{ "id": "2307.06668", "version": "v1", "published": "2023-07-13T10:21:26.000Z", "updated": "2023-07-13T10:21:26.000Z", "title": "Charting the $q$-Askey scheme. III. Verde-Star scheme for $q=1$", "authors": [ "Tom H. Koornwinder" ], "comment": "16 pages, 2 figures; dedicated to the memory of Jos\\'e Carlos Petronilho", "categories": [ "math.CA" ], "abstract": "Following Verde-Star, Linear Algebra Appl. 627 (2021), we label families of orthogonal polynomials in the $q=1$ Askey scheme together with their hypergeometric representations by three sequences $x_k, h_k, g_k$ of polynomials in $k$, two of degree 1 and one of degree 2, satisfying certain constraints. Except for the Hermite polynomials, this gives rise to a precise classification and a very simple uniform parametrization of these families together with their limit transitions. This is displayed in a graphical scheme. We also discuss limits from the $q$-case to the case $q=1$, although this cannot be done in a uniform way.", "revisions": [ { "version": "v1", "updated": "2023-07-13T10:21:26.000Z" } ], "analyses": { "subjects": [ "33C45" ], "keywords": [ "askey scheme", "verde-star scheme", "linear algebra appl", "simple uniform parametrization", "hypergeometric representations" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable" } } }