Results 31 to 40 of about 5,888,750 (277)

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

Some problems in extremal graph theory and finite geometry

open access: yes, 2023
Lazebnik, FelixThis thesis is devoted to the study of several problems in extremal graph theory and finite geometry. We study properties such as girth, spectrum, and automorphism group of various families of algebraically defined graphs. We present a new
Taranchuk, Vladislav
core   +1 more source

On the VC-dimension‎, ‎covering and separating properties of the cycle and spanning tree hypergraphs of graphs [PDF]

open access: yesTransactions on Combinatorics, 2022
In this paper‎, ‎we delve into studying some relations between the structure of the cycles and spanning trees of a graph through the lens of its cycle and spanning tree hypergraphs which are hypergraphs with the edge set of the graph as their vertices ...
Alireza Mofidi
doaj   +1 more source

Problems in Ramsey theory, probabilistic combinatorics and extremal graph theory [PDF]

open access: yes, 2015
In this dissertation, we treat several problems in Ramsey theory, probabilistic combinatorics and extremal graph ...
Narayanan, Bhargav
core   +3 more sources

On the conjunctive capacity of graphs [PDF]

open access: yes, 2013
The investigation of the asymptotic behaviour of various graph parameters in powers of a fixed graph G=(V,E) is motivated by problems in information theory and extremal ...
Chlebikova, Janka   +5 more
core   +1 more source

A Unified Approach for Extremal General Exponential Multiplicative Zagreb Indices

open access: yesAxioms, 2023
The study of the maximum and minimal characteristics of graphs is the focus of the significant field of mathematics known as extreme graph theory. Finding the biggest or smallest graphs that meet specified criteria is the main goal of this discipline ...
Rashad Ismail   +4 more
doaj   +1 more source

On a problem in extremal graph theory

open access: yesJournal of Combinatorial Theory, Series B, 1977
From the authors introduction. Let \(G(n,m)\) denote a graph \((V,E)\) with \(n\) vertices and \(m\) edges and \(K_1\) a complete graph with \(i\) vertices. \textit{P.Turán} proved that every \(G(n,T(n,k))\) contains a \(K_k\), where \[ T(n,k) = \frac{k-2}{2(k-1)}(n^2-r^2)+\binom r2+1, \] \(r\equiv n(\mod k-1)\) and \(0\leq r\leq k-2\).
D. T. Busolini, Paul Erdös
openaire   +1 more source

On the number of pentagons in triangle-free graphs [PDF]

open access: yes, 2013
Using the formalism of flag algebras, we prove that every triangle-free graph G with n vertices contains at most (n/5)(5) cycles of length five. Moreover, the equality is attained only when n is divisible by five and G is the balanced blow-up of the ...
Hatami, Hamed   +4 more
core   +1 more source

Two Extremal Problems in Graph Theory

open access: yesThe 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
openaire   +2 more sources

Compactness results in extremal graph theory [PDF]

open access: yesCombinatorica, 1982
(From the authors' abstract:) ``Let \(L\) be a given family of \dots 'prohibited graphs'. Let \(\text{ex}(n,L)\) denote the maximum number of edges a simple graph of order n can have without containing subgraphs from \(L\). A typical extremal graph problem is to determine \(\text{ex}(n,L)\), or, at least, to find good bounds on it.
Paul Erdös, Miklós Simonovits
openaire   +3 more sources

Home - About - Disclaimer - Privacy