Vacuum polarisation and the initial conditions of cosmological evolution

Abstract

The evolution of spatially closed cosmological models including vacuum polarisation effects is discussed. An intermediate inflationary stage and the later particle production and thermalisation lead to the transition of the initially Planck sized vacuum universe to the standard radiation dominated Friedman universe of reasonable size. The non-linearity of the equations causes the essential dependence of the global behaviour of solutions on the initial conditions and the existence of oscillating vacuum solutions for discrete initial values.