New Insights on Axion Stars and Dark Matter Constraints

Recent research by Jae Hyeok Chang, Patrick J. Fox, and Huangyu Xiao, titled "Axion Stars: Mass Functions and Constraints," explores the implications of axion-like particles as dark matter candidates. The study, available on arXiv, examines how these particles can lead to the formation of axion miniclusters and subsequently axion stars, particularly in scenarios where the Peccei-Quinn symmetry is broken after cosmic inflation.

The authors compute the mass function of axion stars based on recent studies of axion miniclusters and simulations of Bose stars. They find that axion-like particles with masses ranging from approximately $1.8 \times 10^{-21}~\text{eV}$ to $3.3 \times 10^{-17}~\text{eV}$ are constrained by the absence of dynamical heating of stars in ultrafaint dwarf galaxies. This finding suggests that current microlensing surveys may not be sensitive enough to detect QCD axion stars.

The research highlights the potential for indirect searches for axions, opening new avenues for understanding dark matter substructures. The results are significant as they provide constraints on the properties of axion stars and their detectability, which could influence future astrophysical observations and theories regarding dark matter.

For further details, the paper can be accessed at arXiv:2406.09499.