future events

Dark matter revealed by the first stars?

Speaker:Prof. Rennan Barkana
Affiliation:Tel-Aviv University
Organizer:Hagai Perets
Time:14:30 - 15:30
Location:Lidow Rosen Auditorium (323)
The cosmic radio spectrum is expected to show a strong absorption
signal around redshift 20 that corresponds to the rise of the first
stars; specifically, the stellar radiation turns on 21-cm absorption
by atomic hydrogen. The EDGES global 21-cm experiment has detected the
first such signal, finding a stronger absorption than the maximum
expected. This absorption can be explained by invoking excess cooling
of the cosmic gas induced by an interaction with dark matter. This
would have far reaching consequences, including an upper limit on the
mass of dark matter particles that conflicts with the expectations for
WIMPs. Specific particle physics models are highly constrained, but
observations will decide. In particular, we predict that 21-cm
fluctuations at cosmic dawn could be much larger than
previously expected, exhibiting a specific signature of dark matter.