2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/90726We study the quantum-mechanical tunneling phenomenon in models which include the existence of non-equivalent vacua. For such a purpose we evaluate the euclidean propagator between two minima of the potential at issue in terms of the quadratic fluctuations over the corresponding instantons. The effect of the multi-instanton configurations are included by means of the alternate dilute-gas approximation.12 pages. Presented at the Seventh International Wigner Symposium. August 2001. College Park, MD, USAQuantum Physicstext