{ "id": "0908.3778", "version": "v1", "published": "2009-08-26T09:31:36.000Z", "updated": "2009-08-26T09:31:36.000Z", "title": "Extremal Subgraphs of Random Graphs: an Extended Version", "authors": [ "Graham Brightwell", "Konstantinos Panagiotou", "Angelika Steger" ], "comment": "36 pages, 2 figures", "categories": [ "math.PR", "math.CO" ], "abstract": "We prove that there is a constant $c >0$, such that whenever $p \\ge n^{-c}$, with probability tending to 1 when $n$ goes to infinity, every maximum triangle-free subgraph of the random graph $G_{n,p}$ is bipartite. This answers a question of Babai, Simonovits and Spencer (Journal of Graph Theory, 1990). The proof is based on a tool of independent interest: we show, for instance, that the maximum cut of almost all graphs with $M$ edges, where $M >> n$, is ``nearly unique''. More precisely, given a maximum cut $C$ of $G_{n,M}$, we can obtain all maximum cuts by moving at most $O(\\sqrt{n^3/M})$ vertices between the parts of $C$.", "revisions": [ { "version": "v1", "updated": "2009-08-26T09:31:36.000Z" } ], "analyses": { "subjects": [ "05C80", "05C35", "60C05" ], "keywords": [ "random graph", "extremal subgraphs", "extended version", "maximum cut", "maximum triangle-free subgraph" ], "note": { "typesetting": "TeX", "pages": 36, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0908.3778B" } } }