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arXiv · 2410.17987

Small noise expansion of stochastic inflation

Diego Cruces·Cristiano Germani·Amin Nassiri-Rad·Masahide Yamaguchi
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Abstract

By introducing the small noise expansion techniques, we show that the fully nonlinear (non-Markovian) stochastic inflationary system, may be re-cast in terms of an infinite set of Wiener processes (stochastic equations with white noises). As a byproduct, we show that the Starobinsky test field approximation might only provide information about the linear regime of cosmological perturbations and scalar-feld non-Gaussianities might only appear at leading order in slow-roll parameters.

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Diego Cruces, Cristiano Germani, Amin Nassiri-Rad, Masahide Yamaguchi. 2024-10-23. Small noise expansion of stochastic inflation. https://arxiv.org/abs/2410.17987

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