Results 1 to 10 of about 775 (197)

Ree groups as automorphism groups of block designs

Examples and Counterexamples
A recent classification of flag-transitive 2-designs with parameters (v,k,λ) whose replication number r is coprime to λ gives rise to eight possible infinite families of 2-designs, some of which are with new parameters.
Ashraf Daneshkhah
doaj   +1 more source

Automorphism group of certain power graphs of finite groups

Electronic Journal of Graph Theory and Applications, 2017
The power graph $\mathcal{P}(G)$ of a group $G$ is the graphwith group elements as vertex set and two elements areadjacent if one is a power of the other. The aim of this paper is to compute the automorphism group of the power graph of several well-known
Ali Reza Ashrafi, Ahmad Gholami, Zeinab Mehranian   +2 more
doaj   +1 more source

A Group of Automorphisms of the Homotopy Groups [PDF]

Nagoya Mathematical Journal, 1951
It is well known that the fundamental group π1(X) of an arcwise connected topological space X operates on the n-th homotopy group πn(X) of X as a group of automorphisms. In this paper I intend to construct geometrically a group 𝒰(X) of automorphisms of πn(X), for every integer n ≥ 1, which includes a normal subgroup isomorphic to π1(X) so that the ...
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Automorphisms of groups

Journal of Algebra, 2007
Let \({\mathcal E}\colon N\rightarrowtail G\twoheadrightarrow Q\) be a group extension with coupling \(\chi\colon Q\to\text{Out\,}N\). If \(\Aut\,{\mathcal E}=\{\gamma\in\Aut\,G\mid N^\gamma=N\}\), \(\text{Comp}(\chi)\) the group of all compatible pairs for \(\chi\) and \(A\) the center of \(N\) regarded as a \(Q\)-module via \(\chi\) then it is known [
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Computing automorphism groups of shifts using atypical equivalence classes

Discrete Analysis, 2016
Computing automorphism groups of shifts, using atypical equivalence classes, Discrete Analysis 2016:3, 24 pp. Symbolic dynamics is about dynamical systems of the following type.
Ethan Coven, Anthony Quas, Reem Yassawi
doaj   +1 more source

Compact Manifolds With Unbounded Nilpotent Fundamental Groups and Positive Ricci Curvature

Communications on Pure and Applied Mathematics, EarlyView.
ABSTRACT It follows from the work of Kapovitch and Wilking that a closed manifold with nonnegative Ricci curvature has a uniformly almost nilpotent fundamental group. Leftover questions and conjectures, have asked if in this context the fundamental group is actually uniformly almost abelian. The main goal of this work is to construct examples (Mk9,gk)$(
Elia Bruè, Aaron Naber, Daniele Semola
wiley   +1 more source

On Groups in Which Many Automorphisms Are Cyclic

Mathematics, 2022
Let G be a group. An automorphism α of G is said to be a cyclic automorphism if the subgroup ⟨x,xα⟩ is cyclic for every element x of G. In [F. de Giovanni, M.L. Newell, A. Russo: On a class of normal endomorphisms of groups, J.
Mattia Brescia, Alessio Russo
doaj   +1 more source

A Coarse Geometric Approach to Graph Layout Problems

Journal of Graph Theory, EarlyView.
ABSTRACT We define a range of new coarse geometric invariants based on various graph–theoretic measures of complexity for finite graphs, including treewidth, pathwidth, cutwidth and bandwidth. We prove that, for bounded degree graphs, these invariants can be used to define functions which satisfy a strong monotonicity property, namely, they are ...
Wanying Huang, David Hume, Samuel J. Kelly, Ryan Lam   +3 more
wiley   +1 more source

Group extensions and automorphism group rings [PDF]

Homology, Homotopy and Applications, 2003
The group ring of the automorphism group of a p-group is studied using the automorphism groups of subgroups and quotient groups of P.
Martino, John, Priddy, Stewart
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Unitary $L^{p+}$-representations of almost automorphism groups

Comptes Rendus. Mathématique
Let $G$ be a locally compact group with an open subgroup $H$ with the Kunze–Stein property, and let $\pi $ be a unitary representation of $H$. We show that the representation $\widetilde{\pi }$ of $G$ induced from $\pi $ is an $L^{p+}$-representation if ...
Dabeler, Antje, Mai Elkiær, Emilie, Gerasimova, Maria, de Laat, Tim   +3 more
doaj   +1 more source