Scale without conformal invariance from integrable deformations of coset CFTs

A bstract We construct the integrable λ -model on SU(3) k / U(2) k and we compute the one-loop β -function for the deformation parameter λ . Its non-compact version, corresponding to the coset SU(2 , 1) −k / U(2) −k is also considered. The target space of the latter admits an asymptotic region that can be reached when one of the coordinates becomes large. The asymptotic model can be seen as an integrable deformation of the SU(2) k / U(1) WZW model together with a linear dilaton and a free boson, where integrability is inherited from the parental λ -model. By taking an asymptotic double-scaling limit of the SU(2 , 1) −k / U(2) −k model, we obtain a two-dimensional field theory that is scale-invariant but not conformally invariant at one-loop order. Crucially, this deformation does not admit a Kerr-Schild form, unlike the cases studied in arXiv:2109.05040. However, in a suitable asymptotic regime, scale invariance is enhanced to full conformal invariance. Finally, we construct Type-II supergravity embeddings of the asymptotic model for specific values of the deformation parameter.