Theory Group Special Seminar, 19 January 2016
Dr. Christopher Sheehy, University of Chicago
Improved constraints on cosmic inflation with new 95 GHz data from the
Keck Array
abstract
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 dataset.