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

TL;DR

This paper investigates the evolution of dark energy's equation of state in g-essence models, demonstrating the crossing of the phantom divide line and aligning with recent observational data.

Contribution

It introduces explicit g-essence models that allow the crossing of the phantom divide line, including a transition from non-phantom to phantom phases.

Findings

Models exhibit crossing of $w_{DE}=-1$ line.

Explicit model shows transition from non-phantom to phantom phase.

Results are consistent with recent observational data.

Abstract

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 $w_{\mathrm{DE}}=-1$ as well as the models in which the universe always stays in the non-phantom (quintessence) phase ($w_{\mathrm{DE}}>-1$). In particular, we find an explicit g-essence model with the crossing from the non-phantom phase to the phantom one ($w_{\mathrm{DE}}<-1$). This transition behavior is consistent with the recent observational data analyses.