Vortex density fluctuations in quantum turbulence

TL;DR

This paper analyzes vortex density fluctuations in quantum turbulence, demonstrating Kolmogorov scaling consistent with experimental observations, and interprets this scaling through the spectrum of reconnecting vortex lines using an efficient computational method.

Contribution

It introduces a vortex tree algorithm for faster computation of vortex interactions and links the observed turbulence scaling to vortex reconnection spectra.

Findings

Kolmogorov scaling observed in vortex density fluctuations

Vortex reconnection spectrum explains turbulence scaling

Efficient vortex tree algorithm developed

Abstract

We compute the frequency spectrum of turbulent superfluid vortex density fluctuations and obtain the same Kolmogorov scaling which has been observed in a recent experiment in Helium-4. We show that the scaling can be interpreted in terms of the spectrum of reconnecting material lines. The calculation is performed using a vortex tree algorithm which considerably speeds up the evaluation of Biot-Savart integrals.