DR. ZEESHAN AHMED

The BICEP/Keck Array program comprises a series of telescopes at the South Pole designed to measure cosmic microwave background polarization on degree angular scales, in search of imprints of inflation. This talk will describe the instrumentation, latest science results and recent improvements enabling further scale up of the program. We use BICEP2 and Keck Array data collected through 2014 in 150GHz and 95GHz bands, in combination with Planck and WMAP data to constrain a model consisting of lensed-LCDM, galactic dust and synchrotron emission, and an inflationary gravitational wave component. An excess over lensed-LCDM is detected and is consistent with dust. No significant evidence is found for synchrotron emission. We set a 95% confidence upper limit on inflationary tensor-to-scalar ratio, r<0.07. This represents the first time that limits on inflationary tensors from CMB polarization have surpassed the constraining power of CMB temperature data alone. The 2015 season will include data from two new 220 GHz receivers in the Keck Array to enhance sensitivity to dust emission. We have also developed and deployed BICEP3, a receiver with 10x throughput compared to BICEP2. The various instrumental improvements pioneered in BICEP3 present a path forward to deeper large-sky CMB surveys in the coming decade.