Active Galactic Nuclei in polarized light
  Due to the compactness active galactic nuclei (AGNs) are still unresolved
with optical observations. However, structure and physical conditions of the
matter in their central parts are especially important to study the processes
of the matter accretion to supermassive black holes and eventually these
investigations are essential to understand the galaxy evolution. Polarization
contains information about the interaction of electromagnetic waves with the
environment and provides information about the physical processes in the
central regions of the AGNs that could not be found with the help of other
optical observations. In this paper, the importance of applying polarimetry
methods to the study of geometry, kinematics, and physical processes in active
galactic nuclei (AGN) in polarized light is discussed. An overview of the
mechanisms of polarization formation, their connection with different
structures and scales are provided. Also, we overview the polarimetric
investigations based on different assumptions that are done using the
observations conducted in Special Astrophysical Observatory of the Russian
Academy of Sciences.
