Constraints on MeV dark matter using neutrino detectors and their implication for the 21-cm results

Understand

The recent results of the EDGES collaboration indicate that during the era of reionization, the primordial gas was much colder than expected.

• The cooling of the gas could be explained by interactions between dark matter (DM) and particles in the primordial gas.
• Constraints from cosmology and particle experiments indicate that this DM should be light ($\sim$10-80 MeV), carry a small charge ($\epsilon\sim 10^{-6}$-$10^{-4}$), and only make up a small fraction of the total amount of DM.
• Several constraints on the DM parameter space have already been made.