Inflationary vs. Reionization Features from Planck 2015 Data
  Features during inflation and reionization leave corresponding features in
the temperature and polarization power spectra that could potentially explain
anomalies in the Planck 2015 data but require a joint analysis to disentangle.
We study the interplay between these two effects using a model-independent
parametrization of the inflationary power spectrum and the ionization history.
Preference for a sharp suppression of large scale power is driven by a feature
in the temperature power spectrum at multipoles $\ell \sim 20$, whereas
preference for a component of high redshift ionization is driven by a sharp
excess of polarization power at $\ell \sim 10$ when compared with the lowest
multipoles. Marginalizing inflationary freedom does not weaken the preference
for $z \gtrsim 10$ ionization, whereas marginalizing reionization freedom
slightly enhances the preference for an inflationary feature but can also mask
its direct signature in polarization. The inflation and reionization
interpretation of these features makes predictions for the polarization
spectrum which can be tested in future precision measurements especially at
$10\lesssim \ell \lesssim 40$.
