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Related papers: Einstein-\AE ther Gravity in the light of Event Ho…

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In Einstein-Aether gravity, we revisit the issue of linear stabilities of black holes against odd-parity perturbations on a static and spherically symmetric background. In this theory, superluminal propagation is allowed and there is a…

General Relativity and Quantum Cosmology · Physics 2024-08-13 Shinji Mukohyama , Shinji Tsujikawa , Anzhong Wang

The black hole spacetime is described by general relativity and characterized by two quantities: the black hole mass and spin. Black hole spin measurement requires information from the vicinity of the event horizon, which is spatially…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Kotaro Moriyama , Shin Mineshige , Mareki Honma , Kazunori Akiyama

We report the existence of novel static spherical black-hole solutions in a vector-tensor gravitational theory called the bumblebee gravity model which extends the Einstein-Maxwell theory by allowing the vector to nonminimally couple to the…

General Relativity and Quantum Cosmology · Physics 2023-03-20 Rui Xu , Dicong Liang , Lijing Shao

We explore black hole solutions and some of its physical properties in Einstein's theory in 4D, modified by a cubic gravity term and in the presence of non-linear electrodynamics. In the context of Effective Field Theories (EFT) and under…

General Relativity and Quantum Cosmology · Physics 2024-02-22 Gustavo Gutierrez-Cano , Gustavo Niz

The direct imaging of black holes by the Event Horizon Telescope (EHT) enables strong-field tests of gravity. We study the cosmological evolution and the black-hole shadow radius in 4D Einstein-Gauss-Bonnet (EGB) gravity coupled to…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-12 Xiang-Qian Li , Hao-Peng Yan , Xiao-Jun Yue

We investigate the shadow of a rotating braneworld black hole in dispersive plasma environments and assess the potential of the Event Horizon Telescope (EHT) observations to constrain braneworld gravity. The spacetime around a rotating…

General Relativity and Quantum Cosmology · Physics 2026-05-11 Siddharth Kumar Sahoo , Indrani Banerjee

Recent observations of black hole shadows have revolutionized our ability to probe gravity in extreme environments. This manuscript presents a novel analytic method to calculate, in leading-order terms, the key parameters of photon sphere…

General Relativity and Quantum Cosmology · Physics 2024-06-04 Vitalii Vertogradov , Ali Övgün

We consider a static black hole immersed in the Power-Yang-Mills field in four dimensional Einstein-Gauss-Bonnet gravity and investigate the effect of various parameters on the radius of the photon sphere. The modified form of the…

General Relativity and Quantum Cosmology · Physics 2023-05-29 M. Zubair , Muhammad Ali Raza , Furkat Sarikulov , Javlon Rayimbaev

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 present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. These images show a prominent ring with a diameter of ~40 micro-as, consistent with the size and shape of the lensed…

Astrophysics of Galaxies · Physics 2019-07-08 The Event Horizon Telescope Collaboration

The successful observation of M87 supermassive black hole by the Black Hole Event Horizon Telescope(EHT) provides a very good opportunity to study the theory of gravity. In this work, we obtain the exact solution for the short hair black…

General Relativity and Quantum Cosmology · Physics 2023-01-04 Meirong Tang , Zhaoyi Xu

Einstein's equation could be interpreted as the first law of thermodynamic near the spherically symmetric horizon. Through recalling the Einstein gravity with a more general static spherical symmetric metric, we find that the entropy would…

General Relativity and Quantum Cosmology · Physics 2018-03-13 Miao He , Zi-Liang Wang , Chao Fang , Dao-Quan Sun , Jian-Bo Deng

We study two large classes of alternative theories, modifying the action through algebraic, quadratic curvature invariants coupled to scalar fields. We find one class that admits solutions that solve the vacuum Einstein equations and…

General Relativity and Quantum Cosmology · Physics 2011-05-12 Nicolas Yunes , Leo C. Stein

The recent discovery of the novel four-dimensional static and spherically symmetric Gauss-Bonnet black hole provides a promising bed to test Gauss-Bonnet gravity by using astronomical observations [Phys. Rev. Lett. 124, 081301 (2020)]. In…

General Relativity and Quantum Cosmology · Physics 2024-02-22 Shao-Wen Wei , Yu-Xiao Liu

Black holes with dyonic charges in Einstein-Maxwell-dilaton-axion supergravity theory are revisited in the context of black hole shadows. We consider static as well as rotating (namely the dyonic Kerr-Sen) black holes. The matter…

General Relativity and Quantum Cosmology · Physics 2023-08-08 Soumya Jana , Sayan Kar

The Event Horizon Telescope (EHT) collaboration recently released horizon-scale images of the supermassive black hole M87*. These images are consistently described by an optically thin, lensed accretion flow in the Kerr spacetime. General…

High Energy Astrophysical Phenomena · Physics 2023-05-24 Hadrien Paugnat , Alexandru Lupsasca , Frédéric Vincent , Maciek Wielgus

We construct a charged rotating black hole in 4D Einstein-Gauss-Bonnet (EGB) gravity starting from charged black hole in 4D EGB gravity using complex coordinate transformations suggested by Newman-Janis. Further, we have studied the null…

General Relativity and Quantum Cosmology · Physics 2022-02-15 Uma Papnoi , Farruh Atamurotov

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

Context. The Event Horizon Telescope (EHT) collaboration recently obtained first images of the surroundings of the supermassive compact object M87* at the center of the galaxy M87. Aims. We want to develop a simple analytic disk model for…

General Relativity and Quantum Cosmology · Physics 2021-02-03 F. H. Vincent , M. Wielgus , M. A. Abramowicz , E. Gourgoulhon , J. -P. Lasota , T. Paumard , G. Perrin

Starting from the first law of black hole thermodynamics, we establish an explicit correspondence between the corrected entropy and the metric function under the condition of fixed black hole energy and horizon position. Using the corrected…

General Relativity and Quantum Cosmology · Physics 2026-05-14 Fang Liu , Yu-Bo Ma , Yun-Zhi Du , Huai-Fan Li