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This paper investigates photon motion in black hole of Einstein-Maxwell-dilaton theory, exploring black hole shadows and observational characteristics under various accretion models. We first give the relation of the event horizon, photon…

General Relativity and Quantum Cosmology · Physics 2025-12-16 Junlin Qin , Hong-Er Gong , Yusen Wang , Zhan-Feng Mai , Bofeng Wu , Sen Guo , Enwei Liang

In this paper, we investigate the properties of black holes within the framework of multi-fractional theories of gravity, focusing on the effects of q-derivatives and weighted derivatives. These modifications, which introduce…

General Relativity and Quantum Cosmology · Physics 2025-06-03 Reggie C. Pantig

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

Black holes are among the most compelling predictions of general relativity (GR) and are now strongly supported by observations from gravitational-wave detectors and the Event Horizon Telescope (EHT). While standard black hole solutions…

General Relativity and Quantum Cosmology · Physics 2026-01-13 A. Errehymy , Y. Khedif , M. Daoud , Y. Myrzakulov , O. Donmez , B. Turimov

We consider non-commutating Simpson-Visser spacetime and study the superradiance phenomena and the shadow cast by the back hole associated with this modified spacetime. We extensively study the different aspects of the black hole associated…

General Relativity and Quantum Cosmology · Physics 2022-08-30 Sohan Kumar Jha , Anisur Rahaman

We present a simple gedanken experiment in which a compact object traverses a spacetime with three macroscopic spatial dimensions and $n$ compact dimensions. The compactification radius is allowed to vary, as a function of the object's…

General Relativity and Quantum Cosmology · Physics 2023-05-08 Matthew J. Lake , Shi-Dong Liang , Anucha Watcharapasorn

The Event Horizon Telescope (EHT) image of M87* provides a direct test of strong-field gravity, measuring an angular shadow diameter $\theta_{d}=42\pm 3~\mu\mathrm{as}$ and a circularity deviation $\Delta C\leq 0.1$. Such observations allow…

General Relativity and Quantum Cosmology · Physics 2026-05-13 Kourosh Nozari , Milad Hajebrahimi , Sara Saghafi , G. Mustafa , Emmanuel N. Saridakis

The Event Horizon Telescope Collaboration (EHTC) has presented first - dynamic-range limited - images of the black hole shadows in M87 and Sgr A*. The next generation Event Horizon Telescope (ngEHT) will provide higher sensitivity and…

High Energy Astrophysical Phenomena · Physics 2023-03-14 Bidisha Bandyopadhyay , Christian Fendt , Dominik R. G. Schleicher , Javier Lagunas , Javier Pedreros , Neil M. Nagar , Felipe Agurto

We explore charged black holes in Scalar-Tensor-Vector Gravity (STVG), unveiling their distinctive features across multiple physical domains. Our topological analysis reveals that the STVG coupling parameter $\alpha$ bolsters thermal…

General Relativity and Quantum Cosmology · Physics 2025-11-07 Erdem Sucu , Kuantay Boshkayev , Yassine Sekhmani , İzzet Sakallı , Mohsen Fathi

Motivated by recent Event Horizon Telescope findings, we investigate constrained optics of rotating black holes in Einstein-Maxwell-scalar gravity theory. Precisely, we mainly study the parameter effects on two relevant optical concepts…

High Energy Physics - Theory · Physics 2024-11-19 Hajar Belmahi

We study the effects of emission geometry on the capability to constrain black hole parameters from measurements of the shadow and inner-shadow of a Reissner-Nordstr\"om black hole. We investigate the capability to constrain mass, charge,…

High Energy Astrophysical Phenomena · Physics 2026-02-17 Julien A. Kearns , Dominic O. Chang , Daniel C. M. Palumbo , Shane W. Davis

The purpose of this study is to investigate the quasinormal modes (QNMs), greybody factors (GFs) and shadows in a plasma of a black hole (BH) surrounded by an exotic fluid of quintessence type in a scalar-vector-tensor modified gravity. The…

General Relativity and Quantum Cosmology · Physics 2024-05-21 Ahmad Al-Badawi

We study shadow aspects of superentropic black holes in four dimensions. Using Hamilton-Jacobi formalism, we first get the null geodesic equations. In the celestial coordinate framework relying on fixed positions of observers, we…

High Energy Physics - Theory · Physics 2022-07-27 A. Belhaj , H. Belmahi , M. Benali

The linear-quadratic Generalized uncertainty principle (LQG) is consistent with predictions of a minimum measurable length and a maximum measurable momentum put forth by various theories of quantum gravity. The quantum gravity effect is…

General Relativity and Quantum Cosmology · Physics 2026-01-01 Sohan Kumar Jha

Recent observations of the supermassive black holes M87* and Sgr A* by the Event Horizon Telescope (EHT) have opened new avenues for testing gravity theories through black hole shadow observables. These observations offer a means to…

General Relativity and Quantum Cosmology · Physics 2025-05-05 Mohsen Fathi , Yassine Sekhmani

Recently, the \textit{EHT} collaboration unveiled the shadow images of the supermassive black hole (SMBH) M87* and Sgr A*, with angular radii of $42\pm3$\,$\mu$as and $48.7\pm7.0$\,$\mu$as, respectively. These observations are consistent…

High Energy Astrophysical Phenomena · Physics 2025-10-07 Yuan Tan , Youjun Lu , Kunyu Song

In this study, we delve into the observational implications of rotating Loop Quantum Black Holes (LQBHs) within an astrophysical framework. We employ semi-analytical General Relativistic Radiative Transfer (GRRT) computations to study the…

General Relativity and Quantum Cosmology · Physics 2023-12-29 Hong-Xuan Jiang , Cheng Liu , Indu K. Dihingia , Yosuke Mizuno , Haiguang Xu , Tao Zhu , Qiang Wu

We studied the shadow cast by a rotating Bardeen black hole within the framework of asymptotically safe gravity. The null geodesics were analyzed using the Hamilton Jacobi separation method to derive shadow observables. Our findings show…

General Relativity and Quantum Cosmology · Physics 2026-04-21 Gowtham Sidharth M , Sanjit Das

We investigate the impact of higher-curvature corrections on black-hole observables within a perturbative $f(R, G)$ gravity framework. Working in a static, spherically symmetric spacetime, we construct leading-order deviations from the…

General Relativity and Quantum Cosmology · Physics 2026-05-26 G. G. L. Nashed

The Event Horizon Telescope (EHT) recently released an image of the supermassive black hole Sgr A* showing an angular shadow diameter $d_{sh}= 48.7 \pm 7\,\mu$as and Schwarzschild shadow deviation $\delta =…

General Relativity and Quantum Cosmology · Physics 2023-02-28 Sushant G. Ghosh , Misba Afrin