Generalised teleparallel quintom dark energy non-minimally coupled with the scalar torsion and a boundary term

TL;DR

This paper introduces a new generalized quintom dark energy model within teleparallel gravity, exploring its dynamical behavior and cosmological evolution through phase space analysis and numerical simulations.

Contribution

It proposes a novel non-minimal coupling of scalar fields with torsion and boundary terms in teleparallel gravity, extending previous quintom models.

Findings

Phase space analysis reveals key dynamical effects of torsion and boundary couplings.

The model exhibits diverse cosmological evolution scenarios.

Numerical results support the viability of the proposed dark energy model.

Abstract

Within this work, we propose a new generalised quintom dark energy model in the teleparallel alternative of general relativity theory, by considering a non-minimal coupling between the scalar fields of a quintom model with the scalar torsion component $T$ and the boundary term $B$. In the teleparallel alternative of general relativity theory, the boundary term represents the divergence of the torsion vector, $B=2\nabla_{\mu}T^{\mu}$, and is related to the Ricci scalar $R$ and the torsion scalar $T$, by the fundamental relation: $R=-T+B$. We have investigated the dynamical properties of the present quintom scenario in the teleparallel alternative of general relativity theory by performing a dynamical system analysis in the case of decomposable exponential potentials. The study analysed the structure of the phase space, revealing the fundamental dynamical effects of the scalar torsion and boundary couplings in the case of a more general quintom scenario. Additionally, a numerical approach to the model is presented to analyse the cosmological evolution of the system.