2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/76898The first part of these notes is devoted to an introduction to algebraic $D$-modules. Several basic notions are introduced. In the second part, $D$-modules with group action are treated. Several important examples in this situation are discussed in details. Particularly, the Harish-Chandra systems for group characters and the Gelfand generalized hypergeometric systems are our main topics.36 pagesRepresentation TheoryAlgebraic Geometry22; 35; 14text