Le lemme fondamental pour l'endoscopie tordue: le cas o{ù} le groupe endoscopique non ramifi{é} est un tore

Abstract: We prove the fundamental lemma for twisted endoscopy, for the unit elements of the spherical Hecke algebras, in the case of a non ramified elliptic endo- scopic datum whose underlying group is a torus. This implies that the fundamental lemma for twisted endoscopy is now proved, for all elements in the spherical Hecke algebras, in characteristic zero and any residue characteristic.