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Related papers: Stationary models of magnetized viscous tori aroun…

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A class of nonstationary spacetimes is obtained by means of a conformal transformation of the Schwarzschild metric, where the conformal factor $a(t)$ is an arbitrary function of the time coordinate only. We investigate several situations…

General Relativity and Quantum Cosmology · Physics 2017-05-05 Marina M. C. Mello , Alan Maciel , Vilson T. Zanchin

The behaviour of stationary gravitational perturbations is studied for generalised static black holes in spacetimes of greater than three dimensions, using the formulation developed by the present author and Ishibashi. For the case in which…

High Energy Physics - Theory · Physics 2009-11-10 Hideo Kodama

We study the orbital structure and precession dynamics of neutral test particles in the magnetized Kerr black hole (MKBH) spacetime-an exact electrovacuum solution of the Einstein-Maxwell equations that self-consistently incorporates the…

General Relativity and Quantum Cosmology · Physics 2026-05-12 Karthik Iyer , Chandrachur Chakraborty

We develop here a new procedure within Einstein's theory of gravity to generate equilibrium configurations that result as the final state of gravitational collapse from regular initial conditions. As a simplification, we assume that the…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Pankaj S. Joshi , Daniele Malafarina , Ramesh Narayan

We present fully general relativistic equations governing viscous transonic flows in vertical equilibrium in Kerr geometry. We find the complete set of global solutions (both for Optically thick and optically thin flows) in the weak…

Astrophysics · Physics 2015-06-24 Sandip K. Chakrabarti

Black holes are found to exist in gravitational theories with the presence of quadratic curvature terms and behave differently from the Schwarzschild solution. We present an exhaustive analysis for determining the quasinormal modes of a…

High Energy Physics - Theory · Physics 2016-01-20 Yi-Fu Cai , Hezi Zhang , Junyu Liu , Gong Cheng , Min Wang

Surprisingly, the relict cosmological constant has a crucial influence on properties of accretion discs orbiting black holes in quasars and active galactic nuclei. We show it by considering basic properties of both the geometrically thin…

Astrophysics · Physics 2009-11-13 Z. Stuchlik

We study the stability of standing shock waves in advection-dominated accretion flows into a Schwarzschild black hole by 2D general relativistic hydrodynamic simulations as well as linear analysis in the equatorial plane. We demonstrate…

Astrophysics · Physics 2009-11-13 Hiroki Nagakura , Shoichi Yamada

This work aims to explore the gravitational consequences of a recently proposed black hole solution presented in the literature [Phys. Dark Univ. 50 (2025) 102061]. We initiate our analyzes by taking into account the horizon structure,…

General Relativity and Quantum Cosmology · Physics 2025-09-18 A. A. Araújo Filho , N. Heidari , Iarley P. Lobo

We present, in closed analytic form, a general stationary, slowly rotating black hole, which is solution to a large class of alternative theories of gravity in four dimensions. In these theories, the Einstein-Hilbert action is supplemented…

General Relativity and Quantum Cosmology · Physics 2011-10-27 Paolo Pani , Caio F. B. Macedo , Luis C. B. Crispino , Vitor Cardoso

We study motion of a charged particle in the vicinity of a weakly magnetized Schwarzschild black hole and focus on its bounded trajectories lying in the black hole equatorial plane. If the Lorentz force, acting on the particle, is directed…

General Relativity and Quantum Cosmology · Physics 2010-10-27 Valeri P. Frolov , Andrey A. Shoom

We solved the set of two-dimensional magnetohydrodynamic (MHD) equations for optically thin black hole accretion flows incorporating toroidal component of magnetic field. Following global and local MHD simulations of black hole accretion…

High Energy Astrophysical Phenomena · Physics 2018-01-31 Fatemeh Zahra Zeraatgari , Amin Mosallanezhad , Shahram Abbassi , Ye-Fei Yuan

We investigate ringed accretion disks constituted by two tori (rings) orbiting on the equatorial plane of a central super-massive Kerr black hole. We discuss the emergence of the instability phases of each ring of the macro-configuration…

High Energy Astrophysical Phenomena · Physics 2017-04-26 D. Pugliese , Z. Stuchlík

We study axial perturbations of static black holes with primary hair in a family of degenerate higher-order scalar-tensor (DHOST) theories. These solutions possess a scalar charge, fully independent of the mass, leading to a continuous…

General Relativity and Quantum Cosmology · Physics 2025-04-16 Christos Charmousis , Simon Iteanu , David Langlois , Karim Noui

We discuss the effects of electric charging on the equilibrium configurations of magnetized, rotating fluid tori around black holes of different mass. In the context of gaseous/dusty tori in galactic nuclei, the central black hole dominates…

High Energy Astrophysical Phenomena · Physics 2022-11-28 Vladimir Karas , Ondrej Kopacek , Audrey Trova , Jiri Kovar , Petr Slany , Zdenek Stuchlik

The standard thin accretion disc model predicts that discs around stellar mass black holes become radiation pressure dominated and thermally unstable once their luminosity exceeds L>0.02 L_Edd. Observationally, discs in the high/soft state…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Yucong Zhu , Ramesh Narayan

We reconsider the problem of the formation of a large-scale magnetic field in the accretion disks around black holes. In contrast with previous work we take into account the nonuniform vertical structure of the disk. The high electrical…

Astrophysics · Physics 2009-11-13 G. S. Bisnovatyi-Kogan , R. V. E. Lovelace

We analyzed the effects of a toroidal magnetic field in the formation of several magnetized accretion tori, dubbed as ringed accretion disks (RADs), orbiting around one central Kerr supermassive Black Hole (SMBH) in AGNs, where both…

High Energy Astrophysical Phenomena · Physics 2018-03-14 D. Pugliese , G. Montani

We present a numerical study of the response of a thick accretion disc to a localized, external perturbation with the aim of exciting internal modes of oscillation. We find that the perturbations efficiently excite global modes recently…

Astrophysics · Physics 2007-05-23 Eduardo Rubio-Herrera , William H. Lee

By studying three-dimensional, radiative, global simulations of sub-Eddington, geometrically thin black hole accretion flows we show that thin disks which are dominated by magnetic pressure are stable against thermal instability. Such disks…

High Energy Astrophysical Phenomena · Physics 2017-02-08 Aleksander Sadowski