ZAMOLODCHIKOV-FADDEEV ALGEBRAS FOR YANGIAN DOUBLE AT LEVEL-1

The representation theory of centrally extended Yangian doubles is inv estigated. The intertwining operators are constructed for infinite dim ensional representations of <(DY(Sl(2)))over cap>, which are deformed analogs of the highest weight representations of the affine algebra <( Sl(2))over cap> at level 1. We give bosonized expressions for the inte rtwining operators and verify that they generate an algebra isomorphic to the Zamolodchikov-Faddeev algebra for the SU(2)-invariant Thirring model. From them, we compose L-operators by Miki's method and verify that they coincide with L-operators constructed from the universal R-m atrix. The matrix elements of the product of these operators are calcu lated explicitly and are shown to satisfy the quantum (deformed) Knizh nik-Zamolodchikov equation associated with the universal R-matrix for <(DY(sl(2)))over cap>.