, classical gravitational evolution in $time$ can be understood in terms of certain gauge covariant generalizations of Lie derivatives with respect to a $spatial$ $SU(2)$ Lie algebra valued vector field called the Electric Shift. We present a derivation of a quantum dynamics for Euclidean LQG which is informed by this understanding. In addition to the physically motivated nature of the action of the Euclidean Hamiltonian constraint so derived, the derivation implies that the spin labels of regulating holonomies are determined by corresponding labels of the spin network state being acted upon thus eliminating the `spin $j$-ambiguity' pointed out by Perez. By virtue of Thiemann's seminal work, the Euclidean quantum dynamics plays a crucial role in the construction of the Lorentzian quantum dynamics so that our considerations also have application to Lorentzian LQG.
1806.11439
Yongwan Gim
Yongwan Gim, Hwajin Um, Wontae Kim
Unruh temperatures in circular and drifted Rindler motions
13 pages, 2 figures
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the temperatures for the circular and drifted Rindler motions by employing the Unruh-DeWitt detector method. In the circular motion, the temperature is increasing along the radius of the circular motion until it reaches the maximum, and then it is decreasing and eventually vanishing at the limit to the radius where the proper acceleration is infinite. In fact, the temperature is proportional to the proper acceleration quadratically near the origin of the circular motion as compared to the usual Unruh effect depending on the linear proper acceleration. On the other hand, in the drifted Rindler motion, the observer moves with a relative velocity in the direction transverse to the acceleration. If the detector is moving slowly in the transverse direction with a finite proper acceleration, then the temperature behaves like the usual Unruh temperature, while it vanishes for the speed of light in the transverse direction according to the infinite proper acceleration. Consequently, it turns out that the temperatures behave nonlinearly with respect to the proper acceleration and the infinite proper acceleration would not always permit the divergent temperature.
[ { "created": "Thu, 28 Jun 2018 08:05:43 GMT", "version": "v1" } ]
2018-07-02
[ [ "Gim", "Yongwan", "" ], [ "Um", "Hwajin", "" ], [ "Kim", "Wontae", "" ] ]
We study the temperatures for the circular and drifted Rindler motions by employing the Unruh-DeWitt detector method. In the circular motion, the temperature is increasing along the radius of the circular motion until it reaches the maximum, and then it is decreasing and eventually vanishing at the limit to the radius where the proper acceleration is infinite. In fact, the temperature is proportional to the proper acceleration quadratically near the origin of the circular motion as compared to the usual Unruh effect depending on the linear proper acceleration. On the other hand, in the drifted Rindler motion, the observer moves with a relative velocity in the direction transverse to the acceleration. If the detector is moving slowly in the transverse direction with a finite proper acceleration, then the temperature behaves like the usual Unruh temperature, while it vanishes for the speed of light in the transverse direction according to the infinite proper acceleration. Consequently, it turns out that the temperatures behave nonlinearly with respect to the proper acceleration and the infinite proper acceleration would not always permit the divergent temperature.
1610.06532
Leonid Perlov
Leonid Perlov
Uncertainty Principle in Loop Quantum Cosmology by Moyal Formalism
null
Journal of Mathematical Physics 59, 032304 (2018)
10.1063/1.5013206
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we derive the uncertainty principle for the Loop Quantum Cosmology homogeneous and isotropic FLWR model with the holonomy-flux algebra. The uncertainty principle is between the variables $c$, with the meaning of connection and $\mu$ having the meaning of the physical cell volume to the power $2/3$, i.e $v^{2/3}$ or a plaquette area. Since both $\mu$ and $c$ are not operators, but rather the random variables, the Robertson uncertainty principle derivation that works for hermitian operators, can not be used. Instead we use the Wigner-Moyal-Groenewold phase space formalism. The Wigner-Moyal-Groenewold formalism was originally applied to the Heisenberg algebra of the Quantum Mechanics. One can derive from it both the canonical and path integral QM as well as the uncertainty principle. In this paper we apply it to the holonomy-flux algebra in case of the homogeneous and isotropic space. Another result is the expression for the Wigner function on the space of the cylindrical wave functions defined on $R_b$ in $c$ variables rather than in dual space $\mu$ variables.
[ { "created": "Thu, 20 Oct 2016 18:31:53 GMT", "version": "v1" }, { "created": "Thu, 9 Feb 2017 04:15:14 GMT", "version": "v2" }, { "created": "Wed, 22 Feb 2017 03:51:03 GMT", "version": "v3" }, { "created": "Fri, 6 Apr 2018 03:15:23 GMT", "version": "v4" } ]
2018-04-09
[ [ "Perlov", "Leonid", "" ] ]
In this paper we derive the uncertainty principle for the Loop Quantum Cosmology homogeneous and isotropic FLWR model with the holonomy-flux algebra. The uncertainty principle is between the variables $c$, with the meaning of connection and $\mu$ having the meaning of the physical cell volume to the power $2/3$, i.e $v^{2/3}$ or a plaquette area. Since both $\mu$ and $c$ are not operators, but rather the random variables, the Robertson uncertainty principle derivation that works for hermitian operators, can not be used. Instead we use the Wigner-Moyal-Groenewold phase space formalism. The Wigner-Moyal-Groenewold formalism was originally applied to the Heisenberg algebra of the Quantum Mechanics. One can derive from it both the canonical and path integral QM as well as the uncertainty principle. In this paper we apply it to the holonomy-flux algebra in case of the homogeneous and isotropic space. Another result is the expression for the Wigner function on the space of the cylindrical wave functions defined on $R_b$ in $c$ variables rather than in dual space $\mu$ variables.
gr-qc/0302091
Andrzej Woszczyna
Zdzislaw A. Golda and Andrzej Woszczyna
A field theory approach to cosmological density perturbations
null
Phys.Lett. A310 (2003) 357-362
10.1016/S0375-9601(03)00380-3
null
gr-qc
null
Adiabatic perturbations propagate in the expanding universe like scalar massless fields in some effective Robertson-Walker space-time.
[ { "created": "Sat, 22 Feb 2003 21:16:19 GMT", "version": "v1" }, { "created": "Sat, 24 Apr 2004 20:37:09 GMT", "version": "v2" } ]
2009-11-10
[ [ "Golda", "Zdzislaw A.", "" ], [ "Woszczyna", "Andrzej", "" ] ]
Adiabatic perturbations propagate in the expanding universe like scalar massless fields in some effective Robertson-Walker space-time.
1906.00343
Hamid Reza Sepangi
Mohaddese Heydari-Fard, Malihe Heydari-Fard, Hamid Reza Sepangi
Higher-order geodesic deviations and orbital precession in a Kerr-Newman space-time
15 pages, 3 figures
null
10.1007/s10714-019-2557-7
Gen. Rel. Grav. 51 (2019) no.6, 77
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A novel approximation method in studying the perihelion precession and planetary orbits in general relativity is to use geodesic deviation equations of first and high-orders, proposed by Kerner et.al. Using higher-order geodesic deviation approach, we generalize the calculation of orbital precession and the elliptical trajectory of neutral test particles to Kerr$-$Newman space-times. One of the advantage of this method is that, for small eccentricities, one obtains trajectories of planets without using Newtonian and post-Newtonian approximations for arbitrary values of quantity ${G M}/{R c^2}$.
[ { "created": "Sun, 2 Jun 2019 04:59:43 GMT", "version": "v1" } ]
2019-07-16
[ [ "Heydari-Fard", "Mohaddese", "" ], [ "Heydari-Fard", "Malihe", "" ], [ "Sepangi", "Hamid Reza", "" ] ]
A novel approximation method in studying the perihelion precession and planetary orbits in general relativity is to use geodesic deviation equations of first and high-orders, proposed by Kerner et.al. Using higher-order geodesic deviation approach, we generalize the calculation of orbital precession and the elliptical trajectory of neutral test particles to Kerr$-$Newman space-times. One of the advantage of this method is that, for small eccentricities, one obtains trajectories of planets without using Newtonian and post-Newtonian approximations for arbitrary values of quantity ${G M}/{R c^2}$.
2004.08403
Martin Pernot-Borr\`as
Martin Pernot-Borr\`as, Joel Berg\'e, Philippe Brax, Jean-Philippe Uzan
Fifth force induced by a chameleon field on nested cylinders
Submitted to Phys. Rev. D
Phys. Rev. D 101, 124056 (2020)
10.1103/PhysRevD.101.124056
null
gr-qc astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This article investigates the properties of a scalar fifth force that arises in a scalar tensor-theory with a chameleon screening mechanism in the context of gravity space missions like the MICROSCOPE experiment. In such an experiment, the propagation of the chameleon field inside the nested cylinders of the experiment causes a fifth force when the cylinders are not perfectly co-axial. We propose a semi-analytic method to compute the field distribution and the induced fifth force and compare it to a full numerical simulation, in settings where the cylindrical symmetry is broken. The scaling of the fifth force with both the parameters of the model and the geometry of the experiment is discussed. We show that the fifth force is repulsive, hence adds a destabilizing stiffness that should be included in the force budget acting on the detector. This opens the way to a new method to constrain a scalar fifth force in screened models.
[ { "created": "Fri, 17 Apr 2020 18:00:11 GMT", "version": "v1" } ]
2020-07-01
[ [ "Pernot-Borràs", "Martin", "" ], [ "Bergé", "Joel", "" ], [ "Brax", "Philippe", "" ], [ "Uzan", "Jean-Philippe", "" ] ]
This article investigates the properties of a scalar fifth force that arises in a scalar tensor-theory with a chameleon screening mechanism in the context of gravity space missions like the MICROSCOPE experiment. In such an experiment, the propagation of the chameleon field inside the nested cylinders of the experiment causes a fifth force when the cylinders are not perfectly co-axial. We propose a semi-analytic method to compute the field distribution and the induced fifth force and compare it to a full numerical simulation, in settings where the cylindrical symmetry is broken. The scaling of the fifth force with both the parameters of the model and the geometry of the experiment is discussed. We show that the fifth force is repulsive, hence adds a destabilizing stiffness that should be included in the force budget acting on the detector. This opens the way to a new method to constrain a scalar fifth force in screened models.
2403.19392
Yizhi Zhan
Hengyu Xu, Yizhi Zhan and Shao-Jun Zhang
Tachyonic instability and spontaneous scalarization in parameterized Schwarzschild-like black holes
19 pages,10 figures,published version
Eur. Phys. J. C (2024) 84:617
10.1140/epjc/s10052-024-12968-3
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the phenomenon of spontaneous scalarization in parameterized Schwarzschild-like black holes. Two metrics are considered, the Konoplya-Zhidenko metric and the Johannsen-Psaltis metric. While these metrics can mimic the Schwarzschild black hole well in the weak-field regime, they have deformed geometries in the near-horizon strong-field region. Such deformations notably influence the emergence of tachyonic instability and subsequent spontaneous scalarization, enabling a clear distinction between these parameterized metrics and the standard Schwarzschild metric. These results suggest a possible way to test the parameterized black holes and thus the Kerr hypothesis by observing the phenomenon of spontaneous scalarization.
[ { "created": "Thu, 28 Mar 2024 13:06:07 GMT", "version": "v1" }, { "created": "Thu, 20 Jun 2024 06:18:14 GMT", "version": "v2" } ]
2024-06-21
[ [ "Xu", "Hengyu", "" ], [ "Zhan", "Yizhi", "" ], [ "Zhang", "Shao-Jun", "" ] ]
We study the phenomenon of spontaneous scalarization in parameterized Schwarzschild-like black holes. Two metrics are considered, the Konoplya-Zhidenko metric and the Johannsen-Psaltis metric. While these metrics can mimic the Schwarzschild black hole well in the weak-field regime, they have deformed geometries in the near-horizon strong-field region. Such deformations notably influence the emergence of tachyonic instability and subsequent spontaneous scalarization, enabling a clear distinction between these parameterized metrics and the standard Schwarzschild metric. These results suggest a possible way to test the parameterized black holes and thus the Kerr hypothesis by observing the phenomenon of spontaneous scalarization.
1801.01591
Mauricio Cataldo MC
Mauricio Cataldo and Norman Cruz
The Hubble IR cutoff in holographic ellipsoidal cosmologies
To be published in EPJC, 10 pages, 2 figures
null
10.1140/epjc/s10052-017-5508-z
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well known that for spatially flat FRW cosmologies, the holographic dark energy disfavours the Hubble parameter as a candidate for the IR cutoff. For overcoming this problem, we explore the use of this cutoff in holographic ellipsoidal cosmological models, and derive the general ellipsoidal metric induced by a such holographic energy density. Despite the drawbacks that this cutoff presents in homogeneous and isotropic universes, based on this general metric, we developed a suitable ellipsoidal holographic cosmological model, filled with a dark matter and a dark energy components. At late time stages, the cosmic evolution is dominated by a holographic anisotropic dark energy with barotropic equations of state. The cosmologies expand in all directions in accelerated manner. Since the ellipsoidal cosmologies given here are not asymptotically FRW, the deviation from homogeneity and isotropy of the universe on large cosmological scales remains constant during all cosmic evolution. This feature allows studied holographic ellipsoidal cosmologies to be ruled by an equation of state $\omega=p/\rho$, whose range belongs to quintessence or even phantom matter.
[ { "created": "Fri, 5 Jan 2018 00:40:21 GMT", "version": "v1" } ]
2018-02-14
[ [ "Cataldo", "Mauricio", "" ], [ "Cruz", "Norman", "" ] ]
It is well known that for spatially flat FRW cosmologies, the holographic dark energy disfavours the Hubble parameter as a candidate for the IR cutoff. For overcoming this problem, we explore the use of this cutoff in holographic ellipsoidal cosmological models, and derive the general ellipsoidal metric induced by a such holographic energy density. Despite the drawbacks that this cutoff presents in homogeneous and isotropic universes, based on this general metric, we developed a suitable ellipsoidal holographic cosmological model, filled with a dark matter and a dark energy components. At late time stages, the cosmic evolution is dominated by a holographic anisotropic dark energy with barotropic equations of state. The cosmologies expand in all directions in accelerated manner. Since the ellipsoidal cosmologies given here are not asymptotically FRW, the deviation from homogeneity and isotropy of the universe on large cosmological scales remains constant during all cosmic evolution. This feature allows studied holographic ellipsoidal cosmologies to be ruled by an equation of state $\omega=p/\rho$, whose range belongs to quintessence or even phantom matter.
2303.16815
Celia Escamilla-Rivera
Laura L. Parrilla and Celia Escamilla-Rivera
Chameleon perfect scalar field as a geometric correction in $f(R)$ gravity
9 pages. Contribution to "Gravity, Cosmology and Astrophysics - A Journey of Exploration and Discovery with Female Pioneers". Springer Nature
null
null
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
In this work, we derive the analytical form for a $f(R)$ model that describes a perfect scalar field $\phi$ by assuming the existence of a chameleon mechanism. Based on four statements, at the background and perturbative level, it is possible to relate the extra terms from this theory as a geometrical perfect fluid term, whose has been expressed as possible candidates to explain the nature of the dark sector, and possibly, in the case of a perfect scalar chameleon during inflation, satisfy the big bang nucleosynthesis (BBN) constraints until late times.
[ { "created": "Wed, 29 Mar 2023 16:05:32 GMT", "version": "v1" } ]
2023-03-30
[ [ "Parrilla", "Laura L.", "" ], [ "Escamilla-Rivera", "Celia", "" ] ]
In this work, we derive the analytical form for a $f(R)$ model that describes a perfect scalar field $\phi$ by assuming the existence of a chameleon mechanism. Based on four statements, at the background and perturbative level, it is possible to relate the extra terms from this theory as a geometrical perfect fluid term, whose has been expressed as possible candidates to explain the nature of the dark sector, and possibly, in the case of a perfect scalar chameleon during inflation, satisfy the big bang nucleosynthesis (BBN) constraints until late times.
gr-qc/0004079
Atsushi Higuchi
A. Higuchi and S.S. Kouris
Large-distance behaviour of the graviton two-point function in de Sitter spacetime
19 pages, no figures, misprints and minor errors corrected
Class.Quant.Grav. 17 (2000) 3077-3090
10.1088/0264-9381/17/15/316
null
gr-qc hep-th
null
It is known that the graviton two-point function for the de Sitter invariant "Euclidean" vacuum in a physical gauge grows logarithmically with distance in spatially-flat de Sitter spacetime. We show that this logarithmic behaviour is a gauge artifact by explicitly demonstrating that the same behaviour can be reproduced by a pure-gauge two-point function.
[ { "created": "Thu, 27 Apr 2000 20:09:02 GMT", "version": "v1" }, { "created": "Fri, 7 Jul 2000 16:55:54 GMT", "version": "v2" } ]
2009-10-31
[ [ "Higuchi", "A.", "" ], [ "Kouris", "S. S.", "" ] ]
It is known that the graviton two-point function for the de Sitter invariant "Euclidean" vacuum in a physical gauge grows logarithmically with distance in spatially-flat de Sitter spacetime. We show that this logarithmic behaviour is a gauge artifact by explicitly demonstrating that the same behaviour can be reproduced by a pure-gauge two-point function.
2101.12248
LSC P&P Committee
The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration: R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, A. Adams, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, D. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, T. Akutsu, K. M. Aleman, G. Allen, A. Allocca, P. A. Altin, A. Amato, S. Anand, A. Ananyeva, S. B. Anderson, W. G. Anderson, M. Ando, S. V. Angelova, S. Ansoldi, J. M. Antelis, S. Antier, S. Appert, Koya Arai, Koji Arai, Y. Arai, S. Araki, A. Araya, M. C. Araya, J. S. Areeda, M. Ar\`ene, N. Aritomi, N. Arnaud, S. M. Aronson, H. Asada, Y. Asali, G. Ashton, Y. Aso, S. M. Aston, P. Astone, F. Aubin, P. Auclair, P. Aufmuth, K. AultONeal, C. Austin, S. Babak, F. Badaracco, M. K. M. Bader, S. Bae, Y. Bae, A. M. Baer, S. Bagnasco, Y. Bai, L. Baiotti, J. Baird, R. Bajpai, M. Ball, G. Ballardin, S. W. Ballmer, M. Bals, A. Balsamo, G. Baltus, S. Banagiri, D. Bankar, R. S. Bankar, J. C. Barayoga, C. Barbieri, B. C. Barish, D. Barker, P. Barneo, S. Barnum, F. Barone, B. Barr, L. Barsotti, M. Barsuglia, D. Barta, J. Bartlett, M. A. Barton, I. Bartos, R. Bassiri, A. Basti, M. Bawaj, J. C. Bayley, A. C. Baylor, M. Bazzan, B. B\'ecsy, V. M. Bedakihale, M. Bejger, I. Belahcene, V. Benedetto, D. Beniwal, M. G. Benjamin, T. F. Bennett, J. D. Bentley, M. BenYaala, F. Bergamin, B. K. Berger, S. Bernuzzi, D. Bersanetti, A. Bertolini, J. Betzwieser, R. Bhandare, A. V. Bhandari, D. Bhattacharjee, S. Bhaumik, J. Bidler, I. A. Bilenko, G. Billingsley, R. Birney, O. Birnholtz, S. Biscans, M. Bischi, S. Biscoveanu, A. Bisht, B. Biswas, M. Bitossi, M.-A. Bizouard, J. K. Blackburn, J. Blackman, C. D. Blair, D. G. Blair, R. M. Blair, F. Bobba, N. Bode, M. Boer, G. Bogaert, M. Boldrini, F. Bondu, E. Bonilla, R. Bonnand, P. Booker, B. A. Boom, R. Bork, V. Boschi, N. Bose, S. Bose, V. Bossilkov, V. Boudart, Y. Bouffanais, A. Bozzi, C. Bradaschia, P. R. Brady, A. Bramley, A. Branch, M. Branchesi, J. E. Brau, M. Breschi, T. Briant, J. H. Briggs, A. Brillet, M. Brinkmann, P. Brockill, A. F. Brooks, J. Brooks, D. D. Brown, S. Brunett, G. Bruno, R. Bruntz, J. Bryant, A. Buikema, T. Bulik, H. J. Bulten, A. Buonanno, R. Buscicchio, D. Buskulic, R. L. Byer, L. Cadonati, M. Caesar, G. Cagnoli, C. Cahillane, H. W. Cain III, J. Calder\'on Bustillo, J. D. Callaghan, T. A. Callister, E. Calloni, J. B. Camp, M. Canepa, M. Cannavacciuolo, K. C. Cannon, H. Cao, J. Cao, Z. Cao, E. Capocasa, E. Capote, G. Carapella, F. Carbognani, J. B. Carlin, M. F. Carney, M. Carpinelli, G. Carullo, T. L. Carver, J. Casanueva Diaz, C. Casentini, G. Castaldi, S. Caudill, M. Cavagli\`a, F. Cavalier, R. Cavalieri, G. Cella, P. Cerd\'a-Dur\'an, E. Cesarini, W. Chaibi, K. Chakravarti, B. Champion, C.-H. Chan, C. Chan, C. L. Chan, M. Chan, K. Chandra, P. Chanial, S. Chao, P. Charlton, E. A. Chase, E. Chassande-Mottin, D. Chatterjee, M. Chaturvedi, K. Chatziioannou, A. Chen, C. Chen, H. Y. Chen, J. Chen, K. Chen, X. Chen, Y.-B. Chen, Y.-R. Chen, Z. Chen, H. Cheng, C. K. Cheong, H. Y. Cheung, H. Y. Chia, F. Chiadini, C-Y. Chiang, R. Chierici, A. Chincarini, M. L. Chiofalo, A. Chiummo, G. Cho, H. S. Cho, S. Choate, R. K. Choudhary, S. Choudhary, N. Christensen, H. Chu, Q. Chu, Y-K. Chu, S. Chua, K. W. Chung, G. Ciani, P. Ciecielag, M. Cie\'slar, M. Cifaldi, A. A. Ciobanu, R. Ciolfi, F. Cipriano, A. Cirone, F. Clara, E. N. Clark, J. A. Clark, L. Clarke, P. Clearwater, S. Clesse, F. Cleva, E. Coccia, P.