  Using the model for (bottom-up) hierarchical halo growth recently developed
by Salvador-Sol\'e et al. (2012), we derive the typical spherically averaged
density profile for haloes with several relevant masses in the concordant warm
dark matter (\Lambda WDM) cosmology with non-thermal sterile neutrinos of two
different masses. The predicted density profiles become flat at small radii, as
expected from the effects of the spectrum cutoff. The core cannot be resolved,
however, because the non-null particle velocity yields the fragmentation of
minimum mass protohaloes in small nodes, which invalidates the model at the
corresponding radii.
