Charged thin shells in unimodular gravity

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.

16 pages, 3 figures; v2: improved version, new references added