Unified description of the dynamics of quintessential scalar fields

TL;DR

This paper uses dynamical system methods to analyze the evolution of scalar fields in cosmology, identifying critical points and heteroclinic lines that describe the full dynamics of quintessence dark energy models.

Contribution

It introduces a comprehensive framework using critical points and heteroclinic lines to describe scalar field evolution, highlighting paths relevant for dark energy.

Findings

Heteroclinic lines connect critical points, providing a complete description of scalar field evolution.

The heteroclinic line from perfect fluid domination models viable dark energy.

Attractor properties of heteroclinic lines influence thawing and freezing field behaviors.

Abstract

Using the dynamical system approach, we describe the general dynamics of cosmological scalar fields in terms of critical points and heteroclinic lines. It is found that critical points describe the initial and final states of the scalar field dynamics, but that heteroclinic lines which give a more complete description of the evolution in between the critical points. In particular, the heteroclinic line that departs from the (saddle) critical point of perfect fluid-domination is the representative path in phase space of quintessence fields that may be viable dark energy candidates. We also discuss the attractor properties of the heteroclinic lines, and their importance for the description of thawing and freezing fields.