Dilatons in curved backgrounds by the Poisson--Lie transformation

Transformations between group coordinates of three--dimensional conformal sigma models in the flat background and their flat, i.e. Riemannian coordinates enable to find general dilaton fields for three-dimensional flat sigma models. By the Poisson-Lie transformation we can get dilatons for the dual sigma models in a curved background. Unfortunately, in some cases the dilatons depend on inadmissible auxiliary variables so the procedure is not universal. The cases where the procedure gives proper and nontrivial dilatons in curved backgrounds are investigated and results given.