Studying the perturbed Wess–Zumino–Novikov–Witten SU(2) theory using the truncated conformal spectrum approach
Robert Konik, Tamás Pálmai, G. Takács +1 more
We study the SU ( 2 ) k Wess–Zumino–Novikov–Witten (WZNW) theory perturbed by the trace of the primary field in the adjoint representation, a theory governing the low-energy behavior of a class of strongly correlated electronic systems. While the model is non-integrable, its dynamics can be investigated using the numerical technique of the truncated conformal spectrum approach combined with numerical and analytical renormalization groups (TCSA + RG). The numerical results so obtained provide support for a semiclassical analysis valid at k ≫ 1 . Namely, we find that the low energy behavior is sensitive to the sign of the coupling constant, λ . Moreover, for λ > 0 this behavior depends on whether k is even or odd. With k even, we find definitive evidence that the model at low energies is equivalent to the massive O(3) sigma model. For k odd, the numerical evidence is more equivocal, but we find indications that the low energy effective theory is critical.
arXiv:1505.03860•Nuclear Physics B•Aug 24, 2015•36 citations