2019/01/15 by M. Billi, Billi, M., A. Gruppuso +7 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Geophysics and Gravity Measurements
paper · pdf · doi:10.48550/arxiv.1901.04762
openalex publication_date 2019/01/15 · openalex created_date 2019/01/25 · openalex updated_date 2026/07/28
The lack of power anomaly is an intriguing feature at the largest angular scales of the CMB anisotropy temperature pattern, whose statistical significance is not strong enough to claim any new physics beyond the standard cosmological model. We revisit the former statement by also considering polarisation data. We propose a new one-dimensional estimator which takes jointly into account the information contained in the TT, TE and EE CMB spectra. By employing this estimator on Planck 2015 low-ℓ data, we find that a random ΛCDM realisation is statistically accepted at the level of 3.68 %. Even though Planck polarisation contributes a mere 4 % to the total information budget, its use pushes the lower-tail-probability down from the 7.22 % obtained with only temperature data. Forecasts of future CMB polarised measurements, as e.g. the LiteBIRD satellite, can increase the polarisation contribution up to 6 times with respect to Planck at low-ℓ. We argue that the large-scale E-mode polarisation may play an important role in analysing CMB temperature anomalies with future mission.