-F. Cohadon, D. E. Cohen, L. Cohen, M. Colleoni, C. G. Collette, M. Colpi, C. M. Compton, M. Constancio Jr., L. Conti, S. J. Cooper, P. Corban, T. R. Corbitt, I. Cordero-Carri\'on, S. Corezzi, K. R. Corley, N. Cornish, D. Corre, A. Corsi, S. Cortese, C. A. Costa, R. Cotesta, M. W. Coughlin, S. B. Coughlin, J.-P. Coulon, S. T. Countryman, B. Cousins, P. Couvares, P. B. Covas, D. M. Coward, M. J. Cowart, D. C. Coyne, R. Coyne, J. D. E. Creighton, T. D. Creighton, A. W. Criswell, M. Croquette, S. G. Crowder, J. R. Cudell, T. J. Cullen, A. Cumming, R. Cummings, E. Cuoco, M. Cury{\l}o, T. Dal Canton, G. D\'alya, A. Dana, L. M. DaneshgaranBajastani, B. D'Angelo, S. L. Danilishin, S. D'Antonio, K. Danzmann, C. Darsow-Fromm, A. Dasgupta, L. E. H. Datrier, V. Dattilo, I. Dave, M. Davier, G. S. Davies, D. Davis, E. J. Daw, R. Dean, D. DeBra, M. Deenadayalan, J. Degallaix, M. De Laurentis, S. Del\'eglise, V. Del Favero, F. De Lillo, N. De Lillo, W. Del Pozzo, L. M. DeMarchi, F. De Matteis, V. D'Emilio, N. Demos, T. Dent, A. Depasse, R. De Pietri, R. De Rosa, C. De Rossi, R. DeSalvo, R. De Simone, S. Dhurandhar, M. C. D\'iaz, M. Diaz-Ortiz Jr., N. A. Didio, T. Dietrich, L. Di Fiore, C. Di Fronzo, C. Di Giorgio, F. Di Giovanni, T. Di Girolamo, A. Di Lieto, B. Ding, S. Di Pace, I. Di Palma, F. Di Renzo, A. K. Divakarla, A. Dmitriev, Z. Doctor, L. D'Onofrio, F. Donovan, K. L. Dooley, S. Doravari, I. Dorrington, M. Drago, J. C. Driggers, Y. Drori, Z. Du, J.-G. Ducoin, P. Dupej, O. Durante, D. D'Urso, P.-A. Duverne, S. E. Dwyer, P. J. Easter, M. Ebersold, G. Eddolls, B. Edelman, T. B. Edo, O. Edy, A. Effler, S. Eguchi, J. Eichholz, S. S. Eikenberry, M. Eisenmann, R. A. Eisenstein, A. Ejlli, Y. Enomoto, L. Errico, R. C. Essick, H. Estell\'es, D. Estevez, Z. Etienne, T. Etzel, M. Evans, T. M. Evans, B. E. Ewing, V. Fafone, H. Fair, S. Fairhurst, X. Fan, A. M. Farah, S. Farinon, B. Farr, W. M. Farr, N. W. Farrow, E. J. Fauchon-Jones, M. Favata, M. Fays, M. Fazio, J. Feicht, M. M. Fejer, F. Feng, E. Fenyvesi, D. L. Ferguson, A. Fernandez-Galiana, I. Ferrante, T. A. Ferreira, F. Fidecaro, P. Figura, I. Fiori, M. Fishbach, R. P. Fisher, J. M. Fishner, R. Fittipaldi, V. Fiumara, R. Flaminio, E. Floden, E. Flynn, H. Fong, J. A. Font, B. Fornal, P. W. F. Forsyth, A. Franke, S. Frasca, F. Frasconi, C. Frederick, Z. Frei, A. Freise, R. Frey, P. Fritschel, V. V. Frolov, G. G. Fronz\'e, Y. Fujii, Y. Fujikawa, M. Fukunaga, M. Fukushima, P. Fulda, M. Fyffe, H. A. Gabbard, B. U. Gadre, S. M. Gaebel, J. R. Gair, J. Gais, S. Galaudage, R. Gamba, D. Ganapathy, A. Ganguly, D. Gao, S. G. Gaonkar, B. Garaventa, C. Garc\'ia-N\'u\~nez, C. Garc\'ia-Quir\'os, F. Garufi, B. Gateley, S. Gaudio, V. Gayathri, G. Ge, G. Gemme, A. Gennai, J. George, L. Gergely, P. Gewecke, S. Ghonge, Abhirup. Ghosh, Archisman Ghosh, Shaon Ghosh, Shrobana Ghosh, Sourath Ghosh, B. Giacomazzo, L. Giacoppo, J. A. Giaime, K. D. Giardina, D. R. Gibson, C. Gier, M. Giesler, P. Giri, F. Gissi, J. Glanzer, A. E. Gleckl, P. Godwin, E. Goetz, R. Goetz, N. Gohlke, B. Goncharov, G. Gonz\'alez, A. Gopakumar, M. Gosselin, R. Gouaty, B. Grace, A. Grado, M. Granata, V. Granata, A. Grant, S. Gras, P. Grassia, C. Gray, R. Gray, G. Greco, A. C. Green, R. Green, A. M. Gretarsson, E. M. Gretarsson, D. Griffith, W. Griffiths, H. L. Griggs, G. Grignani, A. Grimaldi, E. Grimes, S. J. Grimm, H. Grote, S. Grunewald, P. Gruning, J. G. Guerrero, G. M. Guidi, A. R. Guimaraes, G. Guix\'e, H. K. Gulati, H.-K. Guo, Y. Guo, Anchal Gupta, Anuradha Gupta, P. Gupta, E. K. Gustafson, R. Gustafson, F. Guzman, S. Ha, L. Haegel, A. Hagiwara, S. Haino, O. Halim, E. D. Hall, E. Z. Hamilton, G. Hammond, W.-B. Han, M. Haney, J. Hanks, C. Hanna, M. D. Hannam, O. A. Hannuksela, H. Hansen, T. J. Hansen, J. Hanson, T. Harder, T. Hardwick, K. Haris, J. Harms, G. M. Harry, I. W. Harry, D. Hartwig, K. Hasegawa, B. Haskell, R. K. Hasskew, C.-J. Haster, K. Hattori, K. Haughian, H. Hayakawa, K. Hayama, F. J. Hayes, J. Healy, A. Heidmann, M. C. Heintze, J. Heinze, J. Heinzel, H. Heitmann, F. Hellman, P. Hello, A. F. Helmling-Cornell, G. Hemming, M. Hendry, I. S. Heng, E. Hennes, J. Hennig, M. H. Hennig, F. Hernandez Vivanco, M. Heurs, S. Hild, P. Hill, Y. Himemoto, A. S. Hines, Y. Hiranuma, N. Hirata, E. Hirose, S. Hochheim, D. Hofman, J. N. Hohmann, A. M. Holgado, N. A. Holland, I. J. Hollows, Z. J. Holmes, K. Holt, D. E. Holz, Z. Hong, P. Hopkins, J. Hough, E. J. Howell, C. G. Hoy, D. Hoyland, A. Hreibi, B-H. Hsieh, Y. Hsu, G-Z. Huang, H-Y. Huang, P. Huang, Y-C. Huang, Y.-J. Huang, Y.-W. Huang, M. T. H\"ubner, A. D. Huddart, E. A. Huerta, B. Hughey, D. C. Y. Hui, V. Hui, S. Husa, S. H. Huttner, R. Huxford, T. Huynh-Dinh, S. Ide, B. Idzkowski, A. Iess, B. Ikenoue, S. Imam, K. Inayoshi, H. Inchauspe, C. Ingram, Y. Inoue, G. Intini, K. Ioka, M. Isi, K. Isleif, K. Ito, Y. Itoh, B. R. Iyer, K. Izumi, V. JaberianHamedan, T. Jacqmin, S. J. Jadhav, S. P. Jadhav, A. L. James, A. Z. Jan, K. Jani, K. Janssens, N. N. Janthalur, P. Jaranowski, D. Jariwala, R. Jaume, A. C. Jenkins, C. Jeon, M. Jeunon, W. Jia, J. Jiang, H.-B. Jin, G. R. Johns, A. W. Jones, D. I. Jones, J. D. Jones, P. Jones, R. Jones, R. J. G. Jonker, L. Ju, K. Jung, P. Jung, J. Junker, K. Kaihotsu, T. Kajita, M. Kakizaki, C. V. Kalaghatgi, V. Kalogera, B. Kamai, M. Kamiizumi, N. Kanda, S. Kandhasamy, G. Kang, J. B. Kanner, Y. Kao, S. J. Kapadia, D. P. Kapasi, C. Karathanasis, S. Karki, R. Kashyap, M. Kasprzack, W. Kastaun, S. Katsanevas, E. Katsavounidis, W. Katzman, T. Kaur, K. Kawabe, K. Kawaguchi, N. Kawai, T. Kawasaki, F. K\'ef\'elian, D. Keitel, J. S. Key, S. Khadka, F. Y. Khalili, I. Khan, S. Khan, E. A. Khazanov, N. Khetan, M. Khursheed, N. Kijbunchoo, C. Kim, J. C. Kim, J. Kim, K. Kim, W. S. Kim, Y.-M. Kim, C. Kimball, N. Kimura, P. J. King, M. Kinley-Hanlon, R. Kirchhoff, J. S. Kissel, N. Kita, H. Kitazawa, L. Kleybolte, S. Klimenko, A. M. Knee, T. D. Knowles, E. Knyazev, P. Koch, G. Koekoek, Y. Kojima, K. Kokeyama, S. Koley, P. Kolitsidou, M. Kolstein, K. Komori, V. Kondrashov, A. K. H. Kong, A. Kontos, N. Koper, M. Korobko, K. Kotake, M. Kovalam, D. B. Kozak, C. Kozakai, R. Kozu, V. Kringel, N. V. Krishnendu, A. Kr\'olak, G. Kuehn, F. Kuei, A. Kumar, P. Kumar, Rahul Kumar, Rakesh Kumar, J. Kume, K. Kuns, C. Kuo, H-S. Kuo, Y. Kuromiya, S. Kuroyanagi, K. Kusayanagi, K. Kwak, S. Kwang, D. Laghi, E. Lalande, T. L. Lam, A. Lamberts, M. Landry, B. B. Lane, R. N. Lang, J. Lange, B. Lantz, I. La Rosa, A. Lartaux-Vollard, P. D. Lasky, M. Laxen, A. Lazzarini, C. Lazzaro, P. Leaci, S. Leavey, Y. K. Lecoeuche, H. K. Lee, H. M. Lee, H. W. Lee, J. Lee, K. Lee, R. Lee, J. Lehmann, A. Lema\^itre, E. Leon, M. Leonardi, N. Leroy, N. Letendre, Y. Levin, J. N. Leviton, A. K. Y. Li, B. Li, J. Li, K. L. Li, T. G. F. Li, X. Li, C-Y. Lin, F-K. Lin, F-L. Lin, H. L. Lin, L. C.-C. Lin, F. Linde, S. D. Linker, J. N. Linley, T. B. Littenberg, G. C. Liu, J. Liu, K. Liu, X. Liu, M. Llorens-Monteagudo, R. K. L. Lo, A. Lockwood, M. L. Lollie, L. T. London, A. Longo, D. Lopez, M. Lorenzini, V. Loriette, M. Lormand, G. Losurdo, J. D. Lough, C. O. Lousto, G. Lovelace, H. L\"uck, D. Lumaca, A. P. Lundgren, L.-W. Luo, R. Macas, M. MacInnis, D. M. Macleod, I. A. O. MacMillan, A. Macquet, I. Maga\~na Hernandez, F. Maga\~na-Sandoval, C. Magazz\`u, R. M. Magee, R. Maggiore, E. Majorana, I. Maksimovic, S. Maliakal, A. Malik, N. Man, V. Mandic, V. Mangano, J. L. Mango, G. L. Mansell, M. Manske, M. Mantovani, F. Marchesoni, M. Marchio, F. Marion, Z. Mark, S. M\'arka, Z. M\'arka, C. Markakis, A. S. Markosyan, A. Markowitz, E. Maros, A. Marquina, S. Marsat, F. Martelli, I. W. Martin, R. M. Martin, M. Martinez, V. Martinez, K. Martinovic, D. V. Martynov, E. J. Marx, H. Masalehdan, K. Mason, E. Massera, A. Masserot, T. J. Massinger, M. Masso-Reid, S. Mastrogiovanni, A. Matas, M. Mateu-Lucena, F. Matichard, M. Matiushechkina, N. Mavalvala, J. J. McCann, R. McCarthy, D. E. McClelland, P. McClincy, S. McCormick, L. McCuller, G. I. McGhee, S. C. McGuire, C. McIsaac, J. McIver, D. J. McManus, T. McRae, S. T. McWilliams, D. Meacher, M. Mehmet, A. K. Mehta, A. Melatos, D. A. Melchor, G. Mendell, A. Menendez-Vazquez, C. S. Menoni, R. A. Mercer, L. Mereni, K. Merfeld, E. L. Merilh, J. D. Merritt, M. Merzougui, S. Meshkov, C. Messenger, C. Messick, P. M. Meyers, F. Meylahn, A. Mhaske, A. Miani, H. Miao, I. Michaloliakos, C. Michel, Y. Michimura, H. Middleton, L. Milano, A. L. Miller, M. Millhouse, J. C. Mills, E. Milotti, M. C. Milovich-Goff, O. Minazzoli, Y. Minenkov, N. Mio, Ll. M. Mir, A. Mishkin, C. Mishra, T. Mishra, T. Mistry, S. Mitra, V. P. Mitrofanov, G. Mitselmakher, R. Mittleman, O. Miyakawa, A. Miyamoto, Y. Miyazaki, K. Miyo, S. Miyoki, Geoffrey Mo, K. Mogushi, S. R. P. Mohapatra, S. R. Mohite, I. Molina, M. Molina-Ruiz, M. Mondin, M. Montani, C. J. Moore, D. Moraru, F. Morawski, A. More, C. Moreno, G. Moreno, Y. Mori, S. Morisaki, Y. Moriwaki, B. Mours, C. M. Mow-Lowry, S. Mozzon, F. Muciaccia, Arunava Mukherjee, D. Mukherjee, Soma Mukherjee, Subroto Mukherjee, N. Mukund, A. Mullavey, J. Munch, E. A. Mu\~niz, P. G. Murray, R. Musenich, S. L. Nadji, K. Nagano, S. Nagano, K. Nakamura, H. Nakano, M. Nakano, R. Nakashima, Y. Nakayama, I. Nardecchia, T. Narikawa, L. Naticchioni, B. Nayak, R. K. Nayak, R. Negishi, B. F. Neil, J. Neilson, G. Nelemans, T. J. N. Nelson, M. Nery, A. Neunzert, K. Y. Ng, S. W. S. Ng, C. Nguyen, P. Nguyen, T. Nguyen, L. Nguyen Quynh, W.