Evolution of the early Universe in the scale invariant theory

Abstract

Analytical solutions are obtained for the early cosmological phases in the scale invariant models with curvature k=0. They complete the analytical solutions already found in the matter--dominated era by (Jesus 2018). The physical properties in the radiative era are derived from the conservation laws and compared to those of current standard models. The critical runs of the temperature T(MeV) and of the expansion rate H of the scale invariant models with low densities, Omega_m=0.04, are quite similar at the time of nucleosynthesis to those of standard models with Omega_m=0.30, leading to the same freezing number ratio of neutrons to protons.These results are consistent with the fact that the scale invariant models appear to not require the presence of dark matter.