Dust Dynamics in Transitional Disks: Clumping and Disk Recession

The role of radiation pressure in dust migration and the opening inner cavities transitional disks is revisited this paper. Dust dynamics including often studied axisymmetric models, but work, we show that highly non-axisymmetric features can arise from an instability at disk edge. grains clump into high density there, allowing to leak around them penetrate deeper disk, changing course migration. Our proof-of-concept, two-dimensional, vertically-averaged simulations combination pressure, shadowing, gas drag produce a net outward migration, or recession, component disk. recession speed edge on order $10^{-5}$ times Keplerian our parameter space, which faster than background viscous flow, assuming Shakura & Sunyaev viscosity alpha $\lesssim 10^{-3}$. This speed, if sustained over lifetime result cavity as large tens au.