SB/BNL Joint Cosmo seminar: Chris Sheehy, Chicago: "New constraints on cosmic inflation from the Keck Array"
The Keck Array, part of the BICEP/Keck program of small aperture cosmic microwave background (CMB) telescopes, is currently taking data at the South Pole in Antarctica. The goal of the BICEP/Keck program is to detect the B-mode pattern in the CMB's polarized anisotropy that would be a signature of cosmic inflation, or, barring a detection, to set upper limits that rule out some of the most favored theoretical scenarios. Previous results from BICEP2 and the Keck Array that detected B-modes at high significance consisted of data taken only at 150 GHz, and which could therefore not conclusively distinguish between a cosmological vs. galactic origin for the signal. A subsequent joint analysis with the Planck satellite collaboration that invoked their comparatively noisy but multifrequency maps revealed a large component of the signal to be from polarized thermal emission of galactic dust. In this talk, I will present the results from the first year of observations with Keck's new 95 GHz receivers. These results set the most stringent limits on cosmic inflation to date and mark the point at which CMB polarization now constrains inflation better than any other data set.