Cosmology from a running vacuum model driven by a scalar field

Abstract

The possibility that the vacuum energy density [Formula: see text] is, indeed, varying in time, has been investigated lately from the running vacuum models perspective. Motivated by such models, in this work, we relate the decaying vacuum energy [Formula: see text] with a scalar field [Formula: see text]. We derive the equations of motion from such a premise and implement the first-order formalism in order to obtain analytical solutions to the cosmological parameters. We show that these are in agreement with recent Planck observational data. We discuss the physical consequences of having [Formula: see text] related to [Formula: see text].