Wave topology of stellar inertial oscillations

TL;DR

This paper explores the topological properties of inertial waves in stars, revealing unique wave modes and phase singularities that could enable robust wave detection in noisy stellar data.

Contribution

It introduces the topological characterization of stellar inertial oscillations, linking wave properties to Chern numbers and phase singularities, a novel approach in astrophysics.

Findings

Identification of a unidirectional prograde mode

Discovery of phase singularities with winding numbers

Robustness of phase winding to noise

Abstract

Inertial waves in convective regions of stars exhibit topological properties linked to a Chern number of 1. The first of these is a unique, unidirectional, prograde oscillation mode within the cavity, which propagates at arbitrarily low frequencies for moderate azimuthal wavenumbers. The second one are phase singularities around which the phase winds in Fourier space, with winding numbers of $\pm 1$ depending on the hemisphere. Phase winding is a collective effect over waves propagating in all directions that is strongly robust to noise. This suggests a topology-based method for wave detection in noisy observational data.