Results 1 to 10 of about 32 (32)

Onto extensions of free groups [PDF]

Groups, Complexity, Cryptology, 2021
An extension of subgroups $H\leqslant K\leqslant F_A$ of the free group of rank $|A|=r\geqslant 2$ is called onto when, for every ambient free basis $A'$, the Stallings graph $\Gamma_{A'}(K)$ is a quotient of $\Gamma_{A'}(H)$.
Sebastià Mijares, Enric Ventura
doaj   +1 more source

On the Nielsen-Schreier Theorem in Homotopy Type Theory [PDF]

Logical Methods in Computer Science, 2022
We give a formulation of the Nielsen-Schreier theorem (subgroups of free groups are free) in homotopy type theory using the presentation of groups as pointed connected 1-truncated types.
Andrew W Swan
doaj   +1 more source

New Zémor-Tillich Type Hash Functions Over GL2 (𝔽pn)

Journal of Mathematical Cryptology, 2020
We present a large class of new Zémor-Tillich type hash functions whose target space is the finite group GL2(𝔽pn) for any prime p and power n. To do so, we use a novel group-theoretic approach that uses Tits’ “Ping-Pong Lemma” to outline conditions under
Tomkins Hayley, Nevins Monica, Salmasian Hadi   +2 more
doaj   +1 more source

Centralizers of automorphisms permuting free generators

Open Mathematics, 2019
By σ ∈ Skm we denote a permutation of the cycle-type km and also the induced automorphism permuting subscripts of free generators in the free group Fkm.
Macedońska Olga, Tomaszewski Witold
doaj   +1 more source

FREE GROUPS AND AUTOMORPHISM GROUPS OF INFINITE STRUCTURES

Forum of Mathematics, Sigma, 2014
Given a cardinal $\lambda $ with $\lambda =\lambda ^{\aleph _0}$
PHILIPP LÜCKE, SAHARON SHELAH
doaj   +1 more source

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

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

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

The monomorphism problem in free groups

, 2020
Let F be a free group of finite rank. We say that the monomorphism problem in F is decidable if there is an algorithm such that, for any two elements u and v in F , it determines whether there exists a monomorphism of F that sends u to v.
L Ciobanu, A Ould Houcine
core  

Genetic snapshots of the Rhizobium species NGR234 genome. [PDF]

Genome Biol, 2000
Viprey V, Rosenthal A, Broughton WJ, Perret X.   +3 more
europepmc   +1 more source