We study the A n -1 (1) spin chain in the critical regime | q | = 1. We give free boson realizations of the vertex operators and their duals. Using these free boson realizations, we give integral representations for the correlation functions.
LEVEL 2 IRREDUCIBLE REPRESENTATIONS OF Uq(sl2), VERTEX OPERATORS, AND THEIR CORRELATIONS
We study zero temperature correlation functions of the spin-21 Heisenberg XXZ model in the critical regime −1<Δ≤1 in a magnetic field by means of the {\tenit Dual Field Approach}. We show for one particular example how to derive determinant representations for correlation functions and how to use these to embed the correlation functions in integrable systems of integro-difference equations (IDE). These IDE are associated with a Riemann-Hilbert problem.