The Early Universe

InUniverseearly|underline this chapter the history of the universe through the first ten microseconds of its existence will be described. First, in Sect. 9.1 the Planck scalePlanckscaleScalePlanck, where quantum-mechanical and gravitational effects both become important, will be defined. This sets the starting point for the theory to be described. In Sects. 9.2 and 9.3 some formulae from statistical and thermal physics will be assembled, which are needed to describe the hot dense phase, out of which the universe then evolved.