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arXiv · hep-th/9708153

Symmetries for generating string cosmologies

E. J. Copeland·James E. Lidsey·David Wands
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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.

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E. J. Copeland, James E. Lidsey, David Wands. 1998-06-05. Symmetries for generating string cosmologies. https://doi.org/10.1103/physrevd.58.043503

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