The fate of shock waves in quantum one-dimensional fluids at late times

Classical hydrodynamics generically leads to the formation of shock waves which, at the most basic level, correspond to nonanalyticities in the fluid density as a function of spatial coordinates.

At this classical level, small and smooth perturbations inevitably lead to such shocks. It is known that in free fermionic systems such classical nonanalyticities are rounded off at the shock points due to semi-classical corrections.

We investigate how shock formation eventually crosses over to the established framework of generalised hydrodynamics at late times, as well as consider the rôle of interactions in the one-dimensional shock problem.