Domain Wall Brane in Eddington Inspired Born-Infeld Gravity

TL;DR

This paper explores a thick brane model within Eddington-inspired Born-Infeld gravity, demonstrating the recovery of Einstein gravity at low energies and ensuring gravitational stability, with implications for singularity avoidance.

Contribution

It introduces a new thick brane solution in Eddington-inspired Born-Infeld gravity and analyzes its stability and recovery of Einstein gravity.

Findings

Four-dimensional Einstein gravity is recovered on the brane.

The model prevents cosmological singularities.

Gravitational perturbations are stable.

Abstract

Recently, inspired by Eddington's theory, an alternative gravity called Eddington-inspired Born-Infeld gravity was proposed by Ba$\tilde{\text{n}}$ados and Ferreira. It is equivalent to Einstein's general relativity in vacuum, but deviates from it when matter is included. Interestingly, it seems that the cosmological singularities are prevented in this theory. Based on the new theory, we investigate a thick brane model with a scalar field presenting in the five-dimensional background. A domain wall solution is obtained, and further, we find that at low energy the four-dimensional Einstein gravity is recovered on the brane. Moreover, the stability of gravitational perturbations is ensured in this model.