Yang–Baxter Sigma Models

An intriguing subject is to consider integrable deformations of 2D non-linear sigma models such as principal chiral models and symmetric coset sigma models. There had been no systematic way to perform integrable deformations for a long time. However, recently an elegant and systematic way, the so-called Yang–Baxter deformation, was invented by Klimcik. We firstly introduce Yang–Baxter deformations of the principal chiral model and present the associated classical Lax pair. Then the deformation procedure is generalized to the symmetric coset sigma model.