The threshold conjecture of Turán properties for random graphs is true

You need to know: Graph, notation K_n for complete graph on n vertices,  notations v(H) and e(H) for the number of vertices and edges in graph H, respectively.

Background:  For a graph F with e(F)\geq 1 and v(F)\geq 3, let m(F) be the maximum value of \frac{e(H)-1}{v(H)-2} over all subgraphs H of F with v(H)\geq 3. We say that a graph is F-free if it does not contain a copy of a graph F as a subgraph. For graph G, we write \text{ex}(G, F) for the maximal number of edges that an F-free subgraph of G may have. Number \pi(F)=\lim\limits_{n\to\infty}\frac{ex(K_n,F)}{e(K_n)} is known as Turán density of graph F. The Erdős-Renyi graph G(n,p) is a random graph with n vertices, such that every possible edge is included independently with probability p=p(n).

The Theorem: On 16th October 2009, Mathias Schacht submitted to the Annals of Mathematics a paper in which he proved that for every graph F with e(F)\geq 1 and v(F)\geq 3 and every \epsilon>0, there exists C=C(\epsilon)>0 such that for every sequence of probabilities q_n \geq Cn^{-1/m(F)}, we have \lim\limits_{n\to\infty} P\left[\text{ex}(G(n,q_n),F) \leq \left(\pi(F)+\epsilon\right)e(G(n,q_n))\right]=1.

Short context: Function \text{ex}(G, F) was first studied by Mantel, Erdős, and Turán. In particular, Turán determined in 1941 \text{ex}(K_n, K_k) for all integers n and k. For general graph G, it is known that \text{ex}(G, F) \geq \pi(F)e(G). The Theorem proves that if G is a random graph, then the opposite inequality \text{ex}(G, F) \leq (\pi(F)+\epsilon)e(G) holds with high probability. It confirms a conjecture of Kohayakawa, Łuczak, and Roedl made in 1997.

Links: Free arxiv version of the original paper is here, journal version is here.

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