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Related papers: Construction of cospectral graphs

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The distance matrix of a connected graph is the symmetric matrix with columns and rows indexed by the vertices and entries that are the pairwise distances between the corresponding vertices. We give a construction for graphs which differ in…

Combinatorics · Mathematics 2016-06-23 Kristin Heysse

This paper presents a multiscale graph construction method using both graph and signal features. Multiscale graph is a hierarchical representation of the graph, where a node at each level indicates a cluster in a finer resolution. To obtain…

Computer Vision and Pattern Recognition · Computer Science 2024-11-14 Reina Kaneko , Hayate Kojima , Kenta Yanagiya , Junya Hara , Hiroshi Higashi , Yuichi Tanaka

Determining whether two graphs are structurally identical is a fundamental problem with applications spanning mathematics, computer science, chemistry, and network science. Despite decades of study, graph isomorphism remains a challenging…

Computational Physics · Physics 2026-04-10 Sara Najem , Amer E. Mouawad

While spectral clustering algorithms for undirected graphs are well established and have been successfully applied to unsupervised machine learning problems ranging from image segmentation and genome sequencing to signal processing and…

Dynamical Systems · Mathematics 2022-11-23 Stefan Klus , Natasa Djurdjevac Conrad

This paper describes a new approach to the problem of the structural research of clusters based on the theory of geodetic and k-geodetic graphs. We firmly believe that this same approach can be used when solving problems of correlation…

Discrete Mathematics · Computer Science 2017-07-17 Carlos E. Frasser , George N. Vostrov

The study of spectral graph determination is a fascinating area of research in spectral graph theory and algebraic combinatorics. This field focuses on examining the spectral characterization of various classes of graphs, developing methods…

Combinatorics · Mathematics 2025-04-14 Igal Sason , Noam Krupnik , Suleiman Hamud , Abraham Berman

Two emerging topics in graph theory are the study of cospectral vertices of a graph, and the study of isospectral reductions of graphs. In this paper, we prove a fundamental relationship between these two areas, which is that two vertices…

Combinatorics · Mathematics 2019-06-19 Mark Kempton , John Sinkovic , Dallas Smith , Benjamin Webb

A connected graph can be associated with two distinct evolution algebras. In the first case, the structural matrix is the adjacency matrix of the graph itself. In the second case, the structural matrix is the transition probabilities matrix…

Combinatorics · Mathematics 2024-05-22 Paula Cadavid , Mary Luz Rodiño Montoya , Pablo M. Rodriguez , Sebastian J. Vidal

A set of graphs are called cospectral if their adjacency matrices have the same characteristic polynomial. In this paper we introduce a simple method for constructing infinite families of cospectral regular graphs. The construction is valid…

Combinatorics · Mathematics 2021-10-12 Michael Haythorpe , Alex Newcombe

We solve the subgraph isomorphism problem in planar graphs in linear time, for any pattern of constant size. Our results are based on a technique of partitioning the planar graph into pieces of small tree-width, and applying dynamic…

Data Structures and Algorithms · Computer Science 2007-05-23 David Eppstein

Statistical models on infinite graphs may exhibit inhomogeneous thermodynamic behaviour at macroscopic scales. This phenomenon is of geometrical origin and may be properly described in terms of spectral partitions into subgraphs with well…

Statistical Mechanics · Physics 2015-06-24 R. Burioni , D. Cassi , C. Destri

In [Steve Butler. A note about cospectral graphs for the adjacency and normalized Laplacian matrices. Linear Multilinear Algebra, 58(3-4):387-390, 2010.], Butler constructed a family of bipartite graphs, which are cospectral for both the…

Combinatorics · Mathematics 2020-02-04 M. Rajesh Kannan , Shivaramakrishna Pragada

The spectrum of the normalized Laplacian matrix cannot determine the number of edges in a graph, however finding constructions of cospectral graphs with differing number of edges has been elusive. In this paper we use basic properties of…

Combinatorics · Mathematics 2014-10-27 Steve Butler

In the branch of mathematics known as graph theory, graphs are considered as a set of points, called vertices, with connections between these points, called edges. The purpose of this paper is to study mappings between two graphs that have…

Combinatorics · Mathematics 2019-03-19 Jeffrey Beyerl , Cameron Sharpe

Spectral hypergraph theory studies the structural properties of a hypergraph that can be inferred from the eigenvalues and the eigenvectors of either matrices or tensors associated with it. In this paper we study the spectral…

Combinatorics · Mathematics 2026-04-08 Aida Abiad , Joshua Cooper , Utku Okur

This paper presents a new graph isomorphism invariant, called $\mathfrak{w}$-labeling, that can be used to design a polynomial-time algorithm for solving the graph isomorphism problem for various graph classes. For example, all…

Data Structures and Algorithms · Computer Science 2023-01-24 Alpár Jüttner , Péter Madarasi

In a recent series of papers, Hosoya drew the attention to a particular aspect of constructing cospectral graphs by using coalescences: that cospectral graphs can be constructed by attaching multiple copies of a rooted graph in different…

Combinatorics · Mathematics 2021-09-21 Salem Al-Yakoob , Ali Kanso , Dragan Stevanović

Graph-based subspace clustering methods have exhibited promising performance. However, they still suffer some of these drawbacks: encounter the expensive time overhead, fail in exploring the explicit clusters, and cannot generalize to…

Machine Learning · Computer Science 2021-02-23 Zhao Kang , Zhiping Lin , Xiaofeng Zhu , Wenbo Xu

From any given sequence of finite or infinite graphs, a nonstandard graph is constructed. The procedure is similar to an ultrapower construction of an internal set from a sequence of subsets of the real line, but now the individual entities…

Combinatorics · Mathematics 2007-05-23 A. H. Zemanian

The monography examines the problem of constructing a group of automorphisms of a graph. A graph automorphism is a mapping of a set of vertices onto itself that preserves adjacency. The set of such automorphisms forms a vertex group of a…

History and Overview · Mathematics 2024-07-18 Sergey Kurapov , Maxim Davidovsky