  Rates for detection of weakly-interacting massive-particle (WIMP) dark matter
are usually carried out assuming the Milky Way halo is an isothermal sphere.
However, it is possible that our halo is not precisely spherical; it may have
some bulk rotation; and the radial profile may differ from that of an
isothermal sphere. In this paper, we calculate detection rates in
observationally consistent alternative halo models that produce the same halo
contributions to the local and asymptotic rotation speeds to investigate the
effects of theoretical uncertainty of the WIMP spatial and velocity
distribution. We use self-consistent models to take into account the effects of
various mass distributions on the local velocity distribution. The local halo
density may be increased up to a factor of 2 by flattening or by an alternative
radial profile (which may also decrease the density slightly). However, changes
in the WIMP velocity distribution in these models produce only negligible
changes in the WIMP detection rate. Reasonable bulk rotations lead to only an
$O(10%)$ effect on event rates. We also show how the nuclear recoil spectrum in
a direct-detection experiment could provide information on the shape and
rotation of the halo.
