%0 Generic %1 hotinli2021probing %A Hotinli, Selim C. %A Marsh, David J. E. %A Kamionkowski, Marc %D 2021 %K library %T Probing ultra-light axions with the 21-cm Signal during Cosmic Dawn %U http://arxiv.org/abs/2112.06943 %X 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 ($k\sim0.1\,Mpc^-1$) modulation, by dark-matter--baryon relative velocities, of the small-scale ($k10-10^3\, Mpc^-1$) 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 $m_\alpha\approx 10^-18eV$, two decades of mass higher than current constraints.

@misc{hotinli2021probing, abstract = {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.}, added-at = {2021-12-15T09:19:19.000+0100}, author = {Hotinli, Selim C. and Marsh, David J. E. and Kamionkowski, Marc}, biburl = {https://www.bibsonomy.org/bibtex/2f21cc8ea9f3d819ac61b634d59fedcc5/gpkulkarni}, description = {Probing ultra-light axions with the 21-cm Signal during Cosmic Dawn}, interhash = {fd407b6ae509da13a0a51c37ad935cb8}, intrahash = {f21cc8ea9f3d819ac61b634d59fedcc5}, keywords = {library}, note = {cite arxiv:2112.06943Comment: 8 pages, 7 figures, comments welcome. arXiv admin note: text overlap with arXiv:2106.11979}, timestamp = {2021-12-15T09:19:19.000+0100}, title = {Probing ultra-light axions with the 21-cm Signal during Cosmic Dawn}, url = {http://arxiv.org/abs/2112.06943}, year = 2021 }