2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/167017We prove a sharp Mihlin-Hormander multiplier theorem for Schroedinger operators $H$ on $\R^n$. The method, which allows us to deal with general potentials, improves Hebisch's method relying on heat kernel estimates for positive potentials. Our result applies to, in particular, the negative Poeschl-Teller potential $V(x)= -ν(ν+1) \sech^2 x $, $ν\in \N$, for which $H$ has a resonance at zero.23 pagesAnalysis of PDEsClassical Analysis and ODEs42B25, 35J10text