2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/139348We consider the Dirichlet Laplacian with a constant magnetic field in a two-dimensional domain of finite measure. We determine the sharp constants in semi-classical eigenvalue estimates and show, in particular, that Polya's conjecture is not true in the presence of a magnetic field.15 pagesMathematical Physicstext