“…Many recent works including our own, have tried to show that in certain manifolds or isotopy classes ergodicity holds for all volume preserving partially hyperbolic diffeomorphisms (see [HHU 2 ,HU,GS,FP,HRHU]). Thanks to the reductions of [GPS, BuW, HHU] the problem boils down to the study of accessibility, and this has become a problem on its own (see [HP, H, HS, FP] for general results about accessibility).…”