Quantum Vortex Tangle Generated by Thermal Activation in Superfluid Liquids

The article presents the results of a numerical and analytical study of the development of a quantum vortex structure in superfluid helium under the influence of a random Langevin force that simulates thermal excitation. The study focuses on issues related to the density of the vortex tangle and distribution of vortex loops by their sizes, as well as the frequency of reconnections. The analytical part presents two methods to solve the problem: continuous and discrete. Numerical simulation is an important tool for solving the stochastic dynamics of quantum vortex filaments subjected to a random force, which is complex task. A comparison of the respective results is carried out.