Brane worlds in gravity with auxiliary fields

TL;DR

This paper extends a gravity theory with auxiliary fields to five dimensions, constructs thick brane models, and demonstrates their stability and localization of gravity, supporting the realization of Newtonian gravity on the brane.

Contribution

It generalizes gravity with auxiliary fields to higher dimensions and analyzes stable thick brane solutions with localized gravity.

Findings

Brane solutions are obtained numerically.

The brane system is stable under tensor perturbations.

Gravity zero mode is localized on the brane.

Abstract

Recently, Pani, Sotiriou, and Vernieri explored a new theory of gravity by adding nondynamical fields, i.e., gravity with auxiliary fields [Phys. Rev. D 88, 121502(R) (2013)]. In this gravity theory, higher-order derivatives of matter fields generically appear in the field equations. In this paper we extend this theory to any dimensions and discuss the thick braneworld model in five dimensions. Domain wall solutions are obtained numerically. The stability of the brane system under the tensor perturbation is analyzed. We find that the system is stable under the tensor perturbation and the gravity zero mode is localized on the brane. Therefore, the four-dimensional Newtonian potential can be realized on the brane.