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Effective noise in stochastic description of inflation

S. Winitzki·A. Vilenkin
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Abstract

Stochastic description of inflationary spacetimes emulates the growth of vacuum fluctuations by an effective stochastic ``noise field'' which drives the dynamics of the volume-smoothed inflaton. We investigate statistical properties of this field and find its correlator to be a function of distance measured in units of the smoothing length. Our results apply for a wide class of smoothing window functions and are different from previous calculations by Starobinsky and others who used a sharp momentum cutoff. We also discuss the applicability of some approximate noise descriptions to simulations of stochastic inflation.

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BibTeXRIS

S. Winitzki, A. Vilenkin. 1999-11-08. Effective noise in stochastic description of inflation. https://doi.org/10.1103/physrevd.61.084008

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