Key points are not available for this paper at this time.
In the framework of a single scalar field quintom model with higher derivative, we construct in this Letter a dark energy model of which the equation of state (EOS) w crosses over the cosmological constant boundary. Interestingly during the evolution of the universe w−1. This avoids the big-rip jeopardy induced by w<−1.
Zhang et al. (Thu,) studied this question.