{ "id": "1306.2387", "version": "v1", "published": "2013-06-11T00:12:08.000Z", "updated": "2013-06-11T00:12:08.000Z", "title": "The number of lines in a matroid with no $U_{2,n}$-minor", "authors": [ "Jim Geelen", "Peter Nelson" ], "categories": [ "math.CO" ], "abstract": "We show that, if $q$ is a prime power at most 5, then every rank-$r$ matroid with no $U_{2,q+2}$-minor has no more lines than a rank-$r$ projective geometry over GF$(q)$. We also give examples showing that for every other prime power this bound does not hold.", "revisions": [ { "version": "v1", "updated": "2013-06-11T00:12:08.000Z" } ], "analyses": { "keywords": [ "prime power", "projective geometry" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1306.2387G" } } }