Gravitational collapse for a radiating anisotropic fluid

TL;DR

This paper investigates the gravitational collapse of a radiating, anisotropic fluid with heat flux and bulk viscosity, analyzing conditions for black hole formation and astrophysical observables.

Contribution

It introduces a model of radiating anisotropic collapse satisfying physical conditions and explores its evolution towards black hole formation.

Findings

Energy conditions hold until black hole formation

Luminosity and mass loss are quantified during collapse

Event horizon formation time is determined

Abstract

Interested in the collapse of a radiating star, we study the temporal evolution of a fluid with heat flux and bulk viscosity, including anisotropic pressure. As a starting point, we adopt an initial configuration that satisfies the regularities conditions as well as the energy conditions to a certain range of the mass-radius ratio for the star, defining acceptable models. For this set of models, we verify that the energy conditions remain satisfied until the black hole formation. Astrophysical relevant quantities, such as the luminosity perceived by an observer at infinity, the time of event horizon formation and the loss of mass during the collapse are presented.