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Related papers: Higher-Dimensional MOG dark compact object: shadow…

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In this work, we study the quasinormal modes (QNMs) and shadow of a Schwarzschild black hole (BH) with higher-order metric corrections, in the framework of the Infinite Derivative theory of Gravity (IDG). We study the effects of corrections…

General Relativity and Quantum Cosmology · Physics 2025-09-19 Rupam Jyoti Borah , Umananda Dev Goswami

We pioneer the black hole mass gap as a powerful new tool for constraining modified gravity theories. These theories predict fifth forces that alter the structure and evolution of population-III stars, exacerbating the pair-instability.…

General Relativity and Quantum Cosmology · Physics 2020-12-16 Maria C. Straight , Jeremy Sakstein , Eric J. Baxter

Using an improved version of the Newman-Janis algorithm, we obtain metrics of rotating black holes for a set of extended gravity theories that extend general relativity in different ways: the Horndeski model, the bumblebee model, the…

General Relativity and Quantum Cosmology · Physics 2025-03-24 Stanislav Alexeyev , Oleg Zenin , Artem Baiderin

Black hole shadows and photon spheres offer valuable tools for investigating black hole properties. Recent observations by the Event Horizon Telescope Collaboration have confirmed the existence of rotating black holes. Black hole parameters…

General Relativity and Quantum Cosmology · Physics 2024-11-26 Vitalii Vertogradov , Ali Övgün , Reggie C. Pantig

A beyond Horndeski theory is considered that admits wormholes, black holes and naked singularities. In this theory the shadow images of the black holes and the exotic compact objects (ECOs), illuminated by an optically and geometrically…

General Relativity and Quantum Cosmology · Physics 2024-01-30 Hyat Huang , Jutta Kunz , Deeshani Mitra

The Event Horizon Telescope has produced resolved images of the supermassive black holes Sgr A* and M87*, which present the largest shadows on the sky. In the next decade, technological improvements and extensions to the array will enable…

The apparent angular size of the shadow of a black hole in an expanding Universe is redshift-dependent. Since cosmological redshifts change with time - known as the redshift drift - all redshift-dependent quantities acquire a…

General Relativity and Quantum Cosmology · Physics 2021-09-16 Emmanuel Frion , Leonardo Giani , Tays Miranda

Latest advances in effective quantum gravity propose a quantum-corrected black hole solution that avoids Cauchy horizons. This paper studies the images of this black hole when illuminated by a static thin accretion disk and explores the…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Shilong Huang , Jiawei Chen , Jinsong Yang

The co-varying physical couplings (CPC) framework states that physical parameters like the speed of light in vacuum $c$, the Newtonian constant $G$, and the cosmological constant $\Lambda$ could indeed vary with the spacetime coordinates…

General Relativity and Quantum Cosmology · Physics 2023-10-18 R. R. Cuzinatto , C. A. M. de Melo , Juliano C. S. Neves

This paper investigates the influence of matter fields on the geometry of black hole horizons within higher-order gravity theories. Focusing on five-dimensional Einstein-Gauss-Bonnet gravity at a critical coupling constant ($\alpha =…

High Energy Physics - Theory · Physics 2025-03-27 Yuxuan Peng

The Event Horizon Telescope (EHT) is a project to assemble a Very Long Baseline Interferometry (VLBI) network of mm wavelength dishes that can resolve strong field General Relativistic signatures near a supermassive black hole. As planned,…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Ru-Sen Lu , Avery E. Broderick , Fabien Baron , John D. Monnier , Vincent L. Fish , Sheperd S. Doeleman , Victor Pankratius

In this paper, we investigate the effect of higher curvature corrections from Gauss-Bonnet gravity on the shadow of charged black holes in both $AdS$ and Minkowski spacetimes. The null geodesic equations are computed in $d=5$ spacetime…

General Relativity and Quantum Cosmology · Physics 2020-02-28 Anish Das , Ashis Saha , Sunandan Gangopadhyay

We consider a static black hole immersed in the Power-Yang-Mills field in four dimensional Einstein-Gauss-Bonnet gravity and investigate the effect of various parameters on the radius of the photon sphere. The modified form of the…

General Relativity and Quantum Cosmology · Physics 2023-05-29 M. Zubair , Muhammad Ali Raza , Furkat Sarikulov , Javlon Rayimbaev

We consider the case of rotating black holes in a dark-matter-emulating theory of gravity called MOG. The latter introduces a gravitational vector field with an associated gravitational charge proportional to the black hole mass and a…

General Relativity and Quantum Cosmology · Physics 2018-12-14 Michael F. Wondrak , Piero Nicolini , John W. Moffat

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

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

Observational data of the Sagittarius A* (Sgr A*) shadow released by the Event Horizon Telescope (EHT) are used to investigate eventual deviations in the black hole shadow radius, aiming to seek physics beyond the Standard Model (SM) coming…

General Relativity and Quantum Cosmology · Physics 2024-09-26 A. S. Lemos , J. A. V. Campos , F. A. Brito

Continuum spectrum emitted by the accretion disk around quasars hold a wealth of information regarding the strong gravitational field produced by the massive central object. Such strong gravity regime is often expected to exhibit deviations…

General Relativity and Quantum Cosmology · Physics 2019-08-30 Indrani Banerjee , Sumanta Chakraborty , Soumitra SenGupta

We investigate constraints on the distribution of dark matter in the neighbourhood of the Galactic centre that may eventually be attained with the high-resolution Event Horizon Telescope (EHT). The shadow of a black hole in vacuum is used…

Astrophysics of Galaxies · Physics 2013-08-15 Thomas Lacroix , Joseph Silk

This work is devoted to investigate some consequences of black holes physics beyond the domain of general relativity, mainly in effective extra dimensional models. The investigation is carried along three gravitational effects, namely the…

General Relativity and Quantum Cosmology · Physics 2019-02-28 Rogerio Teixeira Cavalcanti