ACP Seminar (Astronomy - Cosmology - Particle Physics)

Speaker: Kazunori Nakayama (U Tokyo)
Title: Axion cosmology with high scale inflation
Date (JST): Wed, Jun 04, 2014, 13:30 - 15:00
Place: Seminar Room A
Abstract: We revisit the cosmological aspects of (supersymmetric) axion models in high scale inflation scenario. If the Peccei-Quinn (PQ) symmetry is broken during inflation, too large axion isocurvature perturbation is problematic, while there are some loopholes. If the PQ symmetry is restored during inflation, the PQ scale is severely constrained. In a class of SUSY axion models, thermal inflation happens due to the saxion and the saxion decay would produce too much axion dark radiation. We show that the problem of axion dark radiation overproduction can be avoided by taking account of the finite-temperature dissipation effect appropriately.