A spatially-flat cosmological model

Abstract

Recently a homogeneous cosmological model free from singularities was proposed, based on the general relativity theory. It described a closed universe (k = +1), initially filled with prematter, characterized by a density ρ equal to the Planck density and a pressureP = −ρ, and undergoing oscillations. In the present work the case of a similar, but spatially flat, universe (k = 0) is investigated. In this case there is an initial geometric singularity (the scale factorR = 0), but not a physical one, since the initial density is finite. This universe begins its existence at a timet = −∞ and, after going through the prematter and radiation-dominated eras, reaches the matter-dominated state and continues to expand indefinitely.