Thick branes and Gauss-Bonnet self-interactions

TL;DR

This paper investigates thick brane models with Gauss-Bonnet self-interactions, analyzing mode localization and showing that only the tensor zero mode, responsible for gravity, is localized under certain conditions.

Contribution

It develops a formalism for analyzing mode localization in thick branes with Gauss-Bonnet terms, revealing that vector and scalar zero modes are not localized while tensor modes are.

Findings

Tensor zero mode is localized, enabling 4D gravity.

Vector and scalar zero modes are not localized.

The formalism applies to specific analytical examples.

Abstract

Thick branes obtained from a bulk action containing Gauss-Bonnet self-interactions are analyzed in light of the localization properties of the various modes of the geometry. The entangled system describing the localization of the tensor, vector and scalar fluctuation is decoupled in terms of variables invariant for infinitesimal coordinate transformations. The dynamics of the various zero modes is discussed and solved in general terms. Provided the four-dimensional Planck mass is finite and provided the geometry is everywhere regular, it is shown that the vector and scalar zero modes are not localized. The tensor zero mode is localized leading to four-dimensional gravity. The general formalism is illustrated through specific analytical examples