Gravitational collapse of a Hagedorn fluid in Vaidya geometry

TL;DR

This paper models the gravitational collapse of a Hagedorn fluid within Vaidya geometry, analyzing conditions for black hole or naked singularity formation and exploring potential links to gamma-ray burst sources.

Contribution

It provides an exact parametric solution for collapse dynamics of Hagedorn fluids and investigates criteria for naked singularity formation.

Findings

Collapse can result in black holes or naked singularities.

Conditions for naked singularity formation are identified.

Potential application to gamma-ray burst energy sources.

Abstract

The gravitational collapse of a high-density null charged matter fluid, satisfying the Hagedorn equation of state, is considered in the framework of the Vaidya geometry. The general solution of the gravitational field equations can be obtained in an exact parametric form. The conditions for the formation of a naked singularity, as a result of the collapse of the compact object, are also investigated. For an appropriate choice of the arbitrary integration functions the null radial outgoing geodesic, originating from the shell focussing central singularity, admits one or more positive roots. Hence a collapsing Hagedorn fluid could end either as a black hole, or as a naked singularity. A possible astrophysical application of the model, to describe the energy source of gamma-ray bursts, is also considered.