Results 21 to 30 of about 39,392 (275)

Asymptotic Structure for the Clique Density Theorem

open access: yesDiscrete Analysis, 2020
Asymptotic structure for the clique density theorem, Discrete Analysis 2020:19, 26 pp. Turán's theorem, which is regarded as the "first" result in extremal graph theory, is the statement that the $K_r$-free graph on $n$ vertices with the largest number ...
Jaehoon Kim   +3 more
doaj   +1 more source

Extremal $H$-Free Planar Graphs

open access: yesThe Electronic Journal of Combinatorics, 2019
Given a graph $H$, a graph is $H$-free if it does not contain $H$ as a subgraph. We continue to study the topic of "extremal" planar graphs initiated by Dowden [J. Graph Theory  83 (2016) 213–230], that is, how many edges can an $H$-free planar graph on $n$ vertices have?
Yongxin Lan, Yongtang Shi, Zi-Xia Song
openaire   +4 more sources

Triangles in Ks-saturated graphs with minimum degree t

open access: yesTheory 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
doaj   +1 more source

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 numbers for odd cycles [PDF]

open access: yes, 2013
We describe the C_{2k+1}-free graphs on n vertices with maximum number of edges. The extremal graphs are unique except for n = 3k-1, 3k, 4k-2, or 4k-1. The value of ex(n,C_{2k+1}) can be read out from the works of Bondy, Woodall, and Bollobas, but here ...
Füredi, Zoltan, Gunderson, David S.
core   +1 more source

von Neuman algebras of strongly connected higher-rank graphs [PDF]

open access: yes, 2014
We investigate the factor types of the extremal KMS states for the preferred dynamics on the Toeplitz algebra and the Cuntz--Krieger algebra of a strongly connected finite $k$-graph. For inverse temperatures above 1, all of the extremal KMS states are of
Laca, Marcelo   +4 more
core   +4 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

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

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

Acquisition-extremal graphs

open access: yesDiscrete Applied Mathematics, 2013
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
LeSaulnier, Timothy D., West, Douglas B.
openaire   +1 more source

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