Gravitational collapse in asymptotically Anti-de Sitter/de Sitter backgrounds

TL;DR

This paper investigates gravitational collapse in spacetimes with a cosmological constant, analyzing conditions for bounce, singularity formation, horizon development, and implications for cosmic censorship.

Contribution

It extends previous dust collapse models by including tangential pressure and a cosmological term, deriving new conditions for bounce and singularity formation.

Findings

Conditions for bounce and singularity formation with tangential pressure and cosmological constant

Effect of cosmological term on apparent horizon formation

Analysis of singularity visibility and cosmic censorship implications

Abstract

We study here the gravitational collapse of a matter cloud with a non-vanishing tangential pressure in the presence of a non-zero cosmological term. Conditions for bounce and singularity formation are derived for the model. It is also shown that when the tangential pressures vanish, the bounce and singularity conditions reduce to that of the dust case studied earlier. The collapsing interior is matched with an exterior which is asymptotically de Sitter or anti de Sitter, depending on the sign of cosmological constant. The junction conditions for matching the cloud to exterior are specified. The effect of the cosmological term on apparent horizons is studied in some detail, and the nature of central singularity is analyzed. We also discuss here the visibility of the singularity and implications for the cosmic censorship conjecture.