Flat cosmological models with massive scalar field in gauge theories of gravity

Abstract

Solutions of gravitational equations of gauge theories of gravity in homogeneous isotropic world with massive scalar field are investigated in the case of flat cosmological models. Special attention is dedicated to general behavior of solutions on contraction stage. It is shown, that on expansion stage inflationary solutions are generic feature of the model. At the same time on contraction stage an effective equation of state is similar to the case of massless scalar field $p=ρ$ at the beginning of evolution and tends to the equation of ultrarelativistic gas $p=ρ/3$. The Hubble parameter tends to some negative value on contraction stage, depending on the mass of the scalar field. Nonsingular solutions in this model are unstable.