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

Jinn Ouk Gong, Naoya Kitajima

Research output: Contribution to journalArticlepeer-review

32 Scopus citations


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
StatePublished - 16 Aug 2017

Bibliographical note

Funding Information:
We acknowledge the support from the Korea Ministry of Education, Science and Technology, Gyeongsangbuk-Do and Pohang City for Independent Junior Research Groups at the Asia Pacific Center for Theoretical Physics. JG is also supported in part by a TJ Park Science Fellowship of POSCO TJ Park Foundation, and by the Basic Science Research Program through the National Research Foundation of Korea (NRF) Research Grant NRF-2016R1D1A1B03930408. NK acknowledges the support by Grant-in-Aid for JSPS Fellows.

Publisher Copyright:
© 2017 IOP Publishing Ltd and Sissa Medialab.


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


Dive into the research topics of 'Small-scale structure and 21cm fluctuations by primordial black holes'. Together they form a unique fingerprint.

Cite this