-T. Ni, S. A. Nichols, A. Nishizawa, S. Nissanke, F. Nocera, M. Noh, M. Norman, C. North, S. Nozaki, L. K. Nuttall, J. Oberling, B. D. O'Brien, Y. Obuchi, J. O'Dell, W. Ogaki, G. Oganesyan, J. J. Oh, K. Oh, S. H. Oh, M. Ohashi, N. Ohishi, M. Ohkawa, F. Ohme, H. Ohta, M. A. Okada, Y. Okutani, K. Okutomi, C. Olivetto, K. Oohara, C. Ooi, R. Oram, B. O'Reilly, R. G. Ormiston, N. D. Ormsby, L. F. Ortega, R. O'Shaughnessy, E. O'Shea, S. Oshino, S. Ossokine, C. Osthelder, S. Otabe, D. J. Ottaway, H. Overmier, A. E. Pace, G. Pagano, M. A. Page, G. Pagliaroli, A. Pai, S. A. Pai, J. R. Palamos, O. Palashov, C. Palomba, K. Pan, P. K. Panda, H. Pang, P. T. H. Pang, C. Pankow, F. Pannarale, B. C. Pant, F. Paoletti, A. Paoli, A. Paolone, A. Parisi, J. Park, W. Parker, D. Pascucci, A. Pasqualetti, R. Passaquieti, D. Passuello, M. Patel, B. Patricelli, E. Payne, T. C. Pechsiri, M. Pedraza, M. Pegoraro, A. Pele, F. E. Pe\~na Arellano, S. Penn, A. Perego, A. Pereira, T. Pereira, C. J. Perez, C. P\'erigois, A. Perreca, S. Perri\`es, J. Petermann, D. Petterson, H. P. Pfeiffer, K. A. Pham, K. S. Phukon, O. J. Piccinni, M. Pichot, M. Piendibene, F. Piergiovanni, L. Pierini, V. Pierro, G. Pillant, F. Pilo, L. Pinard, I. M. Pinto, B. J. Piotrzkowski, K. Piotrzkowski, M. Pirello, M. Pitkin, E. Placidi, W. Plastino, C. Pluchar, R. Poggiani, E. Polini, D. Y. T. Pong, S. Ponrathnam, P. Popolizio, E. K. Porter, J. Powell, M. Pracchia, T. Pradier, A. K. Prajapati, K. Prasai, R. Prasanna, G. Pratten, T. Prestegard, M. Principe, G. A. Prodi, L. Prokhorov, P. Prosposito, L. Prudenzi, A. Puecher, M. Punturo, F. Puosi, P. Puppo, M. P\"urrer, H. Qi, V. Quetschke, P. J. Quinonez, R. Quitzow-James, F. J. Raab, G. Raaijmakers, H. Radkins, N. Radulesco, P. Raffai, S. X. Rail, S. Raja, C. Rajan, K. E. Ramirez, T. D. Ramirez, A. Ramos-Buades, J. Rana, P. Rapagnani, U. D. Rapol, B. Ratto, V. Raymond, N. Raza, M. Razzano, J. Read, L. A. Rees, T. Regimbau, L. Rei, S. Reid, D. H. Reitze, P. Relton, P. Rettegno, F. Ricci, C. J. Richardson, J. W. Richardson, L. Richardson, P. M. Ricker, G. Riemenschneider, K. Riles, M. Rizzo, N. A. Robertson, R. Robie, F. Robinet, A. Rocchi, J. A. Rocha, S. Rodriguez, R. D. Rodriguez-Soto, L. Rolland, J. G. Rollins, V. J. Roma, M. Romanelli, R. Romano, C. L. Romel, A. Romero, I. M. Romero-Shaw, J. H. Romie, C. A. Rose, D. Rosi\'nska, S. G. Rosofsky, M. P. Ross, S. Rowan, S. J. Rowlinson, Santosh Roy, Soumen Roy, D. Rozza, P. Ruggi, K. Ryan, S. Sachdev, T. Sadecki, J. Sadiq, N. Sago, S. Saito, Y. Saito, K. Sakai, Y. Sakai, M. Sakellariadou, Y. Sakuno, O. S. Salafia, L. Salconi, M. Saleem, F. Salemi, A. Samajdar, E. J. Sanchez, J. H. Sanchez, L. E. Sanchez, N. Sanchis-Gual, J. R. Sanders, A. Sanuy, T. R. Saravanan, N. Sarin, B. Sassolas, H. Satari, S. Sato, T. Sato, O. Sauter, R. L. Savage, V. Savant, T. Sawada, D. Sawant, H. L. Sawant, S. Sayah, D. Schaetzl, M. Scheel, J. Scheuer, A. Schindler-Tyka, P. Schmidt, R. Schnabel, M. Schneewind, R. M. S. Schofield, A. Sch\"onbeck, B. W. Schulte, B. F. Schutz, E. Schwartz, J. Scott, S. M. Scott, M. Seglar-Arroyo, E. Seidel, T. Sekiguchi, Y. Sekiguchi, D. Sellers, A. Sergeev, A. S. Sengupta, N. Sennett, D. Sentenac, E. G. Seo, V. Sequino, Y. Setyawati, T. Shaffer, M. S. Shahriar, B. Shams, L. Shao, S. Sharifi, A. Sharma, P. Sharma, P. Shawhan, N. S. Shcheblanov, H. Shen, S. Shibagaki, M. Shikauchi, R. Shimizu, T. Shimoda, K. Shimode, R. Shink, H. Shinkai, T. Shishido, A. Shoda, D. H. Shoemaker, D. M. Shoemaker, K. Shukla, S. ShyamSundar, M. Sieniawska, D. Sigg, L. P. Singer, D. Singh, N. Singh, A. Singha, A. M. Sintes, V. Sipala, V. Skliris, B. J. J. Slagmolen, T. J. Slaven-Blair, J. Smetana, J. R. Smith, R. J. E. Smith, S. N. Somala, K. Somiya, E. J. Son, K. Soni, S. Soni, B. Sorazu, V. Sordini, F. Sorrentino, N. Sorrentino, H. Sotani, R. Soulard, T. Souradeep, E. Sowell, V. Spagnuolo, A. P. Spencer, M. Spera, A. K. Srivastava, V. Srivastava, K. Staats, C. Stachie, D. A. Steer, J. Steinlechner, S. Steinlechner, D. J. Stops, M. Stover, K. A. Strain, L. C. Strang, G. Stratta, A. Strunk, R. Sturani, A. L. Stuver, J. S\"udbeck, S. Sudhagar, V. Sudhir, R. Sugimoto, H. G. Suh, T. Z. Summerscales, H. Sun, L. Sun, S. Sunil, A. Sur, J. Suresh, P. J. Sutton, Takamasa Suzuki, Toshikazu Suzuki, B. L. Swinkels, M. J. Szczepa\'nczyk, P. Szewczyk, M. Tacca, H. Tagoshi, S. C. Tait, H. Takahashi, R. Takahashi, A. Takamori, S. Takano, H. Takeda, M. Takeda, C. Talbot, H. Tanaka, Kazuyuki Tanaka, Kenta Tanaka, Taiki Tanaka, Takahiro Tanaka, A. J. Tanasijczuk, S. Tanioka, D. B. Tanner, D. Tao, A. Tapia, E. N. Tapia San Martin, E. N. Tapia San Martin, J. D. Tasson, S. Telada, R. Tenorio, L. Terkowski, M. Test, M. P. Thirugnanasambandam, M. Thomas, P. Thomas, J. E. Thompson, S. R. Thondapu, K. A. Thorne, E. Thrane, Shubhanshu Tiwari, Srishti Tiwari, V. Tiwari, K. Toland, A. E. Tolley, T. Tomaru, Y. Tomigami, T. Tomura, M. Tonelli, A. Torres-Forn\'e, C. I. Torrie, I. Tosta e Melo, D. T\"oyr\"a, A. Trapananti, F. Travasso, G. Traylor, M. C. Tringali, A. Tripathee, L. Troiano, A. Trovato, L. Trozzo, R. J. Trudeau, D. S. Tsai, D. Tsai, K. W. Tsang, T. Tsang, J-S. Tsao, M. Tse, R. Tso, K. Tsubono, S. Tsuchida, L. Tsukada, D. Tsuna, T. Tsutsui, T. Tsuzuki, M. Turconi, D. Tuyenbayev, A. S. Ubhi, N. Uchikata, T. Uchiyama, R. P. Udall, A. Ueda, T. Uehara, K. Ueno, G. Ueshima, D. Ugolini, C. S. Unnikrishnan, F. Uraguchi, A. L. Urban, T. Ushiba, S. A. Usman, A. C. Utina, H. Vahlbruch, G. Vajente, A. Vajpeyi, G. Valdes, M. Valentini, V. Valsan, N. van Bakel, M. van Beuzekom, J. F. J. van den Brand, C. Van Den Broeck, D. C. Vander-Hyde, L. van der Schaaf, J. V. van Heijningen, M. H. P. M. van Putten, N. van Remortel, M. Vardaro, A. F. Vargas, V. Varma, M. Vas\'uth, A. Vecchio, G. Vedovato, J. Veitch, P. J. Veitch, K. Venkateswara, J. Venneberg, G. Venugopalan, D. Verkindt, Y. Verma, D. Veske, F. Vetrano, A. Vicer\'e, A. D. Viets, V. Villa-Ortega, J.-Y. Vinet, S. Vitale, T. Vo, H. Vocca, E. R. G. von Reis, J. von Wrangel, C. Vorvick, S. P. Vyatchanin, L. E. Wade, M. Wade, K. J. Wagner, R. C. Walet, M. Walker, G. S. Wallace, L. Wallace, S. Walsh, J. Wang, J. Z. Wang, W. H. Wang, R. L. Ward, J. Warner, M. Was, T. Washimi, N. Y. Washington, J. Watchi, B. Weaver, L. Wei, M. Weinert, A. J. Weinstein, R. Weiss, C. M. Weller, F. Wellmann, L. Wen, P. We{\ss}els, J. W. Westhouse, K. Wette, J. T. Whelan, D. D. White, B. F. Whiting, C. Whittle, D. Wilken, D. Williams, M. J. Williams, A. R. Williamson, J. L. Willis, B. Willke, D. J. Wilson, W. Winkler, C. C. Wipf, T. Wlodarczyk, G. Woan, J. Woehler, J. K. Wofford, I. C. F. Wong, C. Wu, D. S. Wu, H. Wu, S. Wu, D. M. Wysocki, L. Xiao, W-R. Xu, T. Yamada, H. Yamamoto, Kazuhiro Yamamoto, Kohei Yamamoto, T. Yamamoto, K. Yamashita, R. Yamazaki, F. W. Yang, L. Yang, Yang Yang, Yi Yang, Z. Yang, M. J. Yap, D. W. Yeeles, A. B. Yelikar, M. Ying, K. Yokogawa, J. Yokoyama, T. Yokozawa, A. Yoon, T. Yoshioka, Hang Yu, Haocun Yu, H. Yuzurihara, A. Zadro\.zny, M. Zanolin, S. Zeidler, T. Zelenova, J.-P. Zendri, M. Zevin, M. Zhan, H. Zhang, J. Zhang, L. Zhang, R. Zhang, T. Zhang, C. Zhao, G. Zhao, Yue Zhao, Yuhang Zhao, Z. Zhou, X. J. Zhu, Z.-H. Zhu, M. E. Zucker, J. Zweizig
Constraints on cosmic strings using data from the third Advanced LIGO-Virgo observing run
20 pages, 10 figures
Phys. Rev. Lett. 126, 241102 (2021)
10.1103/PhysRevLett.126.241102
LIGO-P2000506
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 data set. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks and, for the first time, kink-kink collisions.cA template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension, $G\mu$, as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models.cAdditionally, we develop and test a third model which interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on $G\mu$ by one to two orders of magnitude depending on the model which is tested. In particular, for one loop distribution model, we set the most competitive constraints to date, $G\mu\lesssim 4\times 10^{-15}$.
