{ "id": "1810.03448", "version": "v1", "published": "2018-10-08T13:43:23.000Z", "updated": "2018-10-08T13:43:23.000Z", "title": "Plethysms of symmetric functions and highest weight representations", "authors": [ "Melanie de Boeck", "Rowena Paget", "Mark Wildon" ], "comment": "35 pages", "categories": [ "math.RT", "math.CO" ], "abstract": "Let $s_\\nu \\circ s_\\mu$ denote the plethystic product of the Schur functions $s_\\nu$ and $s_\\mu$. In this article we define an explicit polynomial representation corresponding to $s_\\nu \\circ s_\\mu$ with basis indexed by certain `plethystic' semistandard tableaux. Using these representations we prove generalizations of four results on plethysms due to Bruns--Conca--Varbaro, Brion, Ikenmeyer and the authors. In particular, we give a sufficient condition for the multiplicity $\\langle s_\\nu \\circ s_\\mu, s_\\lambda\\rangle$ to be stable under insertion of new parts into $\\mu$ and $\\lambda$. We also characterize all maximal and minimal partitions $\\lambda$ in the dominance order such that $s_\\lambda$ appears in $s_\\nu \\circ s_\\mu$ and determine the corresponding multiplicities using plethystic semistandard tableaux.", "revisions": [ { "version": "v1", "updated": "2018-10-08T13:43:23.000Z" } ], "analyses": { "subjects": [ "05E05", "05E10", "17B10", "20C30", "22E47" ], "keywords": [ "highest weight representations", "symmetric functions", "plethystic semistandard tableaux", "schur functions", "dominance order" ], "note": { "typesetting": "TeX", "pages": 35, "language": "en", "license": "arXiv", "status": "editable" } } }