2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/64927We consider resonances in the semi-classical limit, generated by a single closed hyperbolic orbit, for an operator on ${\bf R}^2$. We determine all such resonancess in a domain independent of the semi-classical parameter As an application we determine all resonances generated by a saddle point in a fixed disc around the critical energy.Spectral TheoryAnalysis of PDEs32A99, 35P20, 35S99, 81U99, 37Dxxtext