[ { "created": "Thu, 28 Jan 2021 19:35:49 GMT", "version": "v1" } ]
2021-06-23
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K.", "" ], [ "Bernuzzi", "S.", "" ], [ "Bersanetti", "D.", "" ], [ "Bertolini", "A.", "" ], [ "Betzwieser", "J.", "" ], [ "Bhandare", "R.", "" ], [ "Bhandari", "A. V.", "" ], [ "Bhattacharjee", "D.", "" ], [ "Bhaumik", "S.", "" ], [ "Bidler", "J.", "" ], [ "Bilenko", "I. A.", "" ], [ "Billingsley", "G.", "" ], [ "Birney", "R.", "" ], [ "Birnholtz", "O.", "" ], [ "Biscans", "S.", "" ], [ "Bischi", "M.", "" ], [ "Biscoveanu", "S.", "" ], [ "Bisht", "A.", "" ], [ "Biswas", "B.", "" ], [ "Bitossi", "M.", "" ], [ "Bizouard", "M. -A.", "" ], [ "Blackburn", "J. K.", "" ], [ "Blackman", "J.", "" ], [ "Blair", "C. D.", "" ], [ "Blair", "D. G.", "" ], [ "Blair", "R. M.", "" ], [ "Bobba", "F.", "" ], [ "Bode", "N.", "" ], [ "Boer", "M.", "" ], [ "Bogaert", "G.", "" ], [ "Boldrini", "M.", "" ], [ "Bondu", "F.", "" ], [ "Bonilla", "E.", "" ], [ "Bonnand", "R.", "" ], [ "Booker", "P.", "" ], [ "Boom", "B. A.", "" ], [ "Bork", "R.", "" ], [ "Boschi", "V.", "" ], [ "Bose", "N.", "" ], [ "Bose", "S.", "" ], [ "Bossilkov", "V.", "" ], [ "Boudart", "V.", "" ], [ "Bouffanais", "Y.", "" ], [ "Bozzi", "A.", "" ], [ "Bradaschia", "C.", "" ], [ "Brady", "P. R.", "" ], [ "Bramley", "A.", "" ], [ "Branch", "A.", "" ], [ "Branchesi", "M.", "" ], [ "Brau", "J. E.", "" ], [ "Breschi", "M.", "" ], [ "Briant", "T.", "" ], [ "Briggs", "J. H.", "" ], [ "Brillet", "A.", "" ], [ "Brinkmann", "M.", "" ], [ "Brockill", "P.", "" ], [ "Brooks", "A. F.", "" ], [ "Brooks", "J.", "" ], [ "Brown", "D. D.", "" ], [ "Brunett", "S.", "" ], [ "Bruno", "G.", "" ], [ "Bruntz", "R.", "" ], [ "Bryant", "J.", "" ], [ "Buikema", "A.", "" ], [ "Bulik", "T.", "" ], [ "Bulten", "H. J.", "" ], [ "Buonanno", "A.", "" ], [ "Buscicchio", "R.", "" ], [ "Buskulic", "D.", "" ], [ "Byer", "R. L.", "" ], [ "Cadonati", "L.", "" ], [ "Caesar", "M.", "" ], [ "Cagnoli", "G.", "" ], [ "Cahillane", "C.", "" ], [ "Cain", "H. 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S.", "" ], [ "Wallace", "L.", "" ], [ "Walsh", "S.", "" ], [ "Wang", "J.", "" ], [ "Wang", "J. Z.", "" ], [ "Wang", "W. H.", "" ], [ "Ward", "R. L.", "" ], [ "Warner", "J.", "" ], [ "Was", "M.", "" ], [ "Washimi", "T.", "" ], [ "Washington", "N. Y.", "" ], [ "Watchi", "J.", "" ], [ "Weaver", "B.", "" ], [ "Wei", "L.", "" ], [ "Weinert", "M.", "" ], [ "Weinstein", "A. J.", "" ], [ "Weiss", "R.", "" ], [ "Weller", "C. M.", "" ], [ "Wellmann", "F.", "" ], [ "Wen", "L.", "" ], [ "Weßels", "P.", "" ], [ "Westhouse", "J. W.", "" ], [ "Wette", "K.", "" ], [ "Whelan", "J. T.", "" ], [ "White", "D. D.", "" ], [ "Whiting", "B. F.", "" ], [ "Whittle", "C.", "" ], [ "Wilken", "D.", "" ], [ "Williams", "D.", "" ], [ "Williams", "M. J.", "" ], [ "Williamson", "A. R.", "" ], [ "Willis", "J. L.", "" ], [ "Willke", "B.", "" ], [ "Wilson", "D. J.", "" ], [ "Winkler", "W.", "" ], [ "Wipf", "C. C.", "" ], [ "Wlodarczyk", "T.", "" ], [ "Woan", "G.", "" ], [ "Woehler", "J.", "" ], [ "Wofford", "J. K.", "" ], [ "Wong", "I. C. F.", "" ], [ "Wu", "C.", "" ], [ "Wu", "D. S.", "" ], [ "Wu", "H.", "" ], [ "Wu", "S.", "" ], [ "Wysocki", "D. M.", "" ], [ "Xiao", "L.", "" ], [ "Xu", "W-R.", "" ], [ "Yamada", "T.", "" ], [ "Yamamoto", "H.", "" ], [ "Yamamoto", "Kazuhiro", "" ], [ "Yamamoto", "Kohei", "" ], [ "Yamamoto", "T.", "" ], [ "Yamashita", "K.", "" ], [ "Yamazaki", "R.", "" ], [ "Yang", "F. W.", "" ], [ "Yang", "L.", "" ], [ "Yang", "Yang", "" ], [ "Yang", "Yi", "" ], [ "Yang", "Z.", "" ], [ "Yap", "M. J.", "" ], [ "Yeeles", "D. W.", "" ], [ "Yelikar", "A. B.", "" ], [ "Ying", "M.", "" ], [ "Yokogawa", "K.", "" ], [ "Yokoyama", "J.", "" ], [ "Yokozawa", "T.", "" ], [ "Yoon", "A.", "" ], [ "Yoshioka", "T.", "" ], [ "Yu", "Hang", "" ], [ "Yu", "Haocun", "" ], [ "Yuzurihara", "H.", "" ], [ "Zadrożny", "A.", "" ], [ "Zanolin", "M.", "" ], [ "Zeidler", "S.", "" ], [ "Zelenova", "T.", "" ], [ "Zendri", "J. -P.", "" ], [ "Zevin", "M.", "" ], [ "Zhan", "M.", "" ], [ "Zhang", "H.", "" ], [ "Zhang", "J.", "" ], [ "Zhang", "L.", "" ], [ "Zhang", "R.", "" ], [ "Zhang", "T.", "" ], [ "Zhao", "C.", "" ], [ "Zhao", "G.", "" ], [ "Zhao", "Yue", "" ], [ "Zhao", "Yuhang", "" ], [ "Zhou", "Z.", "" ], [ "Zhu", "X. J.", "" ], [ "Zhu", "Z. -H.", "" ], [ "Zucker", "M. E.", "" ], [ "Zweizig", "J.", "" ] ]
We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 data set. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks and, for the first time, kink-kink collisions.cA template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension, $G\mu$, as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models.cAdditionally, we develop and test a third model which interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on $G\mu$ by one to two orders of magnitude depending on the model which is tested. In particular, for one loop distribution model, we set the most competitive constraints to date, $G\mu\lesssim 4\times 10^{-15}$.
2207.05858
Siddarth Ajith
Siddarth Ajith, Kent Yagi, Nicol\'as Yunes
I-Love-Q in Ho\v{r}ava-Lifshitz Gravity
18 pages. Added a new Appendix, added additional explanation to Sects. II and III, and added a small clarification to Sect. V, no change to main results
null
10.1103/PhysRevD.106.124002
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ho\v{r}ava-Lifshitz gravity is an alternative theory to general relativity which breaks Lorentz invariance in order to achieve an ultraviolet complete and power-counting renormalizable theory of gravity. In the low energy limit, Ho\v{r}ava-Lifshitz gravity coincides with a vector-tensor theory known as khronometric gravity. The deviation of khronometric gravity from general relativity can be parametrized by three coupling constants: $\alpha$, $\beta$, and $\lambda$. Solar system experiments and gravitational wave observations impose stringent bounds on $\alpha$ and $\beta$, while $\lambda$ is still relatively unconstrained ($\lambda\lesssim 0.01$). In this paper, we study whether one can constrain this remaining parameter with neutron star observations through the universal I-Love-Q relations between the moment of inertia (I), the tidal Love number (Love), and the quadrupole moment (Q), which are insensitive to details in the nuclear matter equation of state. To do so, we perturbatively construct slowly-rotating and weakly tidally-deformed neutron stars in khronometric gravity. We find that the I-Love-Q relations are independent of $\lambda$ in the limit $(\alpha,\beta) \to 0$. Although some components of the field equations depend on $\lambda$, we show through induction and a post-Minkowskian analysis that slowly-rotating neutron stars do not depend on $\lambda$ at all. Tidally deformed neutron stars, on the other hand, are modified in khronometric gravity (though the usual Love number is not modified, as mentioned earlier), and there are potentially new, non-GR Love numbers, though their observability is unclear. These findings indicate that it may be difficult to constrain $\lambda$ with rotating/tidally-deformed neutron stars.
[ { "created": "Tue, 12 Jul 2022 21:46:53 GMT", "version": "v1" }, { "created": "Mon, 12 Dec 2022 01:00:25 GMT", "version": "v2" } ]
2022-12-13
[ [ "Ajith", "Siddarth", "" ], [ "Yagi", "Kent", "" ], [ "Yunes", "Nicolás", "" ] ]
Ho\v{r}ava-Lifshitz gravity is an alternative theory to general relativity which breaks Lorentz invariance in order to achieve an ultraviolet complete and power-counting renormalizable theory of gravity. In the low energy limit, Ho\v{r}ava-Lifshitz gravity coincides with a vector-tensor theory known as khronometric gravity. The deviation of khronometric gravity from general relativity can be parametrized by three coupling constants: $\alpha$, $\beta$, and $\lambda$. Solar system experiments and gravitational wave observations impose stringent bounds on $\alpha$ and $\beta$, while $\lambda$ is still relatively unconstrained ($\lambda\lesssim 0.01$). In this paper, we study whether one can constrain this remaining parameter with neutron star observations through the universal I-Love-Q relations between the moment of inertia (I), the tidal Love number (Love), and the quadrupole moment (Q), which are insensitive to details in the nuclear matter equation of state. To do so, we perturbatively construct slowly-rotating and weakly tidally-deformed neutron stars in khronometric gravity. We find that the I-Love-Q relations are independent of $\lambda$ in the limit $(\alpha,\beta) \to 0$. Although some components of the field equations depend on $\lambda$, we show through induction and a post-Minkowskian analysis that slowly-rotating neutron stars do not depend on $\lambda$ at all. Tidally deformed neutron stars, on the other hand, are modified in khronometric gravity (though the usual Love number is not modified, as mentioned earlier), and there are potentially new, non-GR Love numbers, though their observability is unclear. These findings indicate that it may be difficult to constrain $\lambda$ with rotating/tidally-deformed neutron stars.
1402.7288
Mauricio Bellini
Jes\'us Mart\'in Romero (IFIMAR - UNMdP and CONICET), Mauricio Bellini (IFIMAR - UNMdP and CONICET)
Gravitomagnetic currents in the inflationary universe from WIMT
Version to be published in European Phys. J. C
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using the Weitzenb\"ock representation of a Riemann-flat 5D spacetime, we study the possible existence of primordial gravito-magnetic currents from Gravito-electromagnetic Inflation (GEMI). We found that these currents decrease exponentially in the Weitzenb\"ock representation, but they are null in a Levi-Civita representation because we are dealing with a 5D Riemann-flat spacetime without structure or torsion.
