Cosmological evolution of equation of state for dark energy in G-essence models

摘要

We explore the cosmological evolution of equation of state (EoS) for dark energy in g-essence models, the action of which is described by a function of both the canonical kinetic term of both the scalar and fermionic fields. We examine g-essence models with realizing the crossing of the phantom divide line of w_(DE) = -1 as well as the models in which the universe always stays in the nonphantom (quintessence) phase (wDE > -1). In particular, we find an explicit g-essence model with the crossing from the nonphantom phase to the phantom one (w_(DE) < -1). This transition behavior is consistent with the recent observational data analyses.