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Related papers: Shadows of Kerr black holes with a Gaussian-distri…

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We study the shadow of a charged rotating black hole in $f(R)$ gravity. This black hole is characterized by mass, $M$, spin, $a$, electric charge, $Q$ and $R_{0}$ which is proportional to cosmological constant. We analyze the image of the…

General Relativity and Quantum Cosmology · Physics 2022-10-06 Sara Dastan , Reza Saffari , Saheb Soroushfar

In this paper, we explore the behavior of light ray trajectories in the exterior geometry of a rotating black hole within the Rastall theory of gravity, which is surrounded by an inhomogeneous anisotropic electronic cold plasma. By…

General Relativity and Quantum Cosmology · Physics 2024-08-22 Mohsen Fathi , Marco Olivares , José R. Villanueva , Norman Cruz

We study the shadow of the rotating black hole with quintessential energy i) in vacuum and ii) in the presence of plasma with radial power-law density. For vacuum case the quintessential field parameter of the rotating black hole…

General Relativity and Quantum Cosmology · Physics 2015-12-18 Ahmadjon Abdujabbarov , Bobir Toshmatov , Zdeněk Stuchlík , Bobomurat Ahmedov

Within 5-10 years, submillimeter VLBI facilities will be hopefully able to image the "shadow" of SgrA$^*$. When a black hole is surrounded by an optically thin emitting medium, the boundary of the shadow corresponds to the apparent photon…

General Relativity and Quantum Cosmology · Physics 2017-12-19 Cosimo Bambi

In this paper, the shadows cast by non-rotating and rotating modified gravity black holes are investigated. In addition to the black hole spin parameter $a$ and the inclination angle $\theta$ of observer, another parameter $\alpha$…

General Relativity and Quantum Cosmology · Physics 2019-04-08 Hui-Min Wang , Yu-Meng Xu , Shao-Wen Wei

An inhomogeneous pseudo-scalar field configuration behaves like an optically active medium. Consequently, if a light ray passes through an axion cloud surrounding a Kerr black hole, it may experience a polarization-dependent bending. We…

General Relativity and Quantum Cosmology · Physics 2018-05-16 Alexis D. Plascencia , Alfredo Urbano

The detailed study of the strong gravitational lensing of a Kerr black hole within Quantum Einstein Gravity (QEG) is performed. We calculate the photon sphere, the deflection angle of light, and observables on the equatorial plane under the…

General Relativity and Quantum Cosmology · Physics 2024-09-09 Chen-Hao Xie , Yu Zhang , Bo-Li Liu , Peng-Fei Duan , Yu-Li Lou

The visible universe is filled with different types of plasma media in the form of stars, nebulas and other forms of excited gases. These matter fields have a high influence on the gravity and are likely to be present around the black holes…

General Relativity and Quantum Cosmology · Physics 2024-05-13 Muhammad Ali Raza , M. Zubair , Eiman Maqsood

We consider a simple model of a black hole surrounded by a toroidal structure and experiencing deformation due to magnetic field and the tidal force. For this system we construct the shadows of Preston-Poisson black hole, apply it to…

General Relativity and Quantum Cosmology · Physics 2020-08-14 R. A. Konoplya , Jan Schee , Dmitriy Ovchinnikov

Some active galactic nuclei, microquasars, and gamma ray bursts may be powered by the electromagnetic braking of a rapidly rotating black hole. We investigate this possibility via axisymmetric numerical simulations of a black hole…

Astrophysics · Physics 2008-11-26 Jonathan C. McKinney , Charles F. Gammie

Explicitly covariant analytical expressions are derived that describe the boundaries of shadows cast by massive particles scattered by a gravitating object. This covers scenarios with particles having effectively variable mass, such as…

General Relativity and Quantum Cosmology · Physics 2023-12-15 Kirill Kobialko , Igor Bogush , Dmitri Gal'tsov

In this paper, we first analyze the horizon structure of the Van der Waals(VdW) black hole and then investigate its shadow in the absence of a plasma medium as well as the presence of a homogeneous plasma medium. We find that both the Van…

General Relativity and Quantum Cosmology · Physics 2022-12-06 Niyaz Uddin Molla , Ujjal Debnath

In this work, we have studied weak gravitational lensing effect around black hole and determine shadow radius in GUP-corrected-Schwarzschild spacetime (S-GUP) in presence of plasma environment. We started with orbits of photons around black…

General Relativity and Quantum Cosmology · Physics 2023-12-29 Husanboy Hoshimov , Odil Yunusov , Farruh Atamurotov , Mubasher Jamil , Ahmadjon Abdujabbarov

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

The growth of a massive black hole will steepen the cold dark matter density at the center of a galaxy into a dense spike, enhancing the prospects for indirect detection. We study the impact of black hole spin on the density profile using…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-10 Francesc Ferrer , Augusto Medeiros da Rosa , Clifford M. Will

In this work, we have studied the behavior of null geodesics within a rotating wormhole space-time in non-magnetized pressure-less plasma. By focusing on the dispersion relation of the plasma and disregarding its direct gravitational…

General Relativity and Quantum Cosmology · Physics 2023-08-21 Saurabh Kumar , Akhil Uniyal , Sayan Chakrabarti

We report on the nature of prominent sources of light and shadow in the Galactic Center. With respect to the Bremsstrahlung X-ray emission of the hot plasma in that region the Galactic Center casts a 'shadow'. The 'shadow' is caused by the…

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…

General Relativity and Quantum Cosmology · Physics 2023-07-11 Qian Li , Yu Zhang , Zhi-Wen Lin , Qi-Quan Li , Qi Sun

Quantum effects in general induce scale dependence in the coupling constants. We explore this possibility in gravity, with a scale-dependent Newton coupling. When applied to Kerr black holes with such a running coupling, the consistency of…

General Relativity and Quantum Cosmology · Physics 2026-02-19 Che-Yu Chen , Chiang-Mei Chen , Nobuyoshi Ohta

A black hole casts a shadow as an optical appearance because of its strong gravitational field. We study how to determine the spin parameter and the inclination angle by observing the apparent shape of the shadow, which is distorted mainly…

High Energy Astrophysical Phenomena · Physics 2009-08-05 Kenta Hioki , Kei-ichi Maeda