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Evolution of Fluctuations during Graceful Exit in String Cosmology

Shinsuke Kawai·Jiro Soda
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Abstract

We study the evolution of fluctuations in a universe dominated by a scalar field coupled to the Gauss-Bonnet term. During the graceful exit, we found non-negligible enhancements of both curvature perturbation and gravitational wave in the long wavelength limit, and we also found a short wavelength instability for steep background superinflation just after the completion of the graceful exit. This result for one possible graceful exit mechanism would provide a significant implication on the primordial spectrum from the string cos mology.

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Shinsuke Kawai, Jiro Soda. 1999-06-17. Evolution of Fluctuations during Graceful Exit in String Cosmology. https://doi.org/10.1016/s0370-2693(99)00736-4

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