2016/01/31 by Ken Osato, Toyokazu Sekiguchi, Masato Shirasaki +2
Physics and Astronomy · #Astronomy and Astrophysical Research #Baryogenesis #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Dark matter #Galaxies: Formation, Evolution, Phenomena #Gravitino #Trispectrum #Weak gravitational lensing #astro-ph.CO #hep-ph
paper · pdf · doi:10.1088/1475-7516/2016/06/004
published as JCAP06(2016)004 · 19 pages, 8 figures, JCAP in press
arxiv created 2016/05/19 · openalex publication_date 2016/06/01 · arxiv updated 2016/06/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
Light gravitinos of mass ≲ O (10) eV are of particular interest in cosmology, offering various baryogenesis scenarios without suffering from the cosmological gravitino problem. The gravitino may contribute considerably to the total matter content of the Universe and affect structure formation from early to present epochs. After the gravitinos decouple from other particles in the early Universe, they free-stream and consequently suppress density fluctuations of (sub-)galactic length scales. Observations of structure at the relevant length-scales can be used to infer or constrain the mass and the abundance of light gravitinos. We derive constraints on the light gravitino mass using the data of cosmic microwave background (CMB) lensing from Planck and of cosmic shear from the Canada France Hawaii Lensing Survey survey, combined with analyses of the primary CMB anisotropies and the signature of baryon acoustic oscillations in galaxy distributions. The obtained constraint on the gravitino mass is m 3/2 < 4.7 eV (95 % C.L.), which is substantially tighter than the previous constraint from clustering analysis of Ly-α forests.