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Title: Influence of reheating on the trispectrum and its scale dependence

We study the evolution of the non-linear curvature perturbation during perturbative reheating, and hence how observables evolve to their final values which we may compare against observations. Our study includes the evolution of the two trispectrum parameters, g{sub NL} and τ{sub NL}, as well as the scale dependence of both f{sub NL} and τ{sub NL}. In general the evolution is significant and must be taken into account, which means that models of multifield inflation cannot be compared to observations without specifying how the subsequent reheating takes place. If the trispectrum is large at the end of inflation, it normally remains large at the end of reheating. In the classes of models we study, it remains very hard to generate τ{sub NL} >> f{sub NL}{sup 2}, regardless of the decay rates of the fields. Similarly, for the classes of models in which g{sub NL} ≅ τ{sub NL} during slow-roll inflation, we find the relation typically remains valid during reheating. Therefore it is possible to observationally test such classes of models without specifying the parameters of reheating, even though the individual observables are sensitive to the details of reheating. It is hard to generate an observably large g{sub NL} however. The runnings,more » n{sub f{sub N{sub L}}} and n{sub τ{sub N{sub L}}}, tend to satisfy a consistency relation n{sub τ{sub N{sub L}}} = (3/2)n{sub f{sub N{sub L}}} regardless of the reheating timescale, but are in general too small to be observed for the class of models considered.« less
Authors:
; ;  [1] ;  [2]
  1. School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom)
  2. Astronomy Centre, University of Sussex, Brighton, BN1 9QH (United Kingdom)
Publication Date:
OSTI Identifier:
22282697
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2013; Journal Issue: 08; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; COSMOLOGY; INFLATIONARY UNIVERSE; INFLATONS; NONLINEAR PROBLEMS; PERTURBATION THEORY