{ "id": "0812.2937", "version": "v1", "published": "2008-12-15T22:55:25.000Z", "updated": "2008-12-15T22:55:25.000Z", "title": "On the chromatic number of random d-regular graphs", "authors": [ "Graeme Kemkes", "Xavier Pérez-Giménez", "Nicholas Wormald" ], "categories": [ "math.CO" ], "abstract": "In this work we show that, for any fixed d, random d-regular graphs asymptotically almost surely can be coloured with k colours, where k is the smallest integer satisfying d<2(k-1)log(k-1). From previous lower bounds due to Molloy and Reed, this establishes the chromatic number to be asymptotically almost surely k-1 or k. If moreover d>(2k-3)log(k-1), then the value k-1 is discarded and thus the chromatic number is exactly determined. Hence we improve a recently announced result by Achlioptas and Moore in which the chromatic number was allowed to take the value k+1. Our proof applies the small subgraph conditioning method to the number of balanced k-colourings, where a colouring is balanced if the number of vertices of each colour is equal.", "revisions": [ { "version": "v1", "updated": "2008-12-15T22:55:25.000Z" } ], "analyses": { "subjects": [ "05C80" ], "keywords": [ "chromatic number", "small subgraph conditioning method", "smallest integer", "proof applies", "random d-regular graphs" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2008arXiv0812.2937K" } } }