2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/107561We show that, under some very weak assumption of effective variation for the magnetic field, a periodic Schrödinger operator with magnetic wells on a noncompact Riemannian manifold $M$ such that $H^1(M, \R)=0$ equipped with a properly disconnected, cocompact action of a finitely generated, discrete group of isometries has an arbitrarily large number of spectral gaps in the semi-classical limit.LaTeX 2e, 16 pagesSpectral TheoryMathematical Physicstext