2013/08/31 by Tomohiro Fujita, Masahiro Kawasaki, Yuichiro Tada +1 · 89 citations
Economics, Econometrics and Finance · Engineering · Physics and Astronomy · #Cosmological perturbation theory #Cosmology and Gravitation Theories #Curvature #Field (mathematics) #Fluid dynamics and aerodynamics studies #Inflation (cosmology) #Inflaton #Nonlinear system #Perturbation (astronomy) #Spectral density #Stochastic processes and financial applications #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1088/1475-7516/2013/12/036
published in Journal of Cosmology and Astroparticle Physics 2013(12), 036 (Institute of Physics) · 14 pages, no figure
arxiv created 2013/09/24 · openalex publication_date 2013/12/13 · arxiv updated 2014/03/06 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
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 δ N 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.