Group actions and Helly's theorem
نویسندگان
چکیده
منابع مشابه
Group actions and Helly’s theorem
We describe a connection between the combinatorics of generators for certain groups and the combinatorics of Helly’s 1913 theorem on convex sets. We use this connection to prove fixed point theorems for actions of these groups on nonpositively curved metric spaces. These results are encoded in a property that we introduce called “property FAr”, which reduces to Serre’s property FA when r = 1. T...
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ژورنال
عنوان ژورنال: Advances in Mathematics
سال: 2009
ISSN: 0001-8708
DOI: 10.1016/j.aim.2009.06.004