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Nonequilibrium phenomena in superfluid systems: atomic nuclei, liquid helium, ultracold gases, and neutron stars

The workshop aims to discuss and exchange results and ideas concerning the description of superfluid systems in nonequilibrium conditions. In particular, we would like to focus on fermionic superfluidity, treating bosonic superfluids as auxiliary systems. Thanks to advances in experimental techniques in the field of ultracold gases, we can now explore the BCS-BEC crossover and investigate nonequilibrium phenomena both in the BEC and BCS limits, pinning down differences. These phenomena involve the dynamics of vortices, dissipative flows, dynamics of solitonic excitations, stability of persistent currents or droplet collisions. We may also study the influence of inhomogeneous systems and/or supersolid phases on the behavior of the superflow or the vortex dynamics. On the other hand, superfluid dynamics is crucial for our understanding of other fermionic systems, such as atomic nuclei and neutron stars. In the case of atomic nuclei, two main processes depend crucially on superfluidity among neutrons and protons. These are: induced nuclear fission and nuclear collisions involving heavy nuclei. The peculiarity of superfluidity in finite nuclear systems is related to the fact the size of Cooper pairs is of the order of the size of the system. In the case of neutron stars the superfluidity is at the heart of the so-called `glitches’ observed in pulsars, but also plays a crucial role in determining transport coefficients that can influence the cooling of the star and its gravitational wave emission. To model these phenomena, understanding the dynamics of vortices and dissipative channels related to superflow in an inhomogeneous environment is crucial. Last but not least, it is a well-founded belief that quantum turbulence involving dynamics of a huge number of vortices may occur inside neutron stars. Quantum turbulence has been studied in a number of laboratory systems, and there is a need to understand the differences between fermionic and bosonic turbulence and to identify the main dissipative channels responsible for the decay of a turbulent state. Therefore, we would like to gather experts in the field of low-energy nuclear physics, neutron stars, ultracold gasses and liquid helium, in order to exchange ideas and results that will lead us to a better understanding of nonequilibrium superfluidity. We would like to invite experimentalists performing experiments in ultracold atoms and liquid helium systems in order to suggest experiments, which can answer important questions associated with superfluidity in nuclear systems, both in terrestrial laboratories and in neutron stars