Theory Seminar (High Energy/Cosmology) |
Events During the Week of December 8th through December 15th, 2019
Monday, December 9th, 2019
- No events scheduled
Tuesday, December 10th, 2019
- No events scheduled
Wednesday, December 11th, 2019
- Dark Matter and Dark Radiation from Primordial Black Hole Domination
- Time: 4:00 pm - 5:00 pm
- Place: 5280 Chamberlin Hall
- Speaker: Gordan Krnjaic, Fermilab
- Abstract: If even a relatively small number of black holes were created in the early universe, they will constitute an increasingly large fraction of the total energy density as space expands. It is thus well-motivated to consider scenarios in which the early universe included an era in which primordial black holes dominated the total energy density. Within this context, we consider Hawking radiation as a mechanism to produce both dark radiation and dark matter. If the early universe included a black hole dominated era, we find that Hawking radiation will produce dark radiation at a level ΔNeff∼0.03−0.2 for each light and decoupled species of spin 0, 1/2, or 1. This range is well suited to relax the tension between late and early-time Hubble determinations, and is within the reach of upcoming CMB experiments. The dark matter could also originate as Hawking radiation in a black hole dominated early universe, although such dark matter candidates must be very heavy (mDM>1011 GeV) if they are to avoid exceeding the measured abundance.
- Host: Nicholas Orlofsky
Thursday, December 12th, 2019
- No events scheduled
Friday, December 13th, 2019
- No events scheduled