Memory Effects in Superfluid Hydrodynamics

We explore the hypothesis that on long length-scales, coarse-grained quantum turbulence in superfluids behaves like a classical fluid with emergent effective viscosity, mutual friction between components etc. If true, then microscopic calculations and quantum simulations with cold-atom experiments can be used to study macroscopic phenomenal like pulsar glitches in neutron stars. A confounding issue is memory: even if the microscopic theory is purely deterministic and local in time, the coarse-grained dynamics might require knowledge of the history – especially in the presence of long-range structures like topological defects hidden by coarse graining.