Self-tuning in an Outgoing Brane Wave Model

TL;DR

This paper presents an exact string theory brane-world model with outgoing plane waves that naturally incorporates a self-tuning mechanism, maintaining brane geometry despite changes in vacuum energy, and explores static solutions with contracting geometries.

Contribution

It introduces a new exact brane-world solution with outgoing plane waves that demonstrates a natural self-tuning mechanism for the cosmological constant.

Findings

The model cancels the cosmological constant on the brane.

Brane geometry remains insensitive to vacuum energy changes.

Static solutions can lead to contracting brane geometries.

Abstract

We introduce a new brane-world model in which the bulk solution consists of outgoing plane waves. This is an exact solution to string theory with no naked singularities. The recently discussed self-tuning mechanism to cancel the cosmological constant on a brane is naturally incorporated. We show that even if the vacuum energy on the brane changes, e.g. due to a phase transition, the brane geometry remains insensitive to the local vacuum energy. We also consider the static self-tuning branes introduced earlier, and find a solution in which the brane geometry starts to contract when the vacuum energy on the brane changes.