Group actions on curves and the lifting problem
نویسندگان
چکیده
1.1 The lifting problem The problem we are concerned with in our lectures and which we shall refer to as the lifting problem was originally formulated by Frans Oort in [17]. To state it, we fix an algebraically closed field κ of positive characteristic p. Let W (κ) be the ring of Witt vectors over κ. Throughout our notes, o will denote a finite local ring extension of W (κ) and k = Frac(o) the fraction field of o. Note that o is a complete discrete valuation ring of characteristic zero with residue field κ.
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