Results 31 to 40 of about 605,731 (305)

An Extremal Property of Turán Graphs [PDF]

open access: yesThe 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
openaire   +2 more sources

Extremal graphs for edge blow-up of graphs [PDF]

open access: yesJournal 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.
openaire   +3 more sources

A Tabu Search Based Approach for Graph Layout [PDF]

open access: yes, 2014
This paper describes an automated tabu search based method for drawing general graph layouts with straight lines. To our knowledge, this is the first time tabu methods have been applied to graph drawing.
Rodgers, Peter, Dib, Fadi
core   +2 more sources

Maximum Reciprocal Degree Resistance Distance Index of Bicyclic Graphs

open access: yesDiscrete 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
doaj   +1 more source

Extremal graphs for weights

open access: yesDiscrete 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
openaire   +2 more sources

On Minimum Wiener Polarity Index of Unicyclic Graphs with Prescribed Maximum Degree

open access: yesJournal 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
doaj   +1 more source

The Number of Spanning Trees in Generalized Complete Multipartite Graphs of Fan-Type [PDF]

open access: yes, 2011
Approaching topics such as connected simple graph, k-partite graph, complete graph, tree, Smarandache (E1,E2)-number of ...
Junliang Cai   +3 more
core   +1 more source

Maximum and minimum values of inverse degree and forgotten indices on the class of all unicyclic graphs

open access: yesAKCE International Journal of Graphs and Combinatorics, 2023
For a connected simple graph G, the inverse degree index and forgotten index are defined as [Formula: see text] and [Formula: see text] respectively, where [Formula: see text] denotes the degree of vertex u in G.
Mohammad Ali Manian   +2 more
doaj   +1 more source

Structures of Cycle Bases with Some Extremal Properties [PDF]

open access: yes, 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
core   +1 more source

On Acyclic Structures with Greatest First Gourava Invariant

open access: yesJournal of Chemistry, 2022
Let ξ be a simple connected graph. The first Gourava index of graph ξ is defined as GO1ξ=∑μη∈Eξdμ+dη+dμdη, where dμ indicates the degree of vertex μ.
Mariam Imtiaz   +4 more
doaj   +1 more source

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