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Related papers: Investigating Loop Quantum Gravity with EHT Observ…

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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

The Event Horizon Telescope (EHT) will soon provide the first high-resolution images of the Galactic Centre supermassive black hole (SMBH) candidate Sagittarius A* (Sgr A*), enabling us to probe gravity in the strong-field regime. Besides…

High Energy Astrophysical Phenomena · Physics 2021-05-26 C. M. Fromm , Y. Mizuno , Z. Younsi , H. Olivares , O. Porth , M. De Laurentis , H. Falcke , M. Kramer , L. Rezzolla

We examine a loop quantum gravity (LQG) inspired rotating black hole, treating it as a central supermassive black hole (SMBH) in an extreme mass-ratio inspiral (EMRI) system, where an inspiralling object exhibits eccentric motion around the…

General Relativity and Quantum Cosmology · Physics 2025-05-20 Tieguang Zi , Shailesh Kumar

The Event Horizon Telescope (EHT) Collaboration has recently published the first horizon-scale images of the supermassive black holes M87* and Sgr A* and provided some first information on the physical conditions in their vicinity. The…

High Energy Astrophysical Phenomena · Physics 2023-11-20 Kotaro Moriyama , Alejandro Cruz-Osorio , Yosuke Mizuno , Christian M. Fromm , Antonios Nathanail , Luciano Rezzolla

The Event Horizon Telescope, a global submillimeter wavelength very long baseline interferometry array, produced the first image of supermassive black hole M87* showing a ring of diameter $\theta_d= 42\pm 3\,\mu$as, inferred a black hole…

General Relativity and Quantum Cosmology · Physics 2020-06-18 Rahul Kumar , Amit Kumar , Sushant G. Ghosh

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

In this paper, we construct an effective rotating loop quantum black hole (LQBH) solution, starting from the spherical symmetric LQBH by applying the Newman-Janis algorithm modified by Azreg-A\"{i}nou's non-complexification procedure, and…

General Relativity and Quantum Cosmology · Physics 2021-05-11 Cheng Liu , Tao Zhu , Qiang Wu , Kimet Jusufi , Mubasher Jamil , Mustapha Azreg-Aïnou , Anzhong Wang

For the short hairs that have a significant impact only near the event horizon, studying their strong gravitational lensing effects is of great significance for revealing the properties of these hairs. In this study, we systematically…

General Relativity and Quantum Cosmology · Physics 2025-04-29 Lai Zhao , Meirong Tang , Zhaoyi Xu

Loop quantum gravity inspired partial polymer quantization in four-dimensional spacetime leads to a globally regular black hole with a single horizon. The polymerized black hole metric is characterized by the minimum length parameter $k$,…

General Relativity and Quantum Cosmology · Physics 2023-03-14 Rahul Kumar Walia

According to the celebrated singularity theorems, space-time singularities in general relativity are inevitable. However, it is generally believed that singularities do not exist in nature, and their existence suggests the necessity of a…

General Relativity and Quantum Cosmology · Physics 2024-11-22 Carlos A. Benavides-Gallego , Swarnim Shashank , Haiguang Xu

The Event Horizon Telescope (EHT) collaboration has recently released the first image of a black hole (BH), opening a new window onto tests of general relativity in the strong field regime. In this paper, we derive constraints on the nature…

General Relativity and Quantum Cosmology · Physics 2020-02-24 Cosimo Bambi , Katherine Freese , Sunny Vagnozzi , Luca Visinelli

A general covariant Einstein-Gauss-Bonnet Gravity in Four-Dimensional (4D EGB) spacetime is shown to bypass Lovelock's theorem and is free from Ostrogradsky instability. Meanwhile, the bumblebee theory is a vector-tensor theory. It extends…

General Relativity and Quantum Cosmology · Physics 2024-09-11 Misba Afrin , Sushant G. Ghosh , Anzhong Wang

We investigate strong gravitational lensing by two static black hole models (Model-1 and Model-2) within the Effective Quantum Gravity (EQG) framework, characterized by mass $M$ and parameter $\zeta$. For $\zeta = 0$, they reduce to the…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-17 Yiyang Wang , Amnish Vachher , Qiang Wu , Tao Zhu , Sushant G. Ghosh

The Event Horizon Telescope (EHT), a global sub-millimeter wavelength very long baseline interferometry array, is now resolving the innermost regions around the supermassive black holes Sgr A* and M87. Using black hole images from both…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Angelo Ricarte , Jason Dexter

Our Galactic Center, Sagittarius A* (Sgr A*), is believed to harbour a supermassive black hole (BH), as suggested by observations tracking individual orbiting stars. Upcoming sub-millimetre very-long-baseline-interferometry (VLBI) images of…

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

We study the influence of the loop quantum gravity (LQG) holonomy-correction parameter $\xi$ on black hole horizon structure, timelike geodesic motion, and gravitational wave emission in two rotating LQG-inspired black hole spacetimes,…

General Relativity and Quantum Cosmology · Physics 2026-04-24 Yang Yang , Yu-Xuan Bai , Yong-Zhuang Li , Yu Han

Recently, the Event Horizon Telescope (EHT) achieved the realization of an image of the supermassive black hole $\textrm{Sgr~A}^\star$ showing an angular shadow diameter $\mathcal{D}= 48.7 \pm 7\mu as$ and the fractional deviation…

General Relativity and Quantum Cosmology · Physics 2024-04-23 L. Chakhchi , H. El Moumni , K. Masmar

The unprecedented image of the M87* supermassive black hole has sparked some controversy over its usefulness as a test of the general relativistic Kerr metric. The criticism is mainly related to the black hole's quasi-circular shadow and…

General Relativity and Quantum Cosmology · Physics 2021-10-22 Kostas Glampedakis , George Pappas

The quantum-corrected black hole model demonstrates significant potential in the study of gravitational lensing effects. By incorporating quantum effects, this model addresses the singularity problem in classical black holes. In this paper,…

General Relativity and Quantum Cosmology · Physics 2025-03-12 Lai Zhao , Meirong Tang , Zhaoyi Xu