幾何学コロキウム Visible actions of compact Lie groups on complex spherical varieties

開催日時
2016年   11月 25日 16時 30分 ~   18時 00分
場所
3号館204室
講演者
田中雄一郎(東京大学)
 
With the aim of uniform treatment of multiplicity-free representations
of Lie groups,
T. Kobayashi introduced the theory of visible actions on complex
manifolds.

In this talk we consider visible actions of a compact real form U of
a connected complex reductive algebraic group G
on spherical varieties. Here a connected complex G-variety X
is said to be spherical
if a Borel subgroup of G has an open orbit on X.
The sphericity implies the multiplicity-freeness property of
the space of polynomials on X.
We show the visibility of U-actions on spherical varieties
by using the method of induction of visible actions.
The method of induction of visible actions was introduced by Kobayashi
(2005) for the case of complex spherical nilpotent orbits of type A,
and recently extended by A. Sasaki (2016) to the case of complex
spherical nilpotent orbits of arbitrary type.
Our proof is highly motivated by those earlier results.


<注意>
講演日時の記載が間違っておりましたので, 修正いたしました
(11月16日以前では, 講演日が12月25日となっていました. 11月25日が正しいです).
世話人(北大D3加葉田)の不手際です.
申し訳ありません.


関連項目

研究集会・セミナー・集中講義の一覧へ