Master defense by Sebastian Hausegger

Steps towards a clear view on the Cosmic Microwave Background

The Cosmic Microwave Background is one of the strongest probes of the cosmological his-tory of our Universe. Several experiments from ground as well as from space continue to perform measurements of the CMB with increasing sensitivity. As the detected signal contains microwave emission from our Galaxy as well, the careful separation of the foreground from the background is a delicate act. Approaching the subject from different perspectives, we argue that the physical mechanisms of foregrounds must be better understood before attempting the most ambitious measurements of primordial physics. To this effect, methods for analyzing astrophysical data are proposed, giving us reason to believe the need for a clearer understanding of foregrounds, in addition to reviewing selected topics of relevance.