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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
E-Mail
BKOEBBE@ILLINOIS.EDU
Views
77
Originating Calendar
Physics - High Energy Phenomenology 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.

 
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