Measurement of the Cosmic Microwave Background Polarization Lensing Power Spectrum from Two Years of POLARBEAR Data

TL;DR

This paper reports a precise measurement of the gravitational lensing power spectrum of the cosmic microwave background polarization using two years of POLARBEAR data, confirming the Cold Dark Matter cosmology with high confidence.

Contribution

First measurement of the CMB polarization lensing power spectrum from two years of POLARBEAR data, with improved analysis and error estimation over previous results.

Findings

Lensing spectrum consistent with CDM cosmology

Rejected no-lensing hypothesis at 10.9 sigma

Measured lensing amplitude A_L = 1.33 +/- 0.32

Abstract

We present a measurement of the gravitational lensing deflection power spectrum reconstructed with two seasons cosmic microwave background polarization data from the POLARBEAR experiment. Observations were taken at 150 GHz from 2012 to 2014 which survey three patches of sky totaling 30 square degrees. We test the consistency of the lensing spectrum with a Cold Dark Matter (CDM) cosmology and reject the no-lensing hypothesis at a confidence of 10.9 sigma including statistical and systematic uncertainties. We observe a value of A_L = 1.33 +/- 0.32 (statistical) +/- 0.02 (systematic) +/- 0.07 (foreground) using all polarization lensing estimators, which corresponds to a 24% accurate measurement of the lensing amplitude. Compared to the analysis of the first year data, we have improved the breadth of both the suite of null tests and the error terms included in the estimation of systematic contamination.