The Planck Mission and the Cosmic Microwave Background

Abstract

Relevant observations to test cosmological models have increased dramatically in the last fifteen years. The Planck space mission for the observation of Cosmic Microwave Background has brought a large increase in the accuracy of the maps of its temperature and polarization. These results have confirmed in a spectacular way the ΛCDM model and determined the parameters attached to the present content and dynamics of our universe with sub percent accuracy. The combination with observations of the baryon acoustic oscillations measurements made this set of parameters even tighter. The predictions from the inflation paradigm of the early universe physics have been confirmed. The tensor-to-scalar modes ratio emerging from the early universe is only bounded by an upper limit. We show the robustness of the model by checking its assumptions (flat space geometry, gaussianity and adiabaticity of fluctuations).We also add to the ΛCDM six parameters key physical constants to the cosmological model that we constrain from the CMB anisotropies. This demonstrates the complementarity of the standard model of particle physics and what appears now to be the standard model of cosmology which together account for a very large body of high accuracy observations but need the introduction of new physics.