The problem of ultracompact rotating gravastars

TL;DR

This paper constructs a third-order perturbative solution for rotating gravastars and demonstrates that such solutions cannot be smoothly matched to the Kerr spacetime, challenging previous assumptions about their equivalence.

Contribution

It provides a higher-order perturbative analysis of rotating gravastars, revealing fundamental differences from Kerr black holes.

Findings

Third-order perturbation solution constructed

Rotating gravastars cannot be matched with Kerr spacetime

Challenges previous second-order perturbation assumptions

Abstract

A number of authors provided arguments that a rotating gravastar is a good candidate for a source of the Kerr metric. These arguments were based on the second order perturbation analysis. In the following paper, we construct a perturbative solution of the rotating gravastar up to the third perturbation order and show that it cannot be continuously matched with the Kerr spacetime.