INTERTWINING-OPERATORS FOR VERTEX REPRESENTATIONS OF TOROIDAL LIE-ALGEBRAS

The construction of the vertex representation of the toroidal Lie alge bra tau([n]) depends on the way of labelling the points in the dual Z( n) of the torus T-n. Thus there is a built-in symmetry of the vertex r epresentation with respect to the symmetry of Z(n). In conjunction wit h this, the energy oper ator L-0 gives rise to intertwining operators which reflect the symmetry of the vertex representation with respect t o S-1 action on tau([n]).