{ "id": "1811.05501", "version": "v1", "published": "2018-11-13T19:15:49.000Z", "updated": "2018-11-13T19:15:49.000Z", "title": "A combinatorial $\\mathfrak{sl}_2$-action and the Sperner property for the weak order", "authors": [ "Christian Gaetz", "Yibo Gao" ], "comment": "6 pages", "categories": [ "math.CO", "math.RT" ], "abstract": "We construct a simple combinatorially-defined representation of $\\mathfrak{sl}_2$ which respects the order structure of the weak order on the symmetric group. This is used to resolve a conjecture of Stanley that the weak order has the strong Sperner property, and is therefore a Peck poset.", "revisions": [ { "version": "v1", "updated": "2018-11-13T19:15:49.000Z" } ], "analyses": { "keywords": [ "weak order", "strong sperner property", "order structure", "simple combinatorially-defined representation", "symmetric group" ], "note": { "typesetting": "TeX", "pages": 6, "language": "en", "license": "arXiv", "status": "editable" } } }