A Two-field Dilaton Model of Dark Energy
  We investigate the cosmological evolution of a two-field model of dark energy
where one is a dilaton field with canonical kinetic energy and the other is a
phantom field with a negative kinetic energy term. A phase-plane analysis shows
that the phantom-dominated scaling solution is the stable late-time attractor
of this type of models. We find that during the evolution of the universe, the
equation of state $w$ changes from $w > -1$ to $w <-1$, which is consistent
with the recent observations.
