2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/134881Let $α\in(0,2)$ and $X_t$ be a symmetric $α$-stable process. We define the scattering length $Γ(v)$ of the positive potential $v$ and prove several of its basic properties. We use the scattering length to findestimates for the first eigenvalue of the Schrödinger operator of the ``Neumann'' fractional Laplacian in a cube with potential $v$.preprintProbability60G52; 31C15text