QUANTUM EQUIVALENCE OF SIGMA-MODELS RELATED BY NON-ABELIAN DUALITY TRANSFORMATIONS

Coupling constant renormalization is investigated in two dimensional s igma models related by non-Abelian duality transformations. In this re spect it is shown that in the one loop order of perturbation theory th e duals of a one parameter family of models, interpolating between the SU(2) principal model and the O(3) sigma model, exhibit the same beha vior as the original models. For the O(3) model also the two loop equi valence is investigated, and is found to be broken just like in the al ready known example of the principal model.