Instabilities in Accretion Disks

Abstract

In order to understand the production of jets and winds from disks, or from star-disk interaction, it is important to understand the internal dynamics of the disk itself. This requires studying the nonlinear regime of various hydrodynamic and magnetohydrodynamic (MHD) instabilities that operate in disks, using non-ideal MHD and including the appropriate microphysics. Our current understanding of some of the most important instabilities in disks is reviewed, with focus on the magneto-rotational instability (MRI).