Combins of Semidrect Products and 3-Manifold Groups.
Commutativity in groups presented by finite Church-Rosser Thue systems
Commutator length of finitely generated linear groups.
Commutators and squares in free groups.
Commutators and squares in free nilpotent groups.
Complete growth series and products of groups.
Complete presentations of Coxeter groups.
Completion of Free Groups by Means of Infinite Product Representations.
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.
Conformally non-sperical 2-complexes.
Conjugacy equivalence relation on subgroups
If G is a countable group containing a copy of F₂ then the conjugacy equivalence relation on subgroups of G attains the maximal possible complexity.
Conjugacy of Coxeter elements.
Conjugacy pinched and cyclically pinched one-relator groups.
Here we consider two classes of torsion-free one-relator groups which have proved quite amenable to study-the cyclically pinched one-relator groups and the conjugacy pinched one-relator groups. The former is the class of groups which are free products of free groups with cyclic amalgamations while the latter is the class of HNN extensions of free groups with cyclic associated subgroups. Both are generalizations of surface groups. We compare and contrast results in these classes relative to n-freeness,...
Conjugacy separability of some one-relator groups.
Convex cocompact subgroups of mapping class groups.
Correction to the paper “Generators of an orthogonal group over a finite field”
Coset enumeration of groups generated by symmetric sets of involutions.
Coxeter classes of unitary reflection groups.
Coxeter groups, Salem numbers and the Hilbert metric
Critical constants for recurrence of random walks on -spaces
We introduce the notion of a critical constant for recurrence of random walks on -spaces. For a subgroup of a finitely generated group the critical constant is an asymptotic invariant of the quotient -space . We show that for any infinite -space . We say that is very small if . For a normal subgroup the quotient space is very small if and only if it is finite. However, we give examples of infinite very small -spaces. We show also that critical constants for recurrence can be used...