Cosmological consequences of a possible $\Lambda$-dark matter interaction

Abstract

We propose a general class of interacting models in which the interaction between the CDM component and $\Lambda$ is parameterized by an arbitrary function of the cosmic scale factor $\epsilon(a)$. Differently from other dynamical $\Lambda$ scenarios in which the final stage of cosmic expansion is a de Sitter phase, we find solutions of transient acceleration, in which the $\Lambda$-dark matter interaction will drive the Universe to a new dark matter-dominated era in the future. We investigate some cosmological consequences of this model and discuss some constraints on its parameters from current SNe Ia, BAO, CMB and $H_0$ data.