{ "id": "2211.10584", "version": "v1", "published": "2022-11-19T04:26:10.000Z", "updated": "2022-11-19T04:26:10.000Z", "title": "Chess tableaux, powers of two and affine Lie algebras", "authors": [ "Antoine Labelle", "Stoyan Dimitrov" ], "comment": "14 pages, 3 figures", "categories": [ "math.CO", "math.RT" ], "abstract": "Chess tableaux are a special kind of standard Young tableaux where, in the chessboard coloring of the Young diagram, even numbers always appear in white cells and odd numbers in black cells. If, for $\\lambda$ a partition of $n$, $\\text{Chess}(\\lambda)$ denotes the number of chess tableaux of shape $\\lambda$, then Chow, Eriksson and Fan observed that $\\displaystyle\\sum_{\\lambda \\vdash n} \\text{Chess}(\\lambda)^2$ is divisible by unusually large powers of $2$. In this paper, we give an explanation for this phenomenon, proving a lower bound of $n-O(\\sqrt{n})$ for the $2$-adic valuation of this sum and a generalization of it. We do this by exploiting a connection with a certain representation of the affine Lie algebra $\\widehat{\\mathfrak{sl}_2}$ on the vector space with basis indexed by partitions. Our result about chess tableaux then follows from a study of the basic representation of $\\widehat{\\mathfrak{sl}_2}$ with coefficients taken from the ring of rational numbers with odd denominators.", "revisions": [ { "version": "v1", "updated": "2022-11-19T04:26:10.000Z" } ], "analyses": { "keywords": [ "affine lie algebra", "chess tableaux", "standard young tableaux", "unusually large powers", "basic representation" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }