  We investigate the radiative heat transfer along a chain of nanoparticles
using both a purely kinetic approach based on the solution of a Boltzmann
transport equation and an exact method (Landauer's approach) based on
fluctuational electrodynamics. We show that the kinetic theory generally fails
to predict properly the heat flux transported along the chain both at close
(near-field regime) and large separation (far-field regime) distances. We
report a deviation of a factor two between the heat fluxes predicted by the two
approaches in the diffusive regime of heat transport and we show that this
difference becomes even greater than two orders of magnitude in the ballistic
regime.
