2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/228978The stability issue of a large class of modified gravitational models is discussed with particular emphasis to de Sitter solutions. Three approaches are briefly presented and the generalization to more general cases is mentioned.6 pages, talk delivered at DSU08 CairoGeneral Relativity and Quantum Cosmologytext