代数幾何学セミナー

過去の記録 ~02/04次回の予定今後の予定 02/05~

開催情報 火曜日 10:30~11:30 or 12:00 数理科学研究科棟(駒場) ハイブリッド開催/002号室
担当者 權業 善範・中村 勇哉・田中公

2017年11月07日(火)

15:30-17:00   数理科学研究科棟(駒場) 122号室
村山 匠 氏 (ミシガン大学)
Characterizations of projective space and Seshadri constants in arbitrary characteristic
[ 講演概要 ]
Mori and Mukai conjectured that projective space should be the only n-dimensional Fano variety whose anti-canonical bundle has degree at least n + 1 along every curve. While this conjecture has been proved in characteristic zero, it remains open in positive characteristic. We will present some progress in this direction by giving another characterization of projective space using Seshadri constants and the Frobenius morphism. The key ingredient is a positive-characteristic analogue of Demailly’s criterion for separation of higher-order jets by adjoint bundles, whose proof gives new results for adjoint bundles even in characteristic zero.