Does Planck 2015 polarization favor high redshift reionization?

11 Jun 2018 Heinrich Chen Hu Wayne

We study the relationship between signatures of high redshift ionization in large-angle CMB polarization power spectra and features in the Planck 2015 data. Using a principal component (PC) ionization basis that is complete to the cosmic variance limit out to $z_{\rm max}=30,40,50$, we find a robust $>95\%$ CL preference for ionization at $z>15$ with no preference for $z>40$... (read more)

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