simulations

The stability of magnetic fields in radiative stellar interiors remains a fundamental open question in understanding the rotational and chemical evolution of low-mass stars. Recent high-resolution asteroseismic observations of red giants have revealed unexpectedly slow core rotations and the presence of strong internal magnetic fields, opening a new window on the internal dynamics of evolved stars. In this talk, I will review the main magnetohydrodynamic instabilities expected in radiative stellar interiors and present new 3D direct numerical simulations of the Tayler instability, a kink-type instability of toroidal magnetic fields prevalent in these regions. By combining simulations, linear stability analysis, and stellar evolution models, we identify where and under what conditions the Tayler instability is likely to operate in red giant cores. These results provide new insight into angular momentum transport in evolved low-mass stars and may also have broader implications for other stars with radiative interiors.