For a nilpotent group $G$, let $\Xi(G)$ be the difference between complement of generating graph $G$ and commuting with vertices corresponding to central elements removed. That is, has vertex set $G \setminus Z(G)$, two adjacent if only they do not commute generate $G$. Additionally, $\Xi^+(G)$ subgraph induced by its non-isolated vertices. We show that an edge, then is connected diameter $2$ o...

We study the commuting graph on elements of odd prime order in finite simple groups. The results are used in a forthcoming paper describing the structure of Bruck loops and Bol loops of exponent 2.

"This paper analyses whether the basic monocentric model of urban structure and commuting explains actual commuting in Europe, i.e. The Netherlands. As in the USA much wasteful commuting is established. The basic model has a low degree of explanatory power. In order to get more in line with actual commuting, the paper elaborates two alternatives to the basic model. Besides a deconcentrated mode...

For a finite group G, let Z(G) be the centre of G. Then non-commuting graph on denoted by ΓG, has G\Z(G) as its vertex set with two distinct vertices vp and vq joined an edge whenever vpvq ≠ vqvp. The degree sum matrix is square whose (p,q)-th entry dvp + dvq p different from q, otherwise, it zero, where dvi vi. This study presents general formula for energy, EDS (ΓG), dihedral groups order 2n,...

The commuting graph of a group G, denoted by Γ(G), is the simple undirected graph whose vertices are the non-central elements of G and two distinct vertices are adjacent if and only if they commute. Let Zm be the commutative ring of equivalence classes of integers modulo m. In this paper we investigate the connectivity and diameters of the commuting graphs of GL(n,Zm) to contribute to the conje...

We say that two graphs G and H with the same vertex set commute if their adjacency matrices commute. In this article, we show that for any natural number r, the complete multigraphK n is decomposable into commuting perfect matchings if and only if n is a 2-power. Also, it is shown that the complete graph Kn is decomposable into commuting Hamilton cycles if and only if n is a prime number. © 200...