Decaying vacuum and evolution from early inflation to late acceleration

Abstract

Decaying vacuum models are a class of models that incorporate a time-dependent vacuum energy density that can explain the entire evolution of the universe in a unified framework. A general solution to the Friedmann equation is obtained by considering vacuum energy density as a function of the Hubble parameter. We have obtained the asymptotic solution by choosing the equation of state for matter, [Formula: see text] and radiation, [Formula: see text]. Finite boundaries in the early and late de Sitter epoch are defined by considering the evolution of primordial perturbation wavelength. An epoch invariant number [Formula: see text] determines the number of primordial perturbation modes that cross the Hubble radius during each epoch.