η and λ deformations as EE-models

We show that the so-called λ deformed σ-model as well as the η   deformed one belong to a class of the EE-models introduced in the context of the Poisson–Lie-T-duality. The λ and η theories differ solely by the choice of the Drinfeld double; for the λ   model the double is the direct product G×GG×G while for the η   model it is the complexified group GCGC. As a consequence of this picture, we prove for any G that the target space geometries of the λ-model and of the Poisson–Lie T-dual of the η-model are related by a simple analytic continuation.