Preliminary Exam |
Events During the Week of August 16th through August 23rd, 2026
Monday, August 17th, 2026
- No events scheduled
Tuesday, August 18th, 2026
- No events scheduled
Wednesday, August 19th, 2026
- No events scheduled
Thursday, August 20th, 2026
- Astrophysical Probes of Particle Dark Matter
- Time: 10:00 am - 12:00 pm
- Place: 5280 Chamberlin
- Speaker: Fabrizio Vassallo, Physics PhD Graduate Student
- Abstract: Dark matter remains one of the central open problems in particle physics and cosmology, motivating a broad range of astrophysical searches for its signatures. Interpreting such signatures requires accurate modeling of the connection between fundamental dark matter physics and observable phenomena. In this preliminary exam, I will present two examples of my work in this direction. First, I will discuss models in which dark matter annihilates into new particles carrying baryon and lepton number, leading to greatly enhanced production of cosmic-ray antideuterons and antihelium. Using state-of-the-art simulations of particle production and antinucleus formation, we show that these scenarios can greatly enhance antinucleus yields relative to conventional dark matter annihilation channels, offering a possible explanation for the tentative antinucleus events reported by AMS. I will then present a new framework for forecasting the sensitivity of pulsar timing arrays to compact dark matter substructures, developing the first comprehensive treatment spanning the full range of substructure masses and signal regimes, from rare, nearly static encounters to dynamic flybys and stochastic populations. Combining Monte Carlo simulations with machine-learned surrogate likelihoods, this framework enables efficient and unified sensitivity forecasts across these regimes. Together, these projects illustrate how detailed modeling of astrophysical signatures can improve our ability to probe the nature of dark matter.
- Host: Joshua Foster and Dan Hooper
Friday, August 21st, 2026
- No events scheduled