Thick branes with inner structure in mimetic gravity

TL;DR

This paper explores thick brane models generated by mimetic scalar fields, analyzing their stability, inner structures, and perturbation behaviors, revealing new phenomena related to resonance and matter localization.

Contribution

It constructs and analyzes three novel thick brane models in mimetic gravity, highlighting their unique inner structures and stability properties not present in general relativity.

Findings

Branes have different inner structures, some absent in general relativity.

All models are stable under tensor and scalar perturbations.

Tensor zero modes are localized; scalar perturbations are not.

Abstract

In this paper, thick branes generated by mimetic scalar field are investigated. Three typical thick brane models are constructed and the linear tensor and scalar perturbations are analyzed. These branes have different inner structures, some of which are absent in general relativity. For each brane model, the solution is stable under both tensor and scalar perturbations. The tensor zero modes are localized on the branes, while the scalar perturbations do not propagate and they are not localized on the brane. As the branes split into multi sub-branes for specific parameters, the potentials of the tensor perturbations also split into multi-wells, and this may lead to new phenomenon in the resonance of the tensor perturbation and the localization of matter fields.