High Energy Phenomenology Seminar: Kim Berghaus (Stony Brook) "Dark matter freeze-in produces large post-inflationary isocurvature"
Speaker: |
(sign-up)
Kim Berghaus |
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Date: | 11/4/2022 |
Time: | 11 a.m. |
Location: | Room 464 |
Event Contact: | Brandy Koebbe BKOEBBE@ILLINOIS.EDU |
Sponsor: | Department of Physics |
Event Type: | Seminar/Symposium |
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. |