Institute for Advanced Study Informal Astrophysics Seminar

POLARBEAR is a millimeter wave polarimeter operating from 5,200 meters in the Atacama Desert of northern Chile. The instrument's 3.5 arcminute beam enables measurements of the polarized cosmic microwave background (CMB) lensing signal. After briefly reviewing the instrument, I present results from our first season of observations, including the first measurements of the B-mode polarization power spectrum. I conclude by outlining future plans for the POLARBEAR experiment and the next generation POLARBEAR-2 and Simons Array experiments.