- journal article metadata
European Mathematical Society Publishing House
2016-09-19 17:04:58
Groups, Geometry, and Dynamics
Groups Geom. Dyn.
GGD
1661-7207
1661-7215
Group theory and generalizations
10.4171/GGD
http://www.ems-ph.org/doi/10.4171/GGD
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European Mathematical Society Publishing House
Zuerich, Switzerland
© European Mathematical Society
3
2009
1
Visual decompositions of Coxeter groups
Michael
Mihalik
Vanderbilt University, NASHVILLE, UNITED STATES
Steven
Tschantz
Vanderbilt University, NASHVILLE, UNITED STATES
Coxeter group, group actions on trees, graph of group decompositions, FA groups, accessibility of groups
A Coxeter system is an ordered pair (W,S) where S is the generating set in a particular type of presentation for the Coxeter group W. A subgroup of W is called special if it is generated by a subset of S. Amalgamated product decompositions of a Coxeter group having special factors and special amalgamated subgroup are easily recognized from the presentation of the Coxeter group. If a Coxeter group is a subgroup of the fundamental group of a given graph of groups, then the Coxeter group is also the fundamental group of a graph of special subgroups, where each vertex and edge group is a subgroup of a conjugate of a vertex or edge group of the given graph of groups. A vertex group of an arbitrary graph of groups decomposition of a Coxeter group is shown to split into parts conjugate to special groups and parts that are subgroups of edge groups of the given decomposition. Several applications of the main theorem are produced, including the classification of maximal FA subgroups of a finitely generated Coxeter group as all conjugates of certain special subgroups.
Group theory and generalizations
General
173
198
10.4171/GGD/53
http://www.ems-ph.org/doi/10.4171/GGD/53