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.