Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8141807 | Physics of the Dark Universe | 2018 | 16 Pages |
Abstract
The lack of power of large-angle CMB anisotropies is known to increase its statistical significance at higher Galactic latitudes, where a string-inspired pre-inflationary scale Î can also be detected. Considering the Planck 2015 data, and relying largely on a Bayesian approach, we show that the effect is mostly driven by the even -â harmonic multipoles with ââ²20, which appear sizably suppressed in a way that is robust with respect to Galactic masking, along with the corresponding detections of Î. On the other hand, the first odd -â multipoles are only suppressed at high Galactic latitudes. We investigate this behavior in different sky masks, constraining Î through even and odd multipoles, and we elaborate on possible implications. We include low-â polarization data which, despite being noise-limited, help in attaining confidence levels of about 3 Ï in the detection of Î. We also show by direct forecasts that a future all-sky E-mode cosmic-variance-limited polarization survey may push the constraining power for Î beyond 5 Ï.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Astronomy and Astrophysics
Authors
A. Gruppuso, N. Kitazawa, M. Lattanzi, N. Mandolesi, P. Natoli, A. Sagnotti,