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Title: Thermal effects and sudden decay approximation in the curvaton scenario

We study the impact of a temperature-dependent curvaton decay rate on the primordial curvature perturbation generated in the curvaton scenario. Using the familiar sudden decay approximation, we obtain an analytical expression for the curvature perturbation after the decay of the curvaton. We then investigate numerically the evolution of the background and of the perturbations during the decay. We first show that the instantaneous transfer coefficient, related to the curvaton energy fraction at the decay, can be extended into a more general parameter, which depends on the net transfer of the curvaton energy into radiation energy or, equivalently, on the total entropy ratio after the complete curvaton decay. We then compute the curvature perturbation and compare this result with the sudden decay approximation prediction.
Authors:
; ;  [1] ;  [2] ;  [3]
  1. Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582 (Japan)
  2. Astroparticle and Cosmologie (CNRS-Université Paris 7), 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France)
  3. Department of Physics, Saga University, Saga 840-8502 (Japan)
Publication Date:
OSTI Identifier:
22375830
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; APPROXIMATIONS; COMPARATIVE EVALUATIONS; DECAY; ENTROPY; EVOLUTION; FORECASTING; PERTURBATION THEORY; TEMPERATURE DEPENDENCE