A core-sensitive mixed $f$/$g$ mode of the Sun predicted by wave topology and hydrodynamical simulation

TL;DR

This paper identifies a new mixed $f$/$g$ mode in the Sun through hydrodynamical simulations, revealing its potential to probe the solar core's rotation and internal structure.

Contribution

It introduces the first fully coupled hydrodynamical simulation of compressible and gravity modes in the Sun, uncovering a new mixed mode with core-sensitive properties.

Findings

Discovered a new mixed $f$/$g$ mode with a one-hour period.

Demonstrated the mode's sensitivity to the Sun's core rotation.

Established a link between wave topology theory and mode coupling.

Abstract

Helioseismology has revolutionized our understanding of the Sun by analyzing its global oscillation modes. However, the solar core remains elusive, limiting a full understanding of its evolution. In this work, we study a previously unnoticed global oscillation mode of the Sun using a fully compressible, hydrodynamical simulation of the solar interior, and assess that it is a mixed $f$/$g$ mode with a period of about one hour. This is the first global stellar hydrodynamics simulation that successfuly couple compressible and gravity modes. To understand this coupling, we invoke a recent theory on the nature of $f$-modes seen through the prism of wave topology, characterizing their ability to propagate deep into stellar interiors. We demonstrate that the mixed $f$/$g$ mode is highly sensitive to the core's rotation rate, providing a new promising pathway to explore the Sun's core.