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arXiv · 1801.01481

A Projected Estimate of the Reionization Optical Depth Using the CLASS Experiment's Sample-Variance Limited E-Mode Measurement

Duncan J. Watts·Bingjie Wang·Aamir Ali·John W. Appel·Charles L. Bennett·David T. Chuss·Sumit Dahal·Joseph R. Eimer·Thomas Essinger-Hileman·Kathleen Harrington·Gary Hinshaw·Jeffrey Iuliano·Tobias A. Marriage·Nathan J. Miller·Ivan L. Padilla·Lucas Parker·Matthew Petroff·Karwan Rostem·Edward J. Wollack·Zhilei Xu
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Abstract

We analyze simulated maps of the Cosmology Large Angular Scale Surveyor (CLASS) experiment and recover a nearly cosmic-variance limited estimate of the reionization optical depth $\tau$. We use a power spectrum-based likelihood to simultaneously clean foregrounds and estimate cosmological parameters in multipole space. Using software specifically designed to constrain $\tau$, the amplitude of scalar fluctuations $A_s$, and the tensor-to-scalar ratio $r$, we demonstrate that the CLASS experiment will be able to estimate $\tau$ within a factor of two of the full-sky cosmic variance limit allowed by cosmic microwave background polarization measurements. Additionally, we discuss the role of CLASS's $\tau$ constraint in conjunction with gravitational lensing of the CMB on obtaining a $\gtrsim4\sigma$ measurement of the sum of the neutrino masses.

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Duncan J. Watts, Bingjie Wang, Aamir Ali, John W. Appel, Charles L. Bennett, David T. Chuss, Sumit Dahal, Joseph R. Eimer, Thomas Essinger-Hileman, Kathleen Harrington, Gary Hinshaw, Jeffrey Iuliano, Tobias A. Marriage, Nathan J. Miller, Ivan L. Padilla, Lucas Parker, Matthew Petroff, Karwan Rostem, Edward J. Wollack, Zhilei Xu. 2018-01-04. A Projected Estimate of the Reionization Optical Depth Using the CLASS Experiment's Sample-Variance Limited E-Mode Measurement. https://doi.org/10.3847/1538-4357%2Faad283

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