{ "id": "1412.1838", "version": "v1", "published": "2014-12-04T21:03:43.000Z", "updated": "2014-12-04T21:03:43.000Z", "title": "A note on a problem of Erdos and Rothschild", "authors": [ "Aaron Potechin" ], "comment": "7 pages, 0 figures", "categories": [ "math.CO" ], "abstract": "A set of $q$ triangles sharing a common edge is a called a book of size $q$. Letting $bk(G)$ denote the size of the largest book in a graph $G$, Erd\\H{o}s and Rothschild \\cite{erdostwo} asked what the minimal value of $bk(G)$ is for graphs $G$ with $n$ vertices and a set number of edges where every edge is contained in at least one triangle. In this paper, we show that for any graph $G$ with $n$ vertices and $\\frac{n^2}{4} - nf(n)$ edges where every edge is contained in at least one triangle, $bk(G) \\geq \\Omega\\left(\\min{\\{\\frac{n}{\\sqrt{f(n)}}, \\frac{n^2}{f(n)^2}\\}}\\right)$.", "revisions": [ { "version": "v1", "updated": "2014-12-04T21:03:43.000Z" } ], "analyses": { "keywords": [ "rothschild", "common edge", "largest book", "minimal value", "set number" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1412.1838P" } } }