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Title: Evolution of perturbations and cosmological constraints in decaying dark matter models with arbitrary decay mass products

Decaying dark matter (DDM) is a candidate which can solve the discrepancies between predictions of the concordance ΛCDM model and observations at small scales such as the number counts of companion galaxies of the Milky Way and the density profile at the center of galaxies. Previous studies are limited to the cases where the decay particles are massless and/or have almost degenerate masses with that of mother particles. Here we expand the DDM models so that one can consider the DDM with arbitrary lifetime and the decay products with arbitrary masses. We calculate the time evolutions of perturbed phase-space distribution functions of decay products for the first time and study effects of DDM on the temperature anisotropy in the cosmic microwave background and the matter power spectrum at present. From a recent observational estimate of σ{sub 8}, we derive constraints on the lifetime of DDM and the mass ratio between the decay products and DDM. We also discuss implications of the DDM model for the discrepancy in the measurements of σ{sub 8} recently claimed by the Planck satellite collaboration.
Authors:
; ;  [1] ;  [2]
  1. Department of Physics and Astrophysics, Nagoya University, Nagoya 464-8602 (Japan)
  2. Kobayashi-Maskawa Institute for the Origin of Particles, and the Universe, Nagoya University, Nagoya 464-8602 (Japan)
Publication Date:
OSTI Identifier:
22373464
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2014; Journal Issue: 07; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DAUGHTER PRODUCTS; DISTRIBUTION FUNCTIONS; MASS; MILKY WAY; NONLUMINOUS MATTER; PERTURBATION THEORY; RELICT RADIATION