Results 41 to 50 of about 2,064,253 (190)
On the sum of signless Laplacian spectra of graphs
Karpatsʹkì Matematičnì Publìkacìï, 2019 For a simple graph $G(V,E)$ with $n$ vertices, $m$ edges, vertex set $V(G)=\{v_1, v_2, \dots, v_n\}$ and edge set $E(G)=\{e_1, e_2,\dots, e_m\}$, the adjacency matrix $A=(a_{ij})$ of $G$ is a $(0, 1)$-square matrix of order $n$ whose $(i,j)$-entry is ...
S. Pirzada, H.A. Ganie, A.M. Alghamdi
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On the cozero-divisor graphs associated to rings
AKCE International Journal of Graphs and Combinatorics, 2022 Let R be a ring with unity. The cozero-divisor graph of a ring R, denoted by [Formula: see text] is an undirected simple graph whose vertices are the set of all non-zero and non-unit elements of R, and two distinct vertices x and y are adjacent if and ...
Praveen Mathil +2 more
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On the Laplacian and signless Laplacian spectrum of a graph with k pairwise co-neighbor vertices
, 2012 Consider the Laplacian and signless Laplacian spectrum of a graph G of order n, with k pairwise co-neighbor vertices. We prove that the number of shared neighbors is a Laplacian and a signless Laplacian eigenvalue of G with multiplicity at least k− 1.
Martins, Enide A. +6 more
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New constructions of nonregular cospectral graphs
Special MatricesWe consider two types of joins of graphs G1{G}_{1} and G2{G}_{2}, G1⊻G2{G}_{1}\hspace{0.33em}⊻\hspace{0.33em}{G}_{2} – the neighbors splitting join and G1∨=G2{G}_{1}\mathop{\vee }\limits_{=}{G}_{2} – the nonneighbors splitting join, and compute ...
Hamud Suleiman, Berman Abraham
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Locating Eigenvalues of a Symmetric Matrix whose Graph is Unicyclic
Trends in Computational and Applied Mathematics, 2021 We present a linear-time algorithm that computes in a given real interval the number of eigenvalues of any symmetric matrix whose underlying graph is unicyclic.
R. O. Braga +2 more
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Disjoint unions of complete graphs characterized by their Laplacian spectrum
, 2009 International audienceA disjoint union of complete graphs is in general not determined by its Laplacian spectrum. We show in this paper that if we only consider the family of graphs without isolated vertex then a disjoint union of complete graphs is ...
Boulet, Romain
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The coalescence of multi-wheel and starlike graphs is DLS [PDF]
Journal of Mahani Mathematical ResearchThe Laplacian spectrum of a graph is obtained by taking the difference of the adjacency spectrum from the diagonal matrix of degrees. If a graph has a unique Laplacian spectrum, it means that it can be identified by this spectrum, it is called $DLS ...
Mohammad Hasan Ahangarani Farahani +1 more
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Normalized Laplacian Spectrum of Some Q-Coronas of Two Regular Graphs
Discussiones Mathematicae - General Algebra and Applications, 2021 In this paper we determine the normalized Laplacian spectrum of the Q-vertex corona, Q-edge corona, Q-vertex neighborhood corona, and Q-edge neighborhood corona of a connected regular graph with an arbitrary regular graph in terms of normalized Laplacian
Das Arpita, Panigrahi Pratima
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The spectrum and the signless Laplacian spectrum of coronae
, 2012 Let G1,G2 be two simple connected graphs. Denote the corona and the edge corona of G1,G2 by G1∘G2 and G1♢G2, respectively. In this paper, we first introduce a new invariant, the M-coronal of a graph matrix M, where the matrix M is associated with a graph
Tian, Gui-Xian, Cui, Shu-Yu
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Color signless Laplacian energy of graphs
AKCE International Journal of Graphs and Combinatorics, 2017 In this paper, we introduce the new concept of color Signless Laplacian energy . It depends on the underlying graph and the colors of the vertices. Moreover, we compute color signless Laplacian spectrum and the color signless Laplacian energy of families
Pradeep G. Bhat, Sabitha D’Souza
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