A Model of Dustlike Spherically Symmetric Gravitational Collapse without Event Horizon Formation

Abstract: Some dynamical aspects of gravitational collapse are explored in this paper. A time-dependent spherically symmetric metric is proposed and the corresponding Einstein field equations are derived. An ultrarelativistic dust-like stress-momentum tensor is considered to obtain analytical solutions of these equations, with a perfect fluid consisting of two purely radial fluxes -the inwards flux of collapsing matter and the outwards flux of thermally emitted radiation. Thermal emission is calculated by means of a simplistic but illustrative model of unintercting collapsing shells. Our results show an asymptotic approach to a maxiamal spacetime deformation without the formation of event horizons. Tehe size of the body is slightly larger than the Schwarzschild radius during most of its lifetime, so that tehre is no contradiction with either observations or previous theorems concerning black holes. The relation of the latter with our results is scrutinized in detail.