Instability Criteria for Vibrations of a Vortex Subject to a Gyro-force

TL;DR

This paper investigates how gyro-forces influence vortex stability, showing that even weak gyro-forces make the onset of instability more restrictive, requiring higher friction or steep non-monotonic velocity dependence.

Contribution

It introduces new instability criteria for vortex motion considering the effects of gyro-force, highlighting the stricter conditions for instability onset.

Findings

Weak gyro-force increases the threshold for vortex instability.

Instability requires either high friction or steep non-monotonic velocity dependence.

Gyro-force presence modifies traditional instability conditions.

Abstract

Here we study the instability of the vortex motion caused by vortex velocity non-monotonous dependence of the friction force in the presence of a gyro-force. We demonstrate that even a weak gyro-force renders the condition for onset of instability more strict than for a vortex not subject to gyro-forces: either the friction force must exceed a threshold, or its non-monotonic velocity dependence must be a rather steep function.