Thick brane structures in generalized hybrid metric-Palatini gravity

TL;DR

This paper explores 5D braneworld models within a generalized hybrid metric-Palatini gravity framework, analyzing stability and the influence of scalar fields on gravitational modes, including the potential for internal structure formation.

Contribution

It introduces new braneworld solutions in hybrid metric-Palatini gravity, examining stability and scalar field effects on gravitational zero modes.

Findings

Models are stable against small metric fluctuations.

Additional scalar fields can control the gravitational zero mode profile.

Zero mode profiles can develop internal structure depending on parameters.

Abstract

In this work, we study 5-dimensional braneworld scenarios in the scalar-tensor representation of the generalized hybrid metric-Palatini gravitational theory. We start by considering a model for a brane supported purely by the gravitational scalar fields of the theory and then consider other distinct cases where the models are also supported by an additional matter scalar field. We investigate the stability of the gravity sector and show that the models are all robust against small fluctuations of the metric. In particular, in the presence of the additional scalar field, we find that the profile of the gravitational zero mode may be controlled by the parameters of the model, being also capable of developing internal structure.