ミニワークショップ

Geometry on Groups

日時：２００６年７月３日（月）ー７月７日（金）

場所：ホテルノースイン札幌 北農健保会館 ３３３号室

〒060-0004 札幌市中央区北4条西7丁目1番4

TEL：011-261-3270　FAX：011-261-3298

http://www.hokunoukenpo.or.jp/kaikan/

参加を希望される研究者・大学院生の方に対しまして、限りはありますが

旅費の援助が可能ですので、ご希望の方は納谷までご連絡下さい。

〆切を６月１４日（水）とします。

（援助を希望される方が多数の場合、科研費等の利用が困難な方を優先します。）

世話人：

金井雅彦（名古屋大学）kanai@math.nagoya-u.ac.jp

納谷信（名古屋大学）nayatani@math.nagoya-u.ac.jp

井関裕靖（東北大学）izeki@math.tohoku.ac.jp

プログラム：

７月３日（月）

10:30-11:30 Nicolas Monod (Univ. of Geneva) : CAT0 spaces, splitting and superrigidity (1)

13:30-14:30 Nicolas Monod : CAT0 spaces, splitting and superrigidity (2)

15:00-16:00 Toshiyuki Akita (Hokkaido Univ.) : Cohomological aspects of Coxeter groups

７月４日（火）

10:30-11:30 Nicolas Monod : CAT0 spaces, splitting and superrigidity (3)

13:30-14:30 Koji Fujiwara (Tohoku Univ.) : Asymptotic geometry of curve graphs

15:00-16:00 Takefumi Kondo (Kyoto Univ.) : Fixed-point property for CAT(0) spaces

７月５日（水）

10:30-11:30 Nicolas Monod : CAT0 spaces, splitting and superrigidity (4)

７月６日（木）

10:30-11:30 Nicolas Monod : CAT0 spaces, splitting and superrigidity (5)

13:30-14:30 Narutaka Ozawa (Univ. of Tokyo) : Amenable actions and applications (1)

15:00-16:00 Narutaka Ozawa : Amenable actions and applications (2)

７月７日（金）

10:30-11:30 Nicolas Monod : CAT0 spaces, splitting and superrigidity (6)

13:30-14:30 Taro Yoshino (RIMS) : Existence problem of a compact Clifford-Klein form and tangential homogeneous spaces

Monod氏連続講演のアブストラクト :

The lectures will begin as an introduction to cat(0) spaces, also called Hadamard spaces. These spaces are defined by imposing a simple inequality on triangles in completely general metric spaces in order to imitate the notion of "non-positive sectional curvature" familiar in Riemannian geometry. That level of generality allows to produce relatively simple arguments that are interesting even for the special case of Riemannian manifolds.

We will introduce from the very beginning some of the general techniques in cat(0) geometry. Our guiding goals will be (1) to prove a splitting theorem in the spirit of Lawson-Yau and Gromoll-Wolf; (2) to prove a superrigidity theorem in the spirit of Margulis. This goals will provide motivation for the general theory.