Bad News on the Brane

TL;DR

This paper explores brane-world cosmologies in anti-de Sitter black hole backgrounds, revealing that charge-induced bounce universes are not physically viable under holographic considerations, challenging certain speculative models of the universe.

Contribution

It extends brane-world models to charged black hole backgrounds and analyzes their physical viability from a holographic perspective, highlighting the importance of charge censorship.

Findings

Small bulk charge can create a bounce universe without singularities.

Charge-induced bounce cosmologies are not physically viable holographically.

Bulk charge must be censored to maintain physical consistency.

Abstract

There has been substantial interest in obtaining a quantum-gravitational description of de Sitter space. However, any such attempts have encountered formidable obstacles, and new philosophical directions may be in order. One possibility, although somewhat speculative, would be to view the physical universe as a timelike hypersurface evolving in a higher-dimensional bulk spacetime; that is, the renowned brane-world scenario. In this paper, we extend some recent studies along this line, and consider a non-critical 3-brane moving in the background of an anti-de Sitter Reissner-Nordstrom-like black hole. Interestingly, even an arbitrarily small electrostatic charge in the bulk can induce a singularity-free ``bounce'' universe on the brane, whereas a vanishing charge typically implies a singular cosmology. However, under closer examination, from a holographic (dS/CFT) perspective, we demonstrate that the charge-induced bounce cosmologies are not physically viable. This implies the necessity for censoring against charge in a bulk black hole.