Challenges for String Cosmology
  We critically assess the twin prospects of describing the observed universe in string theory, and using cosmological experiments to probe string theory. For the purposes of this short review, we focus on the limitations imposed by our incomplete understanding of string theory. After presenting an array of significant obstacles, we indicate a few areas that may admit theoretical progress in the near future. 
C.P. Burgess and Liam McAllister
hep-th astro-ph.CO gr-qc hep-ph