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Discrete Mathematics, 1999 The \(\alpha\)-weight of an edge \(xy\) of a graph \(G\) is \(d(x)^\alpha\cdot d(y)^\alpha\) where \(d(x)\) and \(d(y)\) are the degrees of the vertices \(x\) and \(y\). The \(\alpha\)-weight of \(G\) is the sum of the \(\alpha\)-weights of its edges. The authors establish the \(\alpha\)-weight of a graph with any fixed number of edges for \(\alpha=1\)
Béla Bollobás +2 more
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Structures of Cycle Bases with Some Extremal Properties [PDF]
, 2014 In this paper, authors investigate the structures of cycle bases with extremal properties which are related with map geometries, i.e., Smarandache 2-dimensional manifolds.
Han, Ren, Yun Bai, Han Ren, Bai, Yun
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Triangles in Ks-saturated graphs with minimum degree t
Theory and Applications of Graphs, 2020 For $n \geq 15$, we prove that the minimum number of triangles in an $n$-vertex $K_4$-saturated graph with minimum degree 4 is exactly $2n-4$, and that there is a unique extremal graph.
Craig Timmons +3 more
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Maximum Reciprocal Degree Resistance Distance Index of Bicyclic Graphs
Discrete Dynamics in Nature and Society, 2021 The reciprocal degree resistance distance index of a connected graph G is defined as RDRG=∑u,v⊆VGdGu+dGv/rGu,v, where rGu,v is the resistance distance between vertices u and v in G. Let ℬn denote the set of bicyclic graphs without common edges and with n
Gaixiang Cai, Xing-Xing Li, Guidong Yu
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Extremal Graph Realizations and Graph Laplacian Eigenvalues
SIAM Journal on Discrete Mathematics, 2023 For a regular polyhedron (or polygon) centered at the origin, the coordinates of the vertices are eigenvectors of the graph Laplacian for the skeleton of that polyhedron (or polygon) associated with the first (non-trivial) eigenvalue. In this paper, we generalize this relationship.
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An Extremal Property of Turán Graphs [PDF]
The Electronic Journal of Combinatorics, 2010 Let ${\cal F}_{n,t_r(n)}$ denote the family of all graphs on $n$ vertices and $t_r(n)$ edges, where $t_r(n)$ is the number of edges in the Turán's graph $T_r(n)$ – the complete $r$-partite graph on $n$ vertices with partition sizes as equal as possible.
Felix Lazebnik, Spencer Tofts
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Extremal graphs for edge blow-up of graphs [PDF]
Journal of Combinatorial Theory, Series B, 2022 Given a graph $H$ and an integer $p$, the {\it edge blow-up} of $H$, denoted as $H^{p+1}$, is the graph obtained from replacing each edge in $H$ by a clique of size $p+1$ where the new vertices of the cliques are all different. The Turán numbers for edge blow-up of matchings were first studied by Erdős and Moon.
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Ars Mathematica Contemporanea, 2012 A graph G is singular if the zero-one adjacency matrix has the eigenvalue zero. The multiplicity of the eigenvalue zero is called the nullity of G . For two vertices y and z of G , we call ( G , y , z ) a device with respect to y and z .
Irene Sciriha +4 more
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The Upper Monophonic Number of a Graph [PDF]
, 2010 An article about Smarandachely k-monophonic path, and Smarandachely k-monophonic ...
Panchali, S., John, J.
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On Minimum Wiener Polarity Index of Unicyclic Graphs with Prescribed Maximum Degree
Journal of Applied Mathematics, 2014 The Wiener polarity index of a connected graph G is defined as the number of its pairs of vertices that are at distance three. By introducing some graph transformations, in different way with that of Huang et al., 2013, we determine the minimum Wiener ...
Jianping Ou, Xing Feng, Saihua Liu
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