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Characterizations of Continuous and Discrete q-Ultraspherical Polynomials

Published online by Cambridge University Press:  20 November 2018

Mourad E. H. Ismail  and
Josef Obermaier
Mourad E. H. Ismail
Affiliation:
Department of Mathematics, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong and Department of Mathematics, King Saud University, Riyadh, Saudi Arabia email: ismail@math.ucf.edu
Josef Obermaier
Affiliation:
Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Biomathematics and Biometry, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany email: josef.obermaier@helmholtz-muenchen.de
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Abstract

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We characterize the continuous q-ultraspherical polynomials in terms of the special form of the coefficients in the expansion ${{\mathcal{D}}_{q}}{{P}_{n}}\left( x \right)$ in the basis $\left\{ {{P}_{n}}\left( x \right) \right\},{{\mathcal{D}}_{q}}$ being the Askey-Wilson divided difference operator. The polynomials are assumed to be symmetric, and the connection coefficients are multiples of the reciprocal of the square of the ${{L}^{2}}$ norm of the polynomials. A similar characterization is given for the discrete $q$-ultraspherical polynomials. A new proof of the evaluation of the connection coefficients for big $q$-Jacobi polynomials is given.

Keywords

33D4542C05continuous q-ultraspherical polynomialsbig q-Jacobi polynomialsdiscrete q-ultraspherical polynomialsAskey–Wilson operatorq-difference operatorrecursion coefficients
Type
Research Article
Information
Canadian Journal of Mathematics , Volume 63 , Issue 1 , 01 February 2011 , pp. 181 - 199
Copyright
Copyright © Canadian Mathematical Society 2011

References

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