Detection of B-mode Polarization in the Cosmic Microwave Background with Data from the South Pole Telescope

• Main Authors: Hanson, D., Hoover, S., Crites, A., Ade, P. A. R., Aird, K. A., Austermann, J. E., Beall, J. A., Bender, A. N., Benson, B. A., Bleem, L. E., Bock, J. J., Carlstrom, J. E., Chang, C. L., Chiang, H. C., Cho, H-M., Conley, A., Crawford, T. M., de Haan, T., Dobbs, M. A., Everett, W., Gallicchio, J., Gao, J., George, E. M., Halverson, N. W., Harrington, N., Henning, J. W., Hilton, G. C., Holder, G. P., Holzapfel, W. L., Hrubes, J. D., Huang, N., Hubmayr, J., Irwin, K. D., Keisler, R., Knox, L., Lee, A. T., Leitch, E., Li, D., Liang, C., Luong-Van, D., Marsden, G., McMahon, J. J., Mehl, J., Meyer, S. S., Mocanu, L., Montroy, T. E., Natoli, T., Nibarger, J. P., Novosad, V., Padin, S., Pryke, C., Reichardt, C. L., Ruhl, J. E., Saliwanchik, B. R., Sayre, J. T., Schaffer, K. K., Schulz, B., Smecher, G., Stark, A. A., Story, K., Tucker, C., Vanderlinde, K., Vieira, J. D., Viero, M. P., Wang, G., Yefremenko, V., Zahn, O., Zemcov, M.
• Format: Text
• Language: unknown
• Published: arXiv 2013
• Subjects: Cosmology and Nongalactic Astrophysics astro-ph.CO; FOS Physical sciences; Curl; South Pole; South pole
• Online Access: https://dx.doi.org/10.48550/arxiv.1307.5830; https://arxiv.org/abs/1307.5830

Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This "B-mode" signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of gravitational lensing B modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal by combining E-mode polarization measured by SPTpol with estimates of the lensing potential from a Herschel-SPIRE map of the cosmic infrared background. We compare this template to the B modes measured directly by SPTpol, finding a non-zero correlation at 7.7 sigma significance. The correlation has an amplitude and scale-dependence consistent with theoretical expectations, is robust with respect to analysis choices, and constitutes the first measurement of a powerful cosmological observable. : Two additional null tests, matches version published in PRL