Continuous Flavour Symmetries

Flavour symmetries are fundamental tools in the search for an explanation to the flavour puzzle: fermion mass hierarchies, the neutrino mass ordering, the differences between the mixing ma-trices in the quark and lepton sector, can all find an explanation in models where the fermion generations undergo specific geometric relations. An overview on the implementation of contin-uous symmetries in the flavour sector is presented here, focussing on the lepton sector