{ "id": "1209.6111", "version": "v2", "published": "2012-09-27T02:06:55.000Z", "updated": "2013-09-03T02:07:35.000Z", "title": "On balanced incomplete block designs with specified weak chromatic number", "authors": [ "Daniel Horsley", "David A. Pike" ], "comment": "26 pages, 0 figures", "categories": [ "math.CO" ], "abstract": "A weak $c$-colouring of a balanced incomplete block design (BIBD) is a colouring of the points of the design with $c$ colours in such a way that no block of the design has all of its vertices receive the same colour. A BIBD is said to be weakly $c$-chromatic if $c$ is the smallest number of colours with which the design can be weakly coloured. In this paper we show that for all $c \\geq 2$ and $k \\geq 3$ with $(c,k) \\neq (2,3)$, the obvious necessary conditions for the existence of a $(v,k,\\lambda)$-BIBD are asymptotically sufficient for the existence of a weakly $c$-chromatic $(v,k,\\lambda)$-BIBD.", "revisions": [ { "version": "v2", "updated": "2013-09-03T02:07:35.000Z" } ], "analyses": { "subjects": [ "05B05" ], "keywords": [ "balanced incomplete block design", "specified weak chromatic number", "smallest number", "obvious necessary conditions" ], "note": { "typesetting": "TeX", "pages": 26, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1209.6111H" } } }