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Related papers: Shadows from spinning black holes in extended grav…

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In general relativity, the angular radius of the shadow of a black hole is primarily determined by its mass-to-distance ratio and depends only weakly on its spin and inclination. If general relativity is violated, however, the shadow size…

Real astronomical objects possess spin, yet deriving exact solutions for rotating black holes within gravitational theories is a formidable challenge. To understand the shadow of rotating black holes in Lorentz-violating spacetimes induced…

General Relativity and Quantum Cosmology · Physics 2025-08-04 Wentao Liu , Di Wu , Jieci Wang

We present the shape of the black hole shadow on the standard background screen as it is registered by the distant observer. The screen is an infinite plane, emitting the quanta uniformly distributed to a hemisphere. The source of emission…

General Relativity and Quantum Cosmology · Physics 2018-02-14 Serge V. Repin , Dmitry A. Kompaneets , Igor D. Novikov , Valeriya A. Mityagina

The recently released images of the supermassive black holes in the M87 galaxy and the galaxy of our own make probing black hole spacetimes and testing general relativity (GR) possible. The violation of equatorial reflection symmetry of…

General Relativity and Quantum Cosmology · Physics 2022-08-04 Che-Yu Chen

We investigate the astrophysical consequences of black holes in quadratic gravity, characterized by the parameters $S_0$, $S_2$, $m_0$ and $m_2$, in addition to the black hole mass $M$. To evaluate the physical validity of the fundamental…

General Relativity and Quantum Cosmology · Physics 2024-12-24 Somi Aktar , Niyaz Uddin Molla , Farook Rahaman , G. Mustafa

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

We study the shadows of disformal black holes in vector-tensor Galileons modified gravity. Our analysis shows that the apparent image of the black hole in the observer's sky is non-spherical and cuspy, which is in contrast to the Kerr and…

General Relativity and Quantum Cosmology · Physics 2018-01-25 Tsvetan Vetsov , Galin Gyulchev , Stoytcho Yazadjiev

Motivated by the first image of a black hole captured by the Event Horizon Telescope (EHT), there has been a surge of research using observations of black hole shadows to test theories of gravity. In this paper, we carry out a study related…

General Relativity and Quantum Cosmology · Physics 2024-08-06 Qi Sun , Yu Zhang , Chen-Hao Xie , Qi-Quan Li

Dark matter (DM), a fundamental cosmic component, motivates the study of its influence on black hole (BH) shadows, especially for spinning BHs confirmed by EHT observations. This work generalizes the Schwarzschild BH surrounded by DM to an…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Haiyuan Feng , Ziqiang Cai , Rong-Jia Yang , Jinjun Zhang

Collaborative international efforts under the name of the Event Horizon Telescope project, using sub- mm very long baseline interferometry, are soon expected to provide the first images of the shadow cast by the candidate supermassive black…

General Relativity and Quantum Cosmology · Physics 2016-10-26 Ziri Younsi , Alexander Zhidenko , Luciano Rezzolla , Roman Konoplya , Yosuke Mizuno

Black holes have turned into cosmic laboratories to search for ultra-light scalars by virtue of the superradiant instability. In this paper we present a detailed study of the impact of the superradiant evolution on the black hole shadow and…

General Relativity and Quantum Cosmology · Physics 2020-07-03 Gastón Creci , Stefan Vandoren , Helvi Witek

The Event Horizon Telescope (EHT) has provided a new tool for testing the strong-field regime of gravity by imaging the shadows of M87* and Sgr A*. These observations provide the first real opportunity to test whether quantum…

General Relativity and Quantum Cosmology · Physics 2026-05-29 Heena Ali , Sushant G. Ghosh

The presence of a bright "photon ring" surrounding a dark "black hole shadow" has been discussed as an important feature of the observational appearance of emission originating near a black hole. We clarify the meaning and relevance of…

High Energy Astrophysical Phenomena · Physics 2019-07-17 Samuel E. Gralla , Daniel E. Holz , Robert M. Wald

Due to the acceleration of the black hole, the circular orbits of the photons will deviate from the equatorial plane and the property of the black hole shadow will change. We find that the latitude of the circular orbit increases with the…

General Relativity and Quantum Cosmology · Physics 2021-01-20 Ming Zhang , Jie Jiang

We explore the structure of shadow for a Kerr-de Sitter black hole with a non-magnetized, pressureless plasma surrounding it. Specific plasma distributions are considered to separate the Hamilton-Jacobi equation and find the photon regions.…

General Relativity and Quantum Cosmology · Physics 2021-09-16 Abhishek Chowdhuri , Arpan Bhattacharyya

We study the shadow of rotating charge black holes in the presence of quintessence. The shadow of a rotating black hole is a distorted circle and in our study, we find that the shape and size of the black hole shadow depend upon four…

General Relativity and Quantum Cosmology · Physics 2022-05-05 Balendra Pratap Singh

We study analytically the shadow cast by the rotating black hole in the perfect fluid dark matter. The apparent shape of the shadow depends upon the black hole spin $a$ and the perfect fluid dark matter intensity parameter $k$ ($k>0$). In…

General Relativity and Quantum Cosmology · Physics 2018-12-26 Xian Hou , Zhaoyi Xu , Jiancheng Wang

We study black hole shadows in nonminimally coupled Weyl connection gravity, a metric-affine extension of general relativity in which spacetime is described by a metric and a Weyl vector field encoding non-metricity. Despite going beyond…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Cláudio Gomes , Margarida Lima , Francisco S. N. Lobo , Luís F. D. da Silva

In this article, we present the thermodynamic and shadow properties of rotating black holes with global monopole charge. The angular diameter of Sgr A$^{*}$ black hole is 48.7 $\pm$ 7 $\mu as$, which is 8 $kps$ far away having a mass of $M…

General Relativity and Quantum Cosmology · Physics 2025-06-04 Balendra Pratap Singh , Md Sabir Ali

The existence of quintessential dark energy around a black hole has considerable consequences on its spacetime geometry. Hence, in this article, we explore its effect on horizons and the silhouette generated by a Kerr-Newman black hole in…

General Relativity and Quantum Cosmology · Physics 2020-06-23 Saeed Ullah Khan , Jingli Ren