The three-dimensional visualisation above shows a close up of the initial condition used in this work. The red low-density isosurface correspond to quantum vortex lines whereas the greenish rendering are density fluctuations about the bulk value. Remarkably, due to non-local interactions and highly the helical properties of the flow, helical fluctuations of density are observed unlike standard simulations of the Gross-Pitaevskii model.
The figure above displays the kinetic energy spectrum resulting form this initial condition. Two power-laws regimes are observed. At scales much larger than the inter-vortex distance, a Kolmogorov classical turbulent cascade is observed whereas at smaller scales a Kelvin wave cascade emerges.