Charged thin shells in unimodular gravity

TL;DR

This paper explores stable, horizonless, charged thin-shell spacetimes in unimodular gravity, analyzing their stability under symmetric perturbations and comparing findings with general relativity.

Contribution

It introduces a family of spherically symmetric thin-shell solutions in unimodular gravity and studies their stability, highlighting differences from general relativity.

Findings

Stable configurations exist for specific parameter values.

No event horizons or singularities are present in these solutions.

Differences in matter content and stability regions compared to GR.

Abstract

In this article, we construct a broad family of spacetimes with spherically symmetric thin shells in unimodular gravity. We present the framework for the analysis of the dynamical stability of the configurations under perturbations preserving the symmetry. In particular, we consider two different scenarios in which the non-conservation of the energy-momentum tensor is allowed; in both the spacetime has a thin shell with charge surrounding vacuum. Our constructions avoid the existence of event horizons and singularities. In both cases, we have obtained stable configurations for suitable values of the parameters. We compare our results with those corresponding to general relativity, finding some differences in the matter content and in the stability regions in the parameter space.