Jul 22 – 27, 2018
US/Eastern timezone

Searching for Dark Matter at the Cosmic Dawn​

Jul 27, 2018, 12:15 PM
117 (MacMillian)



Brown University Providence, Rhode Island, USA
Talk Astrophysics Dynamics 5.2 Plenary


Julian Munoz Bermejo (Johns Hopkins University)


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. In particular, during ​the cosmic dawn, the baryon-dark matter fluid is the​ slowest​ it will ever be​, making it ideal to search for dark matter elastically scattering with baryons through massless mediators, such as the photon. ​I will describe how dark-matter particles with an electric millicharge can significantly alter the baryonic temperature, and thus explain the anomalous 21-cm depth observed by the EDGES collaboration.

Primary author

Julian Munoz Bermejo (Johns Hopkins University)


Prof. Abraham Loeb (Harvard University) Prof. Cora Dvorkin

Presentation materials