title: Dust density at the onset of the Kelvin-Helmholtz Instability

authors: Yukihiko Hasegawa, Toru Tsuribe

abstract: We reexamine sedimentation of dust grains and the possibility of turbulence in the protoplanetary disk for the both cases without and with dust growth. Dust density in the midplane at the onset of KHI increases with an increase of the dust abundance for the case without dust growth. In the case with dust growth, it is found that the Kelvin-Helmholtz Instability tends to occur before the gravitational instability even in the case with large abundance of dust grains. It is suggested that the difference between the case without dust growth and that with dust growth arises from the change of stopping time of dust grains due to dust growth.