English

Dynamic concentration of the triangle-free process

Combinatorics 2019-09-06 v2

Abstract

The triangle-free process begins with an empty graph on n vertices and iteratively adds edges chosen uniformly at random subject to the constraint that no triangle is formed. We determine the asymptotic number of edges in the maximal triangle-free graph at which the triangle-free process terminates. We also bound the independence number of this graph, which gives an improved lower bound on the Ramsey numbers R(3,t): we show R(3,t) > (1-o(1)) t^2 / (4 log t), which is within a 4+o(1) factor of the best known upper bound. Our improvement on previous analyses of this process exploits the self-correcting nature of key statistics of the process. Furthermore, we determine which bounded size subgraphs are likely to appear in the maximal triangle-free graph produced by the triangle-free process: they are precisely those triangle-free graphs with density at most 2.

Keywords

Cite

@article{arxiv.1302.5963,
  title  = {Dynamic concentration of the triangle-free process},
  author = {Tom Bohman and Peter Keevash},
  journal= {arXiv preprint arXiv:1302.5963},
  year   = {2019}
}

Comments

75 pages, 1 figure

R2 v1 2026-06-21T23:31:50.530Z