Poisson–Lie T–plurality of three–dimensional conformally invariant sigma models II: Nondiagonal metrics and dilaton puzzle

We look for 3–dimensional Poisson–Lie dualizable sigma models that satisfy the vanishing β–function equations with constant dilaton field. Using the Poisson–Lie T–plurality we then construct 3–dimensional sigma models that correspond to various decompositions of Drinfeld double. Models with nontrivial dilaton field may appear. It turns out that for “traceless” dual algebras they satisfy the vanishing β–function equations as well. In certain cases the dilaton cannot be defined in some of the dual models. We provide an explanation why this happens and give criteria predicting when it happens.