Two-scalar-field model for the interaction of dark energy and dark matter

In this paper, we study the effects of an interaction between dark matter and dark energy through a two-scalar-field model with a potential V(φ,χ)=e^-λφP(φ,χ), where P(φ,χ) is a polynomial. We show that the cosmic expansion dynamics of the Universe is reproduced for a large range of the bare mass of the dark matter field and that there exist solutions with transient accelerated expansion. A modification in the exponential behavior of the potential is studied, with important physical implications, including the possibility of more realistic transient acceleration solutions.