Conveners
Axion Structure Formation: Self-Interactions, Multi-Field Dynamics, and Observational Signatures
- Philip Mocz
- (Chair: Andrew Eberhardt)
Description
Ultra-light axions remain a plausible candidate for the dark matter, with wave-like dynamics that can leave distinctive imprints on structure formation across a wide range of scales. I will present results from high-resolution simulations exploring extensions to the canonical fuzzy dark matter (FDM) model motivated by axion theory: attractive self-interactions from a finite decay constant and multi-field "axiverse" scenarios. Attractive self-interactions drive a phase transition from dilute to dense solitons and boost small-scale structure formation. Multi-field FDM yields diverse halo structures and alleviates tensions with dwarf galaxy populations. At high redshift, the observed abundance of prolate galaxies in JWST surveys matches axion predictions, and stellar core–halo structures can trace underlying solitons. Together, these results illustrate how axion-inspired extensions to fuzzy dark matter offer a coherent and testable framework linking particle physics to astrophysical data. I will also introduce Jaxion: a new open-source high-performance Python/JAX code for simulating FDM.
