Dissipative eigenvalue problems for a singular quantum Dirac system

In this paper, dissipative singular $q$-Dirac operators are examined in Hilbert space ${\mathcal{L}}_q^2(q^{\mathbb{Z}};{\mathbb{C}}^2)$, where they arise as extensions of a minimal symmetric operator in the limit-point case. We develop a selfadjoint dilation and get its incoming and outgoing spectral representations, enabling the explicit computation of the scattering matrix associated with the dilation. Furthermore, we construct a functional model for the dissipative operator and express its characteristic function in terms of the Titchmarsh-Weyl function of the corresponding selfadjoint operator. Finally, we establish results concerning the completeness of the system of eigenvectors and associated vectors for these dissipative Dirac operators.