Searching for Dark Matter at the Cosmic Dawn​

The nature of the dark matter is still a mystery, although current and upcoming 21-cm measurements during the cosmic dawn can provide a new arena on the search for the cosmological dark matter. ​This era saw the formation of the first stars, which coupled the spin temperature of hydrogen to its kinetic temperature---​producing 21-cm absorption in the CMB. The strength of this absorption acts as a thermostat, showing us if the baryons have been cooled down or heated up by different processes. I will show the discovery space for new dark-sector interactions, focusing on the case of "minicharged" dark-matter, which can explain the anomalous 21-cm depth observed by the EDGES collaboration.