On the spectral theory of one functional-difference operator from conformal field theory

Ludwig D. Faddeev, Leon A. Takhtajan

In the paper we consider a functional-difference operator $H=U+U^{-1}+V$, where $U$ and $V$ are self-adjoint Weyl operators satisfying $UV=q^{2}VU$ with $q=e^{\pi i\tau }$ and $\tau >0$. The…