2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/173466Driven by the mass problem, we raise some issues of the fundamental interactions in terms of non trivial commutation relations implemented within toy theories.Based on lectures given at the 2008 European School of HEPHigh Energy Physics - PhenomenologyGeneral Relativity and Quantum Cosmologytext