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Title: Constraining warm dark matter with 21 cm line fluctuations due to minihalos

Abstract

Warm dark matter (WDM) with mass m{sub WDM} = O(1) keV has long been discussed as a promising solution for discrepancies between cosmic structures observed at small scales and predications of the concordance CDM model. Though several cosmological observations such as the Lyman-alpha forest have already begun to constrain the range of m{sub WDM}, WDM is yet to be fully excluded as a solution for these so-called small-scale problems. In this paper, we study 21 cm line fluctuations from minihalos in a WDM model and evaluate constraints on m{sub WDM} for future cosmological 21 cm surveys, such as SKA and FFTT. We show that, since WDM with mass m{sub WDM}∼>10 keV decreases the abundance of minihalos by suppressing the matter power spectrum on small scales via free-streaming, such WDM can significantly affect the resultant 21 cm line fluctuations from minihalos. We find that if the 21 cm signal from minihalos can be observed above z≥5, SKA and FFTT can give lower bounds m{sub WDM}∼>24 keV and 31 keV, respectively, which are tighter than the current constraint. These future 21 cm surveys might be able to rule out a WDM model as a solution of small-scale problems.

Authors:
 [1];  [2]
  1. University of Helsinki and Helsinki Institute of Physics, P.O. Box 64, FI-00014, Helsinki (Finland)
  2. Physics Department, Arizona State University, Tempe AZ 85287 (United States)
Publication Date:
OSTI Identifier:
22373418
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2014; Journal Issue: 08; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; CURRENTS; FLUCTUATIONS; KEV RANGE; MASS; MATHEMATICAL SOLUTIONS; NONLUMINOUS MATTER; SIGNALS; SPECTRA

Citation Formats

Sekiguchi, Toyokazu, and Tashiro, Hiroyuki, E-mail: toyokazu.sekiguchi@helsinki.fi, E-mail: hiroyuki.tashiro@nagoya-u.jp. Constraining warm dark matter with 21 cm line fluctuations due to minihalos. United States: N. p., 2014. Web. doi:10.1088/1475-7516/2014/08/007.
Sekiguchi, Toyokazu, & Tashiro, Hiroyuki, E-mail: toyokazu.sekiguchi@helsinki.fi, E-mail: hiroyuki.tashiro@nagoya-u.jp. Constraining warm dark matter with 21 cm line fluctuations due to minihalos. United States. doi:10.1088/1475-7516/2014/08/007.
Sekiguchi, Toyokazu, and Tashiro, Hiroyuki, E-mail: toyokazu.sekiguchi@helsinki.fi, E-mail: hiroyuki.tashiro@nagoya-u.jp. Fri . "Constraining warm dark matter with 21 cm line fluctuations due to minihalos". United States. doi:10.1088/1475-7516/2014/08/007.
@article{osti_22373418,
title = {Constraining warm dark matter with 21 cm line fluctuations due to minihalos},
author = {Sekiguchi, Toyokazu and Tashiro, Hiroyuki, E-mail: toyokazu.sekiguchi@helsinki.fi, E-mail: hiroyuki.tashiro@nagoya-u.jp},
abstractNote = {Warm dark matter (WDM) with mass m{sub WDM} = O(1) keV has long been discussed as a promising solution for discrepancies between cosmic structures observed at small scales and predications of the concordance CDM model. Though several cosmological observations such as the Lyman-alpha forest have already begun to constrain the range of m{sub WDM}, WDM is yet to be fully excluded as a solution for these so-called small-scale problems. In this paper, we study 21 cm line fluctuations from minihalos in a WDM model and evaluate constraints on m{sub WDM} for future cosmological 21 cm surveys, such as SKA and FFTT. We show that, since WDM with mass m{sub WDM}∼>10 keV decreases the abundance of minihalos by suppressing the matter power spectrum on small scales via free-streaming, such WDM can significantly affect the resultant 21 cm line fluctuations from minihalos. We find that if the 21 cm signal from minihalos can be observed above z≥5, SKA and FFTT can give lower bounds m{sub WDM}∼>24 keV and 31 keV, respectively, which are tighter than the current constraint. These future 21 cm surveys might be able to rule out a WDM model as a solution of small-scale problems.},
doi = {10.1088/1475-7516/2014/08/007},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 08,
volume = 2014,
place = {United States},
year = {Fri Aug 01 00:00:00 EDT 2014},
month = {Fri Aug 01 00:00:00 EDT 2014}
}
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