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Black hole accretion disks are a fascinating topic in astrophysics, as they play a crucial role in several high-energy situations. This paper investigates the optical appearance of scalar hairy black holes (SHBHs) with asymmetric potential,…

General Relativity and Quantum Cosmology · Physics 2024-11-21 Carlos A. Benavides-Gallego , Eduard Larrañaga

In this work, we consider a rotating charged black hole surrounded by perfect fluid dark matter. We consider the system to be immersed in non-magnetised, pressureless plasma. First, we evaluate the null geodesics in order to study the…

General Relativity and Quantum Cosmology · Physics 2022-04-06 Anish Das , Ashis Saha , Sunandan Gangopadhyay

In this work we study whether parametrized spherically symmetric black hole solutions in metric theories of gravity can appear to be isospectral when studying perturbations. From a theory agnostic point of view, the test scalar field wave…

General Relativity and Quantum Cosmology · Physics 2019-09-04 Sebastian H. Völkel , Kostas D. Kokkotas

In this paper, we investigate the photon sphere, shadow radius and quasinormal modes of a $4$-dimensional black hole with a deficit solid angle and quintessence-like matter. We find that the radii of the photon sphere and shadow decrease…

General Relativity and Quantum Cosmology · Physics 2022-08-31 Chengye Yu , Deyou Chen , Chuanhong Gao

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

One of the main predictions of general relativity is the existence of black holes featuring a horizon beyond which nothing can escape. Gravitational waves from the remnants of compact binary coalescences have the potential to probe new…

General Relativity and Quantum Cosmology · Physics 2024-11-05 M. V. S. Saketh , Elisa Maggio

We consider a spherically symmetric black hole in equilibrium with surrounding classical matter that is characterized by a nonlinear dependence of the radial pressure p_{r} on the density {\rho}. We examine under which requirements such an…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Oleg B. Zaslavskii

In this note, we have analyzed the circular motion of test particles around the Schwarzschild-MOG black hole. First, we have studied the shadow cast by the spherical symmetric black hole within MOG gravity. It has been shown that due to the…

General Relativity and Quantum Cosmology · Physics 2023-08-28 Madina Boboqambarova , Bobur Turimov , Ahmadjon Abdujabbarov

The abundance of dark matter in the actual universe motivates us to construct the black hole spacetime enveloped by dark matter. In this paper, we derive a new spherically symmetric black hole surrounded by the pseudo-isothermal dark matter…

General Relativity and Quantum Cosmology · Physics 2024-01-29 Yi Yang , Dong Liu , Ali Övgün , Gaetano Lambiase , Zheng-Wen Long

In this paper, we base our analysis on the assumption that the existence of a photon sphere is an intrinsic feature of any ultra-compact gravitational structure with spherical symmetry. Utilizing the concept of a topological photon sphere,…

General Relativity and Quantum Cosmology · Physics 2024-12-24 Mohammad Ali S. Afshar , Jafar Sadeghi

We investigate the particle motion around a Schwarzschild black hole immersed in a swirling Bertotti-Robinson-Bonnor-Melvin background. This spacetime provides a physically well-motivated framework for studying how the two different…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Wenbin Li , Yu-Qi Lei , Xian-Hui Ge

The properties of filamentary interstellar clouds observed at sub-millimetre wavelengths, especially by the Herschel Space Observatory, are analysed with polytropic models in cylindrical symmetry. The observed radial density profiles are…

Solar and Stellar Astrophysics · Physics 2015-06-23 Claudia Toci , Daniele Galli

We study the geodesic motion of massless particles in singly rotating black ring spacetimes. We find stable stationary orbits of massless particles in toroidal spiral shape in the case that the thickness parameter of a black ring is less…

High Energy Physics - Theory · Physics 2013-05-08 Takahisa Igata , Hideki Ishihara , Yohsuke Takamori

The results of an investigation into whether or not eclipse shadow bands have an atmospheric origin are presented. Using high altitude balloon and ground-based photodiode arrays during the 21 August 2017 total solar eclipse, data revealing…

The recent convergence of gravitational-wave (GW) observations and black hole imaging provides complementary probes of strong-gravity dynamics. While the black hole shadow is typically modeled as a static feature, a dynamically perturbed…

High Energy Physics - Theory · Physics 2026-03-03 Reggie C. Pantig

In this paper we aim to investigate the process of massless scalar wave scattering due to a self-dual black hole through the partial wave method. We calculate the phase shift analytically at the low energy limit and we show that the…

High Energy Physics - Theory · Physics 2020-02-28 M. A. Anacleto , F. A. Brito , J. A. V. Campos , E. Passos

Astrophysical black holes (BHs) are universally expected to be described by the Kerr metric, a stationary, vacuum solution of general relativity (GR). Indeed, by imaging M87$^\star$ and Sgr A$^\star$ and measuring the size of their shadows,…

General Relativity and Quantum Cosmology · Physics 2024-03-07 Prashant Kocherlakota , Luciano Rezzolla , Rittick Roy , Maciek Wielgus

Recent observations of the Milky-way galactic center at various frequencies suggest a supermassive compact object. Generally, that supermassive compact object is assumed to be a `Black Hole', having more than four million solar masses. In…

General Relativity and Quantum Cosmology · Physics 2022-02-02 Saurabh , Parth Bambhaniya , Pankaj S. Joshi

A generation method of new metric in the case of static spherically symmetric space-time is derived. Using this approach, we construct a metric which describes Euler-Heisenberg black hole surrounded by perfect fluid dark matter and…

General Relativity and Quantum Cosmology · Physics 2024-06-14 Shi-Jie Ma , Rui-Bo Wang , Jian-Bo Deng , Xian-Ru Hu

We investigate a general class of $d$-dimensional regular black holes characterized by a de Sitter core, which arises from the gravitational collapse of a polytropic star with an arbitrary polytropic index $n$. This framework generalizes…

General Relativity and Quantum Cosmology · Physics 2026-05-28 A. Sadeghi , F. Shojai
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