Date: Wednesday, October 29, 2014 - 3:30pm
We live in a universe whose properties are remarkably well described by a very early epoch of accelerating expansion, termed inflation. One generic prediction of inflation is a relic background of stochastic gravitational radiation. These tensor metric perturbations leave a distinctive imprint in the polarization of the microwave background. In March 2014, the BICEP experiment at the South Pole announced the detection of this signal for the first time, although subsequent analysis cast doubt on whether polarized emission from dust in the Milky Way galaxy might be contaminating the signal.