Black Hole Evaporation in (3+1) D: From a nonthermal to a thermal spectrum

Black hole evaporation is studied in the case of a (3+1)D nonrotating black hole that forms from the collapse of a null shell. Unlike the usual treatment, numerical calculations are carried out to compute the particle production that happens both during and after the collapse. The evolution from a nonthermal spectrum at early times to a thermal one at late times will be explored.