English
Related papers

Related papers: New matrices for spectral hypergraph theory, II

200 papers

Let $G$ be a connected simple graph on $n$ vertices. Let $\mathcal{L}(G)$ be the normalized Laplacian matrix of $G$ and $\rho_{n-1}(G)$ be the second least eigenvalue of $\mathcal{L}(G)$. Denote by $\nu(G)$ the independence number of $G$.…

Combinatorics · Mathematics 2020-07-24 Fenglei Tian , Junqing Cai , Zuosong Liang , Xuntuan Su

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

Graph learning from data represents a canonical problem that has received substantial attention in the literature. However, insufficient work has been done in incorporating prior structural knowledge onto the learning of underlying…

Machine Learning · Statistics 2019-04-23 Sandeep Kumar , Jiaxi Ying , José Vinícius de M. Cardoso , Daniel Palomar

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

Several new spectral properties of the normalized Laplacian defined for oriented hypergraphs are shown. The eigenvalue $1$ and the case of duplicate vertices are discussed; two Courant nodal domain theorems are established; new quantities…

Combinatorics · Mathematics 2021-03-23 Raffaella Mulas , Dong Zhang

Given a digraph D, the complementarity spectrum of the digraph is defined as the set of complementarity eigenvalues of its adjacency matrix. This complementarity spectrum has been shown to be useful in several fields, particularly in…

Combinatorics · Mathematics 2023-04-06 Diego Bravo , Florencia Cubría , Marcelo Fiori , Vilmar Trevisan

In a paper by Nishikawa and Motter, a quantity called the normalized spread of the Laplacian eigenvalues is used to measure the synchronizability of certain network dynamics. Through simulations, and without theoretical validation, it is…

Optimization and Control · Mathematics 2026-01-09 Susie Lu , John Urschel , Ji Liu

This note introduces a result on the location of eigenvalues, i.e., the spectrum, of the Laplacian for a family of undirected graphs with self-loops. We extend on the known results for the spectrum of undirected graphs without self-loops or…

Optimization and Control · Mathematics 2015-06-09 Behcet Acikmese

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

Laplacian Eigenvectors of the graph constructed from a data set are used in many spectral manifold learning algorithms such as diffusion maps and spectral clustering. Given a graph constructed from a random sample of a $d$-dimensional…

Machine Learning · Statistics 2015-10-29 Xu Wang

We introduce the concept of a $k$-token signed graph and study some of its combinatorial and algebraic properties. We prove that two switching isomorphic signed graphs have switching isomorphic token graphs. Moreover, we show that the…

Combinatorics · Mathematics 2024-03-06 C. Dalfó , M. A. Fiol , E. Steffen

In this paper, the Laplacian characteristic polynomial of uniform hypergraphs with cut vertices or pendant edges and the Laplacian matching polynomial of uniform hypergraphs are characterized.The multiplicity of the zero Laplacian…

Combinatorics · Mathematics 2023-10-03 Ge Lin , Changjiang Bu

Let G be a graph on n vertices. The Laplacian matrix of G, denoted by L(G), is defined as L(G) = D(G) - A(G), where A(G) is the adjacency matrix of G and D(G) is the diagonal matrix of the vertex degrees of G. A graph G is said to be…

Combinatorics · Mathematics 2020-09-28 Anderson Fernandes Novanta , Carla S. Oliveira , Leonardo S. de Lima

In this paper we generalise the results on eigenvalues and eigenvectors of unnormalized (combinatorial) Laplacian of two-dimensional grid presented by Edwards:2013 first to a grid graph of any dimension, and second also to other types of…

Classical Analysis and ODEs · Mathematics 2019-09-02 Mieczysław A. Kłopotek

We consider the problem of finding universal bounds of "isoperimetric" or "isodiametric" type on the spectral gap of the Laplacian on a metric graph with natural boundary conditions at the vertices, in terms of various analytical and…

Spectral Theory · Mathematics 2016-08-24 James B. Kennedy , Pavel Kurasov , Gabriela Malenova , Delio Mugnolo

A hypergraph is linear if each pair of distinct vertices appears in at most one common edge. We say $\varGamma=(V,E)$ is an associated graph of a linear hypergraph $\mathcal{H}=(V, X)$ if for any $x\in X$, the induced subgraph…

Combinatorics · Mathematics 2025-03-25 Kai Yuan , Qi Wang , Rongquan Feng , Yan Wang

Graph matrices are a type of matrix which has played a crucial role in analyzing the sum of squares hierarchy on average case problems. However, except for rough norm bounds, little is known about graph matrices. In this paper, we take a…

Combinatorics · Mathematics 2024-06-26 Wenjun Cai , Aaron Potechin

One of the best known results in spectral graph theory is the following lower bound on the chromatic number due to Alan Hoffman, where mu_1 and mu_n are respectively the maximum and minimum eigenvalues of the adjacency matrix: chi >= 1 +…

Combinatorics · Mathematics 2014-10-30 Clive Elphick , Pawel Wocjan

The $d$-th order Laplacian spectral moment of a $k$-uniform hypergraph is the sum of the $d$-th powers of all eigenvalues of its Laplacian tensor. In this paper, we obtain some expressions of the Laplacian spectral moments for $k$-uniform…

Combinatorics · Mathematics 2023-10-04 Jueru Liu , Lixiang Chen , Changjiang Bu

Spectral hypergraph theory mainly concerns using hypergraph spectra to obtain structural information about the given hypergraphs. The study of cospectral hypergraphs is important since it reveals which hypergraph properties cannot be…

Combinatorics · Mathematics 2024-06-14 Aida Abiad , Antonina P. Khramova