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Askey-Wilson polynomials for root systems of type \(BC\). (English) Zbl 0797.33014

Richards, Donald St. P. (ed.), Hypergeometric functions on domains of positivity, Jack polynomials, and applications. Proceedings of an AMS special session held March 22-23, 1991 in Tampa, FL, USA. Providence, RI: American Mathematical Society. Contemp. Math. 138, 189-204 (1992).
The author describes Macdonald’s orthogonal polynomials associated with root systems, observes that for the root system \(BC_ 1\) these are a special case of the Askey-Wilson polynomials, and then finds a generalization of the Macdonald polynomials for \(BC_ n\) that introduces two additional parameters so that when \(n=3D1\) these become the Askey- Wilson polynomials. These generalized Askey-Wilson polynomials are orthogonal with respect to the weight \[ \prod_{\alpha \in R_ 1} {(e^ \alpha;q)_ \infty \over (ae^{\alpha/2}, be^{\alpha/2}, ce^{\alpha/2}, de^{\alpha/2};q)_ \infty} = 20 \prod {(e^ \alpha; q)_ \infty \over (te^ \alpha;q)_ \infty}, \] where \(R_ 1=3D \{\pm 2 \varepsilon_ j \}_{j=3D1,\dots,n}\), \(R_ 2=3D= \{\pm \varepsilon_ i \pm \varepsilon_ j\}_{1 \leq i<j \leq n}\).
For the entire collection see [Zbl 0771.00045].

MSC:

33D70 Other basic hypergeometric functions and integrals in several variables
33D80 Connections of basic hypergeometric functions with quantum groups, Chevalley groups, \(p\)-adic groups, Hecke algebras, and related topics
17B20 Simple, semisimple, reductive (super)algebras