Does the particle creation mechanism favour the formation of a black hole or a naked singularity?

TL;DR

This paper investigates how particle creation during stellar collapse influences whether a black hole or a naked singularity forms, using non-equilibrium thermodynamics with bulk viscosity and specific particle creation rates.

Contribution

It introduces a model linking particle creation rates to collapse outcomes, showing that the end state can be either a black hole or a naked singularity depending on the creation rate.

Findings

Collapse outcome depends on particle creation rate

Both black holes and naked singularities are possible

The model connects thermodynamics with gravitational collapse

Abstract

The paper deals with collapse dynamics of a spherically symmetric massive star in the framework of non-equilibrium themodynamic prescription through particle creation mechanism. The matter content in the star is in the form of perfect uid with barotropic equation of state and the dissipative phenomena due to non-equilibrium thermodynamics is in the form of bulk viscosity. For simplicity, the thermodynamic system is chosen to be adiabatic (i.e., isentropic) so that the effective bulk viscous pressure is linearly related to the particle creation rate. As a result, the evolution of the collapsing star also depends on the particle creation rate. By proper choice of creation rate as a function of the Hubble parameter, it is found that the end state of the collapse may be either a black hole or a naked singularity.