Dependence of Dark Matter - Electron Scattering on the Galactic Dark
  Matter Velocity Distribution
  The rate of dark matter-electron scattering depends on the underlying
velocity distribution of the dark matter halo. Importantly, dark
matter-electron scattering is particularly sensitive to the high-velocity tail,
which differs significantly amongst the various dark matter halo models. In
this work, we summarize the leading halo models and discuss the various
parameters which enter them. We recommend updated values for these parameters
based on recent studies and measurements. Furthermore, we quantify the
dependence of the dark matter-electron scattering rate on the choice of halo
model and parameters, and demonstrate how these choices propagate to the
predicted cross-section limits. The rate is most sensitive to changes in the
circular velocity v0; in silicon targets, we find that the changes in the rate
predictions can range from O(0.01%) to O(100%) for contact interactions and
O(10%) to O(100%) for long-range interactions.
