(Non)-universality of vortex reconnections in superfluids

TL;DR

This paper investigates vortex reconnections in superfluids using analytical and numerical methods, revealing universal scaling laws and the influence of vortex configuration on reconnection dynamics.

Contribution

It provides new insights into the universality and variability of vortex reconnection behavior in superfluids through combined analytical and numerical analysis.

Findings

Vortex lines approach and separate following a $ frac{1}{2}$ power-law scaling.

Curvature exhibits self-similar behavior near reconnection points.

Torsion development can disrupt curvature self-similarity, indicating complex reconnection dynamics.

Abstract

An insight into vortex reconnections in superfluids is presented making use of analytical results and numerical simulations of the Gross--Pitaevskii model. Universal aspects of the reconnection process are investigated by considering different initial vortex configurations and making use of a recently developed tracking algorithm to reconstruct the vortex filaments. We show that during a reconnection event the vortex lines approach and separate always accordingly to the time scaling $ \delta \sim t^{1/2} $ with pre-factors that depend on the vortex configuration. We also investigate the behavior of curvature and torsion close to the reconnection point, demonstrating analytically that the curvature can exhibit a self-similar behavior that might be broken by the development of shock-like structures in the torsion.