Charting the Parameter Space of the 21-cm Power Spectrum

Understand

The high-redshift 21-cm signal of neutral hydrogen is expected to be observed within the next decade and will reveal epochs of cosmic evolution that have been previously inaccessible.

• Due to the lack of observations, many of the astrophysical processes that took place at early times are poorly constrained.
• In recent work we explored the astrophysical parameter space and the resulting large variety of possible global (sky-averaged) 21-cm signals.
• Here we extend our analysis to the fluctuations in the 21-cm signal, accounting for those introduced by density and velocity, Ly$\alpha$ radiation, X-ray heating, and ionization.