Separate Constraints on Early and Late Cosmology
  Since the public release of Planck data, several attempts have been made to
explain the observed small tensions with other data-sets, most of them
involving an extension of the {\Lambda}CDM Model. We try here an alternative
approach to the data analysis, based on separating the constraints coming from
the different epochs in cosmology, in order to assess which part of the
Standard Model generates the tension with the data. To this end, we perform a
particular analysis of Planck data probing only the early cosmological
evolution, until the time of photon decoupling. Then, we utilise this result to
see if the {\Lambda}CDM model can fit all observational constraints probing
only the late cosmological background evolution, discarding any information
concerning the late perturbation evolution. We find that all tensions between
the datasets are removed, suggesting that our standard assumptions on the
perturbed late-time history, as well as on reionisation, could sufficiently
bias our parameter extraction and be the source of the alleged tensions.
