POLARBEAR/Simons Array is an experiment located in the Atacama desert in Chile, designed to map the cosmic microwave background’s B-mode polarization signal. This faint pattern arises from gravitational lensing of the CMB, and is a powerful probe to study the composition and large-scale structure of the universe. A unique B-mode polarization pattern would also be imprinted by inflationary gravitational in the early universe. Measuring this signal would provide direct evidence for inflation, as well as provide insight into the mechanism and energy scale of inflation.
POLARBEAR-1 started observations in 2012, and after just one year of observations reached a map depth that enabled detection of B-mode polarization.
Since POLARBEAR-1 began observations, we have been developing a powerful new instrument, POLARBEAR-2, and we have expanded our site to include two new telescopes, known as the Simons Array. With high sensitivity and large sky coverage, POLARBEAR-2/Simons Array will create a detailed survey of B-mode polarization, with spectral information used to isolate the CMB signal from astrophysical foregrounds.