Don't cross the streams: caustics from Fuzzy Dark Matter

Understand

We study how tidal streams from globular clusters may be used to constrain the mass of ultra-light dark matter particles, called `fuzzy' dark matter (FDM).

• A general feature of FDM models is the presence of ubiquitous density fluctuations in bound, virialized dark matter structures, on the scale of the de Broglie wavelength, arising from wave interference in the evolving dark matter distribution.
• These time-varying fluctuations can disturb the motions of stars, leading to potentially observable signatures in cold thin tidal streams in our own Galaxy.
• The study of this effect has been hindered by the difficulty in simulating the FDM wavefunction in Milky Way-sized systems.