Radiating stars with generalised Vaidya atmospheres

TL;DR

This paper models the gravitational behavior of radiating stars with a generalized Vaidya exterior, analyzing how heat flux and string density influence collapse and horizon formation.

Contribution

It introduces a model combining shear-free interior with a superposed null and string fluid exterior, exploring boundary conditions and collapse outcomes.

Findings

Boundary pressure depends on interior heat flux and exterior string density

Collapse can occur without horizon formation at the boundary

Special case analysis of nonadiabatic relativistic collapse

Abstract

We model the gravitational behaviour of a radiating star when the exterior geometry is the generalised Vaidya spacetime. The interior matter distribution is shear-free and undergoing radial heat flow. The exterior energy momentum tensor is a superposition of a null fluid and a string fluid. An analysis of the junction conditions at the stellar surface shows that the pressure at the boundary depends on the interior heat flux and the exterior string density. The results for a relativistic radiating star undergoing nonadiabatic collapse are obtained as a special case. For a particular model we demonstrate that the radiating fluid sphere collapses without the appearance of the horizon at the boundary.