arXiv:1608.07548 · Journal of Statistical Mechanics Theory and Experiment
Non relativistic limit of integrable QFT and Lieb–Liniger models
Alvise Bastianello, Andrea De Luca, Giuseppe Mussardo
Abstract
Abstract In this paper we study a suitable limit of integrable QFT with the aim to identify continuous non-relativistic integrable models with local interactions. This limit amounts to sending to infinity the speed of light c but simultaneously adjusting the coupling constant g of the quantum field theories in such a way to keep finite the energies of the various excitations. The QFT considered here are Toda field theories and the O ( N ) non-linear sigma model. In both cases the resulting non-relativistic integrable models consist only of Lieb–Liniger models, which are fully decoupled for the Toda theories while symmetrically coupled for the O ( N ) model. These examples provide explicit evidence of the universality and ubiquity of the Lieb–Liniger models and, at the same time, suggest that these models may exhaust the list of possible non-relativistic integrable theories of bosonic particles with local interactions.