{ "id": "2307.01184", "version": "v1", "published": "2023-07-03T17:50:07.000Z", "updated": "2023-07-03T17:50:07.000Z", "title": "Finding dense minors using average degree", "authors": [ "Kevin Hendrey", "Sergey Norin", "Raphael Steiner", "Jérémie Turcotte" ], "comment": "14 pages", "categories": [ "math.CO" ], "abstract": "Motivated by Hadwiger's conjecture, we study the problem of finding the densest possible $t$-vertex minor in graphs of average degree at least $t-1$. We show that if $G$ has average degree at least $t-1$, it contains a minor on $t$ vertices with at least $(\\sqrt{2}-1-o(1))\\binom{t}{2}$ edges. We show that this cannot be improved beyond $\\left(\\frac{3}{4}+o(1)\\right)\\binom{t}{2}$. Finally, for $t\\leq 6$ we exactly determine the number of edges we are guaranteed to find in the densest $t$-vertex minor in graphs of average degree at least $t-1$.", "revisions": [ { "version": "v1", "updated": "2023-07-03T17:50:07.000Z" } ], "analyses": { "subjects": [ "05C07", "05C35", "05C83" ], "keywords": [ "average degree", "finding dense minors", "vertex minor", "hadwigers conjecture", "exactly determine" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }