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Related papers: Classical Dressing of Timelike Naked Singularities

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We analyze here the issue of local versus the global visibility of a singularity that forms in gravitational collapse of a dust cloud, which has important implications for the weak and strong versions of the cosmic censorship hypothesis. We…

General Relativity and Quantum Cosmology · Physics 2015-06-25 S. S. Deshingkar , S. Jhingan , P. S. Joshi

The Janis-Newman-Winicour metric is a solution of Einstein's gravity minimally coupled to a real massless scalar field. The $\gamma$-metric is instead a vacuum solution of Einstein's gravity. These spacetimes have no horizon and possess a…

General Relativity and Quantum Cosmology · Physics 2018-03-08 Hrishikesh Chakrabarty , Carlos A. Benavides-Gallego , Cosimo Bambi , Leonardo Modesto

Metrics representing black holes in General Relativity may exhibit naked singularities for certain values of their parameters. This is the case for super-extremal ($J^2 > M>0$) Kerr and super-extremal ($|Q|>M>0$) Reissner-N\"ordstrom…

General Relativity and Quantum Cosmology · Physics 2009-04-24 Gustavo Dotti , Reinaldo J. Gleiser , Jorge Pullin , Ignacio F. Ranea-Sandoval , Héctor Vucetich

It was recently shown that the von Neumann algebras of observables dressed to the mass of a Schwarzschild-AdS black hole or an observer in de Sitter are Type II, and thus admit well-defined traces. The von Neumann entropies of…

High Energy Physics - Theory · Physics 2025-01-17 Jonah Kudler-Flam , Samuel Leutheusser , Gautam Satishchandran

Various astrophysical and cosmological observations today serve as an indirect evidence of the existence of dark matter in the universe. In the present work, we propose a class of spacetimes that show some important characteristics relevant…

General Relativity and Quantum Cosmology · Physics 2022-12-07 Ashok B. Joshi , Divya Tahelyani , Dipanjan Dey , Pankaj S. Joshi

The $f(R)$ gravity models formulated in Einstein conformal frame are equivalent to Einstein gravity together with a minimally coupled scalar field. The scalar field couples with the matter sector and the coupling term is given by the…

General Relativity and Quantum Cosmology · Physics 2012-07-24 Yousef Bisabr

Gravitational collapse of the Brans-Dicke scalar field with non-zero potential in the presence of matter fluid obeying the barotropic equation of state, $p=w\rho$ is studied. Utilizing the concept of expansion parameter, it is seen that the…

General Relativity and Quantum Cosmology · Physics 2014-11-20 A. H. Ziaie , K. Atazadeh , Y. Tavakoli

In the realm of astrophysics, black holes exist within nonvacuum cosmological backgrounds, making it crucial to investigate how these backgrounds influence the properties of black holes. In this work, we first introduce a novel static…

General Relativity and Quantum Cosmology · Physics 2023-11-15 Yaghoub Heydarzade , Maxim Misyura , Vitalii Vertogradov

We consider a static, axially symmetric, and asymptotically flat exact solution of the Einstein vacuum equations, known as the gamma metric. This is characterized by two constant parameters $m$ and $\gamma$. We find that the total energy…

General Relativity and Quantum Cosmology · Physics 2007-05-23 K. S. Virbhadra

We develop a unified framework for analyzing black hole thermodynamics and spacetime structure in Einstein gravity coupled to causal nonlinear electrodynamics (NED) in asymptotically anti-de Sitter backgrounds. The electromagnetic sector is…

High Energy Physics - Theory · Physics 2026-03-24 H. Babaei-Aghbolagh , Komeil Babaei Velni , Song He , Fateme Isapour

Motivated by cosmic censorship in general relativity and string theory, we extend Christodoulou's celebrated examples of naked singularity formation in the Einstein-massless scalar field system to include a positive or negative scalar…

General Relativity and Quantum Cosmology · Physics 2018-02-06 Xuefeng Zhang , Xinliang An

Classical general relativity predicts that a contracting, spherically symmetric matter system with a large-enough mass will result in the formation of a trapped region whose outer boundary is an apparent horizon where the gravitational…

General Relativity and Quantum Cosmology · Physics 2026-04-01 Ram Brustein , A. J. M. Medved , Hagar Meir

We present an axially symmetric, asymptotically flat empty space solution of the Einstein field equations containing a naked singularity. The spacetime is regular everywhere except on the symmetry axis where it possess a true curvature…

General Relativity and Quantum Cosmology · Physics 2017-04-26 Debojit Sarma , Faizuddin Ahmed , Mahadev Patgiri

We consider exact solutions of Einstein equations defining static black holes parametrized by off-diagonal metrics which by anholonomic mappings can be equivalently transformed into some diagonal metrics with coefficients being very similar…

High Energy Physics - Theory · Physics 2007-05-23 Sergiu I. Vacaru , Evghenii Gaburov

In the context of the recently proposed type-II minimally modified gravity theory, i.e. a metric theory of gravity with two local physical degrees of freedom that does not possess an Einstein frame, we study spherically symmetric vacuum…

General Relativity and Quantum Cosmology · Physics 2021-03-12 Antonio De Felice , Andreas Doll , François Larrouturou , Shinji Mukohyama

Motivated by the lack of rotating solutions sourced by matter in General Relativity as well as in modified gravity theories, we extend a recently discovered exact rotating solution of the minimal Einstein-scalar theory to its counterpart in…

General Relativity and Quantum Cosmology · Physics 2021-03-17 Wei-Hsiang Shao , Che-Yu Chen , Pisin Chen

We construct new classes of exact solutions in metric--affine gravity (MAG) with string corrections by the antisymmetric $H$--field. The solutions are parametrized by generic off--diagonal metrics possessing noncommutative symmetry…

High Energy Physics - Theory · Physics 2007-05-23 Sergiu I. Vacaru , Evghenii Gaburov

A naked singularity occurs in the generic collapse of an inhomogeneous dust ball. We study the even-parity mode of gravitational waves from a naked singularity of the Lema\^{\i}tre-Tolman-Bondi spacetime. The wave equations for…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Hideo Iguchi , Tomohiro Harada , Ken-ichi Nakao

We construct a class of stationary, axisymmetric, horizonless spacetimes whose curvature is generated entirely by smooth, localised differential rotation $\Omega(r)$, while the spatial geometry remains exactly flat. Despite vanishing ADM…

General Relativity and Quantum Cosmology · Physics 2026-04-14 Francisco S. N. Lobo , Tiberiu Harko

Utilizing various gauges of the radial coordinate we give a description of static spherically symmetric space-times with point singularity at the center and vacuum outside the singularity. We show that in general relativity (GR) there exist…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Plamen Fiziev