{ "id": "1901.00197", "version": "v1", "published": "2019-01-01T18:57:44.000Z", "updated": "2019-01-01T18:57:44.000Z", "title": "Is the Symmetric Group Sperner?", "authors": [ "Larry H. Harper", "Gene B. Kim" ], "comment": "7 pages, 7 figures", "categories": [ "math.CO" ], "abstract": "An antichain A in a poset P is a subset of P in which no two elements are comparable. Sperner showed that the maximal antichain in the Boolean lattice, B_n, is the largest rank (of size n choose n/2). This type of problem has since been generalized, and a graded poset P is said to be Sperner if the largest rank of P is its maximal antichain. In this paper, we will show that the symmetric group S_n, partially ordered by refinement (or equivalently by absolute order), is Sperner.", "revisions": [ { "version": "v1", "updated": "2019-01-01T18:57:44.000Z" } ], "analyses": { "subjects": [ "05A05", "05E99", "60F05" ], "keywords": [ "symmetric group sperner", "maximal antichain", "largest rank", "boolean lattice", "absolute order" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable" } } }