{ "id": "2105.12168", "version": "v1", "published": "2021-05-25T18:46:23.000Z", "updated": "2021-05-25T18:46:23.000Z", "title": "The jump of the clique chromatic number of random graphs", "authors": [ "Lyuben Lichev", "Dieter Mitsche", "Lutz Warnke" ], "comment": "14 pages", "categories": [ "math.CO", "cs.DM", "math.PR" ], "abstract": "The clique chromatic number of a graph is the smallest number of colors in a vertex coloring so that no maximal clique is monochromatic. In 2016 McDiarmid, Mitsche and Pralat noted that around p \\approx n^{-1/2} the clique chromatic number of the random graph G_{n,p} changes by n^{\\Omega(1)} when we increase the edge-probability p by n^{o(1)}, but left the details of this surprising phenomenon as an open problem. We settle this problem, i.e., resolve the nature of this polynomial `jump' of the clique chromatic number of the random graph G_{n,p} around edge-probability p \\approx n^{-1/2}. Our proof uses a mix of approximation and concentration arguments, which enables us to (i) go beyond Janson's inequality used in previous work and (ii) determine the clique chromatic number of G_{n,p} up to logarithmic factors for any edge-probability p.", "revisions": [ { "version": "v1", "updated": "2021-05-25T18:46:23.000Z" } ], "analyses": { "subjects": [ "05C15", "05C80", "60C05" ], "keywords": [ "clique chromatic number", "random graph", "edge-probability", "logarithmic factors", "smallest number" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }