http://arxiv.org/abs/2305.08593
The 21-cm signal from the dark ages provides a potential new probe of fundamental cosmology. While exotic physics could be discovered, here we quantify the expected benefits within the standard cosmology. A measurement of the global (sky-averaged) 21-cm signal to the precision of thermal noise from a 1,000 hour integration would yield a $5.5\%$ measurement of a combination of cosmological parameters. A 10,000 hour integration would improve this to $1.8\%$, and constrain the cosmic Helium fraction as well as Planck. Precision cosmology with 21-cm fluctuations requires a collecting area of $10\,{\rm km}^2$ (which corresponds to 400,000 stations), which with a 1,000 hour integration would exceed the same global case. Enhancing the collecting area or integration time $\times$10 would yield a $0.5\%$ parameter combination, a Helium measurement five times better than Planck, and a constraint on the neutrino mass as good as Planck. Our analysis sets a baseline for upcoming lunar and space-based dark ages experiments.
R. Mondal and R. Barkana
Tue, 16 May 23
54/83
Comments: 30 pages, 3 (+ 5 in the appendix) figures