Results 61 to 70 of about 2,494 (128)
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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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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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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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
semanticscholar +1 more source
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 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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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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Spectral Radius and Hamiltonicity of Graphs
Discussiones Mathematicae Graph Theory, 2019 In this paper, we study the Hamiltonicity of graphs with large minimum degree. Firstly, we present some conditions for a simple graph to be Hamilton-connected and traceable from every vertex in terms of the spectral radius of the graph or its complement,
Yu Guidong +3 more
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Bounds on F-index of tricyclic graphs with fixed pendant vertices
Open Mathematics, 2020 The F-index F(G) of a graph G is obtained by the sum of cubes of the degrees of all the vertices in G. It is defined in the same paper of 1972 where the first and second Zagreb indices are introduced to study the structure-dependency of total π-electron ...
Akram Sana +2 more
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The Laplacian Eigenvalues and Invariants of Graphs
, 2014 In this paper, we investigate some relations between the invariants (including vertex and edge connectivity and forwarding indices) of a graph and its Laplacian eigenvalues.
Pan, Rong-Ying +2 more
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