…
►For asymptotic expansions of Wilsonpolynomials of large degree see Wilson (1991), and for asymptotic approximations to their largest zeros see Chen and Ismail (1998).
►Koornwinder (2009) rescales and reparametrizes Racah polynomials and Wilsonpolynomials in such a way that they are continuous in their four parameters, provided that these parameters are nonnegative.
…
…
►Table 18.25.1 lists the transformations of variable, orthogonality ranges, and parameter constraints that are needed in §18.2(i) for the Wilsonpolynomials
, continuous dual Hahn polynomials
, Racah polynomials
, and dual Hahn polynomials
.
►
Table 18.25.1: Wilson class OP’s: transformations of variable, orthogonality ranges, and parameter constraints.
►
§18.29 Asymptotic Approximations for -Hahn and Askey–Wilson Classes
►Ismail (1986) gives asymptotic expansions as , with and other parameters fixed, for continuous -ultraspherical, big and little -Jacobi, and Askey–Wilsonpolynomials.
…For Askey–Wilson
the leading term is given by
…
…
►Koornwinder has published numerous papers on special functions, harmonic analysis, Lie groups, quantum groups, computer algebra, and their interrelations, including an interpretation of Askey–Wilsonpolynomials on quantum SU(2), and a five-parameter extension (the Macdonald–Koornwinder polynomials) of Macdonald’s polynomials for root systems BC.
…
…
►
…
►If we consider this abstract algebra with additional relation (18.38.9) and with dependence on according to (18.38.7) then it is isomorphic with the algebra generated by given by (18.28.6_2), and given by (18.38.4), and act on the linear span of the Askey–Wilsonpolynomials (18.28.1).
See Zhedanov (1991), Granovskiĭ et al. (1992, §3), Koornwinder (2007a, §2) and Terwilliger (2011).
…
►The Dunkl type operator is a -difference-reflection operator acting on Laurent polynomials and its eigenfunctions, the nonsymmetric Askey–Wilsonpolynomials, are linear combinations of the symmetric Laurent polynomial
and the ‘anti-symmetric’ Laurent polynomial
, where is given in (18.28.1_5).
…
►Dunkl type operators and nonsymmetric polynomials have been associated with various other families in the Askey scheme and -Askey scheme, in particular with Wilsonpolynomials, see Groenevelt (2007), and with Jacobi polynomials, see Koornwinder and Bouzeffour (2011, §7).
…
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►►►Figure 18.21.1: Askey scheme.
…It increases by one for each row ascended in the scheme, culminating with four free real parameters for the Wilson and Racah polynomials.
…
Magnify
T. H. Koornwinder (1992)Askey-WilsonPolynomials for Root Systems of Type
.
In Hypergeometric Functions on Domains of Positivity, Jack
Polynomials, and Applications (Tampa, FL, 1991),
Contemp. Math., Vol. 138, pp. 189–204.