{ "id": "1110.1756", "version": "v1", "published": "2011-10-08T18:28:03.000Z", "updated": "2011-10-08T18:28:03.000Z", "title": "About dependence of the number of edges and vertices in hypergraph clique with chromatic number 3", "authors": [ "D. D. Cherkashin", "A. B. Kulikov", "A. M. Raigorodskii" ], "comment": "6 pages", "categories": [ "math.CO" ], "abstract": "In 1973 P. Erd\\H{o}s and L. Lov\\'asz noticed that any hypergraph whose edges are pairwise intersecting has chromatic number 2 or 3. In the first case, such hypergraph may have any number of edges. However, Erd\\H{o}s and Lov\\'asz proved that in the second case, the number of edges is bounded from above. For example, if a hypergraph is $ n $-uniform, has pairwise intersecting edges, and has chromatic number 3, then the number of its edges does not exceed $ n^n $. Recently D.D. Cherkashin improved this bound (see \\cite{Ch}). In this paper, we further improve it in the case when the number of vertices of an $n$-uniform hypergraph is bounded from above by $ n^m $ with some $ m = m(n) $.", "revisions": [ { "version": "v1", "updated": "2011-10-08T18:28:03.000Z" } ], "analyses": { "keywords": [ "chromatic number", "hypergraph clique", "dependence", "uniform hypergraph", "second case" ], "note": { "typesetting": "TeX", "pages": 6, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1110.1756C" } } }