{ "id": "1202.4701", "version": "v2", "published": "2012-02-21T17:01:35.000Z", "updated": "2013-05-06T16:22:14.000Z", "title": "The width of 5-dimensional prismatoids", "authors": [ "Benjamin Matschke", "Francisco Santos", "Christophe Weibel" ], "comment": "31 pages, 10 figures. Changes from v1: the introduction has been edited, and a minor correction made in the statement of Proposition 1.5", "categories": [ "math.CO" ], "abstract": "Santos' construction of counter-examples to the Hirsch Conjecture (2012) is based on the existence of prismatoids of dimension d of width greater than d. Santos, Stephen and Thomas (2012) have shown that this cannot occur in $d \\le 4$. Motivated by this we here study the width of 5-dimensional prismatoids, obtaining the following results: - There are 5-prismatoids of width six with only 25 vertices, versus the 48 vertices in Santos' original construction. This leads to non-Hirsch polytopes of dimension 20, rather than the original dimension 43. - There are 5-prismatoids with $n$ vertices and width $\\Omega(\\sqrt{n})$ for arbitrarily large $n$. Hence, the width of 5-prismatoids is unbounded.", "revisions": [ { "version": "v2", "updated": "2013-05-06T16:22:14.000Z" } ], "analyses": { "subjects": [ "52B05", "52B55", "90C05" ], "keywords": [ "prismatoids", "hirsch conjecture", "width greater", "original construction", "non-hirsch polytopes" ], "note": { "typesetting": "TeX", "pages": 31, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1202.4701M" } } }