A new approach to unified field theories

Summary  The idea that an internal-symmetry groupG is implied by a dynamical higher space-time symmetry groupK of a given field theory is presented. Using this idea, we have classified admissible simple Lie groupsK and we have explicitly determined the internal-symmetry groupG implied byK. We have shown that the groupsG are «quantized» and in this framework they areU(2),U(4),U(8), …,U(2 N ), depending on the rank ofK. We have also determined the boson and the fermion field content in the considered models. The proposed formalism admits a new interesting mechanism of dynamical-symmetry breaking which is different from the spontaneous-breaking one.