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We investigate a compelling model of a rotating black hole that is deformed by the effects of loop quantum gravity (LQG). We present a simplified metric and explore two distinct geometries: one in which the masses of the black hole and…

General Relativity and Quantum Cosmology · Physics 2024-12-24 Jafar Khodagholizadeh , Ghadir Jafari , Alireza Allahyari , Ali Vahedi

We calculate the intrinsic entropy of a Schwarzschild black hole in an asymptotically antide Sitter space. The statistical calculation of the entropy is based on a model for particle structure that leads to confinement. The constituents of…

General Relativity and Quantum Cosmology · Physics 2019-07-15 Moorad Alexanian

This work studies the dynamics of geodesic motion within a curved spacetime around a Schwarzschild black hole, perturbed by a gravitational field of a far axisymmetric distribution of mass enclosing the system. This spacetime can serve as a…

General Relativity and Quantum Cosmology · Physics 2023-11-16 Michal Stratený , Georgios Lukes-Gerakopoulos

We study test-particle dynamics in the equatorial plane of a Kerr-Bertotti-Robinson black hole (BH) immersed in a cloud of strings (CS), with mass M , rotation a, magnetic parameter B, and string parameter {\alpha}. Using the Hamilton…

High Energy Astrophysical Phenomena · Physics 2026-05-12 Faizuddin Ahmed , Orhan Donmez , Ahmad Al-Badawi , Izzet Sakalli

We investigate the shadow of an exact black hole solution of Einstein's equations recently proposed by Cardoso et al., to describe a supermassive black hole immersed in a dark matter halo. We analyze and discuss the light rings and the…

General Relativity and Quantum Cosmology · Physics 2023-04-03 Sérgio V. M. C. B. Xavier , Haroldo C. D. Lima Junior , Luís C. B. Crispino

We study the spectrum of the bound state perturbations in the interior of the Schwarzschild black hole for the scalar, electromagnetic and gravitational perturbations. Demanding that the perturbations to be regular at the center of the…

General Relativity and Quantum Cosmology · Physics 2018-05-31 Hassan Firouzjahi

We study collision of particles in the vicinity of a horizon of a weakly magnetized non-rotating black hole. In the presence of the magnetic field innermost stable circular orbits (ISCO) of charged particles can be located close to the…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Valeri P. Frolov

In this paper, we study the motion of test particles around two exact charged black-hole solutions in Einstein-{\AE}ther theory. Specifically, we first consider the quasi-periodic oscillations (QPOs) and their resonances generated by the…

General Relativity and Quantum Cosmology · Physics 2020-08-18 Mustapha Azreg-Aïnou , Zihang Chen , Bojun Deng , Mubasher Jamil , Tao Zhu , Qiang Wu , Yen-Kheng Lim

Astrophysical black holes are invariably embedded in matter environments whose gravitational influence can alter key strong-field features of the spacetime. In this work, we investigate the impact of spherically symmetric dark-matter…

General Relativity and Quantum Cosmology · Physics 2025-12-30 Dylan S. Fonseca , Caio F. B. Macedo , Mateus Malato Corrêa , Diego Rubiera-Garcia

The Schwarzschild black hole metric with mass $M$ has the limit of the vanishing mass when one get the Minkowski space. We study behavior of the entanglement entropy by using the island formula and the limit of the vanishing black hole…

High Energy Physics - Theory · Physics 2023-08-10 Daniil Stepanenko , Igor Volovich

Marginally stable circular orbits (MSCOs) of a massive test particle are investigated in the spacetime geometry of Schwarzschild black hole surrounded by quintessence. For that matter we consider three important scenarios where the equation…

General Relativity and Quantum Cosmology · Physics 2016-08-10 Ibrar Hussain , Sajid Ali

We investigate a recently derived Schwarzschild-like black hole immersed in a Dehnen-type $(\alpha,\beta,\gamma)=(1,4,5/2)$ dark matter (DM) halo. We obtain constraints on the two model parameters, i.e., the halo core radius $r_s$ and the…

General Relativity and Quantum Cosmology · Physics 2025-10-29 Tursunali Xamidov , Sanjar Shaymatov , Qiang Wu , Tao Zhu

This work on spin-0 amplitudes in black-hole evaporation is based on the underlying results and methods outlined in our first paper, "I. Complex Approach". The main result here, and the model calculation for work on all higher spins, as…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. N. St. J. Farley , P. D. D'Eath

We study the inner-most stable circular orbit(ISCO) of Kerr black hole in MOdified gravity(Kerr-MOG black hole) which is one of the exact solution of the field equation of modified gravity in strong gravity regime. Kerr-MOG black hole is…

General Relativity and Quantum Cosmology · Physics 2017-10-25 Hyun-Chul Lee , Yong-Jin Han

We present analytical solutions for the thermodynamic (temperature, pressure, density, etc.) properties of thin accretion flows in the region within the innermost stable circular orbit (ISCO) of a Kerr black hole, the first analytical…

High Energy Astrophysical Phenomena · Physics 2023-03-08 Andrew Mummery , Steven Balbus

In this paper, we study the motion of neutral and electrically charged particles in the vicinity of a deformed-Schwarzschild black hole inspired by Loop Quantum Gravity (LQG). To examine the motion of an electrically charged test particle,…

General Relativity and Quantum Cosmology · Physics 2025-11-26 Kourosh Nozari , Sara Saghafi , Milad Hajebrahimi , Kimet Jusufi

The innermost stable circular orbits (ISCO) of coalescing neutron star-black hole binary are studied taking into account both the tidal and relativistic effects. We adopt the generalized pseudo-Newtonian potential to mimic the general…

Astrophysics · Physics 2009-10-28 Keisuke Taniguchi , Takashi Nakamura

Using the post-Newtonian (PN) expansion technique of the gravitational wave perturbation around a Schwarzschild black hole, we calculate analytically the energy flux of gravitational waves induced by a particle in circular orbits up to the…

General Relativity and Quantum Cosmology · Physics 2009-10-09 T. Tanaka , H. Tagoshi , M. Sasaki

Recently, two independent calculations have been presented of finite-mass ("self-force") effects on the orbit of a point mass around a Schwarzschild black hole. While both computations are based on the standard mode-sum method, they differ…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Norichika Sago , Leor Barack , Steven Detweiler

We revisit the problem of scalar and electromagnetic waves impinging upon a Schwarzschild black hole from complex angular momentum techniques. We focus more particularly on the associated differential scattering cross sections. We derive an…

General Relativity and Quantum Cosmology · Physics 2019-06-04 Antoine Folacci , Mohamed Ould El Hadj