TY - JOUR

T1 - Thermal effects and sudden decay approximation in the curvaton scenario

AU - Kitajima, Naoya

AU - Langlois, David

AU - Takahashi, Tomo

AU - Takesako, Tomohiro

AU - Yokoyama, Shuichiro

PY - 2014/10/1

Y1 - 2014/10/1

N2 - 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.

AB - 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.

KW - cosmological perturbation theory

KW - ination

KW - particle physics - cosmology connection

KW - physics of the early universe

UR - http://www.scopus.com/inward/record.url?scp=84908512203&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84908512203&partnerID=8YFLogxK

U2 - 10.1088/1475-7516/2014/10/032

DO - 10.1088/1475-7516/2014/10/032

M3 - Article

AN - SCOPUS:84908512203

VL - 2014

JO - Journal of Cosmology and Astroparticle Physics

JF - Journal of Cosmology and Astroparticle Physics

SN - 1475-7516

IS - 10

M1 - 032

ER -