Magnetorotational instability: recent developments.

The magnetorotational instability is believed to play an important role in accretion disc physics in extracting angular momentum from the disc and allowing accretion to take place. For this reason the instability has been the subject of numerous numerical simulations and, increasingly, laboratory experiments. In this review, recent developments in both areas are surveyed, and a new theoretical approach to understanding the nonlinear processes involved in the saturation of the instability is outlined.