{ "id": "1104.5168", "version": "v3", "published": "2011-04-27T15:52:21.000Z", "updated": "2011-11-16T03:46:00.000Z", "title": "Neighborliness of the symmetric moment curve", "authors": [ "Alexander Barvinok", "Seung Jin Lee", "Isabella Novik" ], "comment": "28 pages, proofs are simplified and results are strengthened somewhat", "doi": "10.1112/S0025579312000010", "categories": [ "math.MG", "math.CO" ], "abstract": "We consider the convex hull B_k of the symmetric moment curve U(t)=(cos t, sin t, cos 3t, sin 3t, ..., cos (2k-1)t, sin (2k-1)t) in R^{2k}, where t ranges over the unit circle S= R/2pi Z. The curve U(t) is locally neighborly: as long as t_1, ..., t_k lie in an open arc of S of a certain length phi_k>0, the convex hull of the points U(t_1), ..., U(t_k) is a face of B_k. We characterize the maximum possible length phi_k, proving, in particular, that phi_k > pi/2 for all k and that the limit of phi_k is pi/2 as k grows. This allows us to construct centrally symmetric polytopes with a record number of faces.", "revisions": [ { "version": "v3", "updated": "2011-11-16T03:46:00.000Z" } ], "analyses": { "subjects": [ "52A20", "52B12", "26C10" ], "keywords": [ "symmetric moment curve", "neighborliness", "convex hull", "construct centrally symmetric polytopes", "cos 3t" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 28, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1104.5168B" } } }