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Kavli Institute for Cosmology, Cambridge

A Reanalysis of Planck

Members of KICC since its foundation and longstanding members of the Planck collaboration, Prof. George Efstathiou and Dr. Steven Gratton recently uploaded their detailed reanalysis of the Planck satellite Cosmic Microwave Background data to the arXiv preprint server.

Their undertaking complements and confirms the Planck collaboration findings about the “Lambda-cold-dark-matter” (LCDM) standard cosmological model as summarized in the 2018 Planck Parameters Paper. 

Benefitting from an additional year of work, an improved accounting of cosmic dust contamination allowed the use of data from more of the sky for cosmology. This, along with a special handling of effective calibrations in Planck’s polarization data, yielded improved temperature and polarization power spectra (which are measures of the levels of fluctuations on the sky with respect to angular scale).  These spectra give an even better agreement with LCDM and show even better internal consistency within Planck.  Constraints for extended cosmological models are also refined.

The preprint is available at: .  Illustrated below, in a plot taken from the paper, is the Planck temperature data power spectrum compared to the best-fit LCDM model:


As is clear from the tiny residuals, as far as the Planck data is concerned, LCDM is doing better than ever!