Compactifying coverings of 3-manifolds.
Compactly supported cohomology of systolic 3-pseudomanifolds
We show that the second group of cohomology with compact supports is nontrivial for three-dimensional systolic pseudomanifolds. It follows that groups acting geometrically on such spaces are not Poincaré duality groups.
Compatible elements in partly ordered groups.
Complements, baseless subgroups and sylow subgroups of infinite wreath products
Complete growth series and products of groups.
Complete metacyclic groups
Complete presentations of Coxeter groups.
Completely positive maps on Coxeter groups and the ultracontractivity of the q-Ornstein-Uhlenbeck semigroup
Completely positive maps on Coxeter groups, deformed commutation relations, and operator spaces.
Completion of a cyclically ordered group
Completion of Free Groups by Means of Infinite Product Representations.
Completions of lattice ordered groups
Complexity of some natural problems in automatic structures.
Comportement harmonique des densités conformes et frontière de Martin
Traitant la série de Poincaré d’un groupe discret d’isométries en courbure négative comme un noyau de Green, on établit une théorie du potentiel assez comparable à la théorie classique pour affirmer un parallèle entre densités conformes à la Patterson-Sullivan et densités harmoniques, et notamment définir une frontière de Martin où les densités ergodiques forment la partie minimale, et enfin l’identifier géométriquement sous hypothèse d’hyperbolicité.
Computation in Coxeter groups. I: Multiplication.
Computation of centralizers in Braid groups and Garside groups.
We give a new method to compute the centralizer of an element in Artin braid groups and, more generally, in Garside groups. This method, together with the solution of the conjugacy problem given by the authors in [9], are two main steps for solving conjugacy systems, thus breaking recently discovered cryptosystems based in braid groups [2]. We also present the result of our computations, where we notice that our algorithm yields surprisingly small generating sets for the centralizers.
Computational aspects of group extensions and their applications in topology.
Computer calculation of the degree of maps into the Poincaré homology sphere.
Computing Adams operations on the Burnside ring of a finite group.
Computing crossed modules induced by an inclusion of a normal subgroup, with applications to homotopy 2-types.