超平面配置セミナー
Hyperplane Arrangement Seminar
プログラム
[第7回]
- 日時：
- 2007年10月30日（火） 10：30-12：00
- 場所：
- 北大理学部8号館302号室
- 講演者：
- 吉永正彦（神戸大学）
- 講演題名：
- On the extendability for some free multiarrangements
- 要旨：
- A free multiarrangement of rank k is defined to be extendable if it is obtained from a simple rank (k+1)free arrangement by the natural restriction (in the sense of Ziegler) to a hyperplane. Not all free multiarrangements are extendable. We will concentrate on a special class of extendable free multiarrangements. As an application, we find a large class of totally non-free arrangements.
[第8回]
- 日時：
- 2007年10月30日（火） 13：00-14：30
- 場所：
- 北大理学部8号館302号室
- 講演者：
- 川原行人（慶應志木高校）
- 講演題名：
- Combinatorics of arrangements with non-vanishing twisted cohomology
- 要旨：
- In the general twist case, twisted cohomology on the complement of hyperplanes vanishes except in the highest dimension. For the special arrangement of hyperplanes, there is a twist with non-vanishing twisted cohomology. In this talk, we construct such arrangements, using some combinatorics.
