We show how so-called Yang-Baxter (YB) deformations of sigma models, based on an R-matrix solving the classical Yang-Baxter equation (CYBE), give rise to marginal current-current deformations when applied to the Wess-Zumino-Witten (WZW) model. For non-compact groups these marginal deformations are more general than the ones usually considered, since they can involve a non-abelian current subalgebra. We classify such deformations of the AdS 3 × S 3 string.
8) while forThis fact will later play an important role in our discussion.4 In our conventions B = 1 2 Bnmdx m ∧ dx n . 5 We will interchangeably place the bar on an object or on its index, in other wordska or kā have the same meaning. For readability sometimes we will prefer the former.