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Consider a group $\mathbb{G}$ and construct its power graph, whose vertex set consists of the elements of $\mathbb{G}$. Two distinct vertices (elements) are adjacent in the graph if and only if one element can be expressed as an integral…

Spectral Theory · Mathematics 2026-03-03 Priti Prasanna Mondal , Basit Auyoob Mir , Fouzul Atik

Current methods of graph signal processing rely heavily on the specific structure of the underlying network: the shift operator and the graph Fourier transform are both derived directly from a specific graph. In many cases, the network is…

Signal Processing · Electrical Eng. & Systems 2023-03-31 Kathryn Beck , Mahya Ghandehari , Jeannette Janssen , Nauzer Kalyaniwalla

We characterize the graphs with loops whose degree sequences have no repeated values and find their adjacency spectrum. In the case of simple graphs, such graphs are called anti-regular graphs and are examples of threshold graphs. The…

Combinatorics · Mathematics 2019-12-16 Cesar O. Aguilar

Construction of non-isomorphic cospectral graphs is a nontrivial problem in spectral graph theory specially for large graphs. In this paper, we establish that graph theoretical partial transpose of a graph is a potential tool to create…

Combinatorics · Mathematics 2018-08-13 Supriyo Dutta , Bibhas Adhikari

The purpose of this paper is to highlight the role played by the anti-regular graph within the class of threshold graphs. Using the fact that every threshold graph contains a maximal anti-regular graph, we show that some known results, and…

Combinatorics · Mathematics 2019-12-11 Cesar O. Aguilar , Matthew Ficarra , Natalie Schurman , Brittany Sullivan

In this paper, we investigate the spectral properties of Andr\'asfai graphs, focusing on key parameters: the second-largest and smallest eigenvalues, the number of distinct eigenvalues, and the multiplicities of the eigenvalues 1 and -1.…

Spectral Theory · Mathematics 2024-03-13 Bharani Dharan K , S Radha

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

We give a combinatorial characterization of graphs whose normalized Laplacian has three distinct eigenvalues. Strongly regular graphs and complete bipartite graphs are examples of such graphs, but we also construct more exotic families of…

Combinatorics · Mathematics 2012-02-15 Edwin R. van Dam , Gholamreza Omidi

We show the maximality of subfields as cliques in a special family of Cayley graphs defined on the additive group of a finite field. In particular, this confirms a conjecture of Yip on generalized Paley graphs.

Combinatorics · Mathematics 2023-08-30 Chi Hoi Yip

We investigate connections between the symmetries (automorphisms) of a graph and its spectral properties. Whenever a graph has a symmetry, i.e. a nontrivial automorphism $\phi$, it is possible to use $\phi$ to decompose any matrix…

Combinatorics · Mathematics 2016-10-07 Wayne Barrett , Amanda Francis , Ben Webb

The relative Cayley graph of a group $G$ with respect to its proper subgroup $H$, is a graph whose vertices are elements of $G$ and two vertices $h\in H$ and $g\in G$ are adjacent if $g=hc$ for some $c\in C$, where $C$ is an inversed-closed…

Combinatorics · Mathematics 2015-10-14 Mohammad Farrokhi Derakhshandeh Ghouchan , Mehdi Rajabian , Ahmad Erfanian

In this paper, we compute Laplacian energy of the non-commuting graphs of some classes of finite non-abelian groups.

Group Theory · Mathematics 2017-05-31 Parama Dutta , Rajat Kanti Nath

In this note, we provide several constructions of Deza Cayley graphs over groups having a generalized dihedral subgroup. These constructions are based on a usage of (relative) difference sets.

Combinatorics · Mathematics 2026-01-15 Grigory Ryabov

We construct a new large family of finitely generated groups with continuum many values of the following monotone parameters: spectral radius, critical percolation, and asymptotic entropy. We also present several open problems on other…

Group Theory · Mathematics 2024-05-20 Martin Kassabov , Igor Pak

A new family of strongly regular graphs, called the general symplectic graphs $Sp(2\nu, q)$, associated with nonsingular alternate matrices is introduced. Their parameters as strongly regular graphs, their chromatic numbers as well as their…

Combinatorics · Mathematics 2007-05-23 Zhongming Tang , Zhe-xian Wan

Let $G$ be a finite group and $S$ be a symmetric generating set of $G$ with $|S| = d$. We show that if the undirected Cayley sum graph $C_{\Sigma}(G,S)$ is an expander graph and is non-bipartite, then the spectrum of its normalised…

Combinatorics · Mathematics 2019-07-23 Arindam Biswas , Jyoti Prakash Saha

Normally one assumes isolated surface singularities to be normal. The purpose of this paper is to show that it can be useful to look at nonnormal singularities. By deforming them interesting normal singularities can be constructed, such as…

Algebraic Geometry · Mathematics 2015-12-14 Jan Stevens

We present the spectrum of the (normalized) graph Laplacian as a systematic tool for the investigation of networks, and we describe basic properties of eigenvalues and eigenfunctions. Processes of graph formation like motif joining or…

Adaptation and Self-Organizing Systems · Physics 2012-10-19 Anirban Banerjee , Jürgen Jost

In this paper, rough approximations of Cayley graphs are studied and rough edge Cayley graphs are introduced. Furthermore, a new algebraic definition called pseudo-Cayley graphs containing Cayley graphs is proposed. Rough approximation is…

Group Theory · Mathematics 2012-03-13 M. H. Shahzamanian , M. Shirmohammadi , B. Davvaz

We establish a necessary and sufficient condition for a normal subgroup of a finite group to be a subgroup perfect code.

Combinatorics · Mathematics 2025-05-08 Masoumeh Koohestani , Doost Ali Mojdeh , Mohsen Ghasemi , Hassan Khodaiemehr