Gravitational leptogenesis, C, CP and strong equivalence

TL;DR

This paper explores how quantum loop effects in curved spacetime could naturally generate interactions that violate the strong equivalence principle, enabling gravitational leptogenesis through C, CP, and CPT symmetry breaking.

Contribution

It demonstrates that quantum corrections in curved spacetime can induce the necessary symmetry violations for gravitational leptogenesis.

Findings

Quantum loop effects can generate strong equivalence principle violations.

Discrete symmetries C, CP, and CPT can be broken via quantum corrections.

Quantum corrections affect neutrino dispersion relations in curved spacetime.

Abstract

The origin of matter-antimatter asymmetry is one of the most important outstanding problems at the interface of particle physics and cosmology. Gravitational leptogenesis (baryogenesis) provides a possible mechanism through explicit couplings of spacetime curvature to appropriate lepton (or baryon) currents. In this paper, the idea that these strong equivalence principle violating interactions could be generated automatically through quantum loop effects in curved spacetime is explored, focusing on the realisation of the discrete symmetries C, CP and CPT which must be broken to induce matter-antimatter asymmetry. The related issue of quantum corrections to the dispersion relation for neutrino propagation in curved spacetime is considered within a fully covariant framework.