Hydrodynamics of noncircular vortices in beams of light and other two-dimensional fluids

TL;DR

This paper develops a model describing how noncircular vortices, such as optical vortices, move and interact in two-dimensional fluids, revealing the influence of vortex shape and density gradients on their dynamics.

Contribution

It introduces a novel kinetic equation linking vortex ellipticity and fluid density gradients, applicable to quantum fluids, classical hydrodynamics, and optical vortices.

Findings

Model accurately predicts vortex motion and interactions.

Optical experiments confirm the model's predictions.

Applicable to both quantum and classical fluid systems.

Abstract

The motion of noncircular two-dimensional vortices is shown to depend on a form of coupling between vortex ellipticity and the gradient of fluid density. The approach is based on the perspective that an elliptic vortex can be described as the projection of a virtual construct, a circular vortex with a symmetry axis that is tilted with respect to the direction of propagation. The resulting kinetic equation offers insights into how tilt and vortex velocity coevolve in few-body nonequilibrium settings such as vortex pair nucleation and annihilation. The model is developed and applied in association with optical vortices, and optical experiments are used to verify its predictive power. It is valid for quantum fluids and classical hydrodynamics settings as well.