2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/137441We determine the blocks of the walled Brauer algebra in characteristic zero. These can be described in terms of orbits of the action of a Weyl group of type $A$ on a certain set of weights. In positive characteristic we give a linkage principle in terms of orbits of the corresponding affine Weyl group. We also classify the semisimple walled Brauer algebras in all characteristics.40 pages, 16 figuresRepresentation Theory20G05text