2009/07/05 by Kazunori Nakayama, Fuminobu Takahashi
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Particle physics theoretical and experimental studies #astro-ph.CO #hep-ph
paper · pdf · doi:10.1016/j.physletb.2009.08.020
published as Phys. Lett. B 679 (2009) 436-439 · 10 pages, 2 figures
arxiv created 2009/07/05 · openalex publication_date 2009/08/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/02
We study cosmological implications of an R-axion, a pseudo Nambu–Goldstone boson associated with spontaneous breaking of an U(1)R symmetry, focusing on its quantum fluctuations generated during inflation. We show that, in the anomaly mediation, the R-axion decays into a pair of gravitinos, which eventually decay into the visible particles producing the neutralino LSP. As a result, the quantum fluctuations of the R-axion are inherited by the cold dark matter isocurvature density perturbation with potentially large non-Gaussianity. The constraints on the inflation scale and the initial misalignment are derived.