2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/162845A tensor model structure is constructed on the category of chain complexes of presheaves of R-modules for a sheaf of rings R in a Grothendieck topos. If the topos has enough points, then the homotopy category is equivalent to the derived category. Some t-structures, generalizing the perverse t-structures, are constructed on the derived category.22 pagesAlgebraic GeometryCategory Theory18E30; 18G55text