Explaining the structure of quark and lepton mass matrices via flavour non-universal gauge groups

The origin of the hierarchical structure of quark and lepton mass matrices is one of the main open problems in particle physics. An interesting attempt to address this problem is offered by the hypothesis of flavour non-universal gauge groups. More precisely, by the hypothesis that the ultraviolet completion of the Standard Model features a deconstruction in flavour-space of the flavour-universal gauge symmetries observed at low energies. In this thesis this option is explored in detail, analysing different options of the ultraviolet gauge symmetry, with focus on models where the non-universality of the third family occurs already at the TeV scale.