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We investigate here quantum effects in gravitational collapse of a scalar field model which classically leads to a naked singularity. We show that non-perturbative semi-classical modifications near the singularity, based on loop quantum…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Rituparno Goswami , Pankaj S. Joshi , Parampreet Singh

This paper is a further development of the approach to weak cosmic censorship proposed by the authors in Ref. 5. We state and prove a modified version of that work's main result under significantly relaxed assumptions on the asymptotic…

General Relativity and Quantum Cosmology · Physics 2009-11-11 W. Rudnicki , R. J. Budzynski , W. Kondracki

In this note a time dependent spacetime is explored in the background of $f(R,T)$ gravity via the gravitational collapse of a massive star. The star is modelled by the Vaidya spacetime which is time dependent in nature. The coupling of…

General Relativity and Quantum Cosmology · Physics 2020-06-02 Prabir Rudra

The occurrence of singularities where spacetime curvature becomes infinite and geodesic evolution breaks down are inevitable events in classical general relativity (GR) unless one chooses an exotic matter violating weak energy condition.…

General Relativity and Quantum Cosmology · Physics 2024-11-05 Bao-Fei Li , Parampreet Singh

It is shown that there are large static black holes for which all curvature invariants are small near the event horizon, yet any object which falls in experiences enormous tidal forces outside the horizon. These black holes are charged and…

High Energy Physics - Theory · Physics 2014-11-18 Gary T. Horowitz , Simon F. Ross

We investigate the occurrence and nature of naked singularity for the inhomogeneous gravitational collapse of Tolman-Bondi dust clouds.It is shown that the naked singularities form at the center of the collapsing cloud in a wide class of…

General Relativity and Quantum Cosmology · Physics 2009-10-22 P. S. Joshi , I. H. Dwivedi

The existence of spacetime singularities is one of the biggest problems of nowadays physics. According to Penrose, each physical singularity should be covered by a "cosmic censor" which prevents any external observer from perceiving their…

General Relativity and Quantum Cosmology · Physics 2018-08-15 Alfio Bonanno , Benjamin Koch , Alessia Platania

We study the final outcome of gravitational collapse resulting from the plane symmetric charged Vaidya spacetime. Using the field equations, we show that the weak energy condition is always satisfied by collapsing fluid. It is found that…

General Relativity and Quantum Cosmology · Physics 2011-03-17 M. Sharif , Aisha Siddiqa

It is now known that when a massive star collapses under the force of its own gravity, the final fate of such a continual gravitational collapse will be either a black hole or a naked singularity under a wide variety of physically…

General Relativity and Quantum Cosmology · Physics 2012-04-20 Pankaj S. Joshi , Daniele Malafarina

This article gives an elementary overview of the end-state of gravitational collapse according to classical general relativity. The focus of discussion is the formation of black holes and naked singularities in various physically reasonable…

General Relativity and Quantum Cosmology · Physics 2007-05-23 T. P. Singh

One or two negative mass singularities are found to occur in static inhomogeneous spatially closed solutions to the Einstein equations. The singularities produce a positive Komar mass, and this decreases the size of the cosmological…

General Relativity and Quantum Cosmology · Physics 2026-04-29 Bob Holdom

In this paper, we study the gravitational collapse of null dust in the cylindrically symmetric spacetime. The naked singularity necessarily forms at the symmetry axis. We consider the situation in which null dust is emitted again from the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Yasunari Kurita , Ken-ichi Nakao

We present a novel example of a 2-dimensional space-time naked singularity. The solution has a gravity singularity and no-horizon. This example is only a toy model and as such its motivation is mathematical. In the physical sense it is very…

General Relativity and Quantum Cosmology · Physics 2015-11-19 J. Manuel Garcia-Islas

In this work, we have investigated the outcome of gravitational collapse in Husain space-time in the presence of electro-magnetic and a scalar field with potential. In order to study the nature of the singularity, global behavior of radial…

General Relativity and Quantum Cosmology · Physics 2012-03-12 Ujjal Debnath , Prabir Rudra , Ritabrata Biswas

We investigate the occurrence and nature of a naked singularity in the gravitational collapse of an inhomogeneous dust cloud described by higher dimensional Tolman-Bondi space-times. The naked singularities are found to be gravitationally…

General Relativity and Quantum Cosmology · Physics 2009-11-07 S G Ghosh , A Beesham

Electromagnetic waves propagating in the background provided by a spacetime hosting a strong curvature, naked singularity, are fully studied. The analysis is performed not only in the realm of geometrical optics -- which, not surprisingly,…

General Relativity and Quantum Cosmology · Physics 2025-04-25 Franco Fiorini , Santiago Hernandez , Juan Manuel Paez

This paper is a continuation of the papers [gr-qc/9409010, gr-qc/9505034, gr-qc/9603022, gr-qc/9609035, gr-qc/9609046, gr-qc/9704033]. The aim of the paper is to incorporate singularities---both local (black hole and naked singularity) and…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Vladimir S. Mashkevich

The formation of black holes or naked singularities is studied in a model in which a homogeneous time-dependent scalar field with an exponential potential couples to four dimensional gravity with negative cosmological constant. An analytic…

General Relativity and Quantum Cosmology · Physics 2015-06-10 R. Baier , Hiromichi Nishimura , S. A. Stricker

It is known now that a typical gravitational collapse in general relativity, evolving from regular initial data and under physically reasonable conditions would end in either a black hole or a naked singularity final state. An important…

General Relativity and Quantum Cosmology · Physics 2011-06-21 Daniele Malafarina , Pankaj S. Joshi

We provide evidence that ``super-extremal'' black hole space-times (either with charge larger than mass or angular momentum larger than mass), which contain naked singularities, are unstable under linearized perturbations. This is given by…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Gustavo Dotti , Reinaldo Gleiser , Jorge Pullin