Article,
The big-bang theory: construction, evolution and status
(2016)cite arxiv:1606.06112Comment: 69 pages, introductory lecture notes from the Poincaré seminar XX (2015) and Les Houches school "Cosmology after Planck: what is next?" (2016).
Abstract
Over the past century, rooted in the theory of general relativity, cosmology
has developed a very successful physical model of the universe: the \em
big-bang model. Its construction followed different stages to incorporate
nuclear processes, the understanding of the matter present in the universe, a
description of the early universe and of the large scale structure. This model
has been confronted to a variety of observations that allow one to reconstruct
its expansion history, its thermal history and the structuration of matter.
Hence, what we refer to as the big-bang model today is radically different from
what one may have had in mind a century ago. This construction changed our
vision of the universe, both on observable scales and for the universe as a
whole. It offers in particular physical models for the origins of the atomic
nuclei, of matter and of the large scale structure. This text summarizes the
main steps of the construction of the model, linking its main predictions to
the observations that back them up. It also discusses its weaknesses, the open
questions and problems, among which the need for a dark sector including dark
matter and dark energy.
