{ "id": "1008.4044", "version": "v1", "published": "2010-08-24T13:47:03.000Z", "updated": "2010-08-24T13:47:03.000Z", "title": "The K_4-free process", "authors": [ "Guy Wolfovitz" ], "comment": "36 pages", "categories": [ "math.CO" ], "abstract": "We consider the K_4-free process. In this process, the edges of the complete n-vertex graph are traversed in a uniformly random order, and each traversed edge is added to an initially empty evolving graph, unless the addition of the edge creates a copy of K_4. Let M(n) denote the graph that is produced by that process. We prove that a.a.s., the number of edges in M(n) is O( n^{8/5} (\\ln n)^{1/5} ). This matches, up to a constant factor, a lower bound of Bohman. As a by-product, we prove the following Ramsey-type result: for every n there exists a K_4-free n-vertex graph, in which the largest set of vertices that doesn't span a triangle has size O( n^{3/5} (\\ln n)^{1/5} ). This improves, by a factor of (\\ln n)^{3/10}, an upper bound of Krivelevich.", "revisions": [ { "version": "v1", "updated": "2010-08-24T13:47:03.000Z" } ], "analyses": { "keywords": [ "complete n-vertex graph", "uniformly random order", "upper bound", "edge creates", "constant factor" ], "note": { "typesetting": "TeX", "pages": 36, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1008.4044W" } } }