If a component of cosmological dark matter is made up of massive particles - such as sterile neutrinos - that decay with cosmological lifetime to emit photons, the reionization history of the universe would be affected, and cosmic microwave background anisotropies can be used to constrain such a decaying particle model of dark matter. The optical depth depends rather sensitively on the decaying dark matter particle mass mdm, lifetime τdm, and the mass fraction of cold dark matter f that they account for in this model. Assuming that there are no other sources of reionization and using the Wilkinson Microwave Anisotropy Probe 7-year data, we find that 250eV ≲ mdm ≲ 1 MeV, whereas 2.23 × 10³ yr ≲ τdm/f ≲ 1.23 × 10¹⁸ yr. The best-fit values for mdm and τdm/f are 17.3 keV and 2.03 × 10¹⁶ yr, respectively. Copyright © 2012 The American Astronomical Society. All rights reserved.
CitationYeung, S., Chan, M. H., & Chu, M.-C. (2012). Cosmic microwave background constraints of decaying dark matter particle properties. Astrophysical Journal, 755. Retrieved from https://doi.org/10.1088/0004-637X/755/2/108
- Cosmic background radiation
- Dark ages
- First star
- Dark matter