{ "id": "2405.09846", "version": "v1", "published": "2024-05-16T06:48:34.000Z", "updated": "2024-05-16T06:48:34.000Z", "title": "Delta Operators on Almost Symmetric Functions", "authors": [ "Milo Bechtloff Weising" ], "comment": "20 pages. arXiv admin note: text overlap with arXiv:2307.05864", "categories": [ "math.RT", "math.CO" ], "abstract": "We construct $\\Delta$-operators $F[\\Delta]$ on the space of almost symmetric functions $\\mathscr{P}_{as}^{+}$. These operators extend the usual $\\Delta$-operators on the space of symmetric functions $\\Lambda \\subset \\mathscr{P}_{as}^{+}$ central to Macdonald theory. The $F[\\Delta]$ operators are constructed as certain limits of symmetric functions in the Cherednik operators $Y_i$ and act diagonally on the stable-limit non-symmetric Macdonald functions $\\widetilde{E}_{(\\mu|\\lambda)}(x_1,x_2,\\ldots;q,t).$ Using properties of Ion-Wu limits, we are able to compute commutation relations for the $\\Delta$-operators $F[\\Delta]$ and many of the other operators on $\\mathscr{P}_{as}^{+}$ introduced by Ion-Wu. Using these relations we show that there is an action of $\\mathbb{B}_{q,t}^{\\text{ext}}$ on almost symmetric functions which we show is isomorphic to the polynomial representation of $\\mathbb{B}_{q,t}^{\\text{ext}}$ constructed by Gonz\\'{a}lez-Gorsky-Simental.", "revisions": [ { "version": "v1", "updated": "2024-05-16T06:48:34.000Z" } ], "analyses": { "keywords": [ "symmetric functions", "delta operators", "stable-limit non-symmetric macdonald functions", "cherednik operators", "operators extend" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }