English
Related papers

Related papers: QED Effects on Kerr Black Hole Shadows immersed in…

200 papers

Soft hairs of black holes are the Noether charges associated with the generalized Bondi-Metzner-Sachs symmetries. In this work, the images of soft-haired Kerr black holes are studied. For an eternal black hole, the image is rotated,…

General Relativity and Quantum Cosmology · Physics 2026-05-12 Shaoqi Hou , Zong-Hong Zhu

The effect of vacuum birefringence is one of the first predictions of quantum electrodynamics (QED): the presence of a charged Dirac field makes the vacuum birefringent when threaded by magnetic fields. This effect, extremely weak for…

High Energy Astrophysical Phenomena · Physics 2018-05-29 Ilaria Caiazzo , Jeremy Heyl

We study the impact of different fluid matter scenarios on the shadow of black holes (BH) and on frequencies of quasinormal modes (QNM) for a black hole subjected to scalar perturbations, with a comparison to the standard Kerr. The analysis…

General Relativity and Quantum Cosmology · Physics 2026-02-10 Reza Pourkhodabakhshi , Jorge G. Russo

We propose a new method to determine the physical parameters of Kerr black holes (namely, specific angular momentum $a$, inclination angle $i$, and distance $D$ from an observer) only from the shadow's information such as the size and…

General Relativity and Quantum Cosmology · Physics 2024-02-20 Kenta Hioki , Umpei Miyamoto

A distinct visual signature occurs in black holes that are surrounded by optically thin and geometrically thick emission regions. This signature is a sharp-edged dip in brightness that is coincident with the black-hole shadow, which is the…

High Energy Astrophysical Phenomena · Physics 2021-11-03 Thomas Bronzwaer , Heino Falcke

Very-long baseline interferometric observations have resolved structure on scales of only a few Schwarzschild radii around the supermassive black holes at the centers of our Galaxy and M87. In the near future, such observations are expected…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Tim Johannsen

In this work, we explore the properties and shadows of spin-induced scalarized black holes, as well as investigate how a Ricci coupling influences them. Our findings reveal significant deviations from the Kerr metric in terms of the…

General Relativity and Quantum Cosmology · Physics 2025-08-19 Pedro G. S. Fernandes , Clare Burrage , Astrid Eichhorn , Thomas P. Sotiriou

In this paper, we investigate the observational appearances of magnetically charged black holes in Born-Infeld (BI) electrodynamics. We examine the effects of the magnetic charge and the BI parameter on the geodesics with different impact…

General Relativity and Quantum Cosmology · Physics 2023-04-20 Shangyu Wen , Wei Hong , Jun Tao

We study the shadows cast by rotating hairy black holes with two non-trivial time-periodic scalar fields having a non-flat Gaussian curvature of the target space spanned by the scalar fields. Such black holes are a viable alternative to the…

General Relativity and Quantum Cosmology · Physics 2024-05-09 Galin N. Gyulchev , Ayush Roy , Lucas G. Collodel , Petya G. Nedkova , Stoytcho S. Yazadjiev , Daniela D. Doneva

Aims. In order to understand the anisotropic properties of local radiation field in the curved spacetime around a rotating black hole, we investigate the appearance of a black hole seen by an observer located near the black hole. When the…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Rohta Takahashi , Masaaki Takahashi

We have studied the shadow of a disformal Kerr black hole with an extra deformation parameter, which belongs to non-stealth rotating solutions in quadratic Degenerate Higher Order Scalar Tensor (DHOST) theory. Our result show that the size…

General Relativity and Quantum Cosmology · Physics 2020-12-29 Fen Long , Songbai Chen , Mingzhi Wang , Jiliang Jing

Context. Quasi-periodic variability has been observed in a number of X-ray binaries harboring black hole candidates. In general relativity, black holes are uniquely described by the Kerr metric and, according to the cosmic censorship…

High Energy Astrophysical Phenomena · Physics 2016-03-09 Federico García , Ignacio F. Ranea-Sandoval , Tim Johannsen

We investigate a rotating black hole embedded in a five-dimensional flat bulk by extending the Kerr metric through the Gurses-Gursey line element. Employing Boyer-Lindquist coordinates, we reinterpret the black hole as a charged-like object…

General Relativity and Quantum Cosmology · Physics 2025-10-10 Abraao J. S. Capistrano , Antonio C. Gutierrez-Pineres , Carlos H. Coimbra-Araujo

We study the gravitational lensing effects of a static, asymptotically flat black hole with primary scalar hair in Beyond Horndeski gravity, focusing on the strong lensing regime. Recently, in Ref. [1], we placed constraints on the scalar…

General Relativity and Quantum Cosmology · Physics 2025-09-09 Mohsen Fathi

The recently obtained hairy Kerr black holes, due to additional sources or surrounding fluid, like dark matter, with conserved energy-momentum tensor, have a deviation $\alpha$ and primary hair $l_0$, apart from rotation parameter $a$ and…

General Relativity and Quantum Cosmology · Physics 2021-06-01 Misba Afrin , Rahul Kumar , Sushant G. Ghosh

We have studied photon motion around axially symmetric rotating Kerr black hole in the presence of plasma with radial power-law density. It is shown that in the presence of plasma the observed shape and size of shadow changes depending on…

General Relativity and Quantum Cosmology · Physics 2015-10-21 Farruh Atamurotov , Bobomurat Ahmedov , Ahmadjon Abdujabbarov

The study of black hole (BH) shadows provide crucial insights into the nature of strong gravitational effects and the intricate structure of the spacetime surrounding BHs. In this paper, we explore the shadow of Kerr MOG BH within a plasma…

General Relativity and Quantum Cosmology · Physics 2025-04-30 Saira Yasmin , Khadije Jafarzade , Mubasher Jamil

We investigate the influence of Born-Infeld (BI) nonlinear electrodynamics on magnetic field configurations, photon orbits, and black hole shadows for Schwarzschild black holes immersed in magnetic fields. Assuming that the BI magnetic…

General Relativity and Quantum Cosmology · Physics 2025-07-03 Yiqian Chen , Guangzhou Guo , Benrong Mu , Peng Wang

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

In this paper, we investigate the gravitational lensing properties of magnetically charged black holes within the framework of nonlinear electrodynamics. We derive the deflection angle and examine the influence of the nonlinear…

General Relativity and Quantum Cosmology · Physics 2025-06-23 Hira Waseem , Nikko John Leo S. Lobos , Ali Övgün , Reggie C. Pantig