Asymptotic Behavior of Spectral Energy Distribution Function of Equilibrium Radiation in Maxwell Plasma at Low Frequencies

The low-frequency asymptotic behavior of the spectral distribution density of equilibrium radiation in collisionless non-degenerate electron plasma is studied. It is shown that the consideration of the spatial dispersion in the electron gas permittivity leads to a logarithmic singularity in the spectral distribution density at low frequencies. In this case, the total radiation energy remains finite. The results of the analytical consideration are identical to numerical calculations.