UTAPwiki/セミナー/初期宇宙・相対論速報
Speaker: Atsuhisa Ota (Tokyo Tech)
Title: Secondary isocurvature perturbations from acoustic reheating
Abstract:
We discuss the secondary isocurvature perturbations from mode coupling
effects called acoustic reheating in the Thomson scattering dominant
universe. The perfect fluid approximation for the photon energy
momentum tensor is invalid deep inside the horizon so that shear
viscosity and thermal conduction occur. They produce the deviations
from the ideal Planck distribution, which can be recast into the entropy
perturbation on superhorizon scales. We also show that the latter effect breaks the
conservation law for the photon energy momentum tensor because
there exists heat conduction from the baryon sector. Therefore, the
superhorizon isocurvature perturbations are generated at second
order.

#This seminar is based on our recent work; arXiv:1705.05196.



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Last-modified: 2017-06-26 (月) 12:30:45 (28d)