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A class of spherical collapsing exact solutions with electromagnetic charge is derived. This class of solutions -- in general anisotropic -- contains however as a particular case the charged dust model already known in literature. Under…

General Relativity and Quantum Cosmology · Physics 2015-06-11 F. Cipolletta , R. Giambò

We investigate the fate of the classical singularity in a collapsing dust cloud. For this purpose, we quantize the marginally bound Lemaitre-Tolman-Bondi model for spherically-symmetric dust collapse by considering each dust shell in the…

General Relativity and Quantum Cosmology · Physics 2019-06-19 Claus Kiefer , Tim Schmitz

Continued gravitational collapse gives rise to curvature singularities. If a curvature singularity is globally naked then the space-time may be causally future ill-behaved admitting closed time-like or null curves which extend to asymptotic…

General Relativity and Quantum Cosmology · Physics 2010-11-11 F. de Felice

We examine the gravitational collapse of an infinite cylindrical distribution of time like dust. In order to simplify the calculation we make an assumption that the axial and azimuthal metric functions are equal. It is shown that the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Sashideep Gutti , T. P. Singh , Pranesh Sundararajan , Cenalo Vaz

We provide a covariant framework to study singularity-free Lema\^itre-Tolman-Bondi spacetimes with effective corrections motivated by loop quantum gravity. We show that, as in general relativity, physically reasonable energy distributions…

General Relativity and Quantum Cosmology · Physics 2024-03-07 Asier Alonso-Bardaji , David Brizuela

We study here the gravitational collapse of dust in $(2+1)$-dimensional spacetimes for the formation of black holes (BH) and naked singularities (NS) as final states in a modified theory of gravity, with vanishing cosmological constant.…

General Relativity and Quantum Cosmology · Physics 2018-07-31 Rajibul Shaikh , Pankaj S. Joshi

Assuming the weak energy condition, we study the nature of the non-central shell-focussing singularity which can form in the gravitational collapse of a spherical compact object in classical general relativity. We show that if the radial…

General Relativity and Quantum Cosmology · Physics 2009-10-28 F. I. Cooperstock , S. Jhingan , P. S. Joshi , T. P. Singh

Generic spherically symmetric self-similar collapse results in strong naked-singularity formation. In this paper we are concerned with particle creation during a naked-singularity formation in spherically symmetric self-similar collapse…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Umpei Miyamoto , Tomohiro Harada

We study an analytical solution to the Einstein's equations in 2+1-dimensions, representing the self-similar collapse of a circularly symmetric, minimally coupled, massless, scalar field. Depending on the value of certain parameters, this…

General Relativity and Quantum Cosmology · Physics 2014-11-17 G. Oliveira-Neto

A new mechanism for causing naked singularities is found in an effective superstring theory. We investigate the gravitational collapse in a spherically symmetric Einstein-Maxwell-dilaton system in the presence of a pure cosmological…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Kengo Maeda , Takashi Torii , Makoto Narita

In this work we initiate the mathematical study of naked singularities for the Einstein vacuum equations in $3+1$ dimensions by constructing solutions which correspond to the exterior region of a naked singularity. A key element is our…

Analysis of PDEs · Mathematics 2022-10-20 Igor Rodnianski , Yakov Shlapentokh-Rothman

In this work we study the dynamics of gravitational collapse of a homogeneous dust sphere in a model exhibiting a linear non-minimal coupling between matter and curvature. The evolution of the scale factor and the matter density is obtained…

General Relativity and Quantum Cosmology · Physics 2012-12-12 J. Páramos , C. Bastos

In a previous paper, some of us studied general relativistic homogeneous gravitational collapses for dust and radiation, in which the density profile was replaced by an effective density justified by some quantum gravity models. It was…

General Relativity and Quantum Cosmology · Physics 2014-08-19 Yue Liu , Daniele Malafarina , Leonardo Modesto , Cosimo Bambi

How to describe a black hole embedded in an expanding universe is an important topic. Some models about this issue are suggested by assuming that the metric is a conformal transformation of the Schwarzschild metric or of the isotropic black…

General Relativity and Quantum Cosmology · Physics 2010-03-18 Cheng-Yi Sun

We investigate the unhindered gravitational collapse of a homogeneous scalar field with nonzero potential, a two-dimensional analog of the Mexican hat-shaped Higgs field potential. The collapsing scalar field is surrounded by an exterior…

General Relativity and Quantum Cosmology · Physics 2022-04-01 Karim Mosani , Dipanjan Dey , Kaushik Bhattacharya , Pankaj S. Joshi

The global visibility of a singularity as an end state of the gravitational collapse of a spherically symmetric pressureless cloud is investigated. We show the existence of a non-zero measured set of parameters: the total mass and the…

General Relativity and Quantum Cosmology · Physics 2022-11-15 Karim Mosani , Dipanjan Dey , Pankaj S. Joshi

Based on the effective dynamics in the $\bar \mu$ scheme of the spherical symmetry reduced model in the reduced phase space formulation of loop quantum gravity (LQG), we investigate the gravitational collapse of a homogeneous dust cloud,…

General Relativity and Quantum Cosmology · Physics 2023-03-08 Kristina Giesel , Muxin Han , Bao-Fei Li , Hongguang Liu , Parampreet Singh

The behaviors of quantum stress tensor for the scalar field on the classical background of spherical dust collapse is studied. In the previous works diverging flux of quantum radiation was predicted. We use the exact expressions in a 2D…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Hideo Iguchi , Tomohiro Harada

Gravitational collapse of a spherically symmetric cloud has been extensively studied to investigate the nature of resulting singularity. However, there has been considerable debate about the admissibility of certain initial density…

General Relativity and Quantum Cosmology · Physics 2008-02-03 H. M. Antia

The causal character of the zero-areal-radius (R=0) singularity in spherically symmetric spacetimes is studied. By using the techniques of the qualitative behaviour of dynamic systems, we are able to present the most comprehensive scheme so…

General Relativity and Quantum Cosmology · Physics 2012-04-23 Francesc Fayos , Ramon Torres