Ross Geoghegan

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This paper is about geometric and topological properties of a proper CAT(0) space X which is cocompact-i.e. which has a compact generating domain with respect to the full isometry group. It is shown that geodesic segments in X can " almost " be extended to geodesic rays. A basic ingredient of the proof of this geometric statement is the topological theorem(More)
Given a set S equipped with a binary operation (we call this a " bracket algebra ") one may ask to what extent the binary operation satisfies some of the consequences of the associative law even when it is not actually associative? We define a subgroup As-soc(S) of Thompson's Group F for each bracket algebra S, and we interpret the size of Assoc(S) as(More)