Institute for Advanced Study Astrophysics Seminar

ABSTRACT: Quasi-Periodic Oscillations (QPOs) have been measured in the tails of 2 out of 3 SGR giant flares. An attractive explanation for these QPOs is that they are due to torsional oscillations of the magnetar driving the flare. This opens up a possibility to perform asteroseismology of neutron stars. I will present a theoretical overview of magnetar oscillations, and will concentrate on the non-trivial dynamics due to a strong hydro-magnetic coupling between the elastic crust and the (multi)fluid core of the neutron star.