Probing ultralight axions with the 21-cm signal during cosmic dawn
| Autor: | Selim C. Hotinli, David J. E. Marsh, Marc Kamionkowski |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Physical Review D. 106 |
| ISSN: | 2470-0029 2470-0010 |
| Popis: | Ultra-light axions (ULAs) are a promising and intriguing set of dark-matter candidates. We study the prospects to use forthcoming measurements of 21-cm fluctuations from cosmic dawn to probe ULAs. We focus in particular on the velocity acoustic oscillations (VAOs) in the large-scale 21-cm power spectrum, features imprinted by the long-wavelength ($k\sim0.1\,{\rm Mpc}^{-1}$) modulation, by dark-matter--baryon relative velocities, of the small-scale ($k\sim 10-10^3\, {\rm Mpc}^{-1}$) power required to produce the stars that heat the neutral hydrogen. Damping of small-scale power by ULAs reduces the star-formation rate at cosmic dawn which then leads to a reduced VAO amplitude. Accounting for different assumptions for feedback and foregrounds, experiments like HERA may be sensitive to ULAs with masses up to $m_{\alpha}\approx 10^{-18}\text{eV}$, two decades of mass higher than current constraints. Comment: version 2: Initial conditions improved, qualitative results unchanged, manuscript matches the published PRD version. version 1: 8 pages, 7 figures, comments welcome. Sec. II covers some pedagogical information similar to arXiv:2106.11979 |
| Databáze: | OpenAIRE |
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