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