  Near-field radiative heat transfer (NFRHT) in nanoparticle networks is
complicated due to the multiple scattering of thermally excited electromagnetic
wave (namely, many-body interaction, MBI). The MBI regime is analyzed using the
many-body radiative heat transfer theory at the particle scale for networks of
a few nanoparticles. Effect of MBI on radiative heat diffusion in networks of a
large number of nanoparticles is analyzed using the normal-diffusion radiative
heat transfer theory at the continuum scale. An influencing factor $\psi$ is
defined to numerically figure out the border of the different many-body
interaction regimes. The whole space near the two nanoparticles can be divided
into four zones, non-MBI zone, enhancement zone, inhibition zone and forbidden
zone, respectively. Enhancement zone is relatively smaller than the inhibition
zone, so many particles can lie in the inhibiting zone that the inhibition
effect of many-body interaction on NFRHT in nanoparticle networks is common in
literature. Analysis on the radiative thermal energy confirms that multiple
scattering caused by the inserted scatter accounts for the enhancement and
inhibition of NFRHT. By arranging the nanoparticle network in aspect of
structures and optical properties, the MBI can be used to modulate radiative
heat diffusion characterized by the radiative effective thermal conductivity
($k_{\rm eff}$) over a wide range, from inhibition (over 55% reduction) to
amplification (30 times of magnitude). To achieve a notable MBI, it is
necessary to introduce particles that have resonances well-matched with those
of the particles of interest, irrespective of their match with the Planckian
window. This work may help for the understanding of the thermal radiation in
nanoparticle networks.
