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We discuss the solution to Einstein's equations for a Lense-Thirring inspired metric describing a slowly rotating black hole coupled to nonlinear electrodynamics. We show that different schemes of rotation for the black hole exist; they…

General Relativity and Quantum Cosmology · Physics 2018-12-26 Claus Lämmerzahl , Marco Maceda , Alfredo Macías

We study a spherically symmetric setup consisting of a Schwarzschild metric as the background geometry in the framework of classical polymerization. This process is an extension of the polymeric representation of quantum mechanics in such a…

High Energy Physics - Theory · Physics 2018-09-24 Babak Vakili

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

We introduce a two-parameter static, nonspherically-symmetric black hole solution in the Einstein theory of gravity coupled with a massless scalar field. The scalar field depends only on the polar coordinate $\theta$ in the spherical…

General Relativity and Quantum Cosmology · Physics 2025-02-21 S. Habib Mazharimousavi

We explore the shadow of certain class generalized Kerr black holes, which are non vacuum solutions of the Einstein equations with exotic matter. The images depend on the angular momentum of the compact object, the characteristic parameter…

General Relativity and Quantum Cosmology · Physics 2016-02-23 Vassil K. Tinchev

We have studied numerically the shadows of a non-Kerr rotating compact object with quadrupole mass moment, which belongs to Manko-Novikov family. The non-integrable photon motion caused by quadrupole mass moment affects sharply the shadow…

General Relativity and Quantum Cosmology · Physics 2018-11-29 Mingzhi Wang , Songbai Chen , Jiliang Jing

We study the shadow produced by a class of rotating black holes surrounded by plasma. The metric for these black holes arises by applying the Newman-Janis algorithm to a family of spherically symmetric spacetimes, which includes several…

General Relativity and Quantum Cosmology · Physics 2021-11-08 Javier Badía , Ernesto F. Eiroa

We consider a static, spherically symmetric space-time with an electric field arising from a quadratic metric-affine extension of General Relativity. Such a space-time is free of singularities in the centre of the black holes, while at…

General Relativity and Quantum Cosmology · Physics 2024-01-17 Ivan De Martino , Riccardo Della Monica , Diego Rubiera-Garcia

Einstein's equations imply that a gravitationally collapsed object forms an event horizon. But what lies on the other side of this horizon? In this paper, we question the reality of the conventional solution (the black hole), and point out…

High Energy Physics - Theory · Physics 2025-05-22 Kostas Tzanavaris , Latham Boyle , Neil Turok

Higher derivative extensions of Einstein gravity are important within the string theory approach to gravity and as alternative and effective theories of gravity. H. L\"u, A. Perkins, C. Pope, K. Stelle [Phys.Rev.Lett. 114 (2015), 171601]…

General Relativity and Quantum Cosmology · Physics 2023-07-10 K. Kokkotas , R. A. Konoplya , A. Zhidenko

The Kerr-Newman metric is the unique vacuum solution of the General Relativistic field equations, in which any singularities or spacetime pathologies are hidden behind horizons. They are believed to describe the spacetimes of massive…

General Relativity and Quantum Cosmology · Physics 2023-04-21 Dimitrios Psaltis

We analyze gravitational lensing and their cast images from thin-disks in shadow observations of a family of spherically symmetric black hole solutions previously derived within the framework of Loop Quantum Gravity. Such black holes depend…

General Relativity and Quantum Cosmology · Physics 2024-09-10 David J. Patiño Pomares , Diego Rubiera-Garcia

We examine the observational discrepancies of two widely used models describing anisotropic (dark) matter distributions around a black hole, focusing on their photon spheres, shadow radii, and lensing observables. The models considered are…

General Relativity and Quantum Cosmology · Physics 2026-03-26 M. F. Fauzi , H. S. Ramadhan , A. Sulaksono

We propose a novel concept of astrophysical mirroring in the schwarzschild framework, which emerges as a direct consequence of gravitational lensing effects occurring in the immediate vicinity of extremely dense massive objects within…

General Relativity and Quantum Cosmology · Physics 2026-04-08 Bikramarka S Choudhury , Aritra Sanyal , Md Khalid Hossain , Farook Rahaman

In a recent work [arXiv:2307.13489 [gr-qc]], we have described spherically symmetric and static quantum black holes as deformations of the classical Schwarzschild metric that depend on the physical distance to the horizon. We have developed…

General Relativity and Quantum Cosmology · Physics 2024-03-20 Manuel Del Piano , Stefan Hohenegger , Francesco Sannino

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

Motivated by recent Event Horizon Telescope findings, we investigate constrained optics of rotating black holes in Einstein-Maxwell-scalar gravity theory. Precisely, we mainly study the parameter effects on two relevant optical concepts…

High Energy Physics - Theory · Physics 2024-11-19 Hajar Belmahi

The spacetime singularities in classical general relativity predicted by the celebrated singularity theorems are formed at the end of gravitational collapse. Quantum gravity is the expected theory to resolve the singularity problem, but we…

General Relativity and Quantum Cosmology · Physics 2020-07-15 Sushant G. Ghosh , Muhammed Amir , Sunil D. Maharaj

We investigate the horizon structure of the rotating Einstein-Born-Infeld solution which goes over to the Einstein-Maxwell's Kerr-Newman solution as the Born-Infeld parameter goes to infinity ($\beta \rightarrow \infty$). We find that for a…

General Relativity and Quantum Cosmology · Physics 2016-06-22 Farruh Atamurotov , Sushant G. Ghosh , Bobomurat Ahmedov

The Chern-Simons modification to general relativity in four dimensions consists of adding to the Einstein-Hilbert term a scalar field that couples to the first class Pontryagin density. In this theory, which has attracted considerable…

General Relativity and Quantum Cosmology · Physics 2010-06-29 Leonardo Amarilla , Ernesto F. Eiroa , Gaston Giribet