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Related papers: Constructing cospectral hypergraphs

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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

Graphs can be associated with a matrix according to some rule and we can find the spectrum of a graph with respect to that matrix. Two graphs are cospectral if they have the same spectrum. Constructions of cospectral graphs help us…

Combinatorics · Mathematics 2020-06-02 Kate Lorenzen

Hypergraphs require higher-dimensional representations, which makes it more difficult to compute and interpret their spectral properties. This survey article uses the framework of hypermatrices to give an in-depth overview of the spectral…

History and Overview · Mathematics 2025-07-21 Shashwath S Shetty , K Arathi Bhat

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

Here, we show a method to reconstruct connectivity hypermatrices of a general hypergraph (without any self loop or multiple edge) using tensor. We also study the different spectral properties of these hypermatrices and find that these…

Spectral Theory · Mathematics 2017-01-24 Anirban Banerjee , Arnab Char , Bibhash Mondal

Two $k$-uniform hypergraphs are said to be cospectral (E-cospectral), if their adjacency tensors have the same characteristic polynomial (E-characteristic polynomial). A $k$-uniform hypergraph $H$ is said to be determined by its spectrum,…

Combinatorics · Mathematics 2014-06-05 Changjiang Bu , Jiang Zhou , Yimin Wei

Here, we suggest a method to represent general directed uniform and non-uniform hypergraphs by different connectivity tensors. We show many results on spectral properties of undirected hypergraphs also hold for general directed uniform…

Spectral Theory · Mathematics 2018-08-16 Anirban Banerjee , Arnab Char

We present a spectral theory of hypergraphs that closely parallels Spectral Graph Theory. A number of recent developments building upon classical work has led to a rich understanding of "hyperdeterminants" of hypermatrices, a.k.a.…

Combinatorics · Mathematics 2011-10-27 Joshua Cooper , Aaron Dutle

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

A constructive method is given for obtaining cospectral vertices in undirected graphs, along with an operation that preserves this construction. We prove that the construction yields cospectral vertices, as well as strongly cospectral…

Combinatorics · Mathematics 2026-01-07 Onur Ege Erden , Fatihcan M. Atay

Two graphs $G$ and $H$ are \emph{cospectral} if the adjacency matrices share the same spectrum. Constructing cospectral non-isomorphic graphs has been studied extensively for many years and various constructions are known in the literature,…

Combinatorics · Mathematics 2024-09-17 Lihuan Mao , Fu Yan

In this paper, we introduce three operations on hypergraphs by using tensors. We show that these three formulations are equivalent and we commonly call them as the tensor join. We show that any hypergraph can be viewed as a tensor join of…

Combinatorics · Mathematics 2023-06-01 R. Vishnupriya , R. Rajkumar

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

In this paper, we investigate spectral properties of the adjacency tensor, Laplacian tensor and signless Laplacian tensor of general hypergraphs (including uniform and non-uniform hypergraphs). We obtain some bounds for the spectral radius…

Combinatorics · Mathematics 2016-05-20 Changjiang Bu , Jiang Zhou , Lizhu Sun

We give some graph theoretical formulas for the trace $Tr_k(\mathbb {T})$ of a tensor $\mathbb {T}$ which do not involve the differential operators and auxiliary matrix. As applications of these trace formulas in the study of the spectra of…

Spectral Theory · Mathematics 2013-07-23 Jia-Yu Shao , Liqun Qi , Shenglong Hu

In 2010, Butler introduced the unfolding operation on a bipartite graph to produce two bipartite graphs, which are cospectral for the adjacency and the normalized Laplacian matrices. In this article, we describe how the idea of unfolding a…

Combinatorics · Mathematics 2024-11-22 M. Rajesh Kannan , Shivaramakrishna Pragada , Hitesh Wankhede

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

Spectral graph theory is a captivating area of graph theory that employs the eigenvalues and eigenvectors of matrices associated with graphs to study them. In this paper, we present a collection of $20$ topics in spectral graph theory,…

Combinatorics · Mathematics 2025-10-16 Lele Liu , Bo Ning

We study both $H$ and $E/Z$-eigenvalues of the adjacency tensor of a uniform multi-hypergraph and give conditions for which the largest positive $H$ or $Z$-eigenvalue corresponds to a strictly positive eigenvector. We also investigate when…

Spectral Theory · Mathematics 2012-09-26 Kelly J. Pearson , Tan Zhang

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
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