Lack of large-angle TT correlations persists in WMAP and Planck

Understand

The lack of large-angle correlations in the observed microwave background temperature fluctuations persists in the final-year maps from WMAP and the first cosmological data release from Planck.

• We find a statistically robust and significant result: p-values for the missing correlations lying below 0.24 per cent (i.e.
• evidence at more than 3 sigma) for foreground cleaned maps, in complete agreement with previous analyses based upon earlier WMAP data.
• A conservative cut-sky analysis of the Planck HFI 100 GHz frequency band, the `cleanest CMB channel', returns a p-value as small as 0.03 per cent, based on the conservative mask defined by WMAP.