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The Event Horizon Telescope (EHT) collaboration's image of the compact object at the galactic center is the first direct evidence of the supermassive black hole (BH) Sgr A$^*$. The shadow of Sgr A$^*$ has an angular diameter $d_{sh}= 48.7…

General Relativity and Quantum Cosmology · Physics 2023-02-24 Misba Afrin , Sunny Vagnozzi , Sushant G. Ghosh

The recent Event Horizon Telescope (EHT) observations of the M87* have led to a surge of interest in studying the shadow of black holes. Besides, investigation of time evolution and lifetime of black holes helps us to veto/restrict some…

General Relativity and Quantum Cosmology · Physics 2023-02-14 S. H. Hendi , Kh. Jafarzade , B. Eslam Panah

We analysed the shadow cast by charged rotating black hole (BH) in presence of perfect fluid dark matter (PFDM). We studied the null geodesic equations and obtained the shadow of the charged rotating BH to see the effects of PFDM parameter…

General Relativity and Quantum Cosmology · Physics 2022-01-05 Farruh Atamurotov , Uma Papnoi , Kimet Jusufi

In this paper, we study the shadow and images of the accretion disk of Kerr-Newman (KN) black hole (BH) in modified gravity (MOG) theory by using backward ray-tracing method. And, the influence of spin parameter ($a$), charge ($Q$), and MOG…

General Relativity and Quantum Cosmology · Physics 2025-02-07 He-Bin Zheng , Meng-Qi Wu , Guo-Ping Li , Qing-Quan Jiang

The shadows cast by non-rotating and rotating modified gravity (MOG) black holes are determined by the two parameters mass $M$ and angular momentum $J=Ma$. The sizes of the shadows cast by the spherically symmetric static Schwarzschild-MOG…

General Relativity and Quantum Cosmology · Physics 2015-03-26 J. W. Moffat

In this study, we investigate black holes (BHs) surrounded by a quintessence field (QF) within the framework of effective quantum gravity (EQG). We analyze the spacetime metric characterized by quantum correction parameter $\xi$ and…

General Relativity and Quantum Cosmology · Physics 2025-03-25 Ahmad Al-Badawi , Faizuddin Ahmed , Tursunali Xamidov , Sanjar Shaymatov , İzzet Sakallı

Loop quantum gravity inspired partial polymer quantization in four-dimensional spacetime leads to a globally regular black hole with a single horizon. The polymerized black hole metric is characterized by the minimum length parameter $k$,…

General Relativity and Quantum Cosmology · Physics 2023-03-14 Rahul Kumar Walia

The Event Horizon Telescope (EHT) has provided a new tool for testing the strong-field regime of gravity by imaging the shadows of M87* and Sgr A*. These observations provide the first real opportunity to test whether quantum…

General Relativity and Quantum Cosmology · Physics 2026-05-29 Heena Ali , Sushant G. Ghosh

We revisit and extend the study of null geodesics around a slowly rotating black hole in Chern-Simons modified gravity. We employ the Hamilton-Jacobi formalism to derive the equations for the shadow profile and determine its shape. We…

General Relativity and Quantum Cosmology · Physics 2025-04-17 Benito Rodríguez , Javier Chagoya , C. Ortiz

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

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

With a semiclassical polymerization in the loop quantum gravity (LQG), the interior of Schwarzschild black holes provides a captivating single-horizon regular black hole spacetime. The shortage of rotating black hole models in loop quantum…

General Relativity and Quantum Cosmology · Physics 2022-11-23 Jitendra Kumar , Shafqat Ul Islam , Sushant G. Ghosh

In this paper we have investigated the dynamics of neutral, electrically charged and magnetized particles around renormalized group improved (RGI) Schwarzschild black hole in the presence of external asymptotically uniform magnetic field.…

General Relativity and Quantum Cosmology · Physics 2020-11-02 Javlon Rayimbaev , Ahmadjon Abdujabbarov , Mubasher Jamil , Bobomurat Ahmedov , Wen-Biao Han

Zhang have obtained recently a twisted rotating black hole metric, which is a vacuum solution in four-dimensional Einstein gravity. This black hole solution has a rotation parameter, but without the total angular moment. Here, we have…

General Relativity and Quantum Cosmology · Physics 2016-10-21 Songbai Chen , Jiliang Jing

The links between the deformation parameter $\beta$ of the generalized uncertainty principle (GUP) to the two free parameters $\hat{\omega}$ and $\gamma$ of the running Newtonian coupling constant of the Asymptotic Safe gravity (ASG)…

General Relativity and Quantum Cosmology · Physics 2023-09-12 Gaetano Lambiase , Reggie C. Pantig , Dhruba Jyoti Gogoi , Ali Övgün

We study the effective action in 2D dilaton-Maxwell quantum gravity. Working with the one-loop renormalizable subset of such theories, we construct the improved effective Lagrangian which contains curvature under logarithm. This effective…

High Energy Physics - Theory · Physics 2009-09-17 Shin'ichi Nojiri , Sergei D. Odintsov

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

We analytically investigate the shadows cast by rotating black holes in the asymptotically safe gravity (ASG) by deriving complete null geodesics and observables using the Hamilton-Jacobi equation and Carter separable method. It turns out…

General Relativity and Quantum Cosmology · Physics 2020-07-13 Rahul Kumar , Balendra Pratap Singh , Sushant G. Ghosh

We study the shadow produced by a class of rotating black holes surrounded by plasma. The metric for these black holes arises by applying the Newman-Janis algorithm to a family of spherically symmetric spacetimes, which includes several…

General Relativity and Quantum Cosmology · Physics 2021-11-08 Javier Badía , Ernesto F. Eiroa

A renormalization-group (RG) improved Schwarzschild-like black hole is investigated, whose lapse function interpolates between the classical Schwarzschild exterior and a quantum-smoothed interior governed by the cutoff scale $\xi$ and…

General Relativity and Quantum Cosmology · Physics 2026-05-08 Ahmad Al-Badawi , Faizuddin Ahmed , İzzet Sakallı