Collaborative Research: Analysis of data from the QUaD experiment

The proposal seeks support to complete the analysis of data from the QUaD experiment located at the U.S. Amundsen-Scott South Pole Station in 2005-2007. QUaD is a 31-pixel polarization-sensitive bolometric camera mounted on a 2.6 meter Cassegrain telescope, which was making maps of the polarization in the Cosmic Microwave Background (CMB) radiation on angular scales from 5 angular minutes to 2 degrees. Recently released results from the first season of observations (2005) improve any previous results obtained by individual small angular scale experiments. A second successful season of data taking (2006) is now complete and data are in an advanced state of the analysis. The third observational season (2007) just completed and the data are undergoing initial checks, characterization of ground spillover and mitigation of its effects by appropriate filters in Fourier space. As processed and analyzed, these data will produce most precise measurements of the CMB polarization spectra in the multipoles range 200-2000. This will permit a detailed test of whether scalar fluctuations in the early Universe were adiabatic as predicted by the simplest inflationary models, or whether there were significant amounts of isocurvature fluctuations. QUaD also serves as a pathfinder for many of the modern observational techniques that will be needed by future experiments, probing systematic effects that must be confronted in the quest to detect the faint polarization signature from tensor modes.