In recent years, exciting developments have taken place in the identification of the role of
cosmic rays in star-forming environments. Observations from radio to infrared wavelengths …

Context. The global size and spatial distribution of dust is an important ingredient in the
structure and evolution of protoplanetary disks and in the formation of larger bodies, such as …

Aims. Recent observations by the Atacama Large Millimeter/submillimeter Array (ALMA) of
disks around young stars revealed distinct asymmetries in the dust continuum emission. In …

Recent observations of extrasolar gas giants suggest super-stellar C/O ratios in planetary
atmospheres, while interior models of observed extrasolar giant planets additionally suggest …

Context. Current models of the size-and radial evolution of dust in protoplanetary disks
generally oversimplify either the radial evolution of the disk (by focussing at one single …

Rapid orbital drift of macroscopic dust particles is one of the major obstacles to planetesimal
formation in protoplanetary disks. We re-examine this problem by considering the porosity …

Context. The sticking of micron-sized dust particles caused by surface forces within
circumstellar disks is the first stage in the production of asteroids and planets. The key …

Aims. We attempt to explain grain growth to mm sized particles and their retention in the
outer regions of protoplanetary disks, as observed at sub-mm and mm wavelengths, by …

Collisions between dust aggregates are the key to understand the formation of
planetesimals because the collision inevitably takes place in protoplanetary disks. To clarify …

Protoplanetary disks (PPDs) are believed to accrete onto their central T Tauri star because
of magnetic stresses. Recently published shearing box simulations indicate that Ohmic …