The role of lepton flavor symmetries in leptogenesis

Abstract

The presence of flavor symmetries in the lepton sector may have several consequences for the generation of the baryon asymmetry of the Universe via leptogenesis. We review the mechanism in general type-I, type-II and type-III seesaw models. We then turn to the discussion of the cases when the asymmetry is generated in the context of seesaw models extended with flavor symmetries, before or after flavor symmetry breaking. Finally we explain how the interplay between type-I and type-II seesaws can (or not) lead to viable models for leptogenesis even when there is an exact mixing pattern enforced by the flavor symmetry.

31 pages, 7 figures; version 2: references added. Review prepared for the special issue of the journal Fortschritte der Physik (Progress of physics) on "Flavor Symmetries and Neutrino Oscillations"