Cohomological dimension and symmetric automorphisms of a free group.
Cohomology rings of Artin groups
In this paper integer cohomology rings of Artin groups associated with exceptional groups are determined. Computations have been carried out by using an effective method for calculation of cup product in cellular cohomology which we introduce here. Actually, our method works in general for any finite regular complex with identifications, the regular complex being geometrically realized by a compact orientable manifold, possibly with boundary.
Cohomology rings of spaces of generic bipolynomials and extended affine Weyl groups of serie
A bipolynomial is a holomorphic mapping of a sphere onto a sphere such that some point on the target sphere has exactly two preimages. The topological invariants of spaces of bipolynomials without multiple roots are connected with characteristic classes of rational functions with two poles and generalized braid groups associated to extended affine Weyl groups of the serie . We prove that the cohomology rings of the spaces of bipolynomials of bidegree stabilize as tends to infinity and that...
Coloured generalised Young diagrams for affine Weyl-Coxeter groups.
Combination of convergence groups.
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).
Commensurations of the Johnson kernel.
Commensurator subgroups of surface groups.
Commutativity Criterions using Normal Subgroup Lattices
Commutativity in groups presented by finite Church-Rosser Thue systems
Commutativity theorems for rings and groups with constraints on commutators.
Commutator length of finitely generated linear groups.
Commutators and associators in Catalan loops
Various commutators and associators may be defined in one-sided loops. In this paper, we approximate and compare these objects in the left and right loop reducts of a Catalan loop. To within a certain order of approximation, they turn out to be quite symmetrical. Using the general analysis of commutators and associators, we investigate the structure of a specific Catalan loop which is non-commutative, but associative, that appears in the original number-theoretic application of Catalan loops.
Commutators and squares in free groups.
Commutators and squares in free nilpotent groups.
Compact hyperbolic Coxeter -polytopes with facets.