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arXiv · 1308.4754

A new algorithm for calculating the curvature perturbations in stochastic inflation

Tomohiro Fujita·Masahiro Kawasaki·Yuichiro Tada·Tomohiro Takesako
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Abstract

We propose a new approach for calculating the curvature perturbations produced during inflation in the stochastic formalism. In our formalism, the fluctuations of the e-foldings are directly calculated without perturbatively expanding the inflaton field and they are connected to the curvature perturbations by the $δN$ formalism. The result automatically includes the contributions of the higher order perturbations because we solve the equation of motion non-perturbatively. In this paper, we analytically prove that our result (the power spectrum and the nonlinearity parameter) is consistent with the standard result in single field slow-roll inflation. We also describe the algorithm for numerical calculations of the curvature perturbations in more general inflation models.

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Tomohiro Fujita, Masahiro Kawasaki, Yuichiro Tada, Tomohiro Takesako. 2013-09-24. A new algorithm for calculating the curvature perturbations in stochastic inflation. https://doi.org/10.1088/1475-7516%2F2013%2F12%2F036

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