Speaker
Description
The 21-cm line of hydrogen is emerging as a promising probe of the first 0.1 billion years of cosmic history. We conduct a suite of hydrodynamical simulations to precisely model the impact of sub-Mpc structure formation on 21-cm emission during these early epochs. We find that this small-scale matter clumping turns highly nonlinear at z≲30, leading to ~10% changes in the sky-averaged 21-cm intensity and ~50% changes in the 21-cm power spectrum in the standard cold dark matter scenario, relative to previous theoretical predictions. These nonlinear clumping effects are highly sensitive to non-standard dark matter scenarios, such as warm or fuzzy dark matter, opening a new avenue for constraining dark matter properties with upcoming lunar and ground-based 21-cm surveys. Our results provide a theoretical framework for interpreting data from these future experiments.