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代数幾何学セミナー
過去の記録 ～05/20｜次回の予定｜今後の予定 05/21～
| 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 |
2025年05月23日(金)
13:30-15:00 数理科学研究科棟(駒場) 118号室
宮本 拓哉 氏 (東京大学)
Pathology of formal locally-trivial
deformations in positive characteristic
宮本 拓哉 氏 (東京大学)
Pathology of formal locally-trivial
deformations in positive characteristic
[ 講演概要 ]
An infinitesimal deformation of an algebraic variety X is called (formally) locally trivial if it is Zariski-locally isomorphic to the trivial deformation. The locally trivial deformation functor of X is the subfunctor of the usual deformation functor associated with X consisting of locally trivial deformations. In this talk, I will construct an explicit example that is an algebraic curve in positive characteristic whose locally trivial deformation functor does not satisfy Schlessinger’s first condition (H_1), in contrast to the complex/characteristic 0 case. In particular, this provides a negative answer to a question posed by H. Flenner and S. Kosarew. I will also mention recent progress on the structure of fibers of locally trivial deformation functors.
An infinitesimal deformation of an algebraic variety X is called (formally) locally trivial if it is Zariski-locally isomorphic to the trivial deformation. The locally trivial deformation functor of X is the subfunctor of the usual deformation functor associated with X consisting of locally trivial deformations. In this talk, I will construct an explicit example that is an algebraic curve in positive characteristic whose locally trivial deformation functor does not satisfy Schlessinger’s first condition (H_1), in contrast to the complex/characteristic 0 case. In particular, this provides a negative answer to a question posed by H. Flenner and S. Kosarew. I will also mention recent progress on the structure of fibers of locally trivial deformation functors.
