Horizonless, singularity-free, compact shells satisfying NEC

Gravitational collapse singularities are undesirable, yet inevitable to a large extent in General Relativity. When matter satisfying null energy condition collapses to the extent a closed trapped surface is formed, a singularity is inevitable according to Penrose's singularity theorem. Since po...

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Bibliographic Details
Published in:arXiv.org 2017-02
Main Author: Shankar, Karthik H
Format: Article
Language:English
Subjects:
Black holes
Event horizon
Gravitation
Gravitational collapse
Naked singularities
Relativity
Online Access:Get full text
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Summary:Gravitational collapse singularities are undesirable, yet inevitable to a large extent in General Relativity. When matter satisfying null energy condition collapses to the extent a closed trapped surface is formed, a singularity is inevitable according to Penrose's singularity theorem. Since positive mass vacuum solutions are generally black holes with trapped surfaces inside the event horizon, matter cannot collapse to an arbitrarily small size without generating a singularity. However, in modified theories of gravity where positive mass vacuum solutions are naked singularities with no trapped surfaces, it is reasonable to expect that matter can collapse to an arbitrarily small size without generating a singularity. Here we examine this possibility in the context of a modified theory of gravity with torsion in an extra dimension. We study singularity-free static shell solutions to evaluate the validity of the null energy condition on the shell. We find that with sufficiently high pressure, matter can be collapsed to arbitrarily small size without violating the null energy condition and without producing a singularity.
ISSN:2331-8422
DOI:10.48550/arxiv.1510.00851