  An analytical representation for the spatial and temporal dynamics of the
simplest of the diffusions -- Bronwian diffusion in an homogeneous slab
geometry, with radial symmetry -- is presented. This representation is useful
since it describes the time-resolved (as well as stationary) radial profiles,
for point-like external excitation, which are more important in practical
experimental situations than the case of plane-wave external excitation. The
analytical representation can be used, under linear system response conditions,
to obtain the full dynamics for any spatial and temporal profiles of initial
perturbation of the system. Its main value is the quantitative accounting of
absorption in the spatial distributions. This can contribute to obtain
unambiguous conclusions in reports of Anderson localization of classical waves
in three dimensions.
