# Einstein-Cartan Cosmologies

## TL;DR

This paper explores cosmological models incorporating torsion in General Relativity, showing they can avoid initial singularities and enable early universe inflation, with various theories arising from different torsion invariants.

## Contribution

It generalizes torsion-based cosmologies by introducing multiple theories through different diffeomorphic invariants, revealing diverse possible universe evolutions.

## Key findings

- Universes can avoid initial singularity in torsion cosmologies.
- Early accelerated expansion is possible in these models.
- Different torsion theories lead to distinct cosmological scenarios.

## Abstract

Cosmologies based on General Relativity encompassing an anti-symmetric connection (torsion) can display nice desirable features as the absence of the initial singularity and the possibility of inflation in the early stage of the universe. After briefly reviewing the standard approach to the cosmology with torsion, we generalize it to demonstrate that several theories of torsion gravity are possible using different choices of the diffeomorphic invariants in the Lagrangians. As a result, distinct cosmologies emerge. In all of them it is possible that the universe avoids the initial singularity and passes through an initial accelerated expansion. Differences between these theories are highlighted.