Polarization of the Cosmic Microwave Background: an introductory review

Abstract

In this short review, I try to give a flavor of what are the motivations and difficulties of observing the Cosmic Microwave Background (CMB) polarization. After describing briefly the physics of CMB polarization, I give a snapshot of the observational status, as well as the data processing techniques developed so far. I end up describing how polarization information should constrain some key aspects of the early universe physics.