  Recent experiments on non-interacting ultra-cold atoms in correlated disorder
have yielded conflicting results regarding the so-called mobility edge, i.e.
the energy threshold separating Anderson localized from diffusive states. At
the same time, there are theoretical indications that the experimental data
overestimate the position of this critical energy, sometimes by a large amount.
The non-trivial effect of anisotropy in the spatial correlations of
experimental speckle potentials have been put forward as a possible cause for
such discrepancy. Using extensive numerical simulations we show that the effect
of anisotropy alone is not sufficient to explain the experimental data. In
particular, we find that, for not-too-strong anisotropy, realistic disorder
configurations are essentially identical to the isotropic case, modulo a simple
rescaling of the energies.
