Decay of Ultralight Axion Condensates

Abstract

Axion particles can form macroscopic condensates, whose size can be galactic in scale for models with very small axion masses $m\sim 10^{-22}$ eV, and which are sometimes referred to under the name of Fuzzy Dark Matter. Many analyses of these condensates are done in the non-interacting limit, due to the weakness of the self-interaction coupling of axions. We investigate here how certain results change upon inclusion of these interactions, finding a decreased maximum mass and a modified mass-radius relationship. Further, these condensates are, in general, unstable to decay through number-changing interactions. We analyze the stability of galaxy-sized condensates of axion-like particles, and sketch the parameter space of stable configurations as a function of a binding energy parameter. We find a strong lower bound on the size of Fuzzy Dark Matter condensates which are stable to decay, with lifetimes longer than the age of the universe.

24 pages, 2 figures. v2: Added brief discussion of angular momentum; extended Appendix A; typos corrected

References in corpus (9)

• Cosmic Structure as the Quantum Interference of a Coherent Dark Wave
• First constraints on fuzzy dark matter from Lyman-$\alpha$ forest data and hydrodynamical simulations
• Bose-Einstein Condensation of Dark Matter Axions
• Relativistic axions from collapsing Bose stars
• Fast Radio Bursts and Axion Miniclusters
• Scalar Field Dark Matter: non-spherical collapse and late time behavior
• Collisions of Dark Matter Axion Stars with Astrophysical Sources
• Open Effective Field Theories from Deeply Inelastic Reactions
• QCD Axion Star Collapse with the Chiral Potential

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