"Teleparallel" Dark Energy

TL;DR

This paper explores a modified gravity model called 'teleparallel' dark energy, where a scalar field nonminimally couples to torsion-based gravity, leading to diverse cosmic behaviors beyond standard quintessence.

Contribution

It introduces a nonminimal coupling in teleparallel gravity, revealing complex dark energy dynamics not reducible to minimally coupled models.

Findings

Nonminimal coupling yields quintessence-like or phantom-like behavior.

The model exhibits phantom-divide crossing.

No conformal transformation to minimal coupling exists.

Abstract

Using the "teleparallel" equivalent of General Relativity as the gravitational sector, which is based on torsion instead of curvature, we add a canonical scalar field, allowing for a nonminimal coupling with gravity. Although the minimal case is completely equivalent to standard quintessence, the nonminimal scenario has a richer structure, exhibiting quintessence-like or phantom-like behavior, or experiencing the phantom-divide crossing. The richer structure is manifested in the absence of a conformal transformation to an equivalent minimally-coupled model.