EXACT SOLUTION OF A Q-BOSON HOPPING MODEL

Quantum-group deformation of ordinary bosons yields the q bosons or nonlinear phonons. We solve exactly, for any real q > 1, including q = infinity, a one-dimensional q-boson lattice ''hopping model,'' and calculate asymptotically its correlation functions. The model is a nonlinear model of strongly interacting ordinary bosons. Our solution solves the equivalent quantum difference differential nonlinear Schrodinger model. Approximation reduces this to a nonintegrable boson Hubbard-type model with q bosons as fundamental particles. One special limit q --> infinity of the hopping model is the classical XY chain.