From Cosmic Strings to Cosmic SUperstrings: Dynamics of Cosmic Superstring Networks

Cosmic strings, a hot subject in the 1980's and early 1990's, lost its appeal 
when it was found that it leads to inconsistencies in the power spectrum of the 
measured cosmic microwave background temperature anisotropies. However, topological 
defects in general, and cosmic strings in particular, are deeply rooted in the 
framework of grand unified theories. Indeed, it was shown that cosmic strings are 
expected to be generically formed within supersymmetric grand unified theories.
This theoretical support gave a new boost to the field of cosmic strings, a boost 
which has been  enhanced when it was shown that cosmic superstrings (fundamental 
or one-dimensional Dirichlet branes) can play the role of cosmic strings, in the 
framework of braneworld cosmologies.
Cosmic superstrings are expected to be formed at the end of brane inflation, within 
the context of brane-world cosmological models inspired from string theory. By 
studying properties of cosmic suprestring networks, and comparing their phenomenological 
consequences against observational data, we aim at pinning down the successful and 
natural inflationary model and get an insight into the stringy description of our universe.

After a short review in the current status of cosmic strings, I will discuss the formation 
and subsequent evolution of cosmic ssuperstrings. I will show how they reach scaling 
and I will then discuss their phenomenological consequences.