Summary of the PhD thesis: Construction and investigation of a neutrino mass model with A4 flavour symmetry by pertubation method

The thesis is devoted to constructing and evaluating versions of the SM extended with an A4 symmetry to explain some of the problems of neutrino physics. Within these extended models, the results on neutrino masses and mixing, derived by the perturbation method, are very closed to the global fit. In two models, a relation between the Dirac CPV phase and the mixing angles is established. In particular, the models predict Dirac CPV phase δCP and effective mass of neutrinoless double beta decay jhmeeij in good agreement with the current experimental data.