How the Charge Can Affect the Formation of Gravastars

TL;DR

This paper investigates how electric charge influences the formation and stability of gravastars, revealing that higher charges can stabilize these objects, whereas lower charges lead to non-gravitational massive objects.

Contribution

It extends previous models by analyzing the impact of charge on gravastar formation, showing charge enhances stability depending on the equation of state parameter.

Findings

Charge increases gravastar stability beyond a critical value.

Small charges result in the formation of massive non-gravitational objects.

The exterior spacetime is described by Reissner-Nordström geometry.

Abstract

In recent work we physically interpreted a special gravastar solution characterized by a zero Schwarzschild mass. In fact, in that case, none gravastar was formed and the shell expanded, leaving behind a de Sitter or a Minkowski spacetime, or collapsed without forming an event horizon, originating what we called a massive non-gravitational object. This object has two components of non zero mass but the exterior spacetime is Minkowski or de Sitter. One of the component is a massive thin shell and the other one is de Sitter spacetime inside. The total mass of this object is zero Schwarzschild mass, which characterizes an exterior vacuum spacetime. Here, we extend this study to the case where we have a charged shell. Now, the exterior is a Reissner-Nordstr\"om spacetime and, depending on the parameter $\omega=1-\gamma$ of the equation of state of the shell, and the charge, a gravastar structure can be formed. We have found that the presence of the charge contributes to the stability of the gravastar, if the charge is greater than a critical value. Otherwise, a massive non-gravitational object is formed for small charges.