Title: Inflationary Features and Shifts in Cosmological Parameters from Planck 2015 Data,
Abstract: We explore the relationship between features in the Planck 2015 temperature
and polarization data, shifts in the cosmological parameters, and features from
inflation. Residuals in the temperature data at low multipole $\ell$, which are
responsible for the high $H_0\approx 70$ km s$^{-1}$Mpc$^{-1}$ and low
$\sigma_8\Omega_m^{1/2}$ values from $\ell<1000$ in power-law $\Lambda$CDM
models, are better fit to inflationary features with a $1.9\sigma$ preference
for running of the running of the tilt or a stronger $99\%$ CL local
significance preference for a sharp drop in power around $k=0.004$ Mpc$^{-1}$
in generalized slow roll and a lower $H_0\approx 67$ km s$^{-1}$Mpc$^{-1}$. The
same in-phase acoustic residuals at $\ell>1000$ that drive the global $H_0$
constraints and appear as a lensing anomaly also favor running parameters which
allow even lower $H_0$, but not once lensing reconstruction is considered.
Polarization spectra are intrinsically highly sensitive to these parameter
shifts, and even more so in the Planck 2015 TE data due to an outlier at $\ell
\approx 165$, which disfavors the best fit $H_0$ $\Lambda$CDM solution by more
than $2\sigma$, and high $H_0$ value at almost $3\sigma$. Current polarization
data also slightly enhance the significance of a sharp suppression of
large-scale power but leave room for large improvements in the future with
cosmic variance limited $E$-mode measurements.