POLARBEAR

POLARBEAR is a cosmic microwave background (CMB) experiment situated on the 3.5-meter diameter Huan Tran Telescope at the James Ax Observatory located at Cerro Toco in the Atacama Desert in Northern Chile (image above by POLARBEAR collaboration). It is designed to make measurements of the CMB polarization on small angular scales in order to detect the B-mode polarization and put limits on inflation. Additionally, a second objective is to reconstruct the lensing potential of the CMB with hopes of providing limits on the neutrino mass.

The first POLARBEAR receiver was deployed to the Huan Tran Telescope in 2012. It contained 1274 antenna-coupled TES bolometers observing at 150 GHz. Observational strategy for the first two years of operation focused on deep surveys of small sky patches. In subsequent years (2014-2016) the POLARBEAR survey was expanded to cover 670 square degrees of sky.

Science results and available data products are described in:

• Measurement of the CMB polarization lensing power spectrum, (POLARBEAR et al 2014a).
• Evidence for Gravitational Lensing of the Cosmic Microwave Background Polarization from Cross-correlation with the Cosmic Infrared Background, (POLARBEAR et al 2014b)
• A Measurement of the Cosmic Microwave Background B-Mode Polarization Power Spectrum at Sub-Degree Scales with POLARBEAR, 2014ApJ...794..171P
• POLARBEAR constraints on cosmic birefringence and primordial magnetic fields, 2015PhRvD..92l3509A
• Measurement of the Cosmic Microwave Background Polarization Lensing Power Spectrum from Two Years of POLARBEAR Data, arxiv.org/abs/1911.10980
• A measurement of the CMB E-mode angular power spectrum at subdegree scales from 670 square degrees of POLARBEAR data, 2020ApJ...904...65A