GRAVITATIONAL LENSING of B-MODE POLARIZATION MEASURED w/ POLARBEAR
Cosmological results from the first season of POLARBEAR observations have been submitted for publication. We measured gravitational lensing of the CMB using CMB polarization alone (arxiv.org/1312.6646), and also showed that the lensing convergence map correlates with the large-scale structure traced by Herschel 500 micron cosmic infrared background observations (arxiv.org/1312.6645)
Polarization lensing power spectra. Polarization lensing power spectra co-added from the three patches and two estimators are shown in red. The lensing signal predicted by the ΛCDM model is shown as the solid black curve. The polarization lensing power spectrum hEEEBi is in blue and hEBEBi dark green. Left: A 4.2σ rejection of the null hypothesis of no lensing. These data indicate a lensing amplitude A = 1.37 ± 0.30 ± 0.13 normalized to the fiducial ΛCDM value. Right: The same data, assuming the existence of gravitational lensing to calculate error bars–including sample variance and including the covariance between hEEEBi and hEBEBi. In this case, the lensing amplitude is measured as A = 1.06 ± 0.47+0.32 −0.27, corresponding to 53% uncertainty on the amplitude of the C dd L power spectrum (26% uncertainty on the amplitude of matter fluctuations). The histograms of the amplitudes A from 500 unlensed and lensed simulations are shown in the inset boxes.
Cross-power spectra of CMB polarization lensing and the 500μm Herschel CIB flux. Top panel: the min- imum variance combination of all polarization lensing measurements cross correlated with the Herschel maps; this result corresponds to 4.0σ evidence for gravitational lensing of CMB polarization.