Generation of exact solutions in cosmology on the basis of five-dimensional projective unified field theory (Q1613308)

Using the arbitrariness in the choice of an equation of state for the scalar substrate energy density \(\theta =\theta(\rho)\) which is not determined within the 5-dimensional projective unified field theory, in which gravitation is described by both space-time curvature and some hypothetical scalar field (\(\sigma\)-field), the authors propose an exact solution generation method for homogeneous and isotropic cosmological models of the Universe, allowing also to find new Friedmann-like solutions for the dust model as well as solutions for a cosmological model in which the contribution of vacuum energy prevails in the total energy density. A power-law behaviour of the scalar factor is considered. Within the framework of exponential-type inflation, the authors obtained a natural explanation of why at present we do not observe \(\sigma\)-field effects or why these effects are negligible.