Common origin of warm dark matter and dark radiation

Manuel A. Buen-Abad, Raymond T. Co, Keisuke Harigaya

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2 Scopus citations


We consider a cosmological scenario where a relativistic particle and a stable massive particle are simultaneously produced from the decay of a late-decaying particle after Big-Bang Nucleosynthesis but before matter-radiation equality. The relativistic and massive particles behave as dark radiation and warm dark matter, respectively. Due to a common origin, the warmness and abundances are closely related. We refer to the models that lead to such a scenario as Common Origin of Warm and Relativistic Decay Products (COWaRD) . We show that COWaRD predicts a correlation between the amount of dark radiation and suppression of the large scale structure, which can be tested in future precision cosmology observations. We demonstrate that COWaRD is realized, as an example, in a class of supersymmetric axion models and that future observations by the next generation Cosmic Microwave Background, Large Scale Structure, and 21-cm surveys can reveal the structure of the theory.

Original languageEnglish (US)
Article number024
JournalJournal of Cosmology and Astroparticle Physics
Issue number12
StatePublished - Dec 2020

Bibliographical note

Publisher Copyright:
© 2020 IOP Publishing Ltd and Sissa Medialab.


  • cosmological parameters from CMBR
  • cosmology of theories beyond the SM
  • dark energy theory
  • particle physics - cosmology connection


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