2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/123416We give a mathematically rigorous analysis which confirms the surprising results in a recent paper of Benilov, O'Brien and Sazonov about the spectrum of a highly singular non-self-adjoint operator that arises in a problem in fluid mechanics.Preprint, 13 pagesSpectral TheoryClassical Analysis and ODEs34Lxx; 76Rxx; 65F15; 65Q05text