The dark side of the torsion: Dark Energy from propagating torsion

TL;DR

This paper proposes a modified Einstein-Cartan theory with a kinetic torsion term that explains dark energy and predicts a bouncing cosmology, constrained by cosmological data.

Contribution

It introduces a novel kinetic term for torsion in Einstein-Cartan theory, linking torsion dynamics to dark energy and bouncing cosmology.

Findings

Kinetic torsion term induces dark energy.

Quadratic torsion acts as a stiff fluid.

Cosmological data constrains bouncing solutions.

Abstract

An extension to the Einstein-Cartan (EC) action is discussed in terms of cosmological solutions. The torsion incorporated in the EC Lagrangian is assumed to be totally anti-symmetric, represented by a time-like axial vector $S^\mu$. The dynamics of torsion is invoked by a novel kinetic term. Here we show that this kinetic term gives rise to dark energy, while the quadratic torsion term, emanating from the EC part, represents a stiff fluid that leads to a bouncing cosmology solution. A constraint on the bouncing solution is calculated using cosmological data from different epochs.