Existence, covolumes and infinite generation of lattices for Davis complexes
Groups, geometry, and dynamics, Tome 6 (2012) no. 4, pp. 765-801
Voir la notice de l'article provenant de la source EMS Press
Let Σ be the Davis complex for a Coxeter system (W,S). The automorphism group G of Σ is naturally a locally compact group, and a simple combinatorial condition due to Haglund–Paulin and White determines when G is nondiscrete. The Coxeter group W may be regarded as a uniform lattice in G. We show that many such G also admit a nonuniform lattice Γ, and an infinite family of uniform lattices with covolumes converging to that of Γ. It follows that the set of covolumes of lattices in G is nondiscrete. We also show that the nonuniform lattice Γ is not finitely generated. Examples of Σ to which our results apply include buildings and non-buildings, and many complexes of dimension greater than 2. To prove these results, we introduce a new tool, that of “group actions on complexes of groups”, and use this to construct our lattices as fundamental groups of complexes of groups with universal cover Σ.
Classification :
22-XX, 57-XX, 00-XX
Mots-clés : Lattice, Davis complex, Coxeter group, building, complex of groups
Mots-clés : Lattice, Davis complex, Coxeter group, building, complex of groups
Affiliations des auteurs :
Anne Thomas  1
Anne Thomas. Existence, covolumes and infinite generation of lattices for Davis complexes. Groups, geometry, and dynamics, Tome 6 (2012) no. 4, pp. 765-801. doi: 10.4171/ggd/174
@article{10_4171_ggd_174,
author = {Anne Thomas},
title = {Existence, covolumes and infinite generation of lattices for {Davis} complexes},
journal = {Groups, geometry, and dynamics},
pages = {765--801},
year = {2012},
volume = {6},
number = {4},
doi = {10.4171/ggd/174},
url = {http://geodesic.mathdoc.fr/articles/10.4171/ggd/174/}
}
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