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Related papers: Spherical photon orbits around Kerr-MOG black hole

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Inspired by the observations of supermassive black hole M87* in \emph{Event Horizon Telescope }(EHT) experiment, a remarkable surge in black hole physics is to use the black hole shadow's observables to distinguish general relativity (GR)…

General Relativity and Quantum Cosmology · Physics 2022-09-20 Yuan Meng , Xiao-Mei Kuang , Zi-Yu Tang

We consider the perturbative, fully explicit, analytical behaviour of photon escape cones in the Kerr spacetime. When one conducts the fully general non-perturbative Kerr analysis, one quickly finds that one must at some point appeal to…

General Relativity and Quantum Cosmology · Physics 2024-04-18 Joshua Baines , Matt Visser

In this paper, we study the gravitational lensing effects of non-linear electrodynamic black holes. Non-linear electrodynamic black holes serve as typical models for multi-event horizon black holes. Depending on the choice of metric…

General Relativity and Quantum Cosmology · Physics 2025-07-18 Siyuan Hui , Benrong Mu , Peng Wang

We investigate analytically gravitational lensing by charged, stationary, axially symmetric Kerr-Sen dilaton-axion black hole in the weak deflection limit. Approximate solutions to the lightlike equations of motion are present up to and…

General Relativity and Quantum Cosmology · Physics 2010-03-25 Galin N. Gyulchev , Stoytcho S. Yazadjiev

We study motion of charged particles in the field of a rotating black hole immersed into an external asymptotically uniform magnetic field, focusing on the epicyclic quasi-circular orbits near the equatorial plane. Separating the circular…

General Relativity and Quantum Cosmology · Physics 2016-05-04 Arman Tursunov , Zdeněk Stuchlík , Martin Kološ

The Kerr metric is one of the most important solutions to Einstein's field equations, describing the gravitational field outside a rotating black hole. We thoroughly analyze the curvature scalar invariants to study the Kerr spacetime by…

General Relativity and Quantum Cosmology · Physics 2013-10-10 Majd Abdelqader , Kayll Lake

The energy dependence of the deflection angle is a common prediction in some quantum gravity theories when the impact parameters are much larger than the photon wavelength. For low energy photons, the deflection angle recovers to the…

General Relativity and Quantum Cosmology · Physics 2019-10-11 Lei Feng

Interpreting horizon-scale observations of astrophysical black holes demands a general understanding of null geodesics in the Kerr spacetime. These may be divided into two classes: "direct" rays that primarily determine the observational…

General Relativity and Quantum Cosmology · Physics 2020-02-18 Samuel E. Gralla , Alexandru Lupsasca

This paper investigates the photon ring and shadow structure of the Reissner-Nordstr\"om black hole in the scalar-tensor-vector gravitational framework. The black hole is characterized by the ( MOG) parameter (\alpha) and the charge (Q).…

General Relativity and Quantum Cosmology · Physics 2026-02-04 Qiao Yue , Zhaoyi Xu , Meirong Tang

Since the full General Theory of Relativity has been unveiled to the scientific community in 1915, many solutions to the vacuum Einstein field equations have been found and studied. This paper aims at documenting exhaustively the derivation…

General Relativity and Quantum Cosmology · Physics 2020-02-18 Onur Uçanok

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

We extract elegant and concise analytic formulae for the mass and rotation parameters of the Kerr black hole as well as its distance from the Earth only in terms of directly measurable quantities of the accretion disk revolving in the black…

General Relativity and Quantum Cosmology · Physics 2025-01-09 Mehrab Momennia

We consider a particle moving towards a rotating black hole. We are interested in the number of its revolution $n$ around a black hole. In our previous work (Pavlov and Zaslavskii in Gen Relativ Gravit 50: 14, 2018. arXiv:1707.02860) we…

General Relativity and Quantum Cosmology · Physics 2019-05-16 Yu. V. Pavlov , O. B. Zaslavskii

The bright ring-like structures observed in the images of M87* and SgrA* captured by the Event Horizon Telescope strongly support the validity of general relativity. Lensed images of the emission region, often referred to as photon rings in…

High Energy Physics - Phenomenology · Physics 2025-12-22 Kiana Salehi , Avery Broderick

Gravitational lensing of luminous matter that surrounds a black hole or some other sufficiently compact object produces an infinite sequence of images. Besides the direct (or primary) image, it comprises demagnified and deformed replicas of…

General Relativity and Quantum Cosmology · Physics 2024-08-21 Fabio Aratore , Oleg Yu. Tsupko , Volker Perlick

The Kerr-Bertotti-Robinson (Kerr-BR) black hole, a theoretical model of a rotating black hole immersed in a uniform magnetic field, has been proposed recently by Podolsky and Ovcharenko. This study investigates the optical characteristics…

General Relativity and Quantum Cosmology · Physics 2025-08-11 Xiao-Xiong Zeng , Chen-Yu Yang , Hao Yu

We present the exact solutions of the homoclinic orbits for the timelike geodesics of the particle on the general nonequatorial orbits in the Kerr-Newman black holes. The homoclinic orbit is the separatrix between bound and plunging…

General Relativity and Quantum Cosmology · Physics 2023-08-11 Yi-Ting Li , Chen-Yu Wang , Da-Shin Lee , Chi-Yong Lin

Classical black holes contain a singularity at their core. This has prompted various researchers to propose a multitude of modified spacetimes that mimic the physically observable characteristics of classical black holes as best as…

General Relativity and Quantum Cosmology · Physics 2020-09-08 Thomas Berry , Alex Simpson , Matt Visser

In this work, we investigate the relationship between the photon sphere radius and the first-order phase transition for the charged EPYM AdS black hole. Through the analysis, we find with a certain condition there exist the non-monotonic…

High Energy Physics - Theory · Physics 2023-02-01 Yun-Zhi Du , Huai-Fan Li , Fang Liu , Li-Chun Zhang

Simulated images of a black hole surrounded by optically thin emission typically display two main features: a central brightness depression and a narrow, bright "photon ring" consisting of strongly lensed images superposed on top of the…

High Energy Astrophysical Phenomena · Physics 2021-09-08 Andrew Chael , Michael D. Johnson , Alexandru Lupsasca