Cosmology constrains gravitational four-fermion interaction

TL;DR

This paper investigates how gravitational four-fermion interactions, possibly arising from torsion, influence cosmological models, finding that the axial-axial component conflicts with standard FLRW cosmology, but vector-vector interactions might resolve this issue.

Contribution

It analyzes the impact of gravitational four-fermion interactions on cosmology and explores potential resolutions involving different interaction components.

Findings

Axial-axial GFFI conflicts with FLRW cosmology.

Vector-vector GFFI could restore agreement with cosmological models.

Dominance of GFFI occurs at the Planck scale.

Abstract

If torsion exists, it generates gravitational four-fermion interaction (GFFI). This interaction gets dominating on the Planck scale. If one confines to the regular, axial-axial part of this interaction, the results do not comply with the Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmology for the spatial flat or closed Universe. In principle, the anomalous, vector-vector interaction could restore the agreement.