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An attempt is made in order to clarify the so called regular black holes issue. It is revisited that if one works within General Relativity minimally coupled with non linear source, mainly of electromagnetic origin, and within a static…

General Relativity and Quantum Cosmology · Physics 2017-05-24 Stefano Chinaglia , Sergio Zerbini

Palatini (or metric-affine) theories of gravity are characterized by having {\it a priori} independent metric and affine structures. The theories built in this framework have their field equations obtained as independent variations of the…

General Relativity and Quantum Cosmology · Physics 2022-09-13 Gonzalo J. Olmo , Diego Rubiera-Garcia

In this paper, we investigate regular black hole solutions in the (2+1)-dimensional versions of General Relativity and $f(R, T)$ gravity, both coupled to nonlinear electrodynamics. By admitting that the matter content that generates such…

General Relativity and Quantum Cosmology · Physics 2025-08-18 Miguel A. S. Pinto , Roberto V. Maluf , Gonzalo J. Olmo

The most general charged and rotating black hole in Kaluza-Klein theory is known to be described by the Rasheed-Larsen solution. When the under-rotating extremal limit of this solution is taken, it falls into a general class of solutions of…

General Relativity and Quantum Cosmology · Physics 2024-02-23 Edward Teo , Thomas Wan

The nonlinear superposition of the delta-metric and the Kerr metric results in delta-Kerr metric that represents a deformed Kerr black hole with delta = 1 + q, where q > 0 is proportional to the nonrelativistic quadrupole moment of the…

General Relativity and Quantum Cosmology · Physics 2020-02-10 Alireza Allahyari , Hassan Firouzjahi , Bahram Mashhoon

While singularities are inevitable in the classical theory of general relativity, it is commonly believed that they will not be present when quantum gravity effects are taken into account in a consistent framework. In particular, the…

General Relativity and Quantum Cosmology · Physics 2018-12-12 Raúl Carballo-Rubio , Francesco Di Filippo , Stefano Liberati , Matt Visser

Gravitational wave astronomy has opened an unprecedented window onto tests of gravity and fundamental physics in the strong-field regime. In this study, we examine a series of well-motivated deviations from the classical Kerr solution of…

General Relativity and Quantum Cosmology · Physics 2026-04-07 Zhe Zhao , Swarnim Shashank , Debtroy Das , Cosimo Bambi

We present a general procedure for constructing exact black hole solutions with electric or magnetic charges in General Relativity coupled to a nonlinear electrodynamics. We obtain a variety of two-parameter family spherically symmetric…

General Relativity and Quantum Cosmology · Physics 2016-12-28 Zhong-Ying Fan , Xiaobao Wang

Within the framework of general relativity, we explore the interior of the Schwarzschild black hole before complete collapse occurs, finding that the exterior is perfectly compatible with a source much more complex than a pointlike mass. We…

General Relativity and Quantum Cosmology · Physics 2024-05-14 J. Ovalle

As argued in arXiv:2104.10172, introducing a non-minimally coupled scalar field, three-dimensional Einstein gravity can be extended by infinite families of theories which admit simple analytic generalizations of the charged BTZ black hole.…

General Relativity and Quantum Cosmology · Physics 2025-08-26 Pablo Bueno , Oscar Lasso Andino , Javier Moreno , Guido van der Velde

We propose a quantum model of spinning black holes with the integrable ring singularities. For the charged Kerr-Newman quantum metric, the complete regularization takes place at fixing of the maximal (cut-off) energy of gravitons,…

General Relativity and Quantum Cosmology · Physics 2024-02-26 V. P. Neznamov , S. Yu. Sedov , V. E. Shemarulin

This paper gives a survey of wave dynamics in the Kerr space-time geometry, the mathematical model of a rotating black hole in equilibrium. After a brief introduction to the Kerr metric, we review the separability properties of linear wave…

Mathematical Physics · Physics 2009-07-25 Felix Finster , Niky Kamran , Joel Smoller , Shing-Tung Yau

Recently the non-local gravity theory has come out to be a good candidate for an effective field theory of quantum gravity and also it can provide rich phenomenology to understand late-time accelerating expansion of the universe. For any…

General Relativity and Quantum Cosmology · Physics 2019-08-23 Utkarsh Kumar , Sukanta Panda , Avani Patel

In this paper, we consider $F(R)=R+f(R)$ theory instead of Einstein gravity with conformal anomaly and look for its analytical solutions. Depending on the free parameters, one may obtain both uncharged and charged solutions for some classes…

General Relativity and Quantum Cosmology · Physics 2012-01-04 S. H. Hendi , D. Momeni

The 1965 Penrose singularity theorem demonstrates the utterly inevitable and unavoidable formation of spacetime singularities under physically reasonable assumptions, and it remains one of the main results in our understanding of black…

General Relativity and Quantum Cosmology · Physics 2020-04-29 Raúl Carballo-Rubio , Francesco Di Filippo , Stefano Liberati , Matt Visser

In 4-dimensional General Relativity, black holes are described by the Kerr solution and are completely specified by their mass $M$ and by their spin angular momentum $J$. A fundamental limit for a black hole in General Relativity is the…

General Relativity and Quantum Cosmology · Physics 2011-04-13 Cosimo Bambi

We derive an exact radiating Kerr-Newman like black hole solution, with constant curvature $R=R_0$ imposed, to {\it metric} $f(R)$ gravity via complex transformations suggested by Newman-Janis. This generates a geometry which is precisely…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Sushant G. Ghosh , Sunil D. Maharaj , Uma Papnoi

X-ray reflection spectroscopy is a powerful technique for probing the nature of gravity around black holes in the so-called strong field regime. One of the most popular of such probes is to look at theory-agnostic deviations away from the…

High Energy Astrophysical Phenomena · Physics 2021-07-27 Askar B. Abdikamalov , Dimitry Ayzenberg , Cosimo Bambi , Sourabh Nampalliwar , Ashutosh Tripathi

Astrophysical black hole candidates are thought to be the Kerr black holes of general relativity, but there is not yet direct observational evidence that the spacetime geometry around these objects is described by the Kerr solution. The…

General Relativity and Quantum Cosmology · Physics 2017-04-10 Cosimo Bambi

So-called "regular black holes" are a topic currently of considerable interest in the general relativity and astrophysics communities. Herein we investigate a particularly interesting regular black hole spacetime described by the line…

General Relativity and Quantum Cosmology · Physics 2019-03-01 Alex Simpson , Matt Visser