Singularity and matter creation in cosmological models

Abstract

Under reasonable "reasonable assumptions" the singularity present in the classical Friedmann cosmological models, and in the gravitational collapse of massive objects, is an unavoidable consequence of general relativity. As a rule, singular solutions are unpalatable to theoreticians and suggest something wrong with the theory. Nevertheless some cosmologists make a virtue of this drawback by arguing that the cosmological singularity describes an unusual event, the creation of the Universe, and as such should not be judged by the usual yardstick. Whatever the merit of this argument, it certainly cannot be applied to the case of collapsing massive objects.