Symmetries for generating string cosmologies
Abstract
We discuss the symmetry properties of the low-energy effective action of the type IIB superstring that may be employed to derive four-dimensional solutions. A truncated effective action, compactified on a six-torus, but including both Neveu/Schwarz-Neveu/Schwarz and Ramond-Ramond field strengths, can be expressed as a non-linear sigma model which is invariant under global SL(3,R) transformations. This group contains as a sub-group the SL(2,R) symmetry of the ten-dimensional theory and a discrete Z2 reflection symmetry which leads to a further SL(2,R) sub-group. The symmetries are employed to analyse a general class of spatially homogeneous cosmological solutions with non-trivial Ramond-Ramond fields.
Cite
@article{arxiv.hep-th/9708153,
title = {Symmetries for generating string cosmologies},
author = {E. J. Copeland and James E. Lidsey and David Wands},
journal= {arXiv preprint arXiv:hep-th/9708153},
year = {2009}
}
Comments
Substantially extended version with new sections on further symmetries and anisotropic cosmological solutions. New title. To appear in Physical Review D. 13 pages, LaTeX, no figures