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A connected linear algebraic group G is called a Cayley group if the Lie algebra of G endowed with the adjoint G-action and the group variety of G endowed with the conjugation G-action are birationally G-isomorphic. In particular, the…

Algebraic Geometry · Mathematics 2009-07-06 Nicole Lemire , Vladimir L. Popov , Zinovy Reichstein

Let $G$ be a finite non-abelian simple group, $C$ a non-identity conjugacy class of $G$, and $\Gamma_C$ the Cayley graph of $G$ based on $C \cup C^{-1}$. Our main result shows that in any such graph, there is an involution at bounded…

Group Theory · Mathematics 2024-10-04 Daniele Dona , Martin W. Liebeck , Kamilla Rekvényi

A finite group $G$ is called Cayley integral if all undirected Cayley graphs over $G$ are integral, i.e., all eigenvalues of the graphs are integers. The Cayley integral groups have been determined by Kloster and Sander in the abelian case,…

Group Theory · Mathematics 2016-08-11 István Estélyi , István Kovács

A Cayley graph $\Cay(G,S)$ is said to be inner-automorphic if $S$ is a union of conjugacy classes of a group $G$, and arc-transitive if its full automorphism group acts transitively on the set of arcs. In this paper, we characterize four…

Group Theory · Mathematics 2026-04-07 Jun-Jie Huang , Jin-Hua Xie

We show that every finitely generated group G with an element of order at least $(5rank(G))^{12}$ admits a locally finite directed Cayley graph with automorphism group equal to G. If moreover G is not generalized dihedral, then the above…

Combinatorics · Mathematics 2025-04-02 Paul-Henry Leemann , Mikael de la Salle

A graph $\G$ with a group $H$ of automorphisms acting semiregularly on the vertices with two orbits is called a {\em bi-Cayley graph} over $H$. When $H$ is a normal subgroup of $\Aut(\G)$, we say that $\G$ is {\em normal} with respect to…

Combinatorics · Mathematics 2016-07-15 Jin-Xin Zhou

For a graph $\Gamma=(V(\Gamma),E(\Gamma))$, a subset $C$ of $V(\Gamma)$ is called an $(\alpha,\beta)$-regular set in $\Gamma$, if every vertex of $C$ is adjacent to exactly $\alpha$ vertices of $C$ and every vertex of $V(\Gamma)\setminus C$…

Combinatorics · Mathematics 2025-10-02 Meiqi Peng , Yuefeng Yang

In this paper, we investigate structural properties of the Cayley graph of a quandle and describe this graph for several important classes of quandles, including conjugation, Takasaki, dihedral, and Alexander quandles. In particular, we…

Geometric Topology · Mathematics 2026-04-21 David Dolžan , Bogdana Oliynyk

In 1988, Duval introduced the concept of directed strongly regular graphs, which can be viewed as a directed graph version of strongly regular graphs. Such directed graphs have similar structural and algebraic properties to strongly regular…

Combinatorics · Mathematics 2022-11-02 Xueyi Huang , Lu Lu , Jongyook Park

A graph is called a GRR if its automorphism group acts regularly on its vertex-set. Such a graph is necessarily a Cayley graph. Godsil has shown that there are only two infinite families of finite groups that do not admit GRRs : abelian…

Combinatorics · Mathematics 2013-10-03 Joy Morris , Pablo Spiga , Gabriel Verret

Let $G$ be a finite group, and $S$ be a subset of $G\setminus\{1\}$ such that $S=S^{-1}$. Suppose that $Cay(G,S)$ is the Cayley graph on $G$ with respect to the set $S$ which is the graph whose vertex set is $G$ and two vertices $a,b\in G$…

Combinatorics · Mathematics 2015-05-05 Alireza Abdollahi , Shahrooz Janbaz , Mojtaba Jazaeri

A connected, locally finite graph $\Gamma$ is a Cayley--Abels graph for a totally disconnected, locally compact group $G$ if $G$ acts vertex-transitively with compact, open vertex stabilizers on $\Gamma$. Define the minimal degree of $G$ as…

Group Theory · Mathematics 2021-05-27 Arnbjörg Soffía Árnadóttir , Waltraud Lederle , Rögnvaldur G. Möller

A digraph is called an $n$-Cayley digraph if its automorphism group has an $n$-orbit semiregular subgroup. We determine the splitting fields of $n$-Cayley digraphs over abelian groups and compute a bound on their algebraic degrees, before…

Combinatorics · Mathematics 2024-01-17 Hao Li , Xiaogang Liu

Let $A$ be an abelian group and let $\iota$ be the automorphism of $A$ defined by $i:a\mapsto a^{-1}$. A Cayley graph $\Gamma=\mathrm{Cay}(A,S)$ is said to have an automorphism group \emph{as small as possible} if $\mathrm{Aut}(\Gamma)=…

Combinatorics · Mathematics 2014-05-09 Edward Dobson , Pablo Spiga , Gabriel Verret

We study bipartite distance-regular Cayley graphs with diameter three or four. We give sufficient conditions under which a bipartite Cayley graph can be constructed on the semidirect product of a group -- the part of this bipartite Cayley…

Combinatorics · Mathematics 2022-03-30 Edwin R. van Dam , Mojtaba Jazaeri

Recently, several works by a number of authors have provided characterizations of integral undirected Cayley graphs over generalized dihedral groups and generalized dicyclic groups. We generalize and unify these results in two different…

Combinatorics · Mathematics 2023-06-26 Angelot Behajaina , François Legrand

A finite group $G$ is a "non-DCI group" if there exist subsets $S_1$ and $S_2$ of $G$, such that the associated Cayley digraphs $C\overrightarrow{ay}(G;S_1)$ and $C\overrightarrow{ay}(G;S_2)$ are isomorphic, but no automorphism of $G$…

Combinatorics · Mathematics 2023-03-08 Dave Witte Morris , Joy Morris

We introduce a family of graphs that generalises the class of Cayley graphs. For non-empty subsets L, R of a group G, the two-sided Cayley graph 2SC(G;L,R) is the directed graph with vertex set G and an arc from x to y if and only if…

Combinatorics · Mathematics 2014-01-14 Moharram N. Iradmusa , Cheryl E. Praeger

Let $G$ be a finite abelian group of order $n$. For any subset $B$ of $G$ with $B=-B$, the Cayley graph $G_B$ is a graph on vertex set $G$ in which $ij$ is an edge if and only if $i-j\in B.$ It was shown by Ben Green that when $G$ is a…

Number Theory · Mathematics 2009-05-20 Gyan Prakash

If $G$ is a group and $S$ a generating set, $G$ canonically embeds into the automorphism group of its Cayley graph and it is natural to try to minimize, over all generating sets, the index of this inclusion. This infimum is called the…

Group Theory · Mathematics 2024-03-21 Paul-Henry Leemann , Mikael de la Salle