Classification of fibred group extensions and H...
Classification of finite groups satisfying a minimal condition.
Classification of pro- subgroups of over a -adic ring, where is an odd prime
Classification of Soluble Groups of Cohomologie Dimension Two.
Clinic obstructions and clinic cohomological groups.
Closedness of a class of groups under free product.
Cœur et nombre d'intersection pour les actions de groupes sur les arbres
Coherence of 3-manifold fundamental groups
Cohomological dimension and symmetric automorphisms of a free group.
Cohomology of Drinfeld symmetric spaces and Harmonic cochains
Let be a non-archimedean local field. This paper gives an explicit isomorphism between the dual of the special representation of and the space of harmonic cochains defined on the Bruhat-Tits building of , in the sense of E. de Shalit [11]. We deduce, applying the results of a paper of P. Schneider and U. Stuhler [9], that there exists a -equivariant isomorphism between the cohomology group of the Drinfeld symmetric space and the space of harmonic cochains.
Cohomology with free coefficients of the fundamental group of a graph of groups.
Combination of convergence groups.
Combinatorial and group-theoretic compactifications of buildings
Let be a building of arbitrary type. A compactification of the set of spherical residues of is introduced. We prove that it coincides with the horofunction compactification of endowed with a natural combinatorial distance which we call the root-distance. Points of admit amenable stabilisers in and conversely, any amenable subgroup virtually fixes a point in . In addition, it is shown that, provided is transitive enough, this compactification also coincides with the group-theoretic...
Combinatorial mapping-torus, branched surfaces and free group automorphisms
We give a characterization of the geometric automorphisms in a certain class of (not necessarily irreducible) free group automorphisms. When the automorphism is geometric, then it is induced by a pseudo-Anosov homeomorphism without interior singularities. An outer free group automorphism is given by a -cocycle of a -complex (a standard dynamical branched surface, see [7] and [9]) the fundamental group of which is the mapping-torus group of the automorphism. A combinatorial construction elucidates...
Combinatorial Modulus on Boundary of Right-Angled Hyperbolic Buildings
In this article, we discuss the quasiconformal structure of boundaries of right-angled hyperbolic buildings using combinatorial tools. In particular, we exhibit some examples of buildings of dimension 3 and 4 whose boundaries satisfy the combinatorial Loewner property. This property is a weak version of the Loewner property. This is motivated by the fact that the quasiconformal structure of the boundary led to many results of rigidity in hyperbolic spaces since G.D.Mostow. In the case of buildings...
Combing Euclidean buildings.
Combins of Semidrect Products and 3-Manifold Groups.
Commensurability of graph products.
Commensurations of Out
Let Out(Fn) denote the outer automorphism group of the free group Fn with n>3. We prove that for any finite index subgroup Γ<Out(Fn), the group Aut(Γ) is isomorphic to the normalizer of Γ in Out(Fn). We prove that Γ is co-Hopfian: every injective homomorphism Γ→Γ is surjective. Finally, we prove that the abstract commensurator Comm(Out(Fn)) is isomorphic to Out(Fn).
Commutativity Criterions using Normal Subgroup Lattices