Mapping classes associated to mixed-sign Coxeter system
トポロジー金曜セミナー
開催期間
2012.5.21(月)
16:00 ~ 17:00
16:00 ~ 17:00
場所
伊都キャンパス伊都図書館3階 小講義室2
講演者
広中 えり子 (Florida State University/University of Tokyo(Visitor))
概要
The smallest known accumulation point of the genus-normalized
dilatations of closed oriented surfaces is L = 1 + golden mean.
In this talk we show how to construct a mapping class on an oriented
surface from an ordered simply-laced Coxeter fat graph. We show that
minimum dilatation orientable pseudo-Anosov mapping classes for small
genus can be constructed using this method. We also find a sequence of
mapping classes with unbounded genus, whose genus-normalized dilatations
converge to L.