2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/48870Applications of the principle of reduction of couplings to the standard model and supersymmetric grand unified theories are reviewed. Phenomenological applications of renormalization group invariant sum rules for soft supersymmetry-breaking parameters are also reviewed.26 pages, 4 figuresHigh Energy Physics - Phenomenologytext