H. Nishino

The POLARBEAR Experiment

We present the design and characterization of the POLARBEAR experiment. POLARBEAR will measure the polarization of the cosmic microwave background (CMB) on angular scales ranging from the experiment’s 3.5’ beam size to several degrees. The experiment utilizes a unique focal plane of 1,274 antenna-coupled, polarization sensitive TES bolometers cooled to 250 milliKelvin. Employing this focal plane along with stringent control over systematic errors, POLARBEAR has the sensitivity to detect the expected small scale B-mode signal due to gravitational lensing and search for the large scale B-mode signal from inflationary gravitational waves. POLARBEAR was assembled for an engineering run in the Inyo Mountains of California in 2010 and was deployed in late 2011 to the Atacama Desert in Chile. An overview of the instrument is presented along with characterization results from observations in Chile.

LiteBIRD: a small satellite for the study of B-mode polarization and inflation from cosmic background radiation detection

LiteBIRD [Lite (Light) satellite for the studies of B-mode polarization and Inflation from cosmic background Radiation Detection] is a small satellite to map the polarization of the cosmic microwave background (CMB) radiation over the full sky at large angular scales with unprecedented precision. Cosmological inflation, which is the leading hypothesis to resolve the problems in the Big Bang theory, predicts that primordial gravitational waves were created during the inflationary era. Measurements of polarization of the CMB radiation are known as the best probe to detect the primordial gravitational waves. The LiteBIRD working group is authorized by the Japanese Steering Committee for Space Science (SCSS) and is supported by JAXA. It has more than 50 members from Japan, USA and Canada. The scientific objective of LiteBIRD is to test all the representative inflation models that satisfy single-field slow-roll conditions and lie in the large-field regime. To this end, the requirement on the precision of the tensor-to-scalar ratio, r, at LiteBIRD is equal to or less than 0.001. Our baseline design adopts an array of multi-chroic superconducting polarimeters that are read out with high multiplexing factors in the frequency domain for a compact focal plane. The required sensitivity of 1.8μKarcmin is achieved with 2000 TES bolometers at 100mK. The cryogenic system is based on the Stirling/JT technology developed for SPICA, and the continuous ADR system shares the design with future X-ray satellites.

POLARBEAR constraints on cosmic birefringence and primordial magnetic fields

Author(s): Ade, PAR; Arnold, K; Atlas, M; Baccigalupi, C; Barron, D; Boettger, D; Borrill, J; Chapman, S; Chinone, Y; Cukierman, A; Dobbs, M; Ducout, A; Dunner, R; Elleflot, T; Errard, J; Fabbian, G; Feeney, S; Feng, C; Gilbert, A; Goeckner-Wald, N; Groh, J; Hall, G; Halverson, NW; Hasegawa, M; Hattori, K; Hazumi, M; Hill, C; Holzapfel, WL; Hori, Y; Howe, L; Inoue, Y; Jaehnig, GC; Jaffe, AH; Jeong, O; Katayama, N; Kaufman, JP; Keating, B; Kermish, Z; Keskitalo, R; Kisner, T; Kusaka, A; Le Jeune, M; Lee, AT; Leitch, EM; Leon, D; Li, Y; Linder, E; Lowry, L; Matsuda, F; Matsumura, T; Miller, N; Montgomery, J; Myers, MJ; Navaroli, M; Nishino, H; Okamura, T; Paar, H; Peloton, J; Pogosian, L; Poletti, D; Puglisi, G; Raum, C; Rebeiz, G; Reichardt, CL; Richards, PL; Ross, C; Rotermund, KM; Schenck, DE; Sherwin, BD; Shimon, M; Shirley, I; Siritanasak, P; Smecher, G; Stebor, N; Steinbach, B; Suzuki, A; Suzuki, JI; Tajima, O; Takakura, S; Tikhomirov, A; Tomaru, T; Whitehorn, N; Wilson, B; Yadav, A; Zahn, A | Abstract:

The bolometric focal plane array of the POLARBEAR CMB experiment

The POLARBEAR Cosmic Microwave Background (CMB) polarization experiment is currently observing from the Atacama Desert in Northern Chile. It will characterize the expected B-mode polarization due to gravitational lensing of the CMB, and search for the possible B-mode signature of inflationary gravitational waves. Its 250 mK focal plane detector array consists of 1,274 polarization-sensitive antenna-coupled bolometers, each with an associated lithographed band-defining filter. Each detector’s planar antenna structure is coupled to the telescope’s optical system through a contacting dielectric lenslet, an architecture unique in current CMB experiments. We present the initial characterization of this focal plane.

A Measurement of the Cosmic Microwave Background B-mode Polarization Power Spectrum at Subdegree Scales from Two Years of polarbear Data

We report an improved measurement of the cosmic microwave background B-mode polarization power spectrum with the Polarbear experiment at 150 GHz. By adding new data collected during the second season of observations (2013–2014) to re-analyzed data from the first season (2012–2013), we have reduced twofold the band-power uncertainties. The band powers are reported over angular multipoles

Performance of a continuously rotating half-wave plate on the POLARBEAR telescope

500\leqslant {\ell }\leqslant 2100

The Simons Array CMB polarization experiment

, where the dominant B-mode signal is expected to be due to the gravitational lensing of E-modes. We reject the null hypothesis of no B-mode polarization at a confidence of 3.1σ including both statistical and systematic uncertainties. We test the consistency of the measured B-modes with the Λ Cold Dark Matter (ΛCDM) framework by fitting for a single lensing amplitude parameter A L relative to the Planck 2015 best-fit model prediction. We obtain

POLARBEAR-2 optical and polarimeter designs

{A}_{L}={0.60}_{-0.24}^{+0.26}(\mathrm{stat}{)}_{-0.04}^{+0.00}(\mathrm{inst})

Current design of the electrical architecture for the payload module of LiteBIRD

± 0.14(foreground) ± 0.04(multi), where

Cosmic Microwave Background B-Mode Polarization Experiment POLARBEAR-2

{A}_{L}=1