  We show that one may view the self and the distinct part of the van Hove
dynamic correlation function of a simple fluid as the one-body density
distributions of a binary mixture that evolve in time according to dynamical
density functional theory. For a test case of soft core Brownian particles the
theory yields results for the van Hove function that agree quantitatively with
those of our Brownian dynamics computer simulations. At sufficiently high
densities the free energy landscape underlying the dynamics exhibits a barrier
as a function of the mean particle displacement, shedding new light on the
nature of glass formation. For hard spheres confined between parallel planar
walls the barrier height oscillates in-phase with the local density, implying
that the mobility is maximal between layers, which should be experimentally
observable in confined colloidal dispersions.
