2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/173945By using the equivalence between metric and Palatini f(R) (or "modified") gravities with omega=0, -3/2 Brans-Dicke theories, it is shown that the Ehlers-Geren-Sachs theorem of general relativity is extended to modified gravity. In the case of metric f(R) gravity previously studied, this agrees with previous literature.10 pages, latex. Contribution to the anniversary volume "Problems of Modern Cosmology" in honour of Prof. S.D. Odintsov to be published by Tomsk UniversityGeneral Relativity and Quantum Cosmologytext