Theory Seminar (High Energy/Cosmology) |
Events During the Week of November 16th through November 22nd, 2025
Monday, November 17th, 2025
- What is the QCD axion mass?
- Time: 1:00 pm - 2:30 pm
- Place: Chamberlin 5280
- Speaker: Joshua N. Benabou, UC, Berkeley
- Abstract: The QCD axion may solve the strong CP problem and constitute the dark matter (DM) abundance in our Universe. Peccei-Quinn (PQ) axions may form axion strings if the PQ phase transition occurs after inflation. I will discuss recent advances in the computation of the QCD axion DM mass in this scenario from the most precise and accurate lattice simulations to-date of axion-string networks, leading to a predicted mass range of 40 - 300 µeV. On the other hand, string theory axions, which are compelling solutions to the PQ quality problem, do not generically form strings - except in special inflationary paradigms such as brane inflation - meaning that there is no unique predicted value for the QCD axion DM mass. Nonetheless, if a Grand Unified Theory is assumed, I will explain why in broad regions of the string landscape, the mass of a stringy QCD axion is expected to be ~ 0.01 to 10 neV, independently of its DM fraction. Video recording:
- Host: Joshua Foster
Tuesday, November 18th, 2025
- No events scheduled
Wednesday, November 19th, 2025
- No events scheduled
Thursday, November 20th, 2025
- No events scheduled
Friday, November 21st, 2025
- No events scheduled