Dervish

Context

The theoretical modeling of a specific kind of (mixed) stellar vibrations in evolved red giant stars needs to be able to explain why the observed frequency splittings (i.e., the lifting of degeneracy due to rotation and/or other symmetry-breaking effects) are asymmetric. Higher-order rotational effects that occur for differentially rotating red giants are typically not included. To model these effects, I developed a computational framework called dervish.

Purpose

Modeling higher-order effects of rotation on adiabatic linear oscillations of a rotating red giant star offers the asteroseismologist a good first window into the importance of different contributing terms. This computational framework revisits published frameworks, and provides the means to distinguish between different origins of different contributions to the rotational perturbation of the oscillation frequency up to second order (for now). It also computes the perturbations of the eigenfunctions due to rotation, and accounts for the rotational distortion (of the star) in a perturbative manner. This allows the user to compute asymmetric rotational splittings for the frequently observed dipole (for now) mixed modes in red giant stars.

Applications

Work in progress.

Citations/using this code

Work in progress.