IPAC Seminar Tony Readhead: The QU Imaging ExperimenT (QUIET)

The cosmic microwave background might well provide a window on the very early universe via observations of B-mode polarization on large angular scales. Apart from galactic foregrounds, which can also produce B-mode signals on these scales, the only other source is through the interaction of long-wavelength gravitational waves, produced in an inflationary epoch in the very early universe, interacting with the plasma at the epoch of decoupling. Several searches for this B-mode signal are under way. I will describe the prototype QU Imaging ExperimenT (QUIET) instrument, which operated in Chile from 2008-2010 at 45 GHz and 90 GHz and describe recent progress on the QUIET detectors, and the status of the observations.