Homotopy invariance of the sheaf WNis and of its cohomology, by Ivan Panin

It is proved that the Nisnevich sheaf associated with the presheaf of Witt groups is homotopy invariant and moreover all its Nisnevich cohomology are homotopy invariant too. The proof is rather short and self-contained.


Ivan Panin <panin@pdmi.ras.ru>