Spectral analysis of two doubly infinite Jacobi matrices with exponential entries

We provide a complete spectral analysis of all self-adjoint operators acting on ${?}^2(\mathbb{Z})$ which are associated with two doubly infinite Jacobi matrices with entries given by

$q^{?n+1}{\delta }_{m,n?1}+q^{?n}{\delta }_{m,n+1}$

and

${\delta }_{m,n?1}+\alpha q^{?n}{\delta }_{m,n}+{\delta }_{m,n+1},$

respectively, where $q\in (0,1)$ and $\alpha \in \mathbb{R}$. As an application, we derive orthogonality relations for the Ramanujan entire function and the third Jackson q-Bessel function.