Stable Gravastar model in Cylindrically Symmetric Space-time

TL;DR

This paper introduces a new stable gravastar model in cylindrical symmetry, featuring a de-Sitter interior, a stiff fluid shell, and an exterior vacuum, avoiding singularities and information paradoxes.

Contribution

It presents a novel cylindrically symmetric gravastar solution with a stable structure and detailed physical properties, expanding the understanding of alternative compact objects.

Findings

The model is free from singularities and information paradox.

The shell satisfies Zel'dovich's criteria with stiff fluid.

Physical quantities like energy, mass, and entropy are explicitly calculated.

Abstract

We represent a class of new Gravastar solutions as obtained by Mazur and Mottola in a gravitational Bose-Einstein condensate (GBEC) in a cylindrical symmetric space-time. A stable gravastar with three distinct regions namely, (i) Interior de-Sitter space, (ii) Intermediate thin shell with a slice of finite length and (iii) exterior vacuum region. The interior region is characterised by positive energy density and negative pressure $(p=-\rho)$, which exerts a repulsive outward force at all points on the thin shell. The thin shell separating the interior and exterior is supposed to be consisting of ultra-relativistic stiff fluid having equation of state $p=\rho$, which satisfies the Zel'dovich's criteria. This thin shell, which is considered as the critical surface for the quantum phase transition, replaces both the classical de-Sitter and Schwarzschild event horizons. The new solution is free from any singularities as well as any information paradox. The energy density, total energy, proper length, mass and entropy of the shell region are explored in this model and the gravastar model is stable and physically viable.