2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/40047Conformal fluctuations of the metric tensor at the Planck scale are considered. They give rise to a lower bound of the proper length. This leads to finite expressions for quantities related to propagators without the need of renormalization or regularization. Quantities like the current quark mass or the effective strong coupling constant have to be reinterpreted.10 pages, LaTeX, new version with minor revisionsHigh Energy Physics - PhenomenologyGeneral Relativity and Quantum Cosmologytext