p-extensions of local fields with Galois groups of nilpotent class

Nilpotent Artin-Schreier theory allows to identify the Galois groups of extensions from the title with groups associated with Lie algebras via the Campbell-Hausdorff group law. Earlier the author applied this construction to describe the ramification subgroups in the characteristic p case. In this talk we discuss the case of local fields of mixed characteristic.