Resolvent bounds imply observability from measurable time sets for Schrödinger equations

We prove that on a compact Riemannian manifold, resolvent bounds for the Laplace–Beltrami operator imply observability, and thus controllability, for the Schrödinger propagator from time sets of positive Lebesgue measure. Applications include almost all cases where observability and controllability hold from time intervals, particularly when the geometric control condition is satisfied or when the manifold is a compact surface of negative curvature.