Narrowing the search for axion dark matter

Cosmic alchemy in the era of gravitational wave astronomy
October 28, 2022

Monday, November 14, 2022 at 4:15 p.m.
Location: Physics North Lecture Hall #1
Speaker: Benjamin Safdi, University of California, Berkeley

Abstract: The quantum chromodynamics axion and axion-like particles are some of the most sought-after beyond the Standard Model particles at present because of their possible connections with the strong-CP problem, dark matter, and ultraviolet physics such as Grand Unification and String Theory.  Laboratory searches are underway around the world to search for these hypothetical particles.  However, these searches are notoriously difficult because the axion mass is currently unknown.  The axion mass is in principle calculable by solving the axion dynamics in the early Universe, but such calculations are made difficult by nonlinear effects in the equations of motion.  I will show how state-of-the-art supercomputing facilities are being leveraged to simulate axion cosmology and inform axion experiments.  The early Universe simulations are part of a broader program, which I will overview, to rule out or confirm the existence of the axion in nature in the coming years.  This broad program ranges from precision laboratory experiments such as ABRACADABRA to studies of small changes in the cooling rates of stars.

Bio: Benjamin Safdi received his undergraduate degree from the University of Colorado at Boulder, a Master of Advanced Study from Cambridge University, as a Churchill Scholar, and his PhD from Princeton University in 2014. He was then a Pappalardo Fellow in physics at the Massachusetts Institute of Technology until 2017, when he started as an assistant professor at the University of Michigan, Ann Arbor. Dr. Safdi moved to LBNL in 2020 and then to UC Berkeley in 2021. He received the Department of Energy Early Career Award in 2018 and the IUPAP C11 Young Scientist Prize in Particles and Fields in 2020.

Research Area: Astrophysics & Particle Physics

Colloquium 11-14-22, Benjamin Safdi

November 14, 2022: Benjamin Safdi