Big bounce and inflation from gravitational four-fermion interaction

TL;DR

This paper explores how gravitational four-fermion interactions, induced by torsion at the Planck scale, can naturally lead to a big bounce and inflationary phase in the early universe.

Contribution

It demonstrates that the anomalous vector-vector component of four-fermion interactions can induce a big bounce and inflation, providing a new mechanism rooted in torsion-induced gravity.

Findings

The vector-vector interaction causes a big bounce at high densities.

This interaction naturally leads to an inflationary phase.

The axial-axial part alone does not prevent gravitational collapse.

Abstract

The four-fermion gravitational interaction is induced by torsion, and gets dominating on the Planck scale. The regular, axial-axial part of this interaction by itself does not stop the gravitational compression. However, the anomalous, vector-vector interaction results in a natural way both in big bounce and in inflation.