Gravitational collapse of null fluid on the brane

TL;DR

This paper derives a brane-world analogue of Vaidya's solution to analyze null fluid collapse, suggesting bulk effects enhance gravity and favor black hole formation over naked singularities.

Contribution

It introduces a new brane-world Vaidya solution to study null fluid collapse, highlighting the influence of bulk back-reaction on gravitational outcomes.

Findings

Bulk back-reaction strengthens gravity on the brane.

Parameter space for naked singularities is reduced.

Black hole formation is favored over naked singularities.

Abstract

We first obtain the analogue of Vaidya's solution on the brane for studying the collapse of null fluid onto a flat Minkowski cavity on the brane. Since the back-reaction of the bulk onto the brane is supposed to strengthen gravity on the brane, it would favour formation of black hole as against naked singularity. That is the parameter window in the initial data set giving rise to naked singularity in the 4D Vaidya case would now get partially covered.