Results 51 to 60 of about 2,420 (96)
Degree Subtraction Adjacency Eigenvalues and Energy of Graphs Obtained From Regular Graphs
Open Journal of Discrete Applied Mathematics, 2018 Let V (G) = {v1, v2, . . . , vn} be the vertex set of G and let dG(vi) be the degree of a vertex vi in G. The degree subtraction adjacency matrix of G is a square matrix DSA(G) = [dij ], in which dij = dG(vi) − dG(vj), if vi is adjacent to vj and dij = 0,
H. Ramane, Hemaraddi N. Maraddi
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On First Hermitian-Zagreb Matrix and Hermitian-Zagreb Energy
International Journal of Scientific Research in Mathematical and Statistical Sciences, 2018 A mixed graph is a graph with edges and arcs, which can be considered as a combination of an undirected graph and a directed graph. In this paper we propose a Hermitian matrix for mixed graphs which is a modified version of the classical adjacency matrix
A. Bharali
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Graphic and Cographic Г-Extensions of Binary Matroids
Discussiones Mathematicae Graph Theory, 2018 Slater introduced the point-addition operation on graphs to characterize 4-connected graphs. The Г-extension operation on binary matroids is a generalization of the point-addition operation. In general, under the Г-extension operation the properties like
Borse Y.M., Mundhe Ganesh
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Open problems on graph eigenvalues studied with AutoGraphiX
EURO Journal on Computational Optimization, 2013 Since the late forties of the last century, methods of operations research have been extensively used to solve problems in graph theory, and graph theory has been extensively used to model operations research problems and to solve optimization problems ...
Mustapha Aouchiche +2 more
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Bounds for Laplacian-type graph energies
, 2015 Let G be an undirected simple and connected graph with n vertices .n 3/ and m edges. Denote by 1 2 n 1 > n D 0, 1 2 n , and 1 2 n 1 > n D 0 , respectively, the Laplacian, signless Laplacian, and normalized Laplacian eigenvalues of G. The Laplacian energy,
I. Gutman +2 more
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Graphs whose Laplacian eigenvalues are almost all 1 or 2
Special MatricesWe explicitly determine all connected graphs whose Laplacian matrices have at most four eigenvalues different from 1 and 2.
Mohammadian Ali, Xu Shanshan
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Cospectral Pairs of Regular Graphs with Different Connectivity
Discussiones Mathematicae Graph Theory, 2020 For vertex- and edge-connectivity we construct infinitely many pairs of regular graphs with the same spectrum, but with different connectivity.
Haemers Willem H.
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A new upper bound on the largest normalized Laplacian eigenvalue
, 2013 Let G be a simple undirected connected graph on n vertices. Suppose that the vertices of G are labelled 1,2, . . . ,n. Let di be the degree of the vertex i.
O. Rojo, R. Soto
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Graphs With All But Two Eigenvalues In [−2, 0]
Discussiones Mathematicae Graph Theory, 2020 The eigenvalues of a graph are those of its adjacency matrix. Recently, Cioabă, Haemers and Vermette characterized all graphs with all but two eigenvalues equal to −2 and 0.
Abreu Nair +4 more
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Turán’s Theorem Implies Stanley’s Bound
Discussiones Mathematicae Graph Theory, 2020 Let G be a graph with m edges and let ρ be the largest eigenvalue of its adjacency matrix.
Nikiforov V.
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