DOI link for Superstring cosmology
Superstring cosmology book
For energies small compared to the string scale (which is of the order of the Planck scale in weakly coupled heterotic string theories), heterotic string theory in ten dimensions reduces to four-dimensional supergravity theory once compactification of extra dimensions has taken place. Thus, the discussion in chapter 8 also applies to heterotic string theory with special choices of the superpotential and Kähler potential derived from specific string theories. However, there are other aspects of string theory cosmology that go beyond supergravity cosmology.