Appears in collection : Conférence à la mémoire de Vadim Knizhnik

We show that sine-Lioville CFT, which is dual to Witten 2-d black hole model, has three different types of integrable perturbations. The corresponding theories also possess non-trivial duality properties. The first two models give the examples of weak-strong coupling dualities between charged fermions and bosons. The third type gives two different field theories, which are dual to massive and massless non-linear sigma models.