Connecting lattice and relativistic models via conformal field theory

Abstract

We consider the quantum group invariant XXZ-model. In the infrared limit it describes a Conformal Field Theory (CFT) with modified energy-momentum tensor. The correlation functions are related to solutions of level −4 of the qKZ equations. We describe these solutions relating them to level 0 solutions. We further consider general matrix elements (form factors) containing local operators and asymptotic states. We explain that the formulae for solutions of the qKZ equations suggest a decomposition of these matrix elements with respect to states of the corresponding CFT.