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Related papers: Integer Laplacian Eigenvalues of Chordal Graphs

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The characteristic polynomials of the adjacency matrix of line graphs of caterpillars and then the characteristic polynomials of their Laplacian or signless Laplacian matrices are characterized, using recursive formulas. Furthermore, the…

Combinatorics · Mathematics 2013-06-20 D. M. Cardoso , M. A. A. de Freitas , E. A. Martins , M. Robbinao , B. San Martín

Spectral hypergraph theory has recently attracted considerable interest as it provides a natural framework for modeling higher-order relationships beyond classical graphs. In this setting, eigenvalues of adjacency, Laplacian, and…

Combinatorics · Mathematics 2026-04-28 Shashwath S Shetty , K Arathi Bhat

Algebraic connectivity is one way to quantify graph connectivity, which in turn gauges robustness as a network. In this paper, we consider the problem of maximising algebraic connectivity both local and globally over all simple, undirected,…

Combinatorics · Mathematics 2024-06-11 Karim Shahbaz , Madhu N. Belur , Ajay Ganesh

Assumed to be undirected, simple, and connected are all of the graphs in this study, and adjacency matrix $A$ serves as the associated matrix. In this paper we show that it is possible to relate a creation sequence for a type of cographs…

Combinatorics · Mathematics 2025-01-09 Santanu Mandal , Ranjit Mehatari

Determining the effect of structural perturbations on the eigenvalue spectra of networks is an important problem because the spectra characterize not only their topological structures, but also their dynamical behavior, such as…

Disordered Systems and Neural Networks · Physics 2010-05-04 Attilio Milanese , Jie Sun , Takashi Nishikawa

This paper establishes new eigenvalue bounds for combinatorial Laplacians of simplicial complexes, extending previous results for flag complexes by Lew (2024) and general complexes by Shukla and Yogeshwaran (2020). Using elementary…

Combinatorics · Mathematics 2025-10-30 Xiongfeng Zhan , Xueyi Huang , Jin-Xin Zhou

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

We give some new bounds for the clique and independence numbers of a graph in terms of its eigenvalues.

Combinatorics · Mathematics 2017-01-31 Vladimir Nikiforov

A sign is introduced in the usual Laplacian on graphs and the corresponding analogue of the isoperimetric constant for this Laplacian is presented, i.e. a geometric quantity which enables to bound from above and below the first eigenvalue.…

Differential Geometry · Mathematics 2019-10-22 Antoine Gournay

We introduce a novel representation of structured polynomial ideals, which we refer to as chordal networks. The sparsity structure of a polynomial system is often described by a graph that captures the interactions among the variables.…

Symbolic Computation · Computer Science 2017-02-15 Diego Cifuentes , Pablo A. Parrilo

We study the eigenvalues of the connection Laplacian on a graph with an orthogonal group or unitary group signature. We establish higher order Buser type inequalities, i.e., we provide upper bounds for eigenvalues in terms of Cheeger…

Spectral Theory · Mathematics 2019-04-03 Shiping Liu , Florentin Münch , Norbert Peyerimhoff

Let $G$ be a finite graph and $\kappa(G)$ the vertex connectivity of $G$. A chordal graph $G$ is called chordal$^*$ if no vertex of $G$ is adjacent to all other vertices of $G$. Using the syzygy theory in commutative algebra, it is proved…

Combinatorics · Mathematics 2025-02-12 Tài Huy Hà , Takayuki Hibi

In this work we introduce a concept of complexity for undirected graphs in terms of the spectral analysis of the Laplacian operator defined by the incidence matrix of the graph. Precisely, we compute the norm of the vector of eigenvalues of…

Information Theory · Computer Science 2022-03-23 Diego M. Mateos , Federico Morana , Hugo Aimar

Recently normalized Laplacian matrices of graphs are studied as density matrices in quantum mechanics. Separability and entanglement of density matrices are important properties as they determine the nonclassical behavior in quantum…

Quantum Physics · Physics 2017-02-28 Chai Wah Wu

A signless Laplacian eigenvalue of a graph $G$ is called a main signless Laplacian eigenvalue if it has an eigenvector the sum of whose entries is not equal to zero. In this paper, all connected bicyclic graphs with exactly two main…

Combinatorics · Mathematics 2013-10-10 He Huang , Hanyuan Deng

Graphs possess exotic features like variable size and absence of natural ordering of the nodes that make them difficult to analyze and compare. To circumvent this problem and learn on graphs, graph feature representation is required. A good…

Machine Learning · Computer Science 2019-12-03 Edouard Pineau

We consider partitions of a finite, simple, weighted graph that minimize a spectral energy functional, defined to be the maximum of the first eigenvalues on each component. These partitions are minimized with respect to a parameter that we…

Spectral Theory · Mathematics 2026-02-23 Connor Menzel

We show that the degree distributions of graphs do not suffice to characterize the synchronization of systems evolving on them. We prove that, for any given degree sequence satisfying certain conditions, there exists a connected graph…

Adaptation and Self-Organizing Systems · Physics 2007-08-30 Fatihcan M. Atay , Tuerker Biyikoglu , Juergen Jost

We study the algebraic connectivity (or second Laplacian eigenvalue) of token graphs, also called symmetric powers of graphs. The $k$-token graph $F_k(G)$ of a graph $G$ is the graph whose vertices are the $k$-subsets of vertices from $G$,…

Combinatorics · Mathematics 2022-09-05 C. Dalfó , M. A. Fiol

We present monotonicity inequalities for certain functions involving eigenvalues of $p$-Laplacians on signed graphs with respect to $p$. Inspired by such monotonicity, we propose new spectrum-based graph invariants, called (variational)…

Spectral Theory · Mathematics 2023-11-01 Chuanyuan Ge , Shiping Liu , Dong Zhang