Distinguish axion models with SPARC
Dr. Chen Sun
Postdoctoral Fellow
Los Alamos National Lab
In this talk I will first discuss how rotation-dominated galaxies can be used to constrain the size of solitons inside galaxy dark matter halos. I will discuss how this confronts the theoretical expectation, which leads to a robust constraint on the fraction of ultralight dark matter in a wide mass range from 10^{-24} eV to 10^{-20} eV. I will then discuss how this bound is affected by the Peccei-Quinn scale and its sensitivity to the type of axion potential. The talk will be based on the work 2111.03070 as well as work in preparation.