ETHOS -- An Effective Theory of Structure Formation: Impact of Dark Acoustic Oscillations on Cosmic Dawn

Understand

Upcoming data of the 21-cm hydrogen line during cosmic dawn ($z\sim 10-30$) will revolutionize our understanding of the astrophysics of the first galaxies.

• Here we present a case study on how to exploit those same measurements to learn about the nature of dark matter (DM) at small scales.
• Focusing on the Effective Theory of Structure Formation (ETHOS) paradigm, we run a suite of simulations covering a broad range of DM microphysics, connecting the output of $N$-body simulations to dedicated 21-cm simulations to predict the evolution of the 21-cm signal across the entire cosmic dawn.
• We find that observatories targeting both the global signal and the 21-cm power spectrum are sensitive to all ETHOS models we study, and can distinguish them from CDM if the suppression wavenumber is smaller than $k\approx 300\, h/$Mpc, even when accounting for feedback with a phenomenological model.