DDP

Abstract

MHD turbulence driven by the magnetoroational instability (MRI) is the most promising mechanism of angular momentum transport in accretion disks. However protoplanetary disks are dense and cold so that the ionization fraction is extremely low. It is known that there must be dead zones in protoplanetary disks where the growth of MRI is suppressed significantly due to non-ideal MHD effects. The size of dead zones are related to the characteristics of dust grains. The gas and dust evolutions, or planet formation, are affected by the existence of the dead zones. The roles of the dead zones in planet formation scenario are summarized in this talk.