Dependence of direct detection signals on the WIMP velocity distribution
  The signals expected in WIMP direct detection experiments depend on the
ultra-local dark matter distribution. Observations probe the local density,
circular speed and escape speed, while simulations find velocity distributions
that deviate significantly from the standard Maxwellian distribution. We
calculate the energy, time and direction dependence of the event rate for a
range of velocity distributions motivated by recent observations and
simulations, and also investigate the uncertainty in the determination of WIMP
parameters. The dominant uncertainties are the systematic error in the local
circular speed and whether or not the MW has a high density dark disc. In both
cases there are substantial changes in the mean differential event rate and the
annual modulation signal, and hence exclusion limits and determinations of the
WIMP mass. The uncertainty in the shape of the halo velocity distribution is
less important, however it leads to a 5% systematic error in the WIMP mass. The
detailed direction dependence of the event rate is sensitive to the velocity
distribution. However the numbers of events required to detect anisotropy and
confirm the median recoil direction do not change substantially.
