Generalised integrable $\lambda$- and $\eta$-deformations and their relation

Understand

We construct two-parameter families of integrable $\lambda$-deformations of two-dimensional field theories.

• These interpolate between a CFT (a WZW/gauged WZW model) and the non-Abelian T-dual of a principal chiral model on a group/symmetric coset space.
• In examples based on the $SU(2)$ WZW model and the $SU(2)/U(1)$ exact coset CFT, we show that these deformations are related to bi-Yang-Baxter generalisations of $\eta$-deformations via Poisson-Lie T-duality and analytic continuation.
• We illustrate the quantum behaviour of our models under RG flow.