2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/90487The level splitting formula of an asymmetric double well potential is calculated taking into account the multi-instanton contributions (dilute gas approximation). Results can be related with known semiclassical ones obtained with a truncated hamiltonian, and the symmetric case is easily recovered.Old paper I found in the backups, written in 1994Quantum Physicstext