Protoplanetary disks exhibit a vertical gradient in angular momentum, rendering them
susceptible to the vertical shear instability (VSI). The most important condition for the onset …

Planets are born in protostellar disks, which are now observed with enough resolution to
address questions about internal gas flows. Magnetic forces are possibly drivers of the flows …

This review examines recent theoretical developments in our understanding of turbulence in
cold, non-magnetically active, planetesimal-forming regions of protoplanetary disks that we …

We identify and study a number of new, rapidly growing instabilities of dust grains in
protoplanetary discs, which may be important for planetesimal formation. The study is based …

We propose an expression for a local planetesimal formation rate proportional to the
instantaneous radial pebble flux. The result—a radial planetesimal distribution—can be …

The outer protoplanetary discs (PPDs) can be subject to the magnetorotational instability
(MRI) and the vertical shear instability (VSI). While both processes can drive turbulence in …

Enhancing the local dust-to-gas ratio in protoplanetary discs is a necessary first step to
planetesimal formation. In laminar discs, dust settling is an efficient mechanism to raise the …

The past decade has seen major progress in our understanding of terrestrial planet
formation. Yet key questions remain. In this review we first address the growth of 100 km …

The streaming instability is a leading candidate mechanism to explain the formation of
planetesimals. However, the role of this instability in the driving of turbulence in …

Small solids embedded in gaseous protoplanetary disks are subject to strong dust–gas
friction. Consequently, tightly coupled dust particles almost follow the gas flow. This near …