Stable gravastars with generalised exteriors

TL;DR

This paper introduces new stable gravastar models with varied exterior geometries, expanding the theoretical landscape of alternative compact objects to black holes.

Contribution

It presents novel stable gravastar solutions with generalized exteriors, including anti-de Sitter and Reissner-Nordström types, using the Visser and Wiltshire construction.

Findings

Identified a wide parameter space for stable gravastar solutions.

Demonstrated stability against radial perturbations.

Explored different equations of state for gravastar interiors.

Abstract

New spherically symmetric gravastar solutions, stable to radial perturbations, are found by utilising the construction of Visser and Wiltshire. The solutions possess an anti--de Sitter or de Sitter interior and a Schwarzschild--(anti)--de Sitter or Reissner--Nordstr\"{o}m exterior. We find a wide range of parameters which allow stable gravastar solutions, and present the different qualitative behaviours of the equation of state for these parameters.