Results 61 to 70 of about 2,420 (96)
Max k-cut and the smallest eigenvalue
, 2016 Let $G$ be a graph of order $n$ and size $m$, and let $\mathrm{mc}_{k}\left( G\right) $ be the maximum size of a $k$-cut of $G.$ It is shown that \[ \mathrm{mc}_{k}\left( G\right) \leq\frac{k-1}{k}\left( m-\frac{\mu_{\min }\left( G\right) n}{2}\right) , \
Nikiforov, V.
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On the α-Spectral Radius of Uniform Hypergraphs
Discussiones Mathematicae Graph Theory, 2020 For 0 ≤ α ---lt--- 1 and a uniform hypergraph G, the α-spectral radius of G is the largest H-eigenvalue of αD(G)+(1−α)A(G), where D(G) and A(G) are the diagonal tensor of degrees and the adjacency tensor of G, respectively. We give upper bounds for the α-
Guo Haiyan, Zhou Bo
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The distance signatures of the incidence graphs of affine resolvable designs
, 2016 In this note, we determined the distance signatures of the incidence matrices of affine resolvable designs.
Ma, Jianmin
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On the Distance Spectral Radius of Trees with Given Degree Sequence
Discussiones Mathematicae Graph Theory, 2020 We consider the problem of maximizing the distance spectral radius and a slight generalization thereof among all trees with some prescribed degree sequence.
Dadedzi Kenneth +2 more
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Linear combinations of graph eigenvalues
, 2006 Let F(G) be a fixed linear combination of the k extremal eigenvalues of a graph G and of its complement. The problem of finding max{F(G):v(G)=n} generalizes a number of problems raised previously in the literature. We show that the limit max{F(G):v(G)=n}/
Nikiforov, Vladimir
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On the Displacement of Eigenvalues When Removing a Twin Vertex
Discussiones Mathematicae Graph Theory, 2020 Twin vertices of a graph have the same open neighbourhood. If they are not adjacent, then they are called duplicates and contribute the eigenvalue zero to the adjacency matrix.
Briffa Johann A., Sciriha Irene
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Closed and asymptotic formulas for energy of some circulant graphs
, 2016 We consider circulant graphs G(r,N) where the vertices are the integers modulo N and the neighbours of 0 are {-r,...,-1,1,...,r}. The energy of G(r,N) is a trigonometric sum of N*r terms. For low values of r we compute this sum explicitly.
Arango, Carlos Alberto Marín +1 more
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The Number of P-Vertices of Singular Acyclic Matrices: An Inverse Problem
Discussiones Mathematicae Graph Theory, 2020 Let A be a real symmetric matrix. If after we delete a row and a column of the same index, the nullity increases by one, we call that index a P-vertex of A.
Du Zhibin, da Fonseca Carlos M.
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The complete positivity of symmetric tridiagonal and pentadiagonal matrices
Special Matrices, 2022 We provide a decomposition that is sufficient in showing when a symmetric tridiagonal matrix AA is completely positive. Our decomposition can be applied to a wide range of matrices.
Cao Lei, McLaren Darian, Plosker Sarah
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Structures of W(2.2) Lie conformal algebra
Open Mathematics, 2016 The purpose of this paper is to study W(2, 2) Lie conformal algebra, which has a free ℂ[∂]-basis {L, M} such that [LλL]=(∂+2λ)L,[LλM]=(∂+2λ)M,[MλM]=0$\begin{equation}[{L_\lambda }L] = (\partial + 2\lambda )L,[{L_\lambda }M] = (\partial + 2\lambda )M,[{M_\
Yuan Lamei, Wu Henan
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