Ramification Theory for Artin-Schreier Extensions of Valuation Rings
  The goal of this paper is to generalize and refine the classical ramification theory of complete discrete valuation rings to more general valuation rings, in the case of Artin-Schreier extensions. We define refined versions of invariants of ramification in the classical ramification theory and compare them. Furthermore, we can treat the defect case. 
Vaidehee Thatte
math.NT