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Initial Kaluza-Klein fluctuations and inflationary gravitational waves in braneworld cosmology

Tsutomu Kobayashi
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Abstract

We study the spectrum of gravitational waves generated from inflation in the Randall-Sundrum braneworld. Since the inflationary gravitational waves are of quantum-mechanical origin, the initial configuration of perturbations in the bulk includes Kaluza-Klein quantum fluctuations as well as fluctuations in the zero mode. We show, however, that the initial fluctuations in Kaluza-Klein modes have no significant effect on the late time spectrum, irrespective of the energy scale of inflation and the equation of state parameter in the post-inflationary stage. This is done numerically, using the Wronskian formulation.

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Tsutomu Kobayashi. 2006-02-17. Initial Kaluza-Klein fluctuations and inflationary gravitational waves in braneworld cosmology. https://doi.org/10.1103/physrevd.73.124031

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