Polarization Predictions for Inflationary CMB Power Spectrum Features

Understand

We conduct a model-independent analysis of temporal features during inflation in the large-scale CMB temperature power spectrum allowing for the possibility of non-negligible tensor contributions.

• Of 20 principal components of the inflationary history, the suppression of power at low multipoles beginning with a glitch at multipoles $\ell \sim 20-40$ implies deviations in 2-3 of them with 2-3$\sigma$ deviations in each, with larger values reflecting cases where tensors are allowed.If tensors are absent, the corresponding $E$-mode polarization features follow a similar pattern but are predicted to be up to twice as large.
• They offer the opportunity to soon double the significance of inflationary features or eliminate them as an explanation of temperature features.
• The tensor degeneracy with features in the temperature power spectrum is broken not only by $B$ but also by $E$-polarization.