[geometry-ml:06935] 東大数理・複素解析幾何セミナー 7/13

[shigeharu takayama]

皆様、

東大数理・複素解析幾何セミナーのお知らせです。

2026年07月13日(月) 10:30-12:00
数理科学研究科棟(駒場) 126号室
講演者：神田 秀峰 氏 (東京大学)
講演題目：Holomorphic polynomial crystallographic actions of nilpotent
groups (Japanese)
[ 講演概要 ]
It is a natural and still open question whether every simply connected
nilpotent Lie group endowed with a left-invariant complex structure is
biholomorphic to $\mathbb{C}^n$. In this talk, we give an affirmative
answer under the additional assumption that the complex structure is
nilpotent. Moreover, we construct such a biholomorphism explicitly by
polynomial maps in exponential coordinates. As a consequence, every
lattice in such a Lie group admits a free, properly discontinuous and
cocompact action on $\mathbb{C}^n$ by holomorphic polynomial
automorphisms. We interpret this as a holomorphic analogue of
polynomial crystallographic actions, namely actions on $\mathbb{R}^n$
by polynomial diffeomorphisms that are free, properly discontinuous
and cocompact, as introduced by Dekimpe, Igodt, and Lee.

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今後の予定はこちら
https://www.ms.u-tokyo.ac.jp/seminar/geocomp/future.html

世話人
高山 茂晴、平地 健吾