Abstract: Stars have global oscillation modes, which can be observed by looking
for periodic brightness variations. If many modes of oscillation have been
identified, one can infer the properties of the deep interiors of
stars. This was first applied to observations of the Sun, but recently
space-based telescopes have measured oscillations in many other stars,
leading to new mysteries in stellar structure and evolution. Recent work
has suggested that low dipole oscillation amplitudes in red giant branch
stars may indicate strong core magnetic fields. Here we present both
numerical simulations and analytic calculations of the interactions of
waves with a strong magnetic field. We can solve the problem very
accurately by using the WKB approximation to reduce the 2D PDE into an
ODE for each height. We find that magnetic fields convert the
buoyancy-driven waves observable at the surface of the star to
magnetic waves, which are not present at the surface, in agreement with
observations.