If Gauss-Bonnet interaction plays the role of dark energy

A cosmological model has been constructed with Gauss-Bonnet-scalar interaction, where the Universe starts with exponential expansion but encounters infinite deceleration, q->∼ and infinite equation of state parameter, w->∼. During evolution it subsequently passes through the stiff fluid era, q=2, w=1, the radiation dominated era, q=1, w=1/3 and the matter dominated era, q=1/2, w=0. Finally, deceleration halts, q=0, w=-1/3, and it then encounters a transition to the accelerating phase. Asymptotically the Universe reaches yet another inflationary phase q->-1, w->-1. Such evolution is independent of the form of the potential and the sign of the kinetic energy term, i.e., even a non-canonical kinetic energy is unable to phantomize (w<-1) the model