{ "id": "1301.6641", "version": "v1", "published": "2013-01-28T18:46:55.000Z", "updated": "2013-01-28T18:46:55.000Z", "title": "Normal forms of convex lattice polytopes", "authors": [ "Roland Grinis", "Alexander Kasprzyk" ], "comment": "28 pages, 2 figures. Includes an appendix describing the Kreuzer-Skarke algorithm", "categories": [ "math.CO" ], "abstract": "We describe an algorithm for determining whether two convex polytopes P and Q, embedded in a lattice, are isomorphic with respect to a lattice automorphism. We extend this to a method for determining if P and Q are equivalent, i.e. whether there exists an affine lattice automorphism that sends P to Q. Methods for calculating the automorphism group and affine automorphism group of P are also described. An alternative strategy is to determine a normal form such that P and Q are isomorphic if and only if their normal forms are equal. This is the approach adopted by Kreuzer and Skarke in their PALP software. We describe the Kreuzer-Skarke method in detail, and give an improved algorithm when P has many symmetries. Numerous examples, plus two appendices containing detailed pseudo-code, should help with any future reimplementations of these techniques. We conclude by explaining how to define and calculate the normal form of a Laurent polynomial.", "revisions": [ { "version": "v1", "updated": "2013-01-28T18:46:55.000Z" } ], "analyses": { "subjects": [ "52B20", "52B55", "52C07" ], "keywords": [ "normal form", "convex lattice polytopes", "affine lattice automorphism", "affine automorphism group", "convex polytopes" ], "note": { "typesetting": "TeX", "pages": 28, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1301.6641G" } } }