Dynamical analysis of interacting running vacuum models in DGP braneworld

Abstract

The time dependent vacuum energy provides new mechanism for describing the entire cosmic history (from inflation to dark energy) of the universe. In the framework of DGP braneworld theory, we discuss the dynamical properties of varying vacuum cosmology by considering the interaction between the cosmological fluids. We engage various functional forms (linear and non-linear) of interaction term and apply dynamical system approach. In each case, we compute critical points as well as examine their existence and stability. These cosmological solutions describe the different cosmological eras. It is observed that in each case, system admits the stable critical points for small values of interaction parameter b (strength of interaction) which is a favorable condition from the observational point of view. We also develop the phase space portraits of the interaction models and find attractive behavior of the universe for the majority cases of interaction models.