String cosmology

In this review, we discuss various cosmological issues related to our Unive rse from a string theoretic perspective. We analyse the pre-big bang cosmol ogical scenario which appears naturally in this context due to the existenc e of scale factor duality symmetry in string theory. We then discuss some o f the attractive and problematic features of this scenario. Finally, we int roduce a method which is powerful enough to search for cosmological solutio ns in various low energy limits of string theories.