Ramification groups in Artin-Schreier-Witt extensions
Let be a local field of characteristic . The aim of this paper is to describe the ramification groups for the pro- abelian extensions over with regards to the Artin-Schreier-Witt theory. We shall carry out this investigation entirely in the usual framework of local class field theory. This leads to a certain non-degenerate pairing that we shall define in detail, generalizing in this way the Schmid formula to Witt vectors of length . Along the way, we recover a result of Brylinski but with...