时间：12月14日（周一）10:00—11:00
地点：数学院南楼913
报告人：胡昊宇（東京大学）
题目：Semi-continuity of total dimension divisors for ℓ-adic sheaves
摘要：
Let ℱ be a lisse ℓ-adic sheaf on an open dense subset U of a smooth variety X
of characteristic p ≠ ℓ. Its non-logarithmic ramification along generic points of X - U, which is
defined by A. Abbes and T. Saito, gives its total dimension divisor supported on X - U. In this
talk, we will show that, in a smooth fibration, the total dimension divisor of the restriction of
an ℓ-adic sheaf on fibers is lower semi-continuous. It is a generalization of the same property for
relative curves obtained by G. Laumon in 1970's in the geometric case. This is a joint work with
E. Yang.
附件：