Matter-antimatter asymmetry and dark matter from torsion

TL;DR

This paper presents a theory-based scenario where spacetime torsion causes matter-antimatter asymmetry and dark matter origin, explaining early Universe phenomena through fermion decay differences.

Contribution

It introduces a novel mechanism linking torsion-induced spin effects in gravity to matter-antimatter asymmetry and dark matter formation.

Findings

Fermions and antifermions have different energy levels in torsion-rich conditions.

Heavy fermions decay preferentially into matter, while antiparticles decay into hidden antimatter.

The total baryon number of the Universe remains conserved at zero.

Abstract

We propose a simple scenario which explains the observed matter-antimatter imbalance and the origin of dark matter in the Universe. We use the Einstein-Cartan-Sciama-Kibble theory of gravity which naturally extends general relativity to include the intrinsic spin of matter. Spacetime torsion produced by spin generates, in the classical Dirac equation, the Hehl-Datta term which is cubic in spinor fields. We show that under a charge-conjugation transformation this term changes sign relative to the mass term. A classical Dirac spinor and its charge conjugate therefore satisfy different field equations. Fermions in the presence of torsion have higher energy levels than antifermions, which leads to their decay asymmetry. Such a difference is significant only at extremely high densities that existed in the very early Universe. We propose that this difference caused a mechanism, according to which heavy fermions existing in such a Universe and carrying the baryon number decayed mostly to normal matter, whereas their antiparticles decayed mostly to hidden antimatter which forms dark matter. The conserved total baryon number of the Universe remained zero.