On equilibrium radiation and zero-point fluctuations in non-relativistic electron gas

Examination of equilibrium radiation in plasma media shows that the spectral the energy distribution of such radiation is different from the Planck equilibrium radiation. Using the previously obtained general relations for the spectral energy density of equilibrium radiation in a system of charged particles, we consider radiation in an electron in the limiting case of an infinitesimal damping. It is shown that zero vacuum fluctuations which are part of the full spectral energy distribution should be renormalized. In this case, the renormalized zero vacuum fluctuations