SATELLITE MISSION OPPORTUNITIES FOR CMB POLARIZATION: WHITE PAPER FOR THE CANADIAN LRP MIDTERM REVIEW

The cosmic microwave background (CMB) is a cornerstone for precision cosmology and Canadian experimenters have been involved with the majority of signicant results over the last 25 years. Canada’s footprint has grown substantially since the LRP, with 4 out of 10 co-authors of this paper having been hired since 2010. The next frontier is a detailed characterization of CMB polarization, with a focus on the subtle B-mode signature. Perhaps the most exciting prospect is the ability to look beyond the surface of last scattering to see or place stringent limits on gravity waves emitted from a period of ination a fraction of a second after the Big Bang. Canadians have played key instrumentation, analysis, and interpretation roles in all B-mode results that have been reported to date. Presently, the vast majority of ground- and balloon-based CMB experiments use TES bolometers, and all of these experiments read out their detector arrays with Canadian technology. TES bolometers are the leading technology for future satellites as well. A dedicated CMB polarization satellite will be a large international partnership. With support from the Canadian Space Agency, Canadian researchers are uniquely positioned to play an international leadership role in this mission, partnering with one or more other agencies to make the denitive measurement of large to medium angular scale CMB polarization. This white paper is written to seek community endorsement for a high prioritization of a Canadian partnership contribution to a near-term future CMB polarization satellite.