CONNECTIONS of the LIOUVILLE MODEL and XXZ SPIN CHAIN

L. D. FADDEEV, O. TIRKKONEN

Published 1995-06-03Version 1

The quantum theory of the Liouville model with imaginary field is considered using the quantum inverse scattering method. An integrable structure with nontrivial spectral parameter dependence is developed for lattice Liouville theory by scaling the $L$-matrix of lattice sine-Gordon theory. This $L$-matrix yields Bethe Ansatz equations for Liouville theory, by the methods of the algebraic Bethe Ansatz. Using the string picture of exited Bethe states, the lattice Liouville Bethe equations are mapped to the corresponding equations for the spin 1/2 XXZ chain. The well developed theory of finite size corrections in spin chains is used to deduce the conformal properties of the lattice Liouville Bethe states. The unitary series of conformal field theories emerge for Liouville couplings of the form $\gam = \pi\frac{\nu}{\nu+1}$, corresponding to root of unity XXZ anisotropies. The Bethe states give the full spectrum of the corresponding unitary conformal field theory, with the primary states in the \Kac table parameterized by a string length $K$, and the remnant of the chain length mod $(\nu+1)$.