Global dynamics of two models for Quintom Friedman-Lema\^itre-Robertson-Walker Universes

TL;DR

This paper analyzes the global dynamics of two quintom cosmological models with interacting scalar fields in a FLRW universe, revealing two inflationary periods linked to early and late-time acceleration.

Contribution

It introduces a new dynamical systems approach for two interacting scalar field quintom models in FLRW cosmology, emphasizing spatial curvature effects.

Findings

Identification of two inflationary phases in the models.

Analysis of spatial curvature's impact on dynamics.

Demonstration of late-time acceleration in the models.

Abstract

We comprehensively analyze the dynamics for the gravitational field equations for the Chiral-Quintom theory in a Friedman-Lema\^itre-Robertson-Walker cosmology with an additional matter source. We consider a new set of dimensionless variables and write the field equations in the equivalent form of an algebraic-differential system. Specifically, we consider two families of quintom models where the two scalar fields interact in the kinetic sector. We mathematically focus on the dynamical effect of spatial curvature. Physically, we find two periods of inflation related to the Universe's early and late-time acceleration phases.