2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/160906We study Robin-to-Robin maps, and Krein-type resolvent formulas for Schrödinger operators on bounded Lipschitz domains in $\bbR^n$, $n\ge 2$, with generalized Robin boundary conditions.25 pages, typos corrected, new material addedAnalysis of PDEsSpectral Theory35J10, 35J25, 35Q40 (Primary); 35P05, 47A10, 47F05 (Secondary)text