%0 Generic %A Pohl, Adriana %D 2018 %F heidok:24039 %R 10.11588/heidok.00024039 %T Structure of planet-forming disks: multi-wavelength polarization diagnostics %U https://archiv.ub.uni-heidelberg.de/volltextserver/24039/ %X The study of dynamic processes that drive the evolution of planet-forming disks is fundamental to understand the origin and diversity of planetary systems. This requires observations at high spatial resolution and sensitivity, which nowadays typically reveal intriguing disk substructures including gaps, rings, spirals, and shadows. This thesis investigates the capability of polarization observations at multiple wavelengths to trace the earliest stages of planet formation. In-depth radiative transfer calculations are carried out in order to link numerical simulations of dust and gas evolution in disks with their observational indicators. This approach demonstrates that measuring polarization is a powerful tool to identify the shaping effects that possible embedded planets have on the density distribution of different dust grain sizes. On the observational part, this work presents several case studies of individual planet-forming disks that were observed with polarimetric imaging by the VLT/SPHERE instrument and subsequently modeled to quantify their structure. A particular focus is the characterization of spiral and ring/gap structures in the context of dust growth, planet-disk interactions, and dust dynamics near ice lines. Furthermore, a modeling study of marginally gravitationally unstable disks is presented to study the influence of the disk self-gravity on the shape and contrast of planet-induced spiral arms in scattered light images. Additionally, it is demonstrated that polarized emission of disks at millimeter wavelengths can be caused by self-scattered thermal dust emission. It is shown that the latter is a viable method to constrain grain properties and identify dust concentrations of different origin. New ALMA observations are presented that offer the first look at a dust trap in polarized scattered light in the sub-millimeter range.