[ { "created": "Fri, 28 Feb 2014 15:52:12 GMT", "version": "v1" }, { "created": "Thu, 24 Apr 2014 19:59:08 GMT", "version": "v2" }, { "created": "Wed, 20 Aug 2014 15:14:16 GMT", "version": "v3" }, { "created": "Fri, 5 Sep 2014 20:22:12 GMT", "version": "v4" } ]
2014-09-09
[ [ "Romero", "Jesús Martín", "", "IFIMAR - UNMdP and CONICET" ], [ "Bellini", "Mauricio", "", "IFIMAR - UNMdP and CONICET" ] ]
Using the Weitzenb\"ock representation of a Riemann-flat 5D spacetime, we study the possible existence of primordial gravito-magnetic currents from Gravito-electromagnetic Inflation (GEMI). We found that these currents decrease exponentially in the Weitzenb\"ock representation, but they are null in a Levi-Civita representation because we are dealing with a 5D Riemann-flat spacetime without structure or torsion.
gr-qc/0607038
Ioannis Raptis
Ioannis Raptis
A Dodecalogue of Basic Didactics from Applications of Abstract Differential Geometry to Quantum Gravity
16 pages, preliminary version
Int.J.Theor.Phys.46:3009-3021,2007
10.1007/s10773-007-9416-0
null
gr-qc
null
We summarize the twelve most important in our view novel concepts that have arisen, based on results that have been obtained, from various applications of Abstract Differential Geometry (ADG) to Quantum Gravity (QG). The present document may be used as a concise, yet informal, discursive and peripatetic conceptual guide-cum-terminological glossary to the voluminous technical research literature on the subject. In a bonus section at the end, we dwell on the significance of introducing new conceptual terminology in future QG research by means of `poetic language'
[ { "created": "Mon, 10 Jul 2006 14:38:35 GMT", "version": "v1" } ]
2008-11-26
[ [ "Raptis", "Ioannis", "" ] ]
We summarize the twelve most important in our view novel concepts that have arisen, based on results that have been obtained, from various applications of Abstract Differential Geometry (ADG) to Quantum Gravity (QG). The present document may be used as a concise, yet informal, discursive and peripatetic conceptual guide-cum-terminological glossary to the voluminous technical research literature on the subject. In a bonus section at the end, we dwell on the significance of introducing new conceptual terminology in future QG research by means of `poetic language'
gr-qc/9510055
Andrew Chubykalo
Andrew E. Chubykalo (EFUAZ, Zacatecas)
Principle of Mach, the Equivalence Principle and concepts of inertial mass
ReVTeX file, 9pp., no figures
Hadronic J. 19 (1996) 607
null
EFUAZ FT-95-21-REV
gr-qc
null
A study of kinematics of a 2-body system is used to show that the Mach principle, previously rejected by general relativity, can still serve as an alternative to the concept of absolute space, if one takes into account that the background of distant stars (galaxies) determines {\it both} the inertial and the gravitational masses of a body.
[ { "created": "Fri, 27 Oct 1995 03:14:05 GMT", "version": "v1" }, { "created": "Wed, 7 Aug 1996 20:17:52 GMT", "version": "v2" } ]
2008-02-03
[ [ "Chubykalo", "Andrew E.", "", "EFUAZ, Zacatecas" ] ]
A study of kinematics of a 2-body system is used to show that the Mach principle, previously rejected by general relativity, can still serve as an alternative to the concept of absolute space, if one takes into account that the background of distant stars (galaxies) determines {\it both} the inertial and the gravitational masses of a body.
gr-qc/0303046
Vladimir Mashkevich
Vladimir S. Mashkevich (CUNY)
Cosmological Quantum Jump Dynamics II. The Retrodictive Universe
8 pages, LATEX 2e
null
null
null
gr-qc quant-ph
null
This paper is a continuation of the paper gr-qc/0203045 and is devoted to the problem of the arrow of time. A deterministic past-directed dynamics is constructed, which results in the retrodictive universe. A future-directed dynamics of the latter is indeterministic and reproduces standard probabilistic quantum dynamics. The arrow of time is inherent in the retrodictive universe as well as a future-directed increase of informational entropy.
[ { "created": "Wed, 12 Mar 2003 03:37:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Mashkevich", "Vladimir S.", "", "CUNY" ] ]
This paper is a continuation of the paper gr-qc/0203045 and is devoted to the problem of the arrow of time. A deterministic past-directed dynamics is constructed, which results in the retrodictive universe. A future-directed dynamics of the latter is indeterministic and reproduces standard probabilistic quantum dynamics. The arrow of time is inherent in the retrodictive universe as well as a future-directed increase of informational entropy.
2010.12387
Sajal Mukherjee
Sayak Datta and Sajal Mukherjee
Possible connection between the reflection symmetry and existence of equatorial circular orbit
9 pages, 2 figures
Phys. Rev. D 103, 104032 (2021)
10.1103/PhysRevD.103.104032
null
gr-qc astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a viable connection between the circular-equatorial orbits and reflection symmetry across the equatorial plane of a vacuum stationary axis-symmetric spacetime in general relativity. The behavior of the circular equatorial orbits in the direction perpendicular to the equatorial plane is studied, and different outcomes in the presence and in the absence of the reflection symmetry are discussed. We conclude that in the absence of the equatorial reflection symmetry neither stable nor unstable circular orbit can exist on the equatorial plane. Moreover, to address the observational aspects, we provide two possible examples relating gravitational wave astronomy and the thin accretion disk which can put constraints on the symmetry breaking parameters.
[ { "created": "Fri, 23 Oct 2020 13:23:05 GMT", "version": "v1" }, { "created": "Thu, 10 Jun 2021 16:16:59 GMT", "version": "v2" } ]
2021-07-29
[ [ "Datta", "Sayak", "" ], [ "Mukherjee", "Sajal", "" ] ]
We study a viable connection between the circular-equatorial orbits and reflection symmetry across the equatorial plane of a vacuum stationary axis-symmetric spacetime in general relativity. The behavior of the circular equatorial orbits in the direction perpendicular to the equatorial plane is studied, and different outcomes in the presence and in the absence of the reflection symmetry are discussed. We conclude that in the absence of the equatorial reflection symmetry neither stable nor unstable circular orbit can exist on the equatorial plane. Moreover, to address the observational aspects, we provide two possible examples relating gravitational wave astronomy and the thin accretion disk which can put constraints on the symmetry breaking parameters.
0910.5763
Olivier Sarbach
Dario Nunez and Olivier Sarbach
Boundary conditions for the Baumgarte-Shapiro-Shibata-Nakamura formulation of Einstein's field equations
20 pages, no figures, small corrections in order to match published version
Phys.Rev.D81:044011,2010
10.1103/PhysRevD.81.044011
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the initial-boundary value problem for the Baumgarte-Shapiro-Shibata-Nakamura evolution system of Einstein's field equations which has been used extensively in numerical simulations of binary black holes and neutron stars. We specify nine boundary conditions for this system with the following properties: (i) they impose the momentum constraint at the boundary, which is shown to preserve all the constraints throughout evolution, (ii) they approximately control the incoming gravitational degrees of freedom by specifying the Weyl scalar Psi_0 at the boundary, (iii) they control the gauge freedom by requiring a Neumann boundary condition for the lapse, by setting the normal component of the shift to zero, and by imposing a Sommerfeld-like condition on the tangential components of the shift, (iv) they are shown to yield a well-posed problem in the limit of weak gravity. Possible numerical applications of our results are also discussed briefly.
[ { "created": "Fri, 30 Oct 2009 00:59:20 GMT", "version": "v1" }, { "created": "Thu, 11 Feb 2010 15:21:57 GMT", "version": "v2" } ]
2010-04-06
[ [ "Nunez", "Dario", "" ], [ "Sarbach", "Olivier", "" ] ]
We discuss the initial-boundary value problem for the Baumgarte-Shapiro-Shibata-Nakamura evolution system of Einstein's field equations which has been used extensively in numerical simulations of binary black holes and neutron stars. We specify nine boundary conditions for this system with the following properties: (i) they impose the momentum constraint at the boundary, which is shown to preserve all the constraints throughout evolution, (ii) they approximately control the incoming gravitational degrees of freedom by specifying the Weyl scalar Psi_0 at the boundary, (iii) they control the gauge freedom by requiring a Neumann boundary condition for the lapse, by setting the normal component of the shift to zero, and by imposing a Sommerfeld-like condition on the tangential components of the shift, (iv) they are shown to yield a well-posed problem in the limit of weak gravity. Possible numerical applications of our results are also discussed briefly.
2401.04584
Mirzabek Alloqulov
Ahmad Al-Badawi, Mirzabek Alloqulov, Sanjar Shaymatov and Bobomurat Ahmedov
Shadows and weak gravitational lensing by the black hole in Einstein-Maxwell-scalar theory
9 pages, one table, 9 captioned figures, Accepted for publication in Chinese Physics C
null
10.1088/1674-1137/ad5a70
null
gr-qc
http://creativecommons.org/licenses/by-nc-nd/4.0/
In this paper, we investigate the optical properties of a charged black hole in Einstein-Maxwell-scalar (EMS) theory. We evaluate the shadow cast by the black hole and obtain analytical solutions for both the radius of the photon sphere and the shadow radius. We observe that the black hole parameters $\gamma$ and $\beta$ both influence the shadow of black hole. It is shown that the photon sphere and the shadow radius increase as a consequence of the presence of parameter $\gamma$. Interestingly, we show that shadow radius decreases first and then remains unchanged due to the impact of parameter $\beta$. Finally, we consider the weak gravitational lensing and the total magnification of lensed images around black hole. We find that the black hole charge and parameter $\beta$ both give rise to a significant effect, reducing the deflection angle. Similarly, the same behavior for the total magnification is observed due to the effect of black hole charge and parameter $\beta$.
[ { "created": "Tue, 9 Jan 2024 14:41:36 GMT", "version": "v1" }, { "created": "Thu, 11 Jan 2024 06:52:57 GMT", "version": "v2" }, { "created": "Mon, 11 Mar 2024 13:09:21 GMT", "version": "v3" }, { "created": "Tue, 12 Mar 2024 05:42:09 GMT", "version": "v4" }, { "created": "Fri, 26 Jul 2024 10:26:00 GMT", "version": "v5" } ]
2024-07-29
[ [ "Al-Badawi", "Ahmad", "" ], [ "Alloqulov", "Mirzabek", "" ], [ "Shaymatov", "Sanjar", "" ], [ "Ahmedov", "Bobomurat", "" ] ]
In this paper, we investigate the optical properties of a charged black hole in Einstein-Maxwell-scalar (EMS) theory. We evaluate the shadow cast by the black hole and obtain analytical solutions for both the radius of the photon sphere and the shadow radius. We observe that the black hole parameters $\gamma$ and $\beta$ both influence the shadow of black hole. It is shown that the photon sphere and the shadow radius increase as a consequence of the presence of parameter $\gamma$. Interestingly, we show that shadow radius decreases first and then remains unchanged due to the impact of parameter $\beta$. Finally, we consider the weak gravitational lensing and the total magnification of lensed images around black hole. We find that the black hole charge and parameter $\beta$ both give rise to a significant effect, reducing the deflection angle. Similarly, the same behavior for the total magnification is observed due to the effect of black hole charge and parameter $\beta$.
gr-qc/0002043
Scott A. Hughes
Scott A. Hughes
Computing radiation from Kerr black holes: Generalization of the Sasaki-Nakamura equation
10 pages, no figures, to appear in Phys. Rev. D. Present version updates the references, fixes some typos, and corrects some of the Introductory text
Phys.Rev.D62:044029,2000; Erratum-ibid.D67:089902,2003
10.1103/PhysRevD.62.044029 10.1103/PhysRevD.67.089902
null
gr-qc astro-ph
null
As shown by Teukolsky, the master equation governing the propagation of weak radiation in a black hole spacetime can be separated into four ordinary differential equations, one for each spacetime coordinate. (``Weak'' means the radiation's amplitude is small enough that its own gravitation may be neglected.) Unfortunately, it is difficult to accurately compute solutions to the separated radial equation (the Teukolsky equation), particularly in a numerical implementation. The fundamental reason for this is that the Teukolsky equation's potentials are long ranged. For non-spinning black holes, one can get around this difficulty by applying transformations which relate the Teukolsky solution to solutions of the Regge-Wheeler equation, which has a short-ranged potential. A particularly attractive generalization of this approach to spinning black holes for gravitational radiation (spin weight s = -2) was given by Sasaki and Nakamura. In this paper, I generalize Sasaki and Nakamura's results to encompass radiation fields of arbitrary integer spin weight, and give results directly applicable to scalar (s = 0) and electromagnetic (s = -1) radiation. These results may be of interest for studies of astrophysical radiation processes near black holes, and of programs to compute radiation reaction forces in curved spacetime.
[ { "created": "Fri, 11 Feb 2000 22:22:38 GMT", "version": "v1" }, { "created": "Fri, 14 Apr 2000 23:57:44 GMT", "version": "v2" } ]
2014-11-17
[ [ "Hughes", "Scott A.", "" ] ]
As shown by Teukolsky, the master equation governing the propagation of weak radiation in a black hole spacetime can be separated into four ordinary differential equations, one for each spacetime coordinate. (``Weak'' means the radiation's amplitude is small enough that its own gravitation may be neglected.) Unfortunately, it is difficult to accurately compute solutions to the separated radial equation (the Teukolsky equation), particularly in a numerical implementation. The fundamental reason for this is that the Teukolsky equation's potentials are long ranged. For non-spinning black holes, one can get around this difficulty by applying transformations which relate the Teukolsky solution to solutions of the Regge-Wheeler equation, which has a short-ranged potential. A particularly attractive generalization of this approach to spinning black holes for gravitational radiation (spin weight s = -2) was given by Sasaki and Nakamura. In this paper, I generalize Sasaki and Nakamura's results to encompass radiation fields of arbitrary integer spin weight, and give results directly applicable to scalar (s = 0) and electromagnetic (s = -1) radiation. These results may be of interest for studies of astrophysical radiation processes near black holes, and of programs to compute radiation reaction forces in curved spacetime.
