Boundary amenability of relatively hyperbolic groups

被引:26
作者
Ozawa, Narutaka [1 ]
机构
[1] Univ Calif Los Angeles, Dept Math, Los Angeles, CA 90095 USA
[2] Univ Tokyo, Dept Math Sci, Komaba 1538914, Japan
基金
日本学术振兴会;
关键词
fine hyperbolic graph; relatively hyperbolic groups; exactness; amenable action;
D O I
10.1016/j.topol.2005.11.001
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
Let K be a fine hyperbolic graph and Gamma be a group acting on K with finite quotient. We prove that Gamma is exact provided that all vertex stabilizers are exact. In particular, a relatively hyperbolic group is exact if all its peripheral groups are exact. We prove this by showing that the group Gamma acts amenably on a compact topological space. We include some applications to the theories of group von Neumann algebras and of measurable orbit equivalence relations. (C) 2005 Elsevier B.V. All rights reserved.
引用
收藏
页码:2624 / 2630
页数:7
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