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Related papers: Integer Laplacian Eigenvalues of Chordal Graphs

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Characterization of k-chordal graphs based on the existence of a "simplicial path" was shown in [Chv{\'a}tal et al. Note: Dirac-type characterizations of graphs without long chordless cycles. Discrete Mathematics, 256, 445-448, 2002]. We…

Combinatorics · Mathematics 2013-01-01 R. Krithika , Rogers Mathew , N. S. Narayanaswamy , N. Sadagopan

In light of recent interest in Hadamard diagonalisable graphs (graphs whose Laplacian matrix is diagonalisable by a Hadamard matrix), we generalise this notion from real to complex Hadamard matrices. We give some basic properties and…

Combinatorics · Mathematics 2020-07-21 Ada Chan , Shaun Fallat , Steve Kirkland , Jephian C. -H. Lin , Shahla Nasserasr , Sarah Plosker

We investigate a graph-theoretic approach to the problem of distinguishing quantum product states in the fundamental quantum communication framework called local operations and classical communication (LOCC). We identify chordality as the…

Quantum Physics · Physics 2023-05-18 Comfort Mintah , David W. Kribs , Michael Nathanson , Rajesh Pereira

The eigenvalues of the Laplacian matrix for a class of directed graphs with both positive and negative weights are studied. First, a class of directed signed graphs is investigated in which one pair of nodes (either connected or not) is…

Optimization and Control · Mathematics 2017-05-15 Saeed Ahmadizadeh , Iman Shames , Samuel Martin , Dragan Nesic

It is known that non-isomorphic strongly regular graphs with the same parameters must be cospectral (have the same eigenvalues). In this paper, we investigate whether the spectra of higher order Laplacians associated with these graphs can…

Combinatorics · Mathematics 2025-08-11 Sebastian M. Cioabă , Krystal Guo , Chunxu Ji , Mutasim Mim

We consider the class of simple graphs with large algebraic connectivity (the second-smallest eigenvalue of the Laplacian matrix). For this class of graphs we determine the asymptotic behavior of the number of Eulerian orientations. In…

Combinatorics · Mathematics 2013-06-10 Mikhail Isaev

A basic fact in spectral graph theory is that the number of connected components in an undirected graph is equal to the multiplicity of the eigenvalue zero in the Laplacian matrix of the graph. In particular, the graph is disconnected if…

Metric Geometry · Mathematics 2014-11-24 James R. Lee , Shayan Oveis Gharan , Luca Trevisan

We provide explicit upper bounds for the eigenvalues of the Laplacian on a finite metric tree subject to standard vertex conditions. The results include estimates depending on the average length of the edges or the diameter. In particular,…

Spectral Theory · Mathematics 2016-07-28 Jonathan Rohleder

With the development of quantum algorithms, high-cost computations are being scrutinized in the hope of a quantum advantage. While graphs offer a convenient framework for multiple real-world problems, their analytics still comes with high…

Quantum Physics · Physics 2020-11-11 Slimane Thabet , Jean-Francois Hullo

An oriented hypergraph is a hypergraph where each vertex-edge incidence is given a label of $+1$ or $-1$. The adjacency and Laplacian eigenvalues of an oriented hypergraph are studied. Eigenvalue bounds for both the adjacency and Laplacian…

Combinatorics · Mathematics 2015-06-18 Nathan Reff

In this article, we introduce a geometric and a spectral preorder relation on the class of weighted graphs with a magnetic potential. The first preorder is expressed through the existence of a graph homomorphism respecting the magnetic…

Combinatorics · Mathematics 2022-07-11 John Stewart Fabila-Carrasco , Fernando Lledó , Olaf Post

Laplacian eigenvectors capture natural community structures on graphs and are widely used in spectral clustering and manifold learning. The use of Laplacian eigenvectors as embeddings for the purpose of multiscale graph comparison has…

Machine Learning · Statistics 2023-02-07 Edric Tam , David Dunson

Hypergraphs are a generalization of graphs in which edges can connect any number of vertices. They allow the modeling of complex networks with higher-order interactions, and their spectral theory studies the qualitative properties that can…

Combinatorics · Mathematics 2021-12-01 Raffaella Mulas

In this paper, we investigate the eigenvalues of the Laplacian matrix of the "graph of graphs", in which cubic graphs of order n are joined together using Whitehead moves. Our work follows recent results from arXiv:2303.13923 , which…

Combinatorics · Mathematics 2024-05-24 Michael Li

We provide upper and lower bounds on the smallest eigenvalue of grounded Laplacian matrices (which are matrices obtained by removing certain rows and columns of the Laplacian matrix of a given graph). The gap between the upper and lower…

Combinatorics · Mathematics 2014-07-08 Mohammad Pirani , Shreyas Sundaram

We prove interlacing inequalities between spectral minimal energies of metric graphs built on Dirichlet and standard Laplacian eigenvalues, as recently introduced in [Kennedy et al, arXiv:2005.01126]. These inequalities, which involve the…

Spectral Theory · Mathematics 2021-07-28 Matthias Hofmann , James B. Kennedy

We study spectral properties of the standard (also called Kirchhoff) Laplacian and the anti-standard (or anti-Kirchhoff) Laplacian on a finite, compact metric graph. We show that the positive eigenvalues of these two operators coincide…

Spectral Theory · Mathematics 2019-09-18 Pavel Kurasov , Jonathan Rohleder

A graph $G$ is said to be chordal if it has no induced cycles of length four or more. In a recent preprint Culbertson, Guralnik, and Stiller give a new characterization of chordal graphs in terms of sequences of what they call…

Combinatorics · Mathematics 2021-02-25 Anton Dochtermann

Effective resistance (ER) is an attractive way to interrogate the structure of graphs. It is an alternative to computing the eigen-vectors of the graph Laplacian. Graph laplacians are used to find low dimensional structures in high…

Machine Learning · Computer Science 2023-06-30 Robi Bhattacharjee , Alex Cloninger , Yoav Freund , Andreas Oslandsbotn

Recently, Braunstein et al. [1] introduced normalized Laplacian matrices of graphs as density matrices in quantum mechanics and studied the relationships between quantum physical properties and graph theoretical properties of the underlying…

Quantum Physics · Physics 2011-11-15 Chai Wah Wu