Résumé :
The dawn of the first generations of luminous baryons signaled the beginning
of an important epoch in cosmic history. I will sketch-out three
likely stages of this extended process, and present the theoretical framework
we currently have to support this narrative. I will then discuss
the potential of the redshifted 21cm line as a direct probe not only of
this epoch of reionization, but also of the dark ages which preceded it.
However, to interpret such a bounty of information, we need efficient
modeling tools capable of exploring the dauntingly large parameter
space and range of scales, such as our newly developed 21cmFAST.
