English
Related papers

Related papers: The Signless Laplacian Matrix of Hypergraphs

200 papers

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

We propose a simple and natural definition for the Laplacian and the signless Laplacian tensors of a uniform hypergraph. We study their H$^+$-eigenvalues, i.e., H-eigenvalues with nonnegative H-eigenvectors, and H$^{++}$-eigenvalues, i.e.,…

Spectral Theory · Mathematics 2013-07-09 Liqun Qi

The spectrum of Laplacian and signless Laplacian matrix for a graph product is obtained, where both underlying graphs are regular. As an application of this, we have been able to generate the Kirchhoff Index and Wiener Index and determine…

Combinatorics · Mathematics 2024-10-18 Bishal Sonar , Ravi Srivastava

Normalized Laplacian matrices of graphs have recently been studied in the context of quantum mechanics as density matrices of quantum systems. Of particular interest is the relationship between quantum physical properties of the density…

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

For a simple graph on $n$ vertices, any of its signless Laplacian eigenvalues is in the interval $[0, 2n-2]$. In this paper, we give relationships between the number of signless Laplacian eigenvalues in specific intervals in $[0, 2n-2]$ and…

Combinatorics · Mathematics 2024-06-04 Leyou Xu , Bo Zhou

In this paper, we characterize all graphs with eigenvectors of the signless Laplacian and adjacency matrices with components equal to $\{- 1, 0, 1\}.$ We extend the graph parameter max $k$-cut to square matrices and prove a general sharp…

Combinatorics · Mathematics 2022-11-29 Jorge Alencar , Leonardo de Lima , Vladimir Nikiforov

The Bridge graph is a special type of graph which are constructed by connecting identical connected graphs with path graphs. We discuss different types of bridge graphs $B_{n\times l}^{m\times k}$ in this paper. In particular, we discuss…

Combinatorics · Mathematics 2023-01-03 Yixin Li

This article deals with the spectra of Laplacians of weighted graphs. In this context, two objects are of fundamental importance for the dynamics of complex networks: the second eigenvalue of such a spectrum (called algebraic connectivity)…

Mathematical Physics · Physics 2017-04-07 Camille Poignard , Tiago Pereira , Jan Philipp Pade

The concept of the integrated adjacency matrix for mixed graphs was first introduced in [9], where its spectral properties were analyzed in relation to the structural characteristics of the mixed graph. Building upon this foundation, this…

Combinatorics · Mathematics 2025-07-08 G. Kalaivani , R. Rajkumar

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

Threshold graphs are graphs that can be characterized in a number of different ways. For example, they are graphs that are $P_4,\ C_4,\ 2K_2$--free. They may also be characterized by a finite sequence of positive integers $a_1, \ldots,…

Combinatorics · Mathematics 2026-05-07 James L. Borg , Irene Sciriha , Zoia Sherman

Determining and analyzing the spectra of graphs is an important and exciting research topic in theoretical computer science. The eigenvalues of the normalized Laplacian of a graph provide information on its structural properties and also on…

Combinatorics · Mathematics 2016-05-20 Pinchen Xie , Zhongzhi Zhang , Francesc Comellas

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

Consider a semigraph $G=(V,\,E)$; in this paper, we study the eigenvalues of the Laplacian matrix of $G$. We show that the Laplacian of $G$ is positive semi-definite, and $G$ is connected if and only if $\lambda_2 >0.$ Along the similar…

Combinatorics · Mathematics 2023-07-10 Pralhad M. Shinde

Here we study the spectral properties of an underlying weighted graph of a non-uniform hypergraph by introducing different connectivity matrices, such as adjacency, Laplacian and normalized Laplacian matrices. We show that different…

Combinatorics · Mathematics 2019-03-28 Anirban Banerjee

We obtain new bounds for the Laplacian spectral radius of a signed graph. Most of these new bounds have a dependence on edge sign, unlike previously known bounds, which only depend on the underlying structure of the graph. We then use some…

Combinatorics · Mathematics 2011-03-25 Nathan Reff

We conjecture that the sum of the square roots of the Laplacian eigenvalues of a graph does not exceed the sum of the square roots of its signless Laplacian eigenvalues.

Combinatorics · Mathematics 2009-09-07 S. Akbari , E. Ghorbani , M. R. Oboudi

Signless Laplacian Estrada index of a graph $G$, defined as $SLEE(G)=\sum^{n}_{i=1}e^{q_i}$, where $q_1, q_2, \cdots, q_n$ are the eigenvalues of the matrix $\mathbf{Q}(G)=\mathbf{D}(G)+\mathbf{A}(G)$. We determine the unique graphs with…

Combinatorics · Mathematics 2017-06-19 H. R. Ellahi , R. Nasiri , G. H. Fath-Tabar , A. Gholami

We introduce the notion of discrete cusp for a weighted graph. In this context, we provethat the form-domain of the magnetic Laplacian and that of thenon-magnetic Laplacian can be different. We establish the emptiness of the essential…

Spectral Theory · Mathematics 2017-06-12 Sylvain Golénia , Françoise Truc

We study the sets of inertias achieved by Laplacian matrices of weighted signed graphs. First we characterize signed graphs with a unique Laplacian inertia. Then we show that there is a sufficiently small perturbation of the nonzero weights…

Spectral Theory · Mathematics 2019-12-10 Keivan Hassani Monfared , Gary MacGillivray , Dale D. Olesky , Pauline van den Driessche