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 $V(\varphi ,\chi )=e^{-\lambda \varphi }P(\varphi ,\chi )$, where $P(\varphi ,\chi )$ 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.

• Received 19 July 2012

DOI:https://doi.org/10.1103/PhysRevD.86.103522