Quantum quenches in the sinh-Gordon and Lieb-Liniger models

The non-relativistic limit of integrable field theories at equilibrium has been intensively studied in the previous years; the simplest non-trivial case relates the sinh-Gordon model to the Lieb-Liniger model. Here we study this non-relativistic limit out of equilibrium, namely in the time evolution after a quantum quench. The obtained results agree with the known ones for the Lieb-Liniger model, thus showing that the non-relativistic limit is applicable in this out-of-equilibrium setting.