A transition between bouncing hyper-inflation to ΛCDM from diffusive scalar fields

Abstract

We consider the history of the universe from a possible big bang or a bounce into a late period of a unified interacting dark energy–dark matter model. The model is based on the Two Measures Theories (TMT) which introduces a metric independent volume element and this allows us to construct a unification of dark energy and dark matter. A generalization of the Two Measures Theories gives a diffusive nonconservative stress-energy–momentum tensor in addition to the conserved stress-energy tensor which appear in Einstein equations. These leads to a formulation of interacting DE–DM dust models in the form of a diffusive-type interacting Unified Dark Energy and Dark Matter scenario. The deviation from [Formula: see text]CDM is determined by the diffusion constant [Formula: see text]. For [Formula: see text] the model is indistinguishable from [Formula: see text]CDM. Numerical solutions of the theories show that in some [Formula: see text] the evolution of the early universe is governed by Stiff equation of state or the universe bounces to hyper-inflation. But all of those solutions have a final transition to [Formula: see text]CDM as a stable fixed point for the late universe.