- Nov. 7, 2022, 2:00 pm US/Central
- DIR/ Curia II-WH2SW - Wilson Hall 2nd fl South West
This activity or event is open to badged Fermilab personnel.
Speaker: Kim Berghaus
Title/Abstract: Dark matter freeze-in produces large post-inflationary isocurvature
In this talk I will show that the nonthermal nature of dark matter freeze-in production leads to large, totally correlated dark matter-photon isocurvature perturbations, which are imprinted in anisotropies of the cosmic microwave background (CMB). Isocurvature is typically expected from inflationary physics but the isocurvature from freeze-in arises post inflation. Using millicharged dark matter as a benchmark model I will discuss how to calculate the amplitude of the generated isocurvature from a Lagrangian description of the dark matter freeze-in process. I will present novel results excluding millicharged dark matter as the sole dark matter component for masses between 1 MeV – 10 GeV, using current CMB observations from Planck. I’ll conclude by commenting on the broader implications of this new avenue for exploring fundamental dark matter physics.
If you are interested in connecting to the talk remotely without a Fermilab Services account, you can contact Dylan Temples, firstname.lastname@example.org.