Small-scale structure and 21cm fluctuations by primordial black holes

Jinn Ouk Gong, Naoya Kitajima

Research output: Contribution to journalArticlepeer-review

31 Citations (Scopus)


We discuss early structure formation of small scales sourced by primordial black holes (PBHs) which constitute a small part of present cold dark matter component. We calculate the mass function and power spectrum of haloes originated from the Poisson fluctuations of PBH number and show that the number of small haloes is significantly modified in the presence of PBHs even if their fraction accounts for only 10-4-10-3 of total dark matter abundance. We then compute the subsequent 21cm signature from those haloes. We find that PBHs can provide major contributions at high redshifts within the detectability of future experiments such as Square Kilometer Array, and provide a forecast constraint on the PBH fraction.

Original languageEnglish
Article number017
JournalJournal of Cosmology and Astroparticle Physics
Issue number8
Publication statusPublished - 2017 Aug 16
Externally publishedYes


  • absorption and radiation processes
  • physics of the early universe
  • primordial black holes

ASJC Scopus subject areas

  • Astronomy and Astrophysics


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