Partially logarithmic ramification theory and characteristic cycle of a rank one sheaf
アブストラクト
Computation of the characteristic cycle, which is introduced by Beilinson and Saito for a constructible sheaf on a smooth variety over a perfect field, gives a computation of the Euler characteristic of the sheaf by the index formula. In this talk, we construct an algebraic cycle by introducing a general theory combining logarithmic and non-logarithmic ramification theory introduced by Brylinski-Kato and Matsuda, respectively, and compare it with the characteristic cycle for a rank one sheaf.