Structures in Dusty Disks
  Optically thin dusty disks around Main Sequence stars consist of debris from catastrophic collisions or from low erosion of long-lived planetesimals. Resolved observations of dusty disks have systematically evidenced asymmetries and annular structures. It has been proposed that some of these structures could be signatures of undetected exoplanets. In this paper, I review and discuss currently proposed models to account for the observed structures. These include the impact of distant exoplanets and/or of stellar companions. The Solar System serves as a reference case for these approaches and similarities are pointed out along the paper as well as some limitations of current modeling efforts. 
J. C. Augereau (1) ((1) Sterrewacht Leiden, The Netherlands)