Equilibrium configurations from gravitational collapse

TL;DR

This paper introduces a new method within Einstein's gravity to generate equilibrium states from gravitational collapse, highlighting potential observational differences between naked singularities and black holes.

Contribution

A novel procedure to produce equilibrium configurations from gravitational collapse with tangential pressure support, expanding understanding of possible end states in Einstein's gravity.

Findings

Equilibrium geometries can be regular or develop naked singularities.

Stable circular orbits differ near naked singularities compared to black holes.

Potential observational signatures distinguish naked singularities from black holes.

Abstract

We develop here a new procedure within Einstein's theory of gravity to generate equilibrium configurations that result as the final state of gravitational collapse from regular initial conditions. As a simplification, we assume that the collapsing fluid is supported only by tangential pressure. We show that the equilibrium geometries generated by this method form a subset of static solutions to the Einstein equations, and that they can either be regular or develop a naked singularity at the center. When a singularity is present, there are key differences in the properties of stable circular orbits relative to those around a Schwarzschild black hole with the same mass. Therefore, if an accretion disk is present around such a naked singularity it could be observationally distinguished from a disk around a black hole.