Ramification of local fields with imperfect residue fields. II

  • Ahmed Abbes

  • Takeshi Saito


In Part I [cf. the authors, Am. J. Math. 124, No. 5, 879–920 (2002; Zbl 1084.11064)], a filtration by ramification groups and its logarithmic version are defined on the absolute Galois group of a complete discrete valuation field without assuming that the residue field is perfect. In this paper, we study the graded pieces of these filtrations and show that they are abelian except possibly in the absolutely unramified and non-logarithmic case.