Diophantine properties of orthogonal polynomials and rational functions

Ismail, Mourad; Rahman, Mizan

doi:10.1090/proc/12355

Diophantine properties of orthogonal polynomials and rational functions
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by Mourad E. H. Ismail and Mizan Rahman PDF

Proc. Amer. Math. Soc. 145 (2017), 2427-2440 Request permission

Abstract:

Calogero and his collaborators recently observed that some hypergeometric polynomials can be factored as a product of two polynomials, one of which is factored into a product of linear terms. Chen and Ismail showed that this property prevails through all polynomials in the Askey scheme. We show that this factorization property is also shared by the associated Wilson and Askey-Wilson polynomials and some biorthogonal rational functions. This is applied to a specific model of an isochronous system of particles with small oscillations around the equilibrium position.

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