{ "id": "2012.11846", "version": "v1", "published": "2020-12-22T06:03:53.000Z", "updated": "2020-12-22T06:03:53.000Z", "title": "Normal polytopes and ellipsoids", "authors": [ "Joseph Gubeladze" ], "comment": "8 pages", "categories": [ "math.CO", "math.NT" ], "abstract": "We show that: (1) unimodular simplices in a lattice 3-polytope cover a neighborhood of the boundary of the polytope if and only if the polytope is very ample, (2) the convex hull of lattice points in every ellipsoid in R^3 has a unimodular cover, and (3) for every d at least 6, there are ellipsoids in R^d, such that the convex hulls of the lattice points in these ellipsoids are not even normal. Part (3) answers a question of Bruns, Michalek, and the author.", "revisions": [ { "version": "v1", "updated": "2020-12-22T06:03:53.000Z" } ], "analyses": { "subjects": [ "52B20", "11H06" ], "keywords": [ "normal polytopes", "convex hull", "lattice points", "unimodular cover", "unimodular simplices" ], "note": { "typesetting": "TeX", "pages": 8, "language": "en", "license": "arXiv", "status": "editable" } } }