Spectral Energy Density in a Kerr Nonlinear Blackbody

In a Kerr nonlinear blackbody, bare photons with opposite wave vectorsand helicities are bound into pairs and unpaired photons are transformedinto a new kind of quasiparticle, the nonpolariton. The nonpolariton systemconstitutes free thermal radiation in the blackbody. The present paperinvestigates the spectral energy density of the thermal radiation. It is found that the spectral energy density of a Kerr nonlinear blackbodyis larger than that of a normal blackbody.