Results 1 to 10 of about 742 (250)

Information Inequalities via Submodularity and a Problem in Extremal Graph Theory [PDF]

open access: yesEntropy, 2022
The present paper offers, in its first part, a unified approach for the derivation of families of inequalities for set functions which satisfy sub/supermodularity properties.
Igal Sason
doaj   +2 more sources

Extremal infinite graph theory

open access: yesDiscrete Mathematics, 2011
We survey various aspects of infinite extremal graph theory and prove several new results. The lead role play the parameters connectivity and degree. This includes the end degree. Many open problems are suggested.
Maya Stein
exaly   +5 more sources

Extremal graph theory and finite forcibility [PDF]

open access: yesElectronic Notes in Discrete Mathematics, 2017
We study the uniqueness of optimal solutions to extremal graph theory problems. Our main result is a counterexample to the following conjecture of Lov´asz, which is often referred to as saying that “every extremal graph theory problem has a finitely forcible optimum”: every finite feasible set of subgraph density constraints can be extended further by ...
Andrzej Grzesik   +2 more
exaly   +2 more sources

Extremal Graph Theory for Metric Dimension and Diameter [PDF]

open access: yesElectronic Notes in Discrete Mathematics, 2007
A set of vertices $S$ resolves a connected graph $G$ if every vertex is uniquely determined by its vector of distances to the vertices in $S$. The metric dimension of $G$ is the minimum cardinality of a resolving set of $G$. Let ${\cal G}_{\beta,D}$ be the set of graphs with metric dimension $\beta$ and diameter $D$.
CARLOS Seara   +2 more
exaly   +6 more sources

On new results on extremal graph theory, theory of algebraic graphs, and their applications

open access: yesДоповiдi Нацiональної академiї наук України, 2022
New explicit constructions of infinite families of finite small world graphs of large girth with well-defined projective limits which is an infinite tree are described.
V.O. Ustimenko
doaj   +3 more sources

On an extremal problem in graph theory [PDF]

open access: yesColloquium Mathematicum, 1964
Let \(l\) and \(p\) be integers such that \(l>p\). It is shown that there exists a constant \(\gamma_{p,l}\) such that if \(n>n_0(p,l)\) then every graph with \(n\) vertices and \([\gamma_{p,l}n^{2-1/p}]\) edges contains a subgraph \(H\) with the following property: the vertices of \(H\) may be labbeled \(x_1,...,x_l\) and \(y_1,...,y_l\) so that every
exaly   +3 more sources

It Is Better to Be Semi-Regular When You Have a Low Degree [PDF]

open access: yesEntropy
We study the algebraic connectivity for several classes of random semi-regular graphs. For large random semi-regular bipartite graphs, we explicitly compute both their algebraic connectivity as well as the full spectrum distribution. For an integer d∈3,7,
Theodore Kolokolnikov
doaj   +2 more sources

On the applications of Extremal Graph Theory to Coding Theory and Cryptography

open access: yesElectronic Notes in Discrete Mathematics, 2013
<p>Explicit constructions in Extremal graph theory give appropriate lower bound for Turan type problems. In the case of prohibited cycles explicit constructions can be used in various problems of Information Security. We observe algebraic constructions of regular graphs of large girth and graphs with large cycle indicator and describe ...
Monika Polak
exaly   +3 more sources

On a valence problem in extremal graph theory

open access: yesDiscrete Mathematics, 1973
Vorliegende Arbeit bezieht sich auf nicht-orientierte, Schlingen und mehrfache Kanten nicht enhaltende Graphen. Bezeichne \(L\) einen solchen vom vollständigen \(p\)-Graphen \(K_p\) verschiedenen \(p\)-chromatischen Graphen, welcher eine Kante \(e\) so enthält, daß \(L-e\) ein \((p-1)\)-chromatischer Graph ist. Als Hauptergebnis der vorliegenden Arbeit
M Simonovits
exaly   +3 more sources

On tricyclic graphs with maximum atom–bond sum–connectivity index [PDF]

open access: yesHeliyon
The sum-connectivity, Randić, and atom-bond connectivity indices have a prominent place among those topological indices that depend on the graph's vertex degrees.
Sadia Noureen   +5 more
doaj   +2 more sources

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