1206.0607
Marc Mars
Marc Mars and Martin Reiris
Global and uniqueness properties of stationary and static spacetimes with outer trapped surfaces
38 pages, 2 figures, Latex
null
10.1007/s00220-013-1739-5
null
gr-qc math.DG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Global properties of maximal future Cauchy developments of stationary, m-dimensional asymptotically flat initial data with an outer trapped boundary are analyzed. We prove that, whenever the matter model is well posed and satisfies the null energy condition, the future Cauchy development of the data is a black hole spacetime. More specifically, we show that the future Killing development of the exterior of a sufficiently large sphere in the initial data set can be isometrically embedded in the maximal Cauchy development of the data. In the static setting we prove, by working directly on the initial data set, that all Killing prehorizons are embedded whenever the initial data set has an outer trapped boundary and satisfies the null energy condition. By combining both results we prove a uniqueness theorem for static initial data sets with outer trapped boundary.
[ { "created": "Mon, 4 Jun 2012 13:06:46 GMT", "version": "v1" } ]
2015-06-05
[ [ "Mars", "Marc", "" ], [ "Reiris", "Martin", "" ] ]
Global properties of maximal future Cauchy developments of stationary, m-dimensional asymptotically flat initial data with an outer trapped boundary are analyzed. We prove that, whenever the matter model is well posed and satisfies the null energy condition, the future Cauchy development of the data is a black hole spacetime. More specifically, we show that the future Killing development of the exterior of a sufficiently large sphere in the initial data set can be isometrically embedded in the maximal Cauchy development of the data. In the static setting we prove, by working directly on the initial data set, that all Killing prehorizons are embedded whenever the initial data set has an outer trapped boundary and satisfies the null energy condition. By combining both results we prove a uniqueness theorem for static initial data sets with outer trapped boundary.
2311.17873
Conner Dailey
Yu Li, Ruolin Liu, Conner Dailey, Niayesh Afshordi
Detecting cosmological scalar fields using orbital networks of quantum sensors
Comments are welcome. 7 pages, 2 figures
null
null
null
gr-qc astro-ph.CO astro-ph.IM hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this Letter, we propose to detect the interaction of a hypothetical coherently evolving cosmological scalar field with an orbital network of quantum sensors, focusing on the GPS satellite network as a test example. Cosmological scenarios, such as a scalar-tensor theory for dark energy or the axi-Higgs model, suggest that such a field may exist. As this field would be (approximately) at rest in the CMB frame, it would exhibit a dipole as a result of the movement of our terrestrial observers relative to the CMB. While the current sensitivity of the GPS network is insufficient to detect a cosmological dipole, future networks of quantum sensors on heliocentric orbits, using state-of-the-art atomic clocks, can reach and exceed this requirement.
[ { "created": "Wed, 29 Nov 2023 18:19:59 GMT", "version": "v1" } ]
2023-12-01
[ [ "Li", "Yu", "" ], [ "Liu", "Ruolin", "" ], [ "Dailey", "Conner", "" ], [ "Afshordi", "Niayesh", "" ] ]
In this Letter, we propose to detect the interaction of a hypothetical coherently evolving cosmological scalar field with an orbital network of quantum sensors, focusing on the GPS satellite network as a test example. Cosmological scenarios, such as a scalar-tensor theory for dark energy or the axi-Higgs model, suggest that such a field may exist. As this field would be (approximately) at rest in the CMB frame, it would exhibit a dipole as a result of the movement of our terrestrial observers relative to the CMB. While the current sensitivity of the GPS network is insufficient to detect a cosmological dipole, future networks of quantum sensors on heliocentric orbits, using state-of-the-art atomic clocks, can reach and exceed this requirement.
1301.2334
Prado Martin-Moruno
Prado Martin-Moruno (Victoria University of Wellington), Matt Visser (Victoria University of Wellington)
Is there vacuum when there is mass? Vacuum and non-vacuum solutions for massive gravity
V1: 9 pages. V2: 10 pages, 5 references added. V3: 11 pages, some discussion added. This version accepted for publication in Classical and Quantum Gravity
Class.Quant.Grav. 30 (2013) 155021
10.1088/0264-9381/30/15/155021
null
gr-qc astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Massive gravity is a theory which has a tremendous amount of freedom to describe different cosmologies; but at the same time the various solutions one encounters must fulfill some rather nontrivial constraints. Most of the freedom comes not from the Lagrangian, which contains only a small number of free parameters (typically 3 depending on counting conventions), but from the fact that one is in principle free to choose the background reference metric almost arbitrarily --- which effectively introduces a non-denumerable infinity of free parameters. In the current paper we stress that although changing the reference metric would lead to a different cosmological model, this does not mean that the dynamics of the universe can be entirely divorced from its matter content. That is, while the choice of reference metric certainly influences the evolution of the physically observable foreground metric, the effect of matter cannot be neglected. Nevertheless, the relation between matter and geometry can be significantly changed in some specific models; effectively since the graviton would be able to curve the spacetime by itself, without the need of matter. Thus, even the set of vacuum solutions for massive gravity can have significant structure. On the other hand, in some cases the effect of the reference metric could be so strong that no conceivable material content would be able to drastically affect the cosmological evolution.
[ { "created": "Thu, 10 Jan 2013 21:26:41 GMT", "version": "v1" }, { "created": "Mon, 21 Jan 2013 23:28:24 GMT", "version": "v2" }, { "created": "Thu, 27 Jun 2013 23:08:49 GMT", "version": "v3" } ]
2013-08-21
[ [ "Martin-Moruno", "Prado", "", "Victoria University of Wellington" ], [ "Visser", "Matt", "", "Victoria University of Wellington" ] ]
Massive gravity is a theory which has a tremendous amount of freedom to describe different cosmologies; but at the same time the various solutions one encounters must fulfill some rather nontrivial constraints. Most of the freedom comes not from the Lagrangian, which contains only a small number of free parameters (typically 3 depending on counting conventions), but from the fact that one is in principle free to choose the background reference metric almost arbitrarily --- which effectively introduces a non-denumerable infinity of free parameters. In the current paper we stress that although changing the reference metric would lead to a different cosmological model, this does not mean that the dynamics of the universe can be entirely divorced from its matter content. That is, while the choice of reference metric certainly influences the evolution of the physically observable foreground metric, the effect of matter cannot be neglected. Nevertheless, the relation between matter and geometry can be significantly changed in some specific models; effectively since the graviton would be able to curve the spacetime by itself, without the need of matter. Thus, even the set of vacuum solutions for massive gravity can have significant structure. On the other hand, in some cases the effect of the reference metric could be so strong that no conceivable material content would be able to drastically affect the cosmological evolution.
gr-qc/9211011
Desmond Mc Manus
Shane J. Hughes, Des J. Mc Manus, and Michel A. Vandyck
Weak-Field Gravity of Circular Cosmic Strings
15 pages
Phys.Rev. D47 (1993) 468-473
10.1103/PhysRevD.47.468
DIAS-STP 92-24
gr-qc
null
A weak-field solution of Einstein's equations is constructed. It is generated by a circular cosmic string externally supported against collapse. The solution exhibits a conical singularity, and the corresponding deficit angle is the same as for a straight string of the same linear energy density. This confirms the deficit-angle assumption made in the Frolov-Israel-Unruh derivation of the metric describing a string loop at a moment of time symmetry.
[ { "created": "Mon, 9 Nov 1992 16:21:40 GMT", "version": "v1" } ]
2009-10-22
[ [ "Hughes", "Shane J.", "" ], [ "Manus", "Des J. Mc", "" ], [ "Vandyck", "Michel A.", "" ] ]
A weak-field solution of Einstein's equations is constructed. It is generated by a circular cosmic string externally supported against collapse. The solution exhibits a conical singularity, and the corresponding deficit angle is the same as for a straight string of the same linear energy density. This confirms the deficit-angle assumption made in the Frolov-Israel-Unruh derivation of the metric describing a string loop at a moment of time symmetry.
gr-qc/0010013
Fatimah Shojai
Ali Shojai
Quantum, Gravity, and Geometry
25 pages
Int.J.Mod.Phys. A15 (2000) 1757-1771
10.1142/S0217751X0000077X
null
gr-qc
null
Recently, it is shown that, the quantum effects of matter are well described by the conformal degree of freedom of the space-time metric. On the other hand, it is a wellknown fact that according to Einstein's gravity theory, gravity and geometry are interconnected. In the new quantum gravity theory, matter quantum effects completely determine the conformal degree of freedom of the space-time metric, while the causal structure of the space-time is determined by the gravitational effects of the matter, as well as the quantum effects through back reaction effects. This idea, previousely, is realized in the framework of scalar-tensor theories. In this work, it is shown that quantum gravity theory can also be realized as a purely metric theory. Such a theory is developed, its consequences and its properties are investigated. The theory is applied, then, to black holes and the radiation-dominated universe. It is shown that the initial singularity can be avoided.
[ { "created": "Wed, 4 Oct 2000 10:53:30 GMT", "version": "v1" } ]
2009-10-31
[ [ "Shojai", "Ali", "" ] ]
Recently, it is shown that, the quantum effects of matter are well described by the conformal degree of freedom of the space-time metric. On the other hand, it is a wellknown fact that according to Einstein's gravity theory, gravity and geometry are interconnected. In the new quantum gravity theory, matter quantum effects completely determine the conformal degree of freedom of the space-time metric, while the causal structure of the space-time is determined by the gravitational effects of the matter, as well as the quantum effects through back reaction effects. This idea, previousely, is realized in the framework of scalar-tensor theories. In this work, it is shown that quantum gravity theory can also be realized as a purely metric theory. Such a theory is developed, its consequences and its properties are investigated. The theory is applied, then, to black holes and the radiation-dominated universe. It is shown that the initial singularity can be avoided.
2203.11846
Daniel Carney
Daniel Carney, Yanbei Chen, Andrew Geraci, Holger M\"uller, Cristian D. Panda, Philip C. E. Stamp, and Jacob M. Taylor
Snowmass 2021 White Paper: Tabletop experiments for infrared quantum gravity
Short contribution to Snowmass 2021. 5 pages, 1 figure. v2: typo fixed
null
null
null
gr-qc hep-ph quant-ph
http://creativecommons.org/licenses/by/4.0/
Progress in the quantum readout and control of mechanical devices from single atoms to large masses may enable a first generation of experiments probing the gravitational interaction in the quantum regime, conceivably within the next decade. In this Snowmass whitepaper, we briefly outline the possibilities and challenges facing the realization of these experiments. In particular, we emphasize the need for detailed theories of modifications to the usual effective QFT of gravitons in the infrared regime $E/L^3 \ll m_{\rm Pl}/\ell_{\rm Pl}^3$ in which these experiments operate, and relations to possible UV completions.
[ { "created": "Tue, 22 Mar 2022 16:23:09 GMT", "version": "v1" }, { "created": "Wed, 23 Mar 2022 19:55:59 GMT", "version": "v2" } ]
2022-03-25
[ [ "Carney", "Daniel", "" ], [ "Chen", "Yanbei", "" ], [ "Geraci", "Andrew", "" ], [ "Müller", "Holger", "" ], [ "Panda", "Cristian D.", "" ], [ "Stamp", "Philip C. E.", "" ], [ "Taylor", "Jacob M.", "" ] ]
Progress in the quantum readout and control of mechanical devices from single atoms to large masses may enable a first generation of experiments probing the gravitational interaction in the quantum regime, conceivably within the next decade. In this Snowmass whitepaper, we briefly outline the possibilities and challenges facing the realization of these experiments. In particular, we emphasize the need for detailed theories of modifications to the usual effective QFT of gravitons in the infrared regime $E/L^3 \ll m_{\rm Pl}/\ell_{\rm Pl}^3$ in which these experiments operate, and relations to possible UV completions.
1605.02648
Abhay Ashtekar
Abhay Ashtekar
Symmetry Reduced Loop Quantum Gravity: A Bird's Eye View
25 pages, 2 figures. References updated; typos corrected. The abstract is expanded for readers who may not see the special volume of the journal in which this article will appear
Int j Mod Phys 25, 1642010 (2016)
10.1142/S0218271816420104
IGC16-05/1
gr-qc astro-ph.CO hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is a brief overview of the current status of symmetry reduced models in Loop Quantum Gravity (LQG), focussing on the very early universe. Over the last 3 years or so the subject has matured sufficiently to make direct contact with observations of the Cosmic Microwave Background (CMB). In particular, thanks to an unforeseen interplay between the ultraviolet features of quantum geometry and the infrared properties of quantum fields representing cosmological perturbations, \emph{Planck scale effects} of LQG can leave imprints on CMB \emph{at the largest angular scales}. In addition to a summary of these results, the article also contains a critical discussion of the symmetry reduction procedure used in discussions of quantum cosmology (and quantum black holes).
[ { "created": "Mon, 9 May 2016 16:26:29 GMT", "version": "v1" }, { "created": "Wed, 15 Jun 2016 01:23:53 GMT", "version": "v2" } ]
2017-06-21
[ [ "Ashtekar", "Abhay", "" ] ]
This is a brief overview of the current status of symmetry reduced models in Loop Quantum Gravity (LQG), focussing on the very early universe. Over the last 3 years or so the subject has matured sufficiently to make direct contact with observations of the Cosmic Microwave Background (CMB). In particular, thanks to an unforeseen interplay between the ultraviolet features of quantum geometry and the infrared properties of quantum fields representing cosmological perturbations, \emph{Planck scale effects} of LQG can leave imprints on CMB \emph{at the largest angular scales}. In addition to a summary of these results, the article also contains a critical discussion of the symmetry reduction procedure used in discussions of quantum cosmology (and quantum black holes).
gr-qc/0412051
Mark D. Roberts
Mark D. Roberts
Interacting with the fifth dimension
10 pages
null
null
null
gr-qc astro-ph hep-th
null
Some new five dimensional minimal scalar-Einstein exact solutions are presented. These new solutions are tested against various criteria used to measure interaction with the fifth dimension.
[ { "created": "Sat, 11 Dec 2004 16:03:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Roberts", "Mark D.", "" ] ]
Some new five dimensional minimal scalar-Einstein exact solutions are presented. These new solutions are tested against various criteria used to measure interaction with the fifth dimension.
2309.07816
Hossein Mohseni Sadjadi
H. Mohseni Sadjadi
Scalar-Gauss-Bonnet model, the coincidence problem and the gravitational wave speed
20 pages, 7 figures, major revision, accepted for publication in Physics Letters B
Phys. Lett. B 850, 138508 (2024)
10.1016/j.physletb.2024.138508
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a dynamical dark energy model wherein quintessence interacts with both the Gauss-Bonnet invariant and dark matter. Initially, the Gauss-Bonnet invariant stabilizes the quintessence at a fixed point, resulting in a negligible density of dark energy. Subsequently, the conformal coupling to dark matter triggers the evolution of dark energy. This model proposes an explanation for the initial absence of dark energy in radiation era and its later emergence during the matter-dominated era, achieving a magnitude comparable to dark matter in the present epoch. In this scenario, the Gauss-Bonnet term does not directly influence late-time cosmic evolution. Our model aligns with the assumption that the speed of gravitational wave is infinitesimally close to the speed of light.
[ { "created": "Thu, 14 Sep 2023 16:10:55 GMT", "version": "v1" }, { "created": "Tue, 30 Jan 2024 05:40:35 GMT", "version": "v2" } ]
2024-05-01
[ [ "Sadjadi", "H. Mohseni", "" ] ]
We introduce a dynamical dark energy model wherein quintessence interacts with both the Gauss-Bonnet invariant and dark matter. Initially, the Gauss-Bonnet invariant stabilizes the quintessence at a fixed point, resulting in a negligible density of dark energy. Subsequently, the conformal coupling to dark matter triggers the evolution of dark energy. This model proposes an explanation for the initial absence of dark energy in radiation era and its later emergence during the matter-dominated era, achieving a magnitude comparable to dark matter in the present epoch. In this scenario, the Gauss-Bonnet term does not directly influence late-time cosmic evolution. Our model aligns with the assumption that the speed of gravitational wave is infinitesimally close to the speed of light.
1811.05332
C. S. Unnikrishnan
C. S. Unnikrishnan and George T. Gillies
Gravitational waves at their own gravitational speed
7 pages. Honorable mention in 2018 Gravity Research Foundation essay competition
null
10.1142/S0218271818470156
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gravitational waves propagate at the speed of light in general relativity, because of its special relativistic basis. However, light propagation is linked to the electromagnetic phenomena, with the permittivity and permeability constants as the determining factors. Is there a deeper reason why waves in a geometric theory of gravity propagate at a speed determined by electromagnetic constants? What is the relation between gravity's own constants and the speed of gravitational waves? Our attempt to answer these fundamental questions takes us far and deep into the universe.
[ { "created": "Mon, 12 Nov 2018 10:01:44 GMT", "version": "v1" } ]
2018-11-14
[ [ "Unnikrishnan", "C. S.", "" ], [ "Gillies", "George T.", "" ] ]
Gravitational waves propagate at the speed of light in general relativity, because of its special relativistic basis. However, light propagation is linked to the electromagnetic phenomena, with the permittivity and permeability constants as the determining factors. Is there a deeper reason why waves in a geometric theory of gravity propagate at a speed determined by electromagnetic constants? What is the relation between gravity's own constants and the speed of gravitational waves? Our attempt to answer these fundamental questions takes us far and deep into the universe.
2303.16973
Pardyumn Kumar Sahoo
Lakhan V. Jaybhaye, Raja Solanki, Sanjay Mandal, Pradyumn Kumar Sahoo
Constraining viscous dark energy equation of state in $f(R,L_m)$ gravity
Universe published version
Universe 9(4) (2023) 163
10.3390/universe9040163
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
In this article, we attempt to describe cosmic late-time acceleration of the universe in the framework of $f(R,L_m)$ gravity by using an effective equation of state when the account is taken of bulk viscosity. We presume a non-linear $f(R,L_m)$ functional form, specifically, $f(R,L_m)=\frac{R}{2}+L_m^\alpha $, where $\alpha$ is free model parameter. We obtain the exact solution of our bulk viscous matter dominated $f(R,L_m)$ model, and then we utilize the combined $H(z)+Pantheon+Analysis$ data sets to estimate the best fit values of the free parameters of our model. Then we characterize the behaviour of the matter-energy density, effective pressure, and the equation of state (EoS) parameter incorporating the viscous type fluid. The evolution profile of the effective EoS parameter depicts an acceleration phase of the cosmic expansion whereas the pressure with the effect of viscosity exhibits negative behaviour that can lead to the accelerating expansion of the universe. Moreover, the cosmic matter-energy density shows expected positive behaviour. Further, we investigate the behaviour of statefinder parameters for the assumed $f(R,L_m)$ model. We find that the evolutionary trajectory of the given model lies in the quintessence region. In addition, we employ the Om diagnostic test that indicates our model exhibits quintessence behavior. Lastly, we check the energy condition criteria and find that violation of SEC occurs in the past, whereas NEC and DEC satisfies the positivity criteria. We find that our $f(R,L_m)$ cosmological model with the effect of bulk viscosity provides a good fit of the recent observational data and can efficiently describe the cosmic expansion scenario.
[ { "created": "Tue, 28 Mar 2023 09:18:58 GMT", "version": "v1" } ]
2023-03-31
[ [ "Jaybhaye", "Lakhan V.", "" ], [ "Solanki", "Raja", "" ], [ "Mandal", "Sanjay", "" ], [ "Sahoo", "Pradyumn Kumar", "" ] ]
In this article, we attempt to describe cosmic late-time acceleration of the universe in the framework of $f(R,L_m)$ gravity by using an effective equation of state when the account is taken of bulk viscosity. We presume a non-linear $f(R,L_m)$ functional form, specifically, $f(R,L_m)=\frac{R}{2}+L_m^\alpha $, where $\alpha$ is free model parameter. We obtain the exact solution of our bulk viscous matter dominated $f(R,L_m)$ model, and then we utilize the combined $H(z)+Pantheon+Analysis$ data sets to estimate the best fit values of the free parameters of our model. Then we characterize the behaviour of the matter-energy density, effective pressure, and the equation of state (EoS) parameter incorporating the viscous type fluid. The evolution profile of the effective EoS parameter depicts an acceleration phase of the cosmic expansion whereas the pressure with the effect of viscosity exhibits negative behaviour that can lead to the accelerating expansion of the universe. Moreover, the cosmic matter-energy density shows expected positive behaviour. Further, we investigate the behaviour of statefinder parameters for the assumed $f(R,L_m)$ model. We find that the evolutionary trajectory of the given model lies in the quintessence region. In addition, we employ the Om diagnostic test that indicates our model exhibits quintessence behavior. Lastly, we check the energy condition criteria and find that violation of SEC occurs in the past, whereas NEC and DEC satisfies the positivity criteria. We find that our $f(R,L_m)$ cosmological model with the effect of bulk viscosity provides a good fit of the recent observational data and can efficiently describe the cosmic expansion scenario.
gr-qc/9903023
Marco Godina
Marco Godina, Paolo Matteucci, Lorenzo Fatibene, Mauro Francaviglia
Two-spinor Formulation of First Order Gravity coupled to Dirac Fields
16 pages, Plain TEX
Gen.Rel.Grav.32:145-160,2000
10.1023/A:1001804718086
null
gr-qc
null
Two-spinor formalism for Einstein Lagrangian is developed. The gravitational field is regarded as a composite object derived from soldering forms. Our formalism is geometrically and globally well-defined and may be used in virtually any 4m-dimensional manifold with arbitrary signature as well as without any stringent topological requirement on space-time, such as parallelizability. Interactions and feedbacks between gravity and spinor fields are considered. As is well known, the Hilbert-Einstein Lagrangian is second order also when expressed in terms of soldering forms. A covariant splitting is then analysed leading to a first order Lagrangian which is recognized to play a fundamental role in the theory of conserved quantities. The splitting and thence the first order Lagrangian depend on a reference spin connection which is physically interpreted as setting the zero level for conserved quantities. A complete and detailed treatment of conserved quantities is then presented.
[ { "created": "Fri, 5 Mar 1999 21:45:00 GMT", "version": "v1" } ]
2008-11-26
[ [ "Godina", "Marco", "" ], [ "Matteucci", "Paolo", "" ], [ "Fatibene", "Lorenzo", "" ], [ "Francaviglia", "Mauro", "" ] ]
Two-spinor formalism for Einstein Lagrangian is developed. The gravitational field is regarded as a composite object derived from soldering forms. Our formalism is geometrically and globally well-defined and may be used in virtually any 4m-dimensional manifold with arbitrary signature as well as without any stringent topological requirement on space-time, such as parallelizability. Interactions and feedbacks between gravity and spinor fields are considered. As is well known, the Hilbert-Einstein Lagrangian is second order also when expressed in terms of soldering forms. A covariant splitting is then analysed leading to a first order Lagrangian which is recognized to play a fundamental role in the theory of conserved quantities. The splitting and thence the first order Lagrangian depend on a reference spin connection which is physically interpreted as setting the zero level for conserved quantities. A complete and detailed treatment of conserved quantities is then presented.
gr-qc/0401097
Enrique Alvarez
Enrique Alvarez
The infinite curvature limit of AdS/CFT
10 pages. Contribution to the proceedings of the 2003 ``Peyresq Physics 8" meeting
Int.J.Theor.Phys. 43 (2004) 905-912
10.1023/B:IJTP.0000048179.43068.9d
IFT-UAM/CSIC-04-02
gr-qc
null
Some kinematical speculations on the infinite curvature limit of the conjectured duality of Maldacena between ten-dimensional strings living in $AdS_5\times S_5$ and a ordinary four-dimensional quantum field theory, namely ${\cal{N}}=4$ super Yang-Mills with gauge group SU(N) are given.
[ { "created": "Fri, 23 Jan 2004 14:59:35 GMT", "version": "v1" } ]
2009-11-10
[ [ "Alvarez", "Enrique", "" ] ]
Some kinematical speculations on the infinite curvature limit of the conjectured duality of Maldacena between ten-dimensional strings living in $AdS_5\times S_5$ and a ordinary four-dimensional quantum field theory, namely ${\cal{N}}=4$ super Yang-Mills with gauge group SU(N) are given.