Collapsing shells of radiation in anti-de Sitter spacetimes and the hoop and cosmic censorship conjectures

TL;DR

This paper investigates gravitational collapse of radiation in anti-de Sitter spacetimes, revealing conditions under which naked singularities or black holes form, and examining implications for the cosmic censorship and hoop conjectures.

Contribution

It demonstrates that in anti-de Sitter backgrounds, spherical collapse can produce naked singularities, while non-spherical collapses form black holes, challenging existing conjectures.

Findings

Spherical collapse can produce naked singularities, violating cosmic censorship.

Non-spherical collapse results in black holes, consistent with cosmic censorship.

Collapse to form non-spherical black holes violates the hoop conjecture in AdS spacetime.

Abstract

Gravitational collapse of radiation in an anti-de Sitter background is studied. For the spherical case, the collapse proceeds in much the same way as in the Minkowski background, i.e., massless naked singularities may form for a highly inhomogeneous collapse, violating the cosmic censorship, but not the hoop conjecture. The toroidal, cylindrical and planar collapses can be treated together. In these cases no naked singularity ever forms, in accordance with the cosmic censorship. However, since the collapse proceeds to form toroidal, cylindrical or planar black holes, the hoop conjecture in an anti-de Sitter spacetime is violated.