Polarization of Microwave Background: Statistical and Physical   Properties
  We discuss statistical and physical properties of cosmic microwave background polarization, both in Fourier and in real space. The latter allows for a more intuitive understanding of some of the geometric signatures. We present expressions that relate electric and magnetic type of polarization to the measured Stokes parameters in real space and discuss how can be constructed locally. We discuss necessary conditions to create polarization and present simulated maps and correlation functions for some typical models. 
Uros Seljak (CfA), Matias Zaldarriaga (MIT)