Transition from quintessence to phantom phase in quintom model

TL;DR

This paper investigates the conditions under which a quintom dark energy model transitions from a quintessence phase to a phantom phase, demonstrating that the crossing of the w=-1 line occurs in specific potential models.

Contribution

It provides necessary conditions for the quintessence to phantom phase transition in quintom models and analyzes the behavior of the Hubble parameter near the transition.

Findings

The w=-1 line is crossed in power-law and exponential potential models.

Necessary conditions for phase transition are derived.

Transition occurs smoothly under certain dynamical conditions.

Abstract

Assuming the Hubble parameter is a continuous and differentiable function of comoving time, we investigate necessary conditions for quintessence to phantom phase transition in quintom model. For power-law and exponential potential examples, we study the behavior of dynamical dark energy fields and Hubble parameter near the transition time, and show that the phantom-divide-line w=-1 is crossed in these models.