Rotation is a physical phenomenon that impacts on the stellar structure and evolution of stars. Despite its importance, rotation in stars is not fully understood. In fact, predicted and observed rotation rates differ by more than an order of magnitude. This difference between observations and models is highly pronounced in red-giant stars. In these stars waves exhibit sensitivity to both the core and the surface, allowing us to infer the radial differential rotation at the core and surface of these stars through so-called rotational inversions. To do so, we need an appropriate model of the star. Given the number of free parameters and one-dimensionality of the models, there is some degeneracy. Hence, models with different parameters could be identified as, or close to, the best-fitting model for a particular star. In this work we investigate how robust the rotation results from rotational inversions are to changes in stellar parameters of the models used.

{"references": ["Beck, Paul et al. (2012). Fast core rotation in red-giant stars as revealed by gravity-dominated mixed modes. arXiv:1112.2825"]}