2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/52877We review a surprising correspondence between certain two-dimensional integrable models and the spectral theory of ordinary differential equations. Particular emphasis is given to the relevance of this correspondence to certain problems in PT-symmetric quantum mechanics.15 pages, 12 figures. Contribution to the Proceedings ``Recent Trends in Exponential Asymptotics", June 28 - July 2 (2004), RIMS, KyotoHigh Energy Physics - Theorytext