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Long-wavelength approximation for string cosmology with barotropic perfect fluid

Piret Kuusk·Margus Saal
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Abstract

The field equations derived from the low energy string effective action with a matter tensor describing a perfect fluid with a barotropic equation of state are solved iteratively using the long-wavelength approximation, i.e. the field equations are expanded by the number of spatial gradients. In the zero order, a quasi-isotropic solution is presented and compared with the general solution of the pure dilaton gravity. Possible cosmological models are analyzed from the point of view of the pre-big bang scenario. The second order solutions are found and their growing and decaying parts are studied.

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Piret Kuusk, Margus Saal. 2002-05-21. Long-wavelength approximation for string cosmology with barotropic perfect fluid. https://doi.org/10.1023/a%3A1021191619689

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