English
Related papers

Related papers: Spectral Properties of Complex Unit Gain Graphs

200 papers

A complex unit gain graph (or ${\mathbb T}$-gain graph) is a triple $\Phi=(G, {\mathbb T}, \varphi)$ (or $(G, \varphi)$ for short) consisting of a simple graph $G$, as the underlying graph of $(G, \varphi)$, the set of unit complex numbers…

Combinatorics · Mathematics 2020-01-07 Shengjie He , Rong-Xia Hao , Fengming Dong

The spectral properties of signed directed graphs, which may be naturally obtained by assigning a sign to each edge of a directed graph, have received substantially less attention than those of their undirected and/or unsigned counterparts.…

Combinatorics · Mathematics 2021-10-12 Pepijn Wissing , Edwin R. van Dam

The Laplacian spread of a graph is the difference between the largest eigenvalue and the second-smallest eigenvalue of the Laplacian matrix of the graph. We find that the class of strongly regular graphs attains the maximum of largest…

Combinatorics · Mathematics 2014-11-25 Fan-Hsuan Lin , Chih-wen Weng

A signed graph has edge signs. A gain graph has oriented edge gains drawn from a group. We define the combination of the two for the abelian case, in which each oriented edge of a signed graph has a gain from an abelian group, concentrating…

Combinatorics · Mathematics 2022-06-22 Laura Anderson , Ting Su , Thomas Zaslavsky

In this article we introduce a definition of k-uniform thresholds hypergraphs through a binary sequence, a natural extension of the classical definition for thresholds graphs. We characterize some of its eigenvalues and multiplicities by…

Combinatorics · Mathematics 2026-02-26 Miriam Abdón , Lucas Portugal , Renata Del-Vecchio , Renata de Freitas

We introduce a hypergraph matrix, named the unified matrix, and use it to represent the hypergraph as a graph. We show that the unified matrix of a hypergraph is identical to the adjacency matrix of the associated graph. This enables us to…

Combinatorics · Mathematics 2024-11-12 R. Vishnupriya , R. Rajkumar

Spectral analysis of networks states that many structural properties of graphs, such as centrality of their nodes, are given in terms of their adjacency matrices. The natural extension of such spectral analysis to higher order networks is…

Spectral Theory · Mathematics 2025-03-17 Gonzalo Contreras-Aso , Cristian Pérez-Corral , Miguel Romance

A new class of isospectral graphs is presented. These graphs are isospectral with respect to both the normalised Laplacian on the discrete graph and the standard differential Laplacian on the corresponding metric graph. The new class of…

Spectral Theory · Mathematics 2023-02-20 Pavel Kurasov , Jacob Muller

In this paper we obtain several tight bounds on different types of alliance numbers of a graph: (global) defensive alliance number, global offensive alliance number and global dual alliance number. In particular, we investigate the…

Combinatorics · Mathematics 2007-05-23 J. A. Rodriguez , J. M. Sigarreta

In this paper, we investigate the spectrum of the unit-graph of the ring of $3 \times 3$ matrices over a finite field $\mathbb{F}_q$, which is equivalently the Cayley digraph $ \mathrm{Cay}\!\left((\mathrm{Mat}_3(\mathbb{F}_q),+),…

Combinatorics · Mathematics 2026-05-08 Yeşim Demiroğlu Karabulut , Heriberto Espinosa

A signed directed graph is a graph with sign and direction information on the edges. Even though signed directed graphs are more informative than unsigned or undirected graphs, they are more complicated to analyze and have received less…

Machine Learning · Computer Science 2023-02-17 Taewook Ko , Chong-Kwon Kim

The enhanced power graph of a group $G$ is a simple undirected graph with vertex set $G$ and two vertices are adjacent if they belong to same cyclic subgroup. In this paper, we study distant properties and detour distant properties such as…

Group Theory · Mathematics 2021-08-31 Parveen , Sandeep Dalal , Jitender Kumar

A signed graph is a graph whose edges are labeled either positive or negative. Corresponding to the two signed distance matrices defined for signed graphs, we define two signed distance laplacian matrices. We characterize balance in signed…

Combinatorics · Mathematics 2020-10-12 Roshni T Roy , K A Germina , K Shahul Hameed , Thomas Zaslavsky

We study the balance of $G$-gain graphs, where $G$ is an arbitrary group, by investigating their adjacency matrices and their spectra. As a first step, we characterize switching equivalence and balance of gain graphs in terms of their…

Combinatorics · Mathematics 2021-07-27 Matteo Cavaleri , Daniele D'Angeli , Alfredo Donno

The properties of a hypergraph explored through the spectrum of its unified matrix was made by the authors in [26]. In this paper, we introduce three different hypergraph matrices: unified Laplacian matrix, unified signless Laplacian…

Combinatorics · Mathematics 2024-11-14 R. Vishnupriya , R. Rajkumar

Graph neural networks have developed by leaps and bounds in recent years due to the restriction of traditional convolutional filters on non-Euclidean structured data. Spectral graph theory mainly studies fundamental graph properties using…

Spectral Theory · Mathematics 2023-09-08 Xinye Chen

For a group $G$, the generating graph $\Gamma(G)$ is defined as the graph with the vertex set $G$, and any two distinct vertices of $\Gamma(G)$ are adjacent if they generate $G$. In this paper, we study the generating graph of $D_n,$ where…

Combinatorics · Mathematics 2025-01-22 A. Satyanarayana Reddy , Kavita Samant

Let $N(X)$ be the Laplacian matrix of a directed graph obtained from the edge adjacency matrix of a graph $X.$ In this work, we study the bipartiteness property of the graph with the help of $N(X).$ We computed the spectrum of the edge…

Combinatorics · Mathematics 2023-09-28 Shivani Chauhan , A. Satyanarayana Reddy

The work in this thesis concerns the investigation of eigenvalues of the Laplacian matrix, normalized Laplacian matrix, signless Laplacian matrix and distance signless Laplacian matrix of graphs. In Chapter 1, we present a brief…

Combinatorics · Mathematics 2021-07-21 Bilal A. Rather

The graphs with all equal negative or positive eigenvalues are special kind in the spectral graph theory. In this article, several iterated line graphs $\mathcal{L}^k(G)$ with all equal negative eigenvalues $-2$ are characterized for $k\ge…

Combinatorics · Mathematics 2025-11-25 Harishchandra S. Ramane , B. Parvathalu , Daneshwari Patil , K. Ashoka