Thermal effects and sudden decay approximation in the curvaton scenario

Naoya Kitajima, David Langlois, Tomo Takahashi, Tomohiro Takesako, Shuichiro Yokoyama

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


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.

Original languageEnglish
Article number032
JournalJournal of Cosmology and Astroparticle Physics
Issue number10
Publication statusPublished - 2014 Oct 1


  • cosmological perturbation theory
  • ination
  • particle physics - cosmology connection
  • physics of the early universe


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