F-characteristic cycle of a rank one sheaf on an arithmetic surface
アブストラクト
The characteristic cycle of a constructible sheaf on a smooth variety was defined on the cotangent bundle by Saito. To consider the characteristic cycle in the mixed characteristic case, as a replacement of the cotangent bundle, Saito defined the FW-cotangent bundle of a regular flat scheme over a discrete valuation ring of mixed characteristic. In this talk, we define the F-characteristic cycle satisfying a conductor formula of a rank one sheaf on an arithmetic surface on the FW-cotangent bundle. The definition is based on the computation of the characteristic cycle in the geometric case by Yatagawa. We discuss some properties of the characteristic form, which are necessary for the definition of the F-characteristic cycle.