2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/63574We give criteria for R-equivalence of torsors under finite constant group schemes over a field. In paticular, using bitorsors, we obtain a Galois devissage result which formalises and generalises a theorem of Philippe Gille in the case of local fields; for instance, Gille's theorem is shown to extend to higher local fields.21 pages, in French, minor changes; to appear in Journal of Number TheoryAlgebraic GeometryNumber Theory12G05; 14G20; 18G50text