I. Loutsenko et al., SPECTRAL-ANALYSIS OF Q-OSCILLATOR WITH GENERAL BILINEAR INTERACTION, Journal of physics. A, mathematical and general (Print), 31(45), 1998, pp. 9081-9094
Spectra of the most general Hermitian Hamiltonian which is bilinear in
the creation and annihilation operators of a q-harmonic oscillator ar
e investigated with the help of the factorization method. It is shown
that there are two factorization schemes leading to discrete spectra o
f complicated forms. For q-oscillator models with continuous spectrum
the Hamiltonian may have normalizable eigenstates of infinite multipli
city. Existence of the continuous spectrum in the interacting system i
s also discussed.