Outer automorphism groups of Bieberbach groups.
Quasiconformal groups of compact type.
We establish that a quasiconformal group is of compact type if and only if its limits set is purely conical and find that the limit set of a quasiconformal group of compact type is uniformly perfect. A key tool is the result of Bowditch-Tukia on compact-type convergence groups. These results provide crucial tools for studying the deformations of quasiconformal groups and in establishing isomorphisms between such groups and conformal groups.
Quotients compacts des groupes ultramétriques de rang un
Soit l’ensemble des points d’un groupe algébrique semi-simple connexe de rang relatif un sur un corps local ultramétrique. Nous décrivons tous les sous-groupes discrets de type fini sans torsion de qui agissent proprement et cocompactement sur par multiplication à gauche et à droite. Nous montrons qu’après une petite déformation dans un tel sous-groupe agit encore librement, proprement discontinûment et cocompactement sur .
Rank gradient, cost of groups and the rank versus Heegaard genus problem
We study the growth of the rank of subgroups of finite index in residually finite groups, by relating it to the notion of cost. As a by-product, we show that the ‘rank vs. Heegaard genus’ conjecture on hyperbolic 3-manifolds is incompatible with the ‘fixed price problem’ in topological dynamics.
Rigidity and crystallographic groups, I.
Semi-free Zp-Actions on Highly-Connected Manifolds.
Some examples of discrete groups and hyperbolic orbifolds of infinite volume.
Stabile Foliations of 4-Manifolds by Closed Surfaces. I. Local Structure and Free Actions of Finite Cyclic and Dihedral Groups on Surfaces.
Strongly geodesically automatic groups are hyperbolic.
Sur la division des domaines de Siegel
Sur les espaces annelés avec groupe d'opérateurs
Tempered subgroups and representations with minimal decay of matrix coefficients
The fixed group of an automorphism of a word hyperbolic group is rational.
The Kahn-Priddy Theorem and Equivariant Vector Fields on Spheres.
The ?-orbifold Group of a Link.
The smallest arithmetic hyperbolic three-orbi-fold.
The Topological-Euclidean Space Form Problem.
Topologie de Gromov équivariante, structures hyperboliques et arbres réels.
Über die Automorphismengruppen von Banach-Mannigfaltigkeiten mit invarianter Metrik.
Vanishing theorems and conjectures for the 2-homology of right-angled Coxeter groups.