O(d,d)-Covariant String Cosmology
نویسندگان
چکیده
The recently discovered O(d; d) symmetry of the space of (slowly-varying) cosmo-logical string vacua in d + 1 dimensions is shown to be preserved in the presence of bulk string matter. The existence of O(d; d) conserved currents allows all the equations of string cosmology to be reduced to rst-order diierential equations. The perfect-uid approximation is not invariant under O(d; d) transformations, implying that stringy uids possess in general a non-vanishing viscosity.
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