A quantum algebra approach to multivariate Askey-Wilson polynomials
arXiv:1809.04327 · doi:10.1093/imrn/rnz182
Abstract
We study matrix elements of a change of base between two different bases of representations of the quantum algebra . The two bases, which are multivariate versions of Al-Salam--Chihara polynomials, are eigenfunctions of iterated coproducts of twisted primitive elements. The matrix elements are identified with Gasper and Rahman's multivariate Askey-Wilson polynomials, and from this interpretation we derive their orthogonality relations. Furthermore, the matrix elements are shown to be eigenfunctions of the twisted primitive elements after a change of representation, which gives a quantum algebraic derivation of the fact that the multivariate Askey-Wilson polynomials are solutions of a multivariate bispectral -difference problem.
26 pages