2006/04/30 by David Seery, Juan Carlos Hidalgo, J. Carlos Hidalgo
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1088/1475-7516/2006/07/008
published as JCAP 0607 (2006) 008 · 30 pages; uses iopart.cls LaTeX style. v2: Replaced with version accepted by JCAP
arxiv created 2006/07/14 · openalex publication_date 2006/07/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
We show how to obtain the probability density function for the amplitude of the curvature perturbation, , produced during an epoch of slow-roll, single-field inflation, working directly from n -point correlation functions of . These n -point functions are the usual output of quantum field theory calculations, and as a result we bypass approximate statistical arguments based on the central limit theorem. Our method can be extended to deal with arbitrary forms of non-Gaussianity, appearing at any order in the n -point hierarchy. We compute the probability density for the total smoothed perturbation within a Hubble volume, , and for the spectrum of . When only the two-point function is retained, exact Gaussian statistics are recovered. For when the three-point function is taken into account, we compute explicitly the leading slow-roll correction to the Gaussian result.