{ "id": "2109.00107", "version": "v1", "published": "2021-08-31T23:13:43.000Z", "updated": "2021-08-31T23:13:43.000Z", "title": "Doubly stochastic matrices and Schur-Weyl duality for partition algebras", "authors": [ "Stephen Doty" ], "comment": "8 pages", "categories": [ "math.CO", "math.RT" ], "abstract": "In 1916 D\\'{e}nes K\\\"{o}nig proved that the permanent of a doubly stochastic matrix is positive; equivalently, the matrix has a positive diagonal. K\\\"{o}nig's result is equivalent to Birkhoff's 1946 result, that the set of $n \\times n$ doubly stochastic matrices is the convex hull of the $n \\times n$ permutation matrices. We conjecture that K\\\"{o}nig's result extends to doubly stochastic matrices in the $\\mathbb{R}$-span of $r$th tensor powers of $n \\times n$ permutation matrices. The conjecture implies a simple new algorithmic proof that Schur--Weyl duality for partition algebras (originally proved over $\\mathbb{C}$ by V.F.R. Jones) holds over any commutative ring.", "revisions": [ { "version": "v1", "updated": "2021-08-31T23:13:43.000Z" } ], "analyses": { "subjects": [ "05E10", "20C30" ], "keywords": [ "doubly stochastic matrix", "schur-weyl duality", "partition algebras", "permutation matrices", "th tensor powers" ], "note": { "typesetting": "TeX", "pages": 8, "language": "en", "license": "arXiv", "status": "editable" } } }