Leptogenesis by curvature coupling of heavy neutrinos

TL;DR

This paper proposes a novel leptogenesis mechanism where a CP-violating curvature coupling of heavy neutrinos in the early universe generates a lepton asymmetry, linking quantum fluctuations to matter-antimatter imbalance.

Contribution

It introduces a new curvature coupling model for leptogenesis, connecting quantum fluctuations during radiation era to lepton asymmetry via neutrino mass splitting.

Findings

Curvature coupling causes mass splitting of heavy neutrinos.

Decay asymmetry leads to net lepton number.

Quantum fluctuations induce non-zero Ricci curvature in radiation era.

Abstract

We introduce a CP violating coupling between the Ricci curvature and the heavy right handed neutrinos. This splits the Majorana masses of the left and the right handed heavy neutrinos. When the heavy neutrinos decay, their decay rates are different into left and right chirality light neutrinos. A time varying non-zero Ricci curvature can give rise to a net lepton asymmetry. The source of a non-zero curvature in a radiation era is the quantum fluctations of primordial fields.