Lepton Flavour Symmetries

Understand

We provide a general classification of flavour symmetries according to their interplay with the proper Poincare' and gauge groups and to their linear or nonlinear action in field space.

• We focus on the lepton sector and we review the different types of symmetries describing neutrino masses and the lepton mixing matrix.
• For each type of symmetry we present several illustrative examples and we discuss specific strengths and limitations.