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Detection of Β-mode polarization in the cosmic microwave background with data from the south pole telescope



Johannes Hubmayr, Hsiao-Mei Cho, Gene C. Hilton, Kent D. Irwin, Duncan Hanson


Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This "Β-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 Β modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing Β-mode signal by combining Ε-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 Β modes measured directly by SPTpol, finding a nonzero correlation at 7.7ς 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.
Physical Review Letters


Hubmayr, J. , Cho, H. , Hilton, G. , Irwin, K. and Hanson, D. (2013), Detection of Β-mode polarization in the cosmic microwave background with data from the south pole telescope, Physical Review Letters, [online], (Accessed June 12, 2024)


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Created September 30, 2013, Updated November 10, 2018