Results 1 to 10 of about 25,547 (250)

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

open access: goldEntropy (Basel), 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. It applies this approach for the derivation of information inequalities with Shannon information measures.
Sason I.
europepmc   +7 more sources

Turan problems in extremal graph theory and flexibility

open access: gold, 2021
In this work we will study two distinct areas of graph theory: generalized Turan problems and graph flexibility. In the first chapter, we will provide some basic definitions and motivation. Chapters 2 and 3 contain two submitted papers showing that two graphs, the cycle on five vertices and the path on four vertices, are maximized by the Turan graph ...
Kyle Murphy
semanticscholar   +6 more sources

Problems in Ramsey theory, probabilistic combinatorics and extremal graph theory

open access: green, 2015
In this dissertation, we treat several problems in Ramsey theory, probabilistic combinatorics and extremal graph theory.
Bhargav Narayanan
semanticscholar   +4 more sources

Two Extremal Problems in Graph Theory

open access: closedThe Electronic Journal of Combinatorics, 1994
We consider the following two problems. (1) Let $t$ and $n$ be positive integers with $n\geq t\geq 2$. Determine the maximum number of edges of a graph of order $n$ that contains neither $K_t$ nor $K_{t,t}$ as a subgraph. (2) Let $r$, $t$ and $n$ be positive integers with $n\geq rt$ and $t\geq 2$. Determine the maximum number of edges of a graph of
Richard A. Brualdi, Stephen Mellendorf
semanticscholar   +4 more sources

Some Problems in Algebraic and Extremal Graph Theory.

open access: gold, 1995
In this dissertation, we consider a wide range of problems in algebraic and extremal graph theory. In extremal graph theory, we will prove that the Tree Packing Conjecture is true for all sequences of trees th a t are ‘almost stars’; and we prove tha t ...
Edward Dobson
semanticscholar   +4 more sources

Some problems in extremal graph theory avoiding the use of the regularity lemma

open access: green, 2009
In this thesis we present two results in Extremal Graph Theory. The first result is a new proof of a conjecture of Bollobas on embedding trees of bounded degree. The second result is a new proof of the Posa conjecture.Let G=(W,E) be a graph on n vertices having minimum degree at least n/2 + c log(n), where c is a constant.
Ian Levitt
semanticscholar   +3 more sources

An extremal problem in graph theory II [PDF]

open access: bronzeJournal of the Australian Mathematical Society, 1980
AbstractWe contine our study of the following combinatorial problem: What is the largest integer N = N (t, m, p) for which there exists a set of N people satisfying the following conditions: (a) each person speaks t languages, (b) among any m people there are two who speak a common language and (c) at most p speak a common language.
H. L. Abbott, Meir Katchalski, A. C. Liu
openalex   +3 more sources

On some interconnections between combinatorial optimization and extremal graph theory [PDF]

open access: yesYugoslav Journal of Operations Research, 2004
The uniting feature of combinatorial optimization and extremal graph theory is that in both areas one should find extrema of a function defined in most cases on a finite set.
Cvetković Dragoš M.   +2 more
doaj   +3 more sources

On an extremal problem in graph theory [PDF]

open access: bronzeColloquium 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
Péter L. Erdős
openalex   +3 more sources

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