Stability analysis of the Randall-Sundrum braneworld in presence of bulk scalar

TL;DR

This paper investigates the stability of the Randall-Sundrum braneworld with bulk scalar fields, showing that standard scalar fields do not stabilize it, but a tachyon-like scalar can, providing a potential resolution to the hierarchy problem.

Contribution

It demonstrates that a tachyon-like scalar field can stabilize the Randall-Sundrum braneworld and derives the full back-reacted metric for this scenario.

Findings

Standard bulk scalar fields do not stabilize the braneworld due to back-reaction.

A tachyon-like scalar field can stabilize the braneworld.

A resolution to the hierarchy problem is achievable with suitable scalar potential parameters.

Abstract

The stability problem of Randall-Sundrum braneworld is readdressed in the light of stabilizing bulk scalar fields. It is shown that in such scenario the instability persists because of back-reaction even when an arbitrary potential is introduced for a canonical scalar field in the bulk. It is further shown that a bulk scalar field can indeed stabilize the braneworld when it has a tachyon-like action. The full back-reacted metric in such model is derived and a proper resolution of the hierarchy problem (for which the Randall Sundrum scenario was originally proposed) is found to exist by suitable adjustments of the parameters of the scalar potential.