{ "id": "2105.01086", "version": "v1", "published": "2021-05-03T18:00:06.000Z", "updated": "2021-05-03T18:00:06.000Z", "title": "Racah algebras, the centralizer $Z_n(\\mathfrak{sl}_2)$ and its Hilbert-Poincaré series", "authors": [ "Nicolas Crampe", "Julien Gaboriaud", "Loïc Poulain d'Andecy", "Luc Vinet" ], "categories": [ "math.RT", "math-ph", "math.MP" ], "abstract": "The higher rank Racah algebra $R(n)$ introduced recently is recalled. A quotient of this algebra by central elements, which we call the special Racah algebra $sR(n)$, is then introduced. Using results from classical invariant theory, this $sR(n)$ algebra is shown to be isomorphic to the centralizer $Z_{n}(\\mathfrak{sl}_2)$ of the diagonal embedding of $U(\\mathfrak{sl}_2)$ in $U(\\mathfrak{sl}_2)^{\\otimes n}$. This leads to a first and novel presentation of the centralizer $Z_{n}(\\mathfrak{sl}_2)$ in terms of generators and defining relations. An explicit formula of its Hilbert-Poincar\\'e series is also obtained and studied. The extension of the results to the study of the special Askey-Wilson algebra and its higher rank generalizations is discussed.", "revisions": [ { "version": "v1", "updated": "2021-05-03T18:00:06.000Z" } ], "analyses": { "keywords": [ "centralizer", "higher rank racah algebra", "special racah algebra", "special askey-wilson algebra", "higher rank generalizations" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }