# Wave-vortex interactions, remote recoil, the Aharonov-Bohm effect and the Craik-Leibovich equation

## TL;DR

This paper investigates non-dissipative wave-vortex interactions, highlighting local and remote recoil forces, with a special case where the recoil force aligns with the Craik-Leibovich vortex force and involves Aharonov-Bohm phase effects.

## Contribution

It identifies a unique parameter regime where the wave-induced recoil force matches the Craik-Leibovich vortex force and emphasizes the topological Aharonov-Bohm effect in this context.

## Key findings

- Remote recoil is prevalent except in a special case.
- The exceptional case links the recoil force to the Craik-Leibovich vortex force.
- Aharonov-Bohm phase jump is the main wave refraction effect in the special case.

## Abstract

Three examples of non-dissipative yet cumulative interaction between a single wavetrain and a single vortex are analysed, with a focus on effective recoil forces, local and remote. Local recoil occurs when the wavetrain overlaps the vortex core. All three examples comply with the pseudomomentum rule. The first two examples are two-dimensional and non-rotating (shallow water or gas dynamical). The third is rotating, with deep-water gravity waves inducing an Ursell `anti-Stokes flow'. The Froude or Mach number, and the Rossby number in the third example, are assumed small. Remote recoil is all or part of the interaction in all three examples, except in one special limiting case. That case is found only within a severely restricted parameter regime and is the only case in which, exceptionally, the effective recoil force can be regarded as purely local and identifiable with the celebrated Craik-Leibovich vortex force -- which corresponds, in the quantum fluids literature, to the Iordanskii force due to a phonon current incident on a vortex. Another peculiarity of that exceptional case is that the only significant wave refraction effect is the Aharonov-Bohm topological phase jump.