Amplitude equations solver: AESolver

Context

The theoretical modeling of (standing) stellar vibrations - also known as stellar oscillation modes - has been the focus of my work for a large part of my (short) academic career. It is quite commonly performed in the linear approximation, which neglects energy exchange among the oscillation modes. To model the (non-linear) energy exchange among oscillation modes, I developed a computational framework called AESolver.

Purpose

Modeling within the linear approximation offers the asteroseismologist theoretically predicted observables - oscillation mode frequencies - that are to be compared to the observed variability frequencies. This computational framework simulates the non-linear energy exchange among oscillation modes, so that mode amplitudes can be modeled. If we account for the projection of the stellar surface onto a telescope, the computed amplitudes (more specifically, their ratios in resonant triads) can be contrasted with the variability amplitudes detected in photometric light curves of variable stars suing that telescope.

Applications

In Van Beeck et al. (2024) we use AESolver to compute amplitudes of gravity modes in a small model grid representative for slowly pulsating B stars. We found that the ratios of amplitudes of modes in a resonant triad that fulfill certain (angular momentum conservation) selection rules (see Van Beeck et al. (2024) for details) are the most promising non-linear theoretically predicted observables for constraining the models of stellar interiors.

Citations/using this code

The theoretical formalism that forms the basis for this computational framework is described in Van Beeck et al. (2024). When using (part of) this code, you should therefore cite that article.