2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/54178We show that the one-instanton sector moduli-space divergence of the O(3) Sigma Model leads to an unacceptable dependence of Green's functions on the arbitrary way that the field is split into a quantum fluctuation about a classical background. Since the divergence is associated with the degeneration of field configurations to those of the zero-instanton sector this arbitrariness may be cancelled by a `topological counter-term' which we construct.Latex, 22 pages, no figuresHigh Energy Physics - Theorytext