Quintom dark energy models with nearly flat potentials

TL;DR

This paper analyzes quintom dark energy models with nearly flat potentials, showing they converge to a universal behavior for the equation-of-state parameter and can describe crossing -1 in the recent universe.

Contribution

It introduces a universal expression for the dark energy equation-of-state in quintom models with nearly flat potentials, clarifying conditions for crossing -1.

Findings

Models converge to a single $w_{DE}(z)$ expression

Allows description of crossing $w_{DE} = -1$

Provides conditions for crossing direction

Abstract

We examine quintom dark energy models, produced by the combined consideration of a canonical and a phantom field, with nearly flat potentials and dark energy equation-of-state parameter $w_{DE}$ close to -1. We find that all such models converge to a single expression for $w_{DE}(z)$, depending only on the initial field values and their derivatives. We show that this quintom paradigm allows for a description of the transition through -1 in the near cosmological past. In addition, we provide the necessary conditions for the determination of the direction of the -1-crossing.