High Energy Phenomenology Seminar: Kim Berghaus (Stony Brook) "Dark matter freeze-in produces large post-inflationary isocurvature"
- Event Type
- Seminar/Symposium
- Sponsor
- Department of Physics
- Location
- Room 464
- Date
- Nov 4, 2022 11:00 am
- Speaker
- Kim Berghaus
- Contact
- Brandy Koebbe
- BKOEBBE@ILLINOIS.EDU
- Views
- 113
- Originating Calendar
- Physics - High Energy Physics Seminar
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.