Results 11 to 20 of about 249 (24)

Limit pretrees for free group automorphisms: existence

Forum of Mathematics, Sigma
To any free group automorphism, we associate a real pretree with several nice properties. First, it has a rigid/non-nesting action of the free group with trivial arc stabilizers.
Jean Pierre Mutanguha
doaj   +1 more source

Extensions of positive definite functions on amenable groups

, 2008
Let $S$ be a subset of a amenable group $G$ such that $e\in S$ and $S^{-1}=S$. The main result of the paper states that if the Cayley graph of $G$ with respect to $S$ has a certain combinatorial property, then every positive definite operator-valued ...
D. Timotin, Dixmier, Golumbic, M. Bakonyi, Rudin   +4 more
core   +1 more source

Limit trees for free group automorphisms: universality

Forum of Mathematics, Sigma
To any free group automorphism, we associate a universal (cone of) limit tree(s) with three defining properties: first, the tree has a minimal isometric action of the free group with trivial arc stabilizers; second, there is a unique expanding dilation ...
Jean Pierre Mutanguha
doaj   +1 more source

On C*-algebras related to constrained representations of a free group

, 2010
We consider representations of the free group $F_2$ on two generators such that the norm of the sum of the generators and their inverses is bounded by $\mu\in[0,4]$.
Chao You, H. Kesten, J. Cuntz, R. Exel, V. M. Manuilov   +4 more
core   +1 more source

On an action of the braid group B_{2g+2} on the free group F_{2g}

, 2013
We construct an action of the braid group B_{2g+2} on the free group F_{2g} extending an action of B_4 on F_2 introduced earlier by Reutenauer and the author.
Birman J. S., Birman J. S., CHRISTIAN KASSEL, Magnus W.   +3 more
core   +1 more source

The conjugacy problem for $\operatorname {Out}(F_3)$

Forum of Mathematics, Sigma
We present a solution to the conjugacy problem in the group of outer automorphisms of $F_3$ , a free group of rank 3. We distinguish according to several computable invariants, such as irreducibility, subgroups of polynomial growth and subgroups ...
François Dahmani, Stefano Francaviglia, Armando Martino, Nicholas Touikan   +3 more
doaj   +1 more source

Achievable ranks of intersections of finitely generated free groups [PDF]

, 2003
We answer a question due to A. Myasnikov by proving that all expected ranks occur as the ranks of intersections of finitely generated subgroups of free groups.Comment: 4 pages, 4 ...
Kent IV, Richard P.
core  

The Tits alternative for generalized triangle groups of type (3, 4, 2) [PDF]

, 2008
A generalized triangle group is a group that can be presented in the form G = h x, y | xp = yq = w(x, y)r = 1 i where p, q, r ? 2 and w(x, y) is a cyclically reduced word of length at least 2 in the free product Zp ?
Howie, J, Williams, G
core   +1 more source

Intersections of automorphism fixed subgroups in the free group of rank three

, 2004
We show that in the free group of rank 3, given an arbitrary number of automorphisms, the intersection of their fixed subgroups is equal to the fixed subgroup of some other single automorphism.Comment: Published by Algebraic and Geometric Topology at ...
Armando Martino, Bestvina, Collins, Dicks, Imrich, Lyndon, Stallings, Whitehead   +7 more
core   +3 more sources

The Topology of Parabolic Character Varieties of Free Groups

, 2012
Let G be a complex affine algebraic reductive group, and let K be a maximal compact subgroup of G. Fix elements h_1,...,h_m in K. For n greater than or equal to 0, let X (respectively, Y) be the space of equivalence classes of representations of the free
A Hatcher, A Neeman, C Florentino, Carlos Florentino, CT Simpson, EH Spanier, I Biswas, I Biswas, I Biswas, Indranil Biswas, IR Shafarevich, Marina Logares, R Steinberg, RL Benedetto, S Lawton, S Lawton, S Lawton, Sean Lawton, V Fock   +18 more
core   +1 more source