2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/123068We introduce group corings, and study functors between categories of comodules over group corings, and the relationship to graded modules over graded rings. Galois group corings are defined, and a Structure Theorem for the $G$-comodules over a Galois group coring is given. We study (graded) Morita contexts associated to a group coring. Our theory is applied to group corings associated to a comodule algebra over a Hopf group coalgebra.38 pagesRings and Algebras16W30, 16W50text