2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/55524We generalise a result of Aste and Scharf saying that, under some reasonable assumptions, consistent with renormalisation theory, the non-Abelian gauge theories describes the only possibility of coupling the gluons. The proof is done using Epstein-Glaser approach to renormalisation theory.Part of subsection 3.2 rewritten, other minor correctionsHigh Energy Physics - TheoryMathematical Physicstext