{ "id": "2006.11798", "version": "v1", "published": "2020-06-21T13:33:51.000Z", "updated": "2020-06-21T13:33:51.000Z", "title": "Further progress towards Hadwiger's conjecture", "authors": [ "Luke Postle" ], "comment": "16 pages", "categories": [ "math.CO", "cs.DM" ], "abstract": "In 1943, Hadwiger conjectured that every graph with no $K_t$ minor is $(t-1)$-colorable for every $t\\ge 1$. In the 1980s, Kostochka and Thomason independently proved that every graph with no $K_t$ minor has average degree $O(t\\sqrt{\\log t})$ and hence is $O(t\\sqrt{\\log t})$-colorable. Recently, Norin, Song and the author showed that every graph with no $K_t$ minor is $O(t(\\log t)^{\\beta})$-colorable for every $\\beta > 1/4$, making the first improvement on the order of magnitude of the $O(t\\sqrt{\\log t})$ bound. Building on that work, we show in this paper that every graph with no $K_t$ minor is $O(t (\\log t)^{\\beta})$-colorable for every $\\beta > 0$; more specifically, they are $t \\cdot 2^{ O((\\log \\log t)^{2/3}) }$-colorable.", "revisions": [ { "version": "v1", "updated": "2020-06-21T13:33:51.000Z" } ], "analyses": { "keywords": [ "hadwigers conjecture", "average degree", "first improvement" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable" } } }