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arXiv · 1409.1784

Parametric Resonance of Entropy Perturbations in Massless Preheating

Hossein Bazrafshan Moghaddam·Robert H. Brandenberger·Yi-Fu Cai·Elisa G. M. Ferreira
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Abstract

Here, we revisit the question of possible preheating of entropy modes in a two field model with a massless inflaton coupled to a matter scalar field. Using a perturbative approximation to the covariant method we demonstrate that there is indeed a parametric instability of the entropy mode which then at second order leads to exponential growth of the curvature fluctuation on super-Hubble scale. Back-reaction effects shut off the induced curvature fluctuations, but possibly not early enough to prevent phenomenological problems. This confirms previous results obtained using different methods and resolves a controversy in the literature.

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Hossein Bazrafshan Moghaddam, Robert H. Brandenberger, Yi-Fu Cai, Elisa G. M. Ferreira. 2015-06-25. Parametric Resonance of Entropy Perturbations in Massless Preheating. https://doi.org/10.1142/s0218271815500820

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