A characterization of continuous $q$-Jacobi, Chebyshev of the first kind and Al-Salam Chihara polynomials (2109.06147v2)

Abstract: The purpose of this note is to characterize those orthogonal polynomials sequences $(P_n){n\geq0}$ for which $$ \pi(x)\mathcal{D}_q P_n(x)=(a_n x+b_n)P_n(x)+c_n P{n-1}(x),\quad n=0,1,2,\dots, $$ where $\mathcal{D}q$ is the Askey-Wilson operator, $\pi$ is a polynomial of degree at most 2, and $(a_n){n\geq0}$, $(b_n){n\geq0}$ and $(c_n){n\geq0}$ are sequences of complex numbers such that $c_n\neq0$ for $n=1,2,\dots$.