Dynamical system analysis in multiscalar-torsion cosmology

TL;DR

This paper analyzes the phase-space of a multiscalar-torsion gravitational theory in a flat cosmological model, revealing equilibrium points that can describe different universe evolution stages, including acceleration phases.

Contribution

It introduces a multiscalar-torsion cosmological model with coupled scalar fields and analyzes its equilibrium points, offering a unified description of dark energy and dark matter.

Findings

Multiple equilibrium points capable of describing various cosmological eras

Model can account for early and late-time acceleration

Potential to unify dark sector components

Abstract

We explore the phase-space of a multiscalar-torsion gravitational theory within a cosmological framework characterized by a spatially flat Friedmann-Lema\^{\i}tre-Robertson-Walker model. Our investigation focuses on teleparallelism and involves a gravitational model featuring two scalar fields, where one scalar field is coupled to the torsion scalar. We consider coupling in the two scalar fields' kinetic and potential components. We employ exponential functions for the scalar field potentials and analyze the field equations' equilibrium points to reconstruct the cosmological evolution. Remarkably, we discover many equilibrium points in this multiscalar field model, capable of describing various eras of cosmological evolution. Hence, this model can be used to describe the early and late time acceleration phases of the universe and as a unification model for the elements of the dark sector of the universe.