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Related papers: Galileon accretion

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We explore the global structure of the accretion flow around a Schwarzschild black hole where the accretion disc is threaded by toroidal magnetic fields. The accretion flow is optically thin and advection dominated. Synchrotron radiation is…

High Energy Astrophysical Phenomena · Physics 2018-03-14 Biplob Sarkar , Santabrata Das

We study the threshold of gravitational collapse in spherically symmetric spacetimes governed by the Einstein-Maxwell-Vlasov equations. We numerically construct solutions describing a collapsing distribution of charged matter that either…

General Relativity and Quantum Cosmology · Physics 2026-04-14 William E. East

Our aim in this work is to outline some physical consequences of the interaction between black holes and scalar field halos in terms of gravitational waves. In doing so, the black hole is taken as a static and spherically symmetric…

General Relativity and Quantum Cosmology · Physics 2011-09-06 Darío Núnez , Juan Carlos Degollado , Claudia Moreno

The description of a point mass in general relativity (GR) is given in the framework of the field formulation of GR where all the dynamical fields, including the gravitational field, are considered in a fixed background spacetime. With the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 A. N. Petrov

A paradigm describing black hole evaporation in non-perturbative quantum gravity is developed by combining two sets of detailed results: i) resolution of the Schwarzschild singularity using quantum geometry methods; and ii) time-evolution…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Abhay Ashtekar , Martin Bojowald

It is recently shown that, besides the Schwarzshcild black hole solution, there exist also scalarized black hole solutions in some Einstein-scalar-Gauss-Bonnet theories. In this paper, we construct analytical expressions for the metric…

General Relativity and Quantum Cosmology · Physics 2019-09-04 Yuan-Xing Gao , Dao-Jun Liu

In this work, we obtain the analytically approximation of static, spherically symmetric black hole solutions to Einstein$-$Weyl squared gravity by using the continued fraction expansion method. The black hole solutions are found for various…

General Relativity and Quantum Cosmology · Physics 2025-01-06 Seyed Naseh Sajadi , Supakchai Ponglertsakul

We study geometrically thick non-self gravitating equilibrium tori orbiting a Schwarzschild black hole immersed in swirling universes. This solution is axially symmetric and non-asymptotically flat, and its north and south hemispheres spin…

General Relativity and Quantum Cosmology · Physics 2024-02-06 Chengjia Chen , Qiyuan Pan , Jiliang Jing

We consider the possible existence of self-similar solutions containing black holes in a Friedmann background with a stiff fluid or a scalar field. We carefully study the relationship between the self-similar equations in these two cases…

Astrophysics · Physics 2008-11-26 Tomohiro Harada , Hideki Maeda , B. J. Carr

First we have assumed the most general static spherically symmetric black hole metric. The accretion of any general kind of fluid flow around the black hole have been investigated. The accretion of fluid flow around the modified Hayward…

General Relativity and Quantum Cosmology · Physics 2015-06-24 Ujjal Debnath

It is typically believed that the additional degrees of freedom in any modification of gravity are completely suppressed by the large energy densities coexisting with an astrophysical black hole. In this paper, we find that this might not…

General Relativity and Quantum Cosmology · Physics 2017-05-31 Andrei V. Frolov , José T. Gálvez Ghersi , Alex Zucca

We have recently proposed a model for a regular black hole, or an ultra-compact object, that is premised on having maximally negative radial pressure throughout the entirety of the object's interior. This model can be viewed as that of a…

General Relativity and Quantum Cosmology · Physics 2022-01-19 Ram Brustein , A. J. M. Medved , Tamar Simhon

We investigate the global structure of the advection dominated accretion flow around a Schwarzschild black hole where the accretion disc is threaded by toroidal magnetic fields. We consider synchrotron radiative process as an effective…

High Energy Astrophysical Phenomena · Physics 2017-11-29 Biplob Sarkar , Santabrata Das , Samir Mandal

We present an analytic solution for accretion of a gaseous medium with adiabatic equation of state onto a charged dilaton black hole which moves at a constant velocity. We determine the four-velocity of accreted flow and find that it…

General Relativity and Quantum Cosmology · Physics 2022-06-07 Rong-Jia Yang , Yinan Jia , Lei Jiao

We study the conditions under which an analog acoustic geometry of a relativistic fluid in flat spacetime can take the same form as the Schwarzschild black hole geometry. We find that the speed of sound must necessarily be equal to the…

General Relativity and Quantum Cosmology · Physics 2021-11-01 Neven Bilić , Hrvoje Nikolić

A particular class of space-time, with a tachyon field, \phi, and a barotropic fluid constituting the matter content, is considered herein as a model for gravitational collapse. For simplicity, the tachyon potential is assumed to be of…

General Relativity and Quantum Cosmology · Physics 2013-01-23 Yaser Tavakoli , João Marto , Amir Hadi Ziaie , Paulo Vargas Moniz

We study the effect of nuclear reaction on a thin, axisymmetric, differentially rotating, inviscid, steady accretion flow around a black hole from an analytical point of view. We find that for most of the reasonable disk parameters, when…

Astrophysics · Physics 2016-08-30 Banibrata Mukhopadhyay , Sandip K. Chakrabarti

Any probe which crosses the horizon of a black hole should be absorbed. In M(atrix) theory, for 0-brane probes of Schwarzschild black holes, we argue that the relevant absorption mechanism is a tachyon instability which sets in at the…

High Energy Physics - Theory · Physics 2010-02-03 Daniel Kabat , Gilad Lifschytz

We investigate how a spherically symmetric fluid modifies the Schwarzschild vacuum solution when there is no exchange of energy-momentum between the fluid and the central source of the Schwarzschild metric. This system is described by means…

General Relativity and Quantum Cosmology · Physics 2018-11-26 J Ovalle , R Casadio , R da Rocha , A Sotomayor , Z Stuchlik

In spherical symmetry, solutions of the semiclassical Einstein equations belong to one of two possible classes. Both classes contain solutions that -- depending on the dynamic behavior of the horizon -- describe evaporating physical black…

General Relativity and Quantum Cosmology · Physics 2022-03-10 Pravin K. Dahal , Sebastian Murk , Daniel R. Terno