Non-minimally Coupled Tachyon Field in Teleparallel Gravity

TL;DR

This paper investigates a dark energy model with a non-minimally coupled tachyon field within teleparallel gravity, revealing a late-time attractor that could address the cosmological coincidence problem.

Contribution

It introduces a novel dark energy model with a non-minimally coupled tachyon field in teleparallel gravity and identifies a late-time scaling attractor solution.

Findings

Existence of a late-time scaling attractor (P4)

Attractor corresponds to an accelerating universe

Dark energy and dark matter densities are comparable at the attractor

Abstract

We perform a full investigation on dynamics of a new dark energy model in which the four-derivative of a non-canonical scalar field (tachyon) is non-minimally coupled to the vector torsion. Our analysis is done in the framework of teleparallel equivalent of general relativity which is based on torsion instead of curvature. We show that in our model there exists a late-time scaling attractor (point $P_{4}$), corresponding to an accelerating universe with the property that dark energy and dark matter densities are of the same order. Such a point can help to alleviate the cosmological coincidence problem. Existence of this point is the most significant difference between our model and another model in which a canonical scalar field (quintessence) is used instead of tachyon field.