2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/149388A detailed analysis of the vacuum structure of non-Abelian Yang--Mills theories over generic asymptotically flat space-times is carried out in hep-th/0011157.This early trial has been withdrawn by the author. For a completed and published version cf. hep-th/0011157High Energy Physics - TheoryGeneral Relativity and Quantum Cosmologytext