Gürses, MetinHeydarzade, Yaghoub2021-02-272021-02-272020-111434-6044http://hdl.handle.net/11693/75634We prove that for the Friedmann–Lemaitre–Robertson–Walker metric, the field equations of any generic gravity theory in arbitrary dimensions are of the perfect fluid type. The cases of general Lovelock and F(R,G)F(R,G) theories are given as examples.EnglishArticle10.1140/epjc/s10052-020-08641-0