English
Related papers

Related papers: Commuting involution graphs for $\tilde C_n$

200 papers

The commuting graph of a semigroup is the set of non-central elements; the edges are defined as pairs $(u,v)$ satisfying $uv=vu$. We provide an example of a field $F$ and an integer $n$ such that the commuting graph of…

Combinatorics · Mathematics 2016-03-11 Yaroslav Shitov

Given a finite group $G$ and a conjugacy class of involutions $X$ of $G$, we define the commuting involution graph $\mathcal{C}(G,X)$ to be the graph with vertex set $X$ and $x,y \in X$ adjacent if and only if $x \neq y$ and $xy =yx$. In…

Group Theory · Mathematics 2026-01-19 James Bryden , Peter Rowley

Let $G$ be a $p$-group. We begin to consider the relationship between the structure of the commuting graph and $|G:Z(G)|$. We also build a family of groups whose commuting graphs have more than one connected component whose diameter is at…

Group Theory · Mathematics 2025-11-18 Mark L. Lewis , Ryan McCulloch

We initiate a systematic investigation of endomorphisms of graph C*-algebras C*(E), extending several known results on endomorphisms of the Cuntz algebras O_n. Most but not all of this study is focused on endomorphisms which permute the…

Operator Algebras · Mathematics 2013-01-11 Roberto Conti , Jeong Hee Hong , Wojciech Szymanski

In an earlier paper, the authors considered three types of graphs, and three equivalence relations, defined on a group, viz.\ the power graph, enhanced power graph, and commuting graph, and the relations of equality, conjugacy, and same…

Group Theory · Mathematics 2024-01-19 G. Arunkumar , Peter J. Cameron , Rajat Kanti Nath

We develop a general diagrammatic theory of welded graphs, and provide an extension of Satoh's Tube map from welded graphs to ribbon surface-links. As a topological application, we obtain a complete link-homotopy classification of so-called…

Geometric Topology · Mathematics 2025-07-29 Benjamin Audoux , Jean-Baptiste Meilhan , Akira Yasuhara

The flip operation on colored inner-triangle-free triangulations of a convex polygon is studied. It is shown that the affine Weyl group $\widetilde{C}_n$ acts transitively on these triangulations by colored flips, and that the resulting…

Combinatorics · Mathematics 2009-01-28 Ron M. Adin , Marcelo Firer , Yuval Roichman

The vertices of commuting graph of $\mathbb{R}^{n\times n}$ are non-scalar matrices; the edges are defined as pairs $(u, v)$ satisfying $uv = vu$. For $n\geqslant 3$, the diameter of this graph is at least four; we give a short proof that…

Combinatorics · Mathematics 2015-01-05 Yaroslav Shitov

Ara\'ujo, Kinyon and Konieczny (2011) pose several problems concerning the construction of arbitrary commuting graphs of semigroups. We observe that every star-free graph is the commuting graph of some semigroup. Consequently, we suggest…

Combinatorics · Mathematics 2017-10-17 Tomer Bauer , Be'eri Greenfeld

The aim of this paper is to see how commuting graphs interact with two semigroup constructions: the zero-union and the direct product. For both semigroup constructions, we investigate the diameter, clique number, girth, chromatic number and…

Combinatorics · Mathematics 2025-11-06 Tânia Paulista

The diameter of a graph measures the maximal distance between any pair of vertices. The diameters of many small-world networks, as well as a variety of other random graph models, grow logarithmically in the number of nodes. In contrast, the…

Combinatorics · Mathematics 2011-04-05 Jens Marklof , Andreas Strömbergsson

The special representations of a Weyl group can be regarded as the vertices of a graph with an involution i such that any edge e has the following property: either e or i(e) joins two vertices whose a-functions differ by 1.

Representation Theory · Mathematics 2021-04-23 G. Lusztig

We present a family of finite, non-abelian groups and propose that there are members of this family whose commuting graphs are connected and of arbitrarily large diameter. If true, this would disprove a conjecture of Iranmanesh and…

Group Theory · Mathematics 2012-08-31 Peter Hegarty , Dmitry Zhelezov

In this paper we compute common neighbourhood (abbreviated as CN) spectrum and energy of commuting conjugacy class graph of several families of finite non-abelian groups. As a consequence of our results we show that the commuting conjugacy…

Group Theory · Mathematics 2022-08-23 Firdous Ee Jannat , Rajat Kanti Nath

The commuting graph of a non-abelian group is a simple graph in which the vertices are the non-central elements of the group, and two distinct vertices are adjacent if and only if they commute. In this paper, we classify (up to isomorphism)…

Group Theory · Mathematics 2013-11-26 Ashish Kumar Das , Deiborlang Nongsiang

We describe a new method for computing the graph of commutation classes of double wiring diagrams. Using these methods we compute the graph for five strings or less which allows us to confirm a positivity conjecture of Fomin and Zelevinsky…

Combinatorics · Mathematics 2010-06-08 Patrick Dukes , Joe Rusinko

The commuting graph of a finite non-commutative semigroup $S$, denoted $\cg(S)$, is a simple graph whose vertices are the non-central elements of $S$ and two distinct vertices $x,y$ are adjacent if $xy=yx$. Let $\mi(X)$ be the symmetric…

Combinatorics · Mathematics 2012-05-09 João Araújo , Wolfram Bentz , Janusz Konieczny

An element of a Coxeter group $W$ is fully commutative if any two of its reduced decompositions are related by a series of transpositions of adjacent commuting generators. In the present work, we focus on fully commutative involutions,…

Combinatorics · Mathematics 2015-05-15 Riccardo Biagioli , Frédéric Jouhet , Philippe Nadeau

For a division ring D, finite dimensional over its center F, we give a condiction for the connectedness of the commuting graph of a matrix ring over $D$. Furthermore, we prove that if the commuting graph is connected, then its diameter is…

Rings and Algebras · Mathematics 2016-10-31 C. Miguel

In this paper we completely characterize the graphs which have an edge weighted adjacency matrix belonging to the class of $n \times n$ involutions with spectrum equal to $\{ \lambda_1^{n-2}, \lambda_2^{2} \}$ for some $\lambda_1$ and some…

Combinatorics · Mathematics 2015-04-17 Karen Meagher , Irene Sciriha