groups are almost convex and have a sub-cubic Dehn function.
L²-homology and reciprocity for right-angled Coxeter groups
Let W be a Coxeter group and let μ be an inner product on the group algebra ℝW. We say that μ is admissible if it satisfies the axioms for a Hilbert algebra structure. Any such inner product gives rise to a von Neumann algebra containing ℝW. Using these algebras and the corresponding von Neumann dimensions we define -Betti numbers and an -Euler charactersitic for W. We show that if the Davis complex for W is a generalized homology manifold, then these Betti numbers satisfy a version of Poincaré...
Large scale Sobolev inequalities on metric measure spaces and applications.
Les groupes de triangles sont déterminés par leur spectre des longueurs
On décrit le début du spectre des longueurs des groupes de triangles ayant un angle droit et on montre que le spectre des longueurs caractérise la classe d’isométrie d’un tel groupe.
Les groupes hyperboliques
L'image d'un groupe dans un groupe hyperbolique.
Limit groups for relatively hyperbolic groups. II: Makanin-Razborov diagrams.
Limits of (certain) CAT(0) groups. I: Compactification.
Limits of relatively hyperbolic groups and Lyndon’s completions
We describe finitely generated groups universally equivalent (with constants from in the language) to a given torsion-free relatively hyperbolic group with free abelian parabolics. It turns out that, as in the free group case, the group embeds into the Lyndon’s completion of the group , or, equivalently, embeds into a group obtained from by finitely many extensions of centralizers. Conversely, every subgroup of containing is universally equivalent to . Since finitely generated...
Localization of group rings and applications to 2-complexes.
Locally finite classical Tits chamber Systems of large order.