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トポロジー火曜セミナー
過去の記録 ～06/26｜次回の予定｜今後の予定 06/27～
| 開催情報 | 火曜日 16:00～17:30 数理科学研究科棟(駒場) 056号室 |
|---|---|
| 担当者 | 池 祐一, 今野 北斗, 逆井卓也 |
| セミナーURL | https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index.html |
2026年07月14日(火)
16:00-17:30 数理科学研究科棟(駒場) hybrid/056号室
Lie群論・表現論セミナーと合同開催。 参加を希望される場合は、セミナーのウェブページをご覧下さい。
田中 雄一郎 氏 (東京大学大学院数理科学研究科)
Visible actions of real reductive groups on complex algebraic varieties (JAPANESE)
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html
Lie群論・表現論セミナーと合同開催。 参加を希望される場合は、セミナーのウェブページをご覧下さい。
田中 雄一郎 氏 (東京大学大学院数理科学研究科)
Visible actions of real reductive groups on complex algebraic varieties (JAPANESE)
[ 講演概要 ]
A unitary representation of a locally compact group is multiplicity-free if each irreducible representation appears at most once in its irreducible decomposition. To provide a unified perspective on this property in the context of Lie group representations, T. Kobayashi introduced the theory of visible action for holomorphic actions of Lie groups on complex manifolds. This approach enables us to understand many known examples uniformly and also leads to the discovery of new ones by utilizing Kobayashi's propagation theorem of multiplicity-freeness property for visible actions. In this talk, we will begin with the definition of visible action, illustrated with examples, and then explore some known results on classifications of visible actions and relationships among the coisotropicity, the sphericity and the visibility for group-actions on complex smooth algebraic varieties. We will also discuss recent results based on unitary tricks for transferring properties of compact group-actions on complex flag manifolds to non-compact ones.
[ 参考URL ]A unitary representation of a locally compact group is multiplicity-free if each irreducible representation appears at most once in its irreducible decomposition. To provide a unified perspective on this property in the context of Lie group representations, T. Kobayashi introduced the theory of visible action for holomorphic actions of Lie groups on complex manifolds. This approach enables us to understand many known examples uniformly and also leads to the discovery of new ones by utilizing Kobayashi's propagation theorem of multiplicity-freeness property for visible actions. In this talk, we will begin with the definition of visible action, illustrated with examples, and then explore some known results on classifications of visible actions and relationships among the coisotropicity, the sphericity and the visibility for group-actions on complex smooth algebraic varieties. We will also discuss recent results based on unitary tricks for transferring properties of compact group-actions on complex flag manifolds to non-compact ones.
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html
