Understand
We present an in-depth exploration of the phenomenon of dynamical friction in a universe where the dark matter is composed entirely of so-called Fuzzy Dark Matter (FDM), ultralight bosons of mass $m\sim\mathcal{O}(10^{-22})\,$eV.
- We review the classical treatment of dynamical friction before presenting analytic results in the case of FDM for point masses, extended mass distributions, and FDM backgrounds with finite velocity dispersion.
- We then test these results against a large suite of fully non-linear simulations that allow us to assess the regime of applicability of the analytic results.
- We apply these results to a variety of astrophysical problems of interest, including infalling satellites in a galactic dark matter background, and determine that \emph{(1)}~for FDM masses $m\gtrsim 10^{-21}\, {\rm eV}\, c^{-2}$, the timing problem of the Fornax dwarf spheroidal's globular clusters is no longer solved and \emph{(2)}~the effects of FDM on the process of dynamical friction for satellites of total mass $M$ and relative velocity $v_{\rm rel}$ should require detailed numerical simulations for $\left(M/10^9~M_{\odot}\right) \left(m/10^{-22}~{\rm eV}\right)\left(100~{\rm km}~{\rm s}^{-1}/v_{\rm rel}\right) \sim 1$, parameters which would lie outside the validated range of applicability of any currently developed analytic theory, due to transient wave structures in the time-dependent regime.