Cosmological consequences of a possibleΛ-dark matter interaction

We propose a general class of interacting models in which the interaction between the cold dark matter component and Λ is parametrized by an arbitrary function of the cosmic scale factor $ϵ(a)$. Differently from other dynamical Λ scenarios in which the final stage of cosmic expansion is a de Sitter phase, we find solutions of transient acceleration, in which the Λ-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 Type Ia aupernovae, baryonic acoustic oscillations, CMB, and H₀ data.