代数幾何学セミナー

過去の記録 ~02/27次回の予定今後の予定 02/28~

開催情報 金曜日 13:30~15:00 数理科学研究科棟(駒場) ハイブリッド開催/117号室
担当者 權業 善範、中村 勇哉、田中 公

2019年05月29日(水)

15:30-17:00   数理科学研究科棟(駒場) 118号室
今学期は基本水曜日とします。部屋も去年度と異なります。
江辰 氏 (Fudan/MSRI)
Minimal log discrepancies of 3-dimensional non-canonical singularities (English)
[ 講演概要 ]
Canonical and terminal singularities, introduced by Reid, appear naturally in minimal model program and play important roles in the birational classification of higher dimensional algebraic varieties. Such singularities are well-understood in dimension 3, while the property of non-canonical singularities is still mysterious. We investigate the difference between canonical and non-canonical singularities via minimal log discrepancies (MLD). We show that there is a gap between MLD of 3-dimensional non-canonical singularities and that of 3-dimensional canonical singularities, which is predicted by a conjecture of Shokurov.
This result on local singularities has applications to global geometry of Calabi–Yau 3-folds. We show that the set of all non-canonical klt Calabi–Yau 3-folds are bounded modulo flops, and the global indices of all klt Calabi–Yau 3-folds are bounded from above.