An integrable vertex model and the quantum affine algebra Uq((sl)over-cap(2)) at the critical level

Based on infinite-dimensional modules of U-q (sl(2)), an integrable model with an inhomogeneity in the spectral parameters is set up. An appropriate generalization of Baxter's method allows to evaluate the eigenvalues of the corner transfer matrices. The spectrum of the latter is related to Wakimoto modules of the quantum affine algebra U-q ((sl) over cap (2)) at its critical level. Two-point functions of the model are expressed by traces over composite vertex operators introduced as lattice objects. An interpretation of these operators in terms of suitable intertwiners of U-q((sl) over cap (2))(-2)-modules is conjectured. (C) 2002 Elsevier Science B.V. All rights reserved.