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Title: Non-perturbative approach for curvature perturbations in stochastic δ N formalism

In our previous paper [1], we have proposed a new algorithm to calculate the power spectrum of the curvature perturbations generated in inflationary universe with use of the stochastic approach. Since this algorithm does not need the perturbative expansion with respect to the inflaton fields on super-horizon scale, it works even in highly stochastic cases. For example, when the curvature perturbations are very large or the non-Gaussianities of the curvature perturbations are sizable, the perturbative expansion may break down but our algorithm enables to calculate the curvature perturbations. We apply it to two well-known inflation models, chaotic and hybrid inflation, in this paper. Especially for hybrid inflation, while the potential is very flat around the critical point and the standard perturbative computation is problematic, we successfully calculate the curvature perturbations.
Authors:
; ;  [1]
  1. Kavli Institute for the Physics and Mathematics of the Universe (WPI), TODIAS, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, 277-8583 (Japan)
Publication Date:
OSTI Identifier:
22375828
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2014; Journal Issue: 10; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALGORITHMS; CHAOS THEORY; EXPANSION; INFLATIONARY UNIVERSE; PERTURBATION THEORY; POTENTIALS; SPECTRA; STOCHASTIC PROCESSES