Results 81 to 90 of about 1,618,968 (159)
Signless Laplacian spectral radius of graphs without short cycles or long cycles [PDF]
, 2022 The signless Laplacian spectral radius of a graph $G$, denoted by $q(G)$, is the largest eigenvalue of its signless Laplacian matrix. In this paper, we investigate extremal signless Laplacian spectral radius for graphs without short cycles or long cycles.
Wang, Bing +5 more
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Mathematische Nachrichten, Volume 297, Issue 5, Page 1749-1771, May 2024.Abstract Landscape functions are a popular tool used to provide upper bounds for eigenvectors of Schrödinger operators on domains. We review some known results obtained in the last 10 years, unify several approaches used to achieve such bounds, and extend their scope to a large class of linear and nonlinear operators. We also use landscape functions to
Delio Mugnolo
wiley +1 more source
Distance Spectra of Some Double Join Operations of Graphs
International Journal of Mathematics and Mathematical Sciences, Volume 2024, Issue 1, 2024.In literature, several types of join operations of two graphs based on subdivision graph, Q‐graph, R‐graph, and total graph have been introduced, and their spectral properties have been studied. In this paper, we introduce a new double join operation based on (H1, H2)‐merged subdivision graph.
B. J. Manjunatha +4 more
wiley +1 more source
An interlacing property of the signless Laplacian of threshold graphs [PDF]
, 2023 We show that for threshold graphs, the eigenvalues of the signless Laplacian matrix interlace with the degrees of the vertices. As an application, we show that the signless Brouwer conjecture holds for threshold graphs, i.e., for threshold graphs the sum
Torres, Guilherme +3 more
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Universal Adjacency Matrices with Two Eigenvalues [PDF]
AMS Mathematics Subject Classification: 05C50.Adjacency matrix;Universal adjacency matrix;Laplacian matrix;signless Laplacian;Graph spectra;Eigenvalues;Strongly regular ...
Omidi, G.R., Haemers, W.H.
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Maxima of the signless Laplacian spectral radius for planar graphs [PDF]
, 2015 The signless Laplacian spectral radius of a graph is the largest eigenvalue of its signless Laplacian. In this paper, we prove that the graph $K_{2}\nabla P_{n-2}$ has the maximal signless Laplacian spectral radius among all planar graphs of order $n\geq
Yu, Guanglong +2 more
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The second least eigenvalue of the signless Laplacian of the complements of trees
Electronic Journal of Graph Theory and Applications, 2019 Suppose that Tnc is a set, such that the elements of Tnc are the complements of trees of order n. In 2012, Li and Wang gave the unique graph in the set Tnc ∖ {K1, n − 1c} with minimum 1st ‘least eigenvalue of the signless Laplacian’ (abbreviated to a ...
Muhammad Ajmal +2 more
doaj +1 more source
Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, 2018 Let G be a simple graph. In this paper, we disprove two conjectures proposed by P. Hansen and C. Lucas in the paper Bounds and conjectures for the signless Laplacian index of graphs. We find an infinite class of graphs as a counterexample for two conjectures relating the spectral radius of the signless Laplacian and the independence number of G.
Jorge Alencar, Leonardo Lima
openaire +2 more sources
The signless Laplacian spectral radii of modified graphs [PDF]
, 2013 In this paper, various modications of a connected graph G are regarded as perturbations of its signless Laplacian matrix. Several results concerning the resulting changes to the signless Laplacian spectral radius of G are obtained by solving ...
Li, Jianxi, Guo, Ji-Ming
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On the Laplacian and signless Laplacian spectra of complete multipartite graphs [PDF]
, 2017 Let G be a finite simple graph with vertex set V(G) = {v1, v2, v3, …, vn} and edge set E(G). The adjacency matrix of G is an (nn)-matrix A(G) = [aij] where aij = 1 if vivj E(G) and aij = 0 elsewhere, and the degree matrix of G is a diagonal (nn)-matrix ...
Ikawati, Deasy Sandhya Elya +2 more
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