Excited DeSitter brane worlds localized by a kink

TL;DR

This paper explores new excited thick brane solutions in five-dimensional space-time with a sine-Gordon scalar field potential, analyzing their stability and ability to localize fermions, thus expanding the understanding of brane-world models.

Contribution

It introduces a series of new, regular, symmetric excited brane solutions with multiple scalar field zeros, extending previous fundamental brane models.

Findings

New excited brane solutions exist with multiple scalar zeros.

These solutions are regular, localized, and mirror symmetric.

Excited branes can localize fermions on or near the brane.

Abstract

We reconsider, in five-dimensional space-time, the issue of thick brane localized in the extra dimension by a kink formed by a scalar field. The localization is achieved by a sine-Gordon potential. Apart from a fundamental brane (discovered by Koley and Kar \cite{koley_kar}) where the scalar field is a monotonic function of the extra dimension), we show that a series of new solutions exist as well, labelled by the number of zeros of the scalar field. These solutions are regular, localized on the brane and mirror symmetric with respect to the extra dimension. They form a tower of "excited branes". The study of some perturbations of the solutions reveals that the new solutions are not stable. Finally, fermions are coupled to the scalar field by means of a Yukawa potential and their localization in the background of the new solutions is examined. %%The influence on the new solutions on the fermions on the brane is investigated. It turns out that the excited branes can localize left and right chiral fermion either on the brane and/or in the bulk but close to the brane.