————(연사 개인 사정으로 연기되었습니다)—————–

December 14 (Tuesday) 19:00-21:00 (KST),
15 (Wednesday) & 16 (Thursday) 16:00-18:00 (KST, GMT +9)

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고등과학원에서 주관하는 집중강연입니다.
https://sites.google.com/view/eag-seminar

DATE: 2021 October 25, 27, 29
TIME: 16:00-18:00
PLACE: Online
SPEAKER: Michel Brion

Lecture 1: Actions and representations of algebraic groups (October 25)
– Overview; basic notions and results on actions and representations of algebraic groups; toric varieties.

Lecture 2: Properties and examples of spherical varieties (October 27)
– Further background on the structure and representations of linear algebraic groups; projective homogeneous varieties; spherical varieties: definition, first properties, local structure.

Lecture 3: Embeddings of spherical homogeneous spaces (October 29)
– Embeddings of spherical homogeneous spaces; wonderful varieties; open questions.

Spherical varieties form a remarkable class of algebraic varieties equipped with an action of an algebraic group, which contains several classes of interest: toric varieties, projective homogeneous varieties, symmetric spaces, wonderful varieties. Toric varieties are classified by fans, which provide a well-developed dictionary between their geometry and combinatorics. This makes toric varieties an excellent testing ground for algebro-geometric questions, even if they form a very special class. Spherical varieties are much more general, and include many examples from classical projective geometry. They also admit a combinatorial classification, whose relation to geometry is less understood. The lectures will present basic results on spherical varieties, together with the relevant background on the structure, actions and representations of algebraic groups. They will conclude with open questions.