English
Related papers

Related papers: Testing loop quantum gravity through EHT observati…

200 papers

We investigate the shadow of Kerr-Bertotti-Robinson black holes (KBRBHs), which have a deviation parameter $B$ that captures the effect of an external magnetic field on the spacetime geometry. These spacetimes of Petrov type $D$ are…

General Relativity and Quantum Cosmology · Physics 2026-01-28 Heena Ali , Sushant G. Ghosh

Future electromagnetic observations of black holes may allow us to test General Relativity in the strong-field regime. Such tests, however, require knowledge of rotating black hole solutions in modified gravity theories, a class of which…

High Energy Astrophysical Phenomena · Physics 2016-04-25 Dimitry Ayzenberg , Kent Yagi , Nicolas Yunes

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…

We show how Event Horizon Telescope (EHT) observations of the supermassive object at the center of M87 can constrain deviations from General Relativity (GR) in a relatively model-independent way. We focus on the class of theories whose…

General Relativity and Quantum Cosmology · Physics 2020-08-26 Markus Rummel , C. P. Burgess

We study the shadows cast by near-extremal Kerr-MOG black holes for different values of the parameter in modified gravity (MOG). In particular, we consider an isotropic emitter orbiting near such black holes and analytically compute the…

General Relativity and Quantum Cosmology · Physics 2018-11-12 Minyong Guo , Niels A. Obers , Haopeng Yan

Among the three known types of static solutions proposed within the Hamiltonian constraint approach to effective quantum gravity (EQG), the first two have been extensively investigated, whereas the third type-which preserves general…

General Relativity and Quantum Cosmology · Physics 2025-11-18 Wentao Liu , Di Wu , Jieci Wang

We present a phenomenological study of rotating, charged black holes in Einstein gravity coupled to a traceless (conformal) matter sector formed by ModMax nonlinear electrodynamics and a Kalb-Ramond two-form that spontaneously breaks local…

General Relativity and Quantum Cosmology · Physics 2025-09-23 Yassine Sekhmani , Kuantay Boshkayev , Mustapha Azreg-Aïnou , Sunil K. Maurya , Mohamed Altanji , Ainur Urazalina

Recent observations of the supermassive black holes $ M87^{*} $ and Sgr A$^{*}$ by the Event Horizon Telescope (EHT) have sparked intensified interest in studying the optical appearance of black holes (BHs). Inspired by this, we carry out a…

General Relativity and Quantum Cosmology · Physics 2025-08-14 Khadije Jafarzade , Zeynab Bazyar , Sara Saghafi , Kourosh Nozari

The images of the supermassive black holes Sgr A* and M87* by the Event Horizon Telescope (EHT) collaboration mark a special milestone in the history of the subject. For the first time we are able to see the shadow of black holes, testing…

High Energy Astrophysical Phenomena · Physics 2022-08-02 Heino Falcke

The images of supermassive black holes surrounded by optically-thin, radiatively-inefficient accretion flows, like those observed with the Event Horizon Telescope, are characterized by a bright ring of emission surrounding the black-hole…

High Energy Astrophysical Phenomena · Physics 2023-02-01 Ziri Younsi , Dimitrios Psaltis , Feryal Özel

The Event Horizon Telescope has recently observed the images and shadows of the compact objects M87$^*$ and Sgr A$^*$ at the centres of the galaxies Messier 87 and Milky Way. This has opened up a new window in observational astronomy to…

General Relativity and Quantum Cosmology · Physics 2023-05-15 Kunal Pal , Kuntal Pal , Rajibul Shaikh , Tapobrata Sarkar

The direct detection of a bright, ring-like structure in horizon-resolving images of M87* by the Event Horizon Telescope is a striking validation of general relativity. The angular size and shape of the ring is a degenerate measure of the…

High Energy Astrophysical Phenomena · Physics 2022-03-09 Avery E. Broderick , Paul Tiede , Dominic W. Pesce , Roman Gold

We consider a Lorentz violating non-commutating Kerr-like spacetime and studied the superradiance effect and the shadow cast by the back hole. We extensively study the different aspects of the black hole associated with a generalized…

General Relativity and Quantum Cosmology · Physics 2022-04-22 Sohan Kumar Jha , Anisur Rahaman

Recently there has been a surge of interest in regularizing, a $ D \to 4 $ limit of, the Einstein-Gauss-Bonnet (EGB) gravity, and the resulting regularized $4D$ EGB gravity has nontrivial dynamics. The theory admits spherically symmetric…

General Relativity and Quantum Cosmology · Physics 2020-07-28 Rahul Kumar , Sushant G. Ghosh

We investigate strong gravitational lensing by two static black hole models (Model-1 and Model-2) within the Effective Quantum Gravity (EQG) framework, characterized by mass $M$ and parameter $\zeta$. For $\zeta = 0$, they reduce to the…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-17 Yiyang Wang , Amnish Vachher , Qiang Wu , Tao Zhu , Sushant G. Ghosh

In this paper, we consider a charged AdS/dS black hole (BH) in $R^{2}$ gravity and study its optical features, including the shadow's geometrical shape and the energy emission rate. Additionally, we look for criteria to restrict the free…

General Relativity and Quantum Cosmology · Physics 2025-03-05 Khadije Jafarzade , Sanjar Shaymatov , Mubasher Jamil

We study the influence of the loop quantum gravity (LQG) holonomy-correction parameter $\xi$ on black hole horizon structure, timelike geodesic motion, and gravitational wave emission in two rotating LQG-inspired black hole spacetimes,…

General Relativity and Quantum Cosmology · Physics 2026-04-24 Yang Yang , Yu-Xuan Bai , Yong-Zhuang Li , Yu Han

This study investigates quantum gravity effects within the framework of an effective loop quantum gravity (LQG) black hole model parameterized by $\zeta$, utilizing precision measurements from solar system experiments and astrophysical…

General Relativity and Quantum Cosmology · Physics 2025-07-28 Wen-Juan Ai , Ruo-Ting Chen , Li-Gang Zhu , Jian-Pin Wu

Recent observation of Sagittarius A$^*$ (Sgr A$^*$) by the Event Horizon Telescope (EHT) collaboration has uncovered various unanswered questions in black hole (BH) physics. Besides, it may also probe various beyond the Standard Model (BSM)…

High Energy Astrophysical Phenomena · Physics 2024-09-10 Akash Kumar Saha , Priyank Parashari , Tarak Nath Maity , Abhishek Dubey , Subhadip Bouri , Ranjan Laha

The successful observation of M87 supermassive black hole by the Black Hole Event Horizon Telescope(EHT) provides a very good opportunity to study the theory of gravity. In this work, we obtain the exact solution for the short hair black…

General Relativity and Quantum Cosmology · Physics 2023-01-04 Meirong Tang , Zhaoyi Xu