Van der Waals quintessence stars

TL;DR

This paper explores inhomogeneous compact stars modeled with a van der Waals equation of state, analyzing their properties and potential origins from cosmological density fluctuations, including solutions like gravastars and wormholes.

Contribution

It constructs and analyzes relativistic van der Waals quintessence star models, including gravastars and wormholes, providing exact solutions and physical insights.

Findings

Exact solutions for van der Waals quintessence stars are obtained.

Inhomogeneous solutions may originate from cosmological density fluctuations.

Properties of gravastars and traversable wormholes are characterized.

Abstract

The van der Waals quintessence equation of state is an interesting scenario for describing the late universe, and seems to provide a solution to the puzzle of dark energy, without the presence of exotic fluids or modifications of the Friedmann equations. In this work, the construction of inhomogeneous compact spheres supported by a van der Waals equation of state is explored. These relativistic stellar configurations shall be denoted as {\it van der Waals quintessence stars}. Despite of the fact that, in a cosmological context, the van der Waals fluid is considered homogeneous, inhomogeneities may arise through gravitational instabilities. Thus, these solutions may possibly originate from density fluctuations in the cosmological background. Two specific classes of solutions, namely, gravastars and traversable wormholes are analyzed. Exact solutions are found, and their respective characteristics and physical properties are further explored.