Recent advances on the Lieb–Liniger $\delta$-Bose gas

Abstract

From the perspectives of both experiment and theory, the Lieb–Liniger $\delta$-Bose gas remains of current interest. My contribution is focused mostly on generalized hydrodynamics of the model. While in the early days of the subject the relevance of generalized Gibbs ensembles (GGE) and their free energy was not noted, the tools for its computation were already available. For the hydrodynamic scale, in addition the GGE-averaged currents are required. To achieve such a goal, a surprisingly simple method will be explained.