MAPPING BETWEEN MULTICHANNEL EXCHANGE MODELS

We establish a mapping between different multichannel exchange models with electron spin s, impurity spin S, and channel number N-f. To cons truct the mapping ae use three different techniques leading to the sam e results: conformal field theory, 1/N-f expansion, and 1/s expansion. According to our calculations two models with N-f and N(f) channels of spin s and s electrons, respectively, coupled to an impurity spin S should show similar low-energy properties provided the following rel ation holds: N(f)s(s+1)(2s+1) =N-fs*(s*+1)(2s*+1), irrespective of th e special value of the impurity spin. This mapping seems, however, not to be consistent with the simple fusing picture used in the Bethe Ans atz solution of the multichannel problems.