2015/04/30 by B. Hoare, A. A. Tseytlin · 2 citations
Physics and Astronomy · #hep-th
paper · pdf · doi:10.1016/j.nuclphysb.2015.06.001
v2: comments and references added; v3: new appendix on an alternative proposal for the dilaton and minor changes, 28 pages; v4: misprint in (B.7) corrected
arxiv created 2015/12/11 · arxiv updated 2015/12/14
We consider two integrable deformations of 2d sigma models on supercosets associated with AdSn x Sn. The first, the "eta-deformation" (based on the Yang-Baxter sigma model), is a one-parameter generalization of the standard superstring action on AdSn x Sn, while the second, the "lambda-deformation" (based on the deformed gauged WZW model), is a generalization of the non-abelian T-dual of the AdSn x Sn superstring. We show that the eta-deformed model may be obtained from the lambda-deformed one by a special scaling limit and analytic continuation in coordinates combined with a particular identification of the parameters of the two models. The relation between the couplings and deformation parameters is consistent with the interpretation of the first model as a real quantum deformation and the second as a root of unity quantum deformation. For the AdS2 x S2 case we then explore the effect of this limit on the supergravity background associated to the lambda-deformed model. We also suggest that the two models may form a dual Poisson-Lie pair and provide direct evidence for this in the case of the integrable deformations of the coset associated with S2.