Numerical Construction of Wave Dark Matter Halos

The prospect of an ultra-light dark matter particle (also known as Fuzzy Dark Matter, or FDM) has recently drawn attention as a promising alternative to standard Cold Dark Matter (CDM). When the mass of the particle reaches below 10^-21 eV, quantum effects can suppress structure formation on galactic scales, potentially alleviating Standard CDM's small-scale tensions. However, a central challenge posed by FDM is the difficulty of simulating it in large volumes; simulations that numerically evolve the Schrödinger-Poisson system must resolve down to the de Broglie wavelength, making it practically impossible to simulate a Milky-Way-like galaxy with today's computational resources. I will present a wave generalization of the classic Schwarzschild method for constructing self-consistent halos -- such a halo consists of a suitable superposition of waves instead of particle orbits, chosen to yield a desired mean density profile. I will demonstrate that this construction method allows us to reliably simulate FDM halos at a fraction of the computational cost of typical FDM simulations. I will share a few preliminary results we have obtained using our construction method, and discuss several tests of FDM that we can now run more efficiently with this code.
 

Date

Speakers

Tomer Yavetz

Affiliation

Columbia University