Superstring cosmology
Abstract
Aspects of superstring cosmology are reviewed with an emphasis on the cosmological implications of duality symmetries in the theory. The string effective actions are summarized and toroidal compactification to four dimensions reviewed. Global symmetries that arise in the compactification are discussed and the duality relationships between the string effective actions are then highlighted. Higherdimensional Kasner cosmologies are presented and interpreted in both string and Einstein frames, and then given in dimensionally reduced forms. String cosmologies containing both nontrivial NeveuSchwarz/NeveuSchwarz and RamondRamond fields are derived by employing the global symmetries of the effective actions. Anisotropic and inhomogeneous cosmologies in four dimensions are also developed. The review concludes with a detailed analysis of the prebig bang inflationary scenario. The generation of primordial spectra of cosmological perturbations in such a scenario is discussed. Possible future directions offered in the HořavaWitten theory are outlined.
 Publication:

Physics Reports
 Pub Date:
 October 2000
 DOI:
 10.1016/S03701573(00)000648
 arXiv:
 arXiv:hepth/9909061
 Bibcode:
 2000PhR...337..343L
 Keywords:

 High Energy Physics  Theory;
 Astrophysics;
 General Relativity and Quantum Cosmology
 EPrint:
 161 pages, latex with epsf, 15 figures. Minor changes, additional references and figures. Version to appear in Physics Reports