English
Related papers

Related papers: Polarized image of a rotating black hole in Scalar…

200 papers

In general relativity, the Kerr metric uniquely represents the geometry surrounding an isolated, rotating black hole. An identification of significant non-Kerr features in some astrophysical source would then provide a `smoking-gun' for the…

General Relativity and Quantum Cosmology · Physics 2020-08-07 Arthur G Suvorov

This paper explores the dynamics of both neutral as well as charged particles orbiting near a rotating black hole in scalar-tensor-vector gravity. We study the conditions for the particle to escape at the innermost stable circular orbit. We…

General Relativity and Quantum Cosmology · Physics 2017-09-13 M. Sharif , Misbah Shahzadi

A covariant scalar-tensor-vector gravity theory is developed which allows the gravitational constant $G$, a vector field coupling $\omega$ and the vector field mass $\mu$ to vary with space and time. The equations of motion for a test…

General Relativity and Quantum Cosmology · Physics 2021-11-22 J. W. Moffat

In this analysis, we investigate the polarization radiation imaging of Kerr-Newman black holes, with a particular focus on the impact of black hole charge on photon propagation and polarization characteristics. By extending the traditional…

General Relativity and Quantum Cosmology · Physics 2026-04-10 Xin Li , Sen Guo , Pei Wang , En-Wei Liang , Huan Deng , Yu Liang , Xiao-Xiong Zeng , Kai Lin , Qing-Quan Jiang

This study investigates photon orbits around Kerr-MOG black holes. The equation of photon of motion around the Kerr-MOG black hole is derived by solving the Hamilton-Jacobi equation, expressed as a sixth-order polynomial involving the…

General Relativity and Quantum Cosmology · Physics 2024-12-24 Shi-Yu Li , Song-Shan Luo , Zhong-Wen Feng

In the work, we have presented detailed analyses of the event horizon and curvature properties of spacetime around a regular black hole in modified gravity so-called regular MOG black hole. The motion of neutral, electrically charged and…

General Relativity and Quantum Cosmology · Physics 2020-10-27 Javlon Rayimbaev , Pulat Tadjimuratov , Ahmadjon Abdujabbarov , Bobomurat Ahmedov , Malika Khudoyberdieva

We present a systematic investigation of the radiative properties and optical appearance of rotating SV black holes surrounded by a thin accretion disks, and mainly analyze the influence of the regularization parameter $g$ on related…

High Energy Astrophysical Phenomena · Physics 2026-02-17 Ziyang Li , Shou-Qi Liu , Jia-Hui Huang

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

We have studied the polarized image of an equatorial emitting ring around a 4D Gauss-Bonnet black hole. Our results show that the effects of Gauss-Bonnet parameter on the polarized image depend on the magnetic field configuration, the…

General Relativity and Quantum Cosmology · Physics 2022-09-21 Xin Qin , Songbai Chen , Jiliang Jing

In this article, we have examined the existence of a static spherically symmetric solution in the Scalar Tensor Vector Gravity (STVG) and investigated its horizon distances to develop boundary limitations for our test particle. We have…

General Relativity and Quantum Cosmology · Physics 2022-11-04 Devansh Shukla , Abhay Menon A , Kamlesh Pathak

In this manuscript, we provide a comprehensive study of gravitational lensing by dark compact objects predicted by a Modified Gravity (MOG) based on the Scalar-Vector-Tensor action, and the aim is to analyze new insights into the nature of…

General Relativity and Quantum Cosmology · Physics 2025-03-07 Nagina Rehman , Zoe C. S. Chan , Mubasher Jamil , Mustapha Azreg-Aïnou

We study spontaneously vectorized black holes in Einstein-vector-Gauss-Bonnet theory with a quadratic coupling function. Besides the static, spherically symmetric black holes carrying an electric charge, there are uncharged static, axially…

General Relativity and Quantum Cosmology · Physics 2026-04-07 Burkhard Kleihaus , Jutta Kunz

The deflection angle of Kerr-MOG black holes is studied for different values of the parameter in modified gravity (MOG). To this end, we employ the Gauss-Bonnet theorem, which was first studied by Gibbons and Werner and then extended by…

General Relativity and Quantum Cosmology · Physics 2019-10-29 Ali Övgün , İzzet Sakallı , Joel Saavedra

A covariant modified gravity (MOG) is formulated by adding to general relativity two new degrees of freedom, a scalar field gravitational coupling strength $G= 1/\chi$ and a gravitational spin 1 vector field $\phi_\mu$. The $G$ is written…

General Relativity and Quantum Cosmology · Physics 2021-02-17 J. W. Moffat

Exact solutions describing rotating black holes can offer important tests for alternative theories of gravity, motivated by the dark energy and dark matter problems. We present an analytic rotating black hole solution for a class of…

High Energy Physics - Theory · Physics 2018-04-10 Francesco Filippini , Gianmassimo Tasinato

This paper investigates the shadow images of rotating charged black holes in Kalb-Ramond (KR) gravity, using an accretion disk that is both optically and geometrically thin and located on the equatorial plane as the light source model. The…

General Relativity and Quantum Cosmology · Physics 2025-08-12 Chen-Yu Yang , Ke-Jian He , Xiao-Xiong Zeng , Li-Fang Li

Polarization wiggling is an observational effect of a gravitational field on the polarization of electromagnetic radiation traversing it. We find that in linear gravity, the polarization wiggle rate contributions from scalar, vector and…

General Relativity and Quantum Cosmology · Physics 2026-04-27 Kjell Tangen

We offer a discussion on the strong field regime predictions of two families of theories that deviate from General Relativity in different aspects: $f(R)$-gravity and Scalar-Tensor-Vector Gravity (STVG). We discuss astrophysical effects in…

General Relativity and Quantum Cosmology · Physics 2020-01-06 Daniela Pérez , Gustavo E. Romero

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

We apply a general relativistic framework to static and rotating black hole solutions in Scalar-Tensor-Vector Gravity or modified gravity (MOG). Our results yield exact analytic, closed-form relations expressing the mass $M$, the MOG…

General Relativity and Quantum Cosmology · Physics 2026-04-10 José Miguel Rojas , Mehrab Momennia