代数幾何学セミナー

過去の記録 ~05/06次回の予定今後の予定 05/07~

開催情報 金曜日 13:30~15:00 数理科学研究科棟(駒場) 118号室
担当者 權業 善範、河上 龍郎 、榎園 誠 

次回の予定

2026年05月12日(火)

13:30-15:00   数理科学研究科棟(駒場) 128号室
斎藤 秀司 氏 (東京大学)
Birational lattices in the cohomology of the structure sheaf over non-archimedean fields
[ 講演概要 ]
We show that the cohomology of the structure sheaf of smooth and proper varieties over a complete non-archimedean field K with the ring R of integers of characteristic zero, can be refined to a birational cohomology theory of smooth (not necessarily proper) varieties over K with values in R-lattices, and the same holds for K of positive characteristic in dimensions at most 3.
As one application, we obtain that the automorphism group of the function field of a proper smooth variety X of dimension at most 3 over any field of positive characteristic acts quasi-unipotently on the cohomology of the canonical sheaf of X. The proof relies on some results from rigid analytic geometry on the cohomology of twisted integral rigid structure sheaves due to Bartenwerfer and van der Put.
This is a joint work with A. Merici and Kay Ruelling.