Avoidance of Naked Singularities in Dilatonic Brane World Scenarios with a Gauss-Bonnet Term

TL;DR

This paper explores 5D dilatonic brane world models with Gauss-Bonnet corrections, presenting solutions that avoid naked singularities and allow self-tuning of the cosmological constant without fine-tuning.

Contribution

It introduces a class of non-singular solutions in dilatonic brane worlds with Gauss-Bonnet terms, enabling self-tuning of the cosmological constant.

Findings

Finite 4D Planck scale achieved

Naked singularities avoided in solutions

Self-tuning mechanism discussed

Abstract

We consider, in 5 dimensions, the low energy effective action induced by heterotic string theory including the leading stringy correction of order alpha'. In the presence of a single positive tension flat brane, and an infinite extra dimension, we present a particular class of solutions with finite 4-dimensional Planck scale and no naked singularity. A ``self-tuning'' mechanism for relaxing the cosmological constant on the brane, without a drastic fine tuning of parameters, is discussed in this context. Our solutions are distinct from the standard self-tuning solutions discussed in the context of vanishing quantum corrections in alpha', and become singular in this limit.