@article{66dcac06e81e47c2bf852b601067ff0b,
title = "Distribution of primordial black holes and 21cm signature",
abstract = "We show that the number of primordial black holes (PBHs) which is originated from primordial density perturbations with moderately-tilted power spectrum fluctuates following the log-normal distribution, while it follows the Poisson distribution if the spectrum is steeply blue. The log-normal, as well as the Poisson, fluctuation of the PBH number behaves as an isocurvature mode and affects the matter power spectrum and the halo mass function in a different way from those for the Poisson case. The future 21cm observation can potentially put a stronger constraint on the PBH fraction than the current one in a wide mass range, 10-5Mo-10Mo.",
keywords = "power spectrum, primordial black holes",
author = "Gong, {Jinn Ouk} and Naoya Kitajima",
note = "Funding Information: We thank Bernard Carr, Misao Sasaki, Takahiro Tanaka, Atsushi Taruya, Shuichiro Yokoyama and Chul-Moon Yoo for helpful discussions. We are grateful to the Yukawa Institute for Theoretical Physics at Kyoto University for hospitality during the workshop YITP-T-17-02 “Gravity and Cosmology 2018” and the YKIS symposium YKIS2018a “General Relativity — The Next Generation –” while this work was under progress. JG is supported in part by the Basic Science Research Program through the National Research Foundation of Korea Research Grant 2016R1D1A1B03930408, and by a TJ Park Science Fellowship of POSCO TJ Park Foundation. NK acknowledges the support by Grant-in-Aid for JSPS Fellows. Publisher Copyright: {\textcopyright} 2018 IOP Publishing Ltd and Sissa Medialab.",
year = "2018",
month = nov,
day = "26",
doi = "10.1088/1475-7516/2018/11/041",
language = "English",
volume = "2018",
journal = "Journal of Cosmology and Astroparticle Physics",
issn = "1475-7516",
publisher = "IOP Publishing Ltd.",
number = "11",
}