Initial-condition dependence of inflationary-universe models

Abstract

An analytical and numerical study of the effects of initial conditions on the evolution of a classical scalar field is presented. In this model, matter consists of a scalar field and a radiation bath. The initial energy density of the scalar field is taken to be equal to the energy density of one degree of freedom of the radiation bath. Even for this subspace of the space of initial conditions, three very different scenarios are possible. One may get chaotic inflation, dynamical relaxation, or a tension energy-dominated universe which results in no inflation. The phase space for each of these scenarios is determined.