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Related papers: Testing EGB gravity coupled to bumblebee field and…

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The EHT observation revealed event horizon-scale images of the supermassive black holes Sgr A* and M87* and these results are consistent with the shadow of a Kerr black hole as predicted by general relativity. However, Kerr-like rotating…

General Relativity and Quantum Cosmology · Physics 2024-10-10 Shafqat Ul Islam , Sushant G. Ghosh , Sunil D. Maharaj

This study probes spacetime solutions within Einstein-Bumblebee gravity, a modified gravitational framework incorporating spontaneous Lorentz symmetry violation through a vector field mechanism. By introducing a cosmological constant into…

General Relativity and Quantum Cosmology · Physics 2025-08-04 Reggie C. Pantig , Shubham Kala , Ali Övgün , Nikko John Leo S. Lobos

The M87* black hole shadow observation by the Event Horizon Telescope (EHT) has enabled us to test the modified gravity theories in the extreme-field regime and estimating the black hole parameters. Having this assertion, we investigate the…

General Relativity and Quantum Cosmology · Physics 2023-02-06 Sushant G. Ghosh , Rahul Kumar Walia

We study Einstein-Gauss-Bonnet gravity coupled to a bumblebee field which leads to a spontaneous Lorentz symmetry breaking in the gravitational sector. We obtain an exact black hole solution and a cosmological solution in four dimensional…

General Relativity and Quantum Cosmology · Physics 2022-02-03 Chikun Ding , Xiongwen Chen , Xiangyun Fu

Recently there has been a surge of interest in regularizing, a $ D \to 4 $ limit of, the Einstein-Gauss-Bonnet (EGB) gravity, and the resulting regularized $4D$ EGB gravity has nontrivial dynamics. The theory admits spherically symmetric…

General Relativity and Quantum Cosmology · Physics 2020-07-28 Rahul Kumar , Sushant G. Ghosh

Bumblebee gravity is one of the simplest gravity theories with spontaneous Lorentz symmetry breaking. Since we know a rotating black hole solution in bumblebee gravity, we can potentially test this model with the available astrophysical…

General Relativity and Quantum Cosmology · Physics 2022-08-16 Jiale Gu , Shafqat Riaz , Askar B. Abdikamalov , Dimitry Ayzenberg , Cosimo Bambi

In this work, the quasinormal modes of a $5$-D black hole in Einstein Gauss-Bonnet Bumblebee theory of gravity have been investigated with the help of the Pad\'e averaged higher order WKB approximation method and the validity of Hod's…

General Relativity and Quantum Cosmology · Physics 2024-07-16 Dhruba Jyoti Gogoi

Recently a $D$-dimensional regularization approach leading to the non-trivial $(3+1)$-dimensional Einstein-Gauss-Bonnet (EGB) effective description of gravity was formulated which was claimed to bypass the Lovelock's theorem and avoid…

General Relativity and Quantum Cosmology · Physics 2020-11-16 R. A. Konoplya , A. F. Zinhailo

The Event Horizon Telescope (EHT) has guided strong-field gravitational physics by providing the first direct images of the supermassive black holes M87* and Sagittarius A*. The EHT observations offer unprecedented opportunities to test…

General Relativity and Quantum Cosmology · Physics 2026-04-16 Towheed Ahmad Nengroo , Shafqat Ul Islam , Sushant G. Ghosh

A Kerr-Sen-like black hole solution results from Einstein-bumblebee gravity. It contains a Lorentz violating (LV) parameter that enters when the bumblebee field receives vacuum expectation value through a spontaneously breaking of the…

General Relativity and Quantum Cosmology · Physics 2022-05-25 Sohan Kumar Jha , Anisur Rahaman

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

Recently, a non-trivial $4D$ Einstein-Gauss-Bonnet (EGB) theory of gravity, by rescaling the GB coupling parameter as $\alpha/(D-4)$, was formulated in \cite{Glavan:2019inb}, which bypasses Lovelock's theorem and avoids Ostrogradsky…

General Relativity and Quantum Cosmology · Physics 2020-09-17 Shafqat Ul Islam , Rahul Kumar , Sushant G. Ghosh

The ability of bumblebee gravity models to explain dark energy, which is the phenomenon responsible for the universe's observed accelerated expansion, is one of their most significant applications. An effect that causes faster expansion can…

General Relativity and Quantum Cosmology · Physics 2023-05-19 M. Mangut , H. Gürsel , S. Kanzi , İ. Sakallı

We investigate Einstein-\AE ther gravity in light of the recent Event Horizon Telescope (EHT) observations of the M87*. The shape and size of the observed black hole shadow contains information of the geometry in its vicinity, and thus one…

General Relativity and Quantum Cosmology · Physics 2021-05-20 Mohsen Khodadi , Emmanuel N. Saridakis

Motivated by (i) more and more interest in strong gravitational lensing by supermassive black holes due to the achievement of EHT observations, (ii) the ongoing popular topic on the possibility of Lorentz symmetry being broken in…

General Relativity and Quantum Cosmology · Physics 2022-11-01 Xiao-Mei Kuang , Ali Övgün

The first images of black hole shadows open new possibilities to constrain modern extended gravity theories. We present the method of shadow background calculation for black hole solutions in the form of Taylor series where $g_{11} = -…

General Relativity and Quantum Cosmology · Physics 2022-09-07 V. Prokopov , S. Alexeyev , O. Zenin

In this work, we investigate the structure of black hole shadows in the bumblebee gravity model formulated within the metric-affine framework, which incorporates spontaneous Lorentz symmetry breaking (LSB) through a vector field $B_\mu$…

General Relativity and Quantum Cosmology · Physics 2026-04-29 Jose R. Nascimento , Ana R. M. Oliveira , Albert Yu. Petrov , Paulo J. Porfírio , Amilcar R. Queiroz

Recently Glavan and Lin [Phys. Rev. Lett. 124, 081301 (2020)] formulated the Einstein-Gauss-Bonnet (EGB) gravity by re-scaling GB coupling constant as $\alpha/(D-4)$ and taking limit $D \to 4$ at the level of field equations. The GB…

General Relativity and Quantum Cosmology · Physics 2020-08-06 Kimet Jusufi , Ayan Banerjee , Sushant G. Ghosh

In the Einstein-bumblebee gravity, the Lorentz symmetry is spontaneously broken by a vector field. In this paper, we attempt to test the Lorentz symmetry via the observation of the shadow cast by the Kerr-like black hole with or without…

General Relativity and Quantum Cosmology · Physics 2021-06-29 Hui-Min Wang , Shao-Wen Wei

We find a Kerr-like black hole solution-a rotating Bumblebee black hole (RBBH) with a Lorentz-violating parameter $\ell$ and examine the strong lensing by it. The parameter $\ell$ changes the event horizon radius and photon sphere,…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Arun Kumar , Shafqat Ul Islam , Sushant G. Ghosh
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