English
Related papers

Related papers: Cayley graphs without a bounded eigenbasis

200 papers

We investigate which finite Cayley graphs admit a quantum ergodic eigenbasis, proving that this holds for any Cayley graph on a group of size $n$ for which the sum of the dimensions of its irreducible representations is $o(n)$, yet there…

Spectral Theory · Mathematics 2022-07-13 Assaf Naor , Ashwin Sah , Mehtaab Sawhney , Yufei Zhao

We prove that a random Cayley graph on a group of order $N$ has clique number $O(\log N \log \log N)$ with high probability. This bound is best possible up to the constant factor for certain groups, including~$\mathbb{F}_2^n$, and improves…

Combinatorics · Mathematics 2024-12-31 David Conlon , Jacob Fox , Huy Tuan Pham , Liana Yepremyan

A discrete analog of quantum unique ergodicity was proved for Cayley graphs of quasirandom groups by Magee, Thomas and Zhao. They show that for large graphs there exist real orthonormal basis of eigenfunctions of the adjacency matrix such…

Mathematical Physics · Physics 2024-12-24 Jon Harrison , Clare Pruss

We present a finer quantitative version of an observation due to Breuillard, Green, Guralnick and Tao which tells that for finite non-bipartite Cayley graphs, once the nontrivial eigenvalues of their normalized adjacency matrices are…

Combinatorics · Mathematics 2023-11-01 Wenbo Li , Shiping Liu

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

A number of authors have studied the question of when a graph can be represented as a Cayley graph on more than one nonisomorphic group. In this paper we give conditions for when a Cayley graph on an abelian group can be represented as a…

Combinatorics · Mathematics 2022-05-04 Joy Morris , Adrian Skelton

In this paper, generalized Cayley graphs are studied. It is proved that every generalized Cayley graph of order 2p is a Cayley graph, where p is a prime. Special attention is given to generalized Cayley graphs on Abelian groups. It is…

Combinatorics · Mathematics 2015-12-02 Ademir Hujdurović , Klavdija Kutnar , Pawel Petecki , Anastasiya Tanana

In this paper, we study self-complementary distance-regular Cayley graphs over abelian groups. We prove that if a regular graph is self-complementary distance-regular, then it is self-complementary strongly regular. We also deal with…

Combinatorics · Mathematics 2023-01-18 Mojtaba Jazaeri

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 $G$ 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

This paper represents a significant leap forward in the problem of enumerating vertex-transitive graphs. Recent breakthroughs on symmetry of Cayley (di)graphs show that almost all finite Cayley (di)graphs have the smallest possible…

Combinatorics · Mathematics 2025-11-25 Yunsong Gan , Pablo Spiga , Binzhou Xia

It is well-known that a complete Riemannian manifold M which is locally isometric to a symmetric space is covered by a symmetric space. Here we prove that a discrete version of this property (called local to global rigidity) holds for a…

Metric Geometry · Mathematics 2019-11-26 Mikael de la Salle , Romain Tessera

Let $G$ be a finite abelian group. Bridges and Mena characterized the Cayley graphs of $G$ that have only integer eigenvalues. Here we consider the $(0,1,-1)$ adjacency matrix of an oriented Cayley graph or of a signed Cayley graph $X$ on…

Combinatorics · Mathematics 2024-05-24 Chris Godsil , Xiaohong Zhang

A Cayley graph of a group $H$ is a finite simple graph $\Gamma$ such that its automorphism group ${\rm Aut}(\Gamma)$ contains a subgroup isomorphic to $H$ acting regularly on $V(\Gamma)$, while a Haar graph of $H$ is a finite simple…

Combinatorics · Mathematics 2019-08-14 Yan-Quan Feng , István Kovács , Jie Wang , Da-Wei Yang

We consider quasirandom properties for Cayley graphs of finite abelian groups. We show that having uniform edge-distribution (i.e., small discrepancy) and having large eigenvalue gap are equivalent properties for such Cayley graphs, even if…

Combinatorics · Mathematics 2016-10-21 Yoshiharu Kohayakawa , Vojtěch Rödl , Mathias Schacht

We prove hypergraph variants of the celebrated Alon-Roichman theorem on spectral expansion of sparse random Cayley graphs. One of these variants implies that for every prime $p\geq 3$ and any $\varepsilon > 0$, there exists a set of…

Combinatorics · Mathematics 2016-11-17 Jop Briët , Shravas Rao

We prove that every vertex transitive, planar, 1-ended, graph covers every graph whose balls of radius r are isomorphic to the ball of radius r in G for a sufficiently large r. We ask whether this is a general property of finitely presented…

Group Theory · Mathematics 2015-04-02 Agelos Georgakopoulos

We present two results on expansion of Cayley graphs. The first result settles a conjecture made by DeVos and Mohar. Specifically, we prove that for any positive constant $c$ there exists a finite connected subset $A$ of the Cayley graph of…

Group Theory · Mathematics 2011-12-12 Martha Giannoudovardi

A Cayley graph $\Ga=\Cay(G,S)$ is said to be normal if $G$ is normal in $\Aut\Ga$. The concept of normal Cayley graphs was first proposed by M.Y.Xu in [Discrete Math. 182, 309-319, 1998] and it plays an important role in determining the…

Combinatorics · Mathematics 2017-02-21 Bo Ling , Ben Gong Lou

An interesting fact is that most of the known connected $2$-arc-transitive nonnormal Cayley graphs of small valency on finite simple groups are $(\mathrm{A}_{n+1},2)$-arc-transitive Cayley graphs on $\mathrm{A}_n$. This motivates the study…

Combinatorics · Mathematics 2021-03-30 Jiangmin Pan , Binzhou Xia , Fugang Yin
‹ Prev 1 2 3 10 Next ›