Equality of two non-logarithmic ramification filtrations of abelianized   Galois group in positive characteristic
  We prove the equality of two non-logarithmic ramification filtrations defined by Matsuda and Abbes-Saito for the abelianized absolute Galois group of a complete discrete valuation field in positive characteristic. We also compute the refined Swan conductor and the characteristic form of a character of the fundamental group of a smooth separated scheme over a perfect field of positive characteristic by using sheaves of Witt vectors. 
Yuri Yatagawa
math.NT math.AG