Theory of Neutrino Masses and Mixing.

We motivate the usage of finite groups as symmetries of the Lagrangian. After a presentation of basic group-theoretical concepts, we introduce the notion of characters and character tables in the context of irreducible representations and discuss their applications. We exemplify these theoretical concepts with the groups S_4 and A_4. Finally, we discuss the relation between tensor products of irreducible representations and Yukawa couplings and describe a model for tri-bimaximal lepton mixing based on A_4.

Comments:	23 pages, lecture presented at IV International Pontecorvo Neutrino Physics School, Nobember 26, 2011, Alushta, Crimea, Ukraine
Subjects:	High Energy Physics - Phenomenology (hep-ph)
Cite as:	arXiv:1112.0172v1 [hep-ph] Canals Gustavo A.Theoretical Physics Dr.