2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/68921We construct a potential $V$ on $\RR^d$, smooth away from one pole, and a sequence of quasi-modes for the operator $-Δ+V$, which concentrate on this pole. No smoothing effect, Strichartz estimates nor dispersive inequalities hold for the corresponding Schrodinger equation.Analysis of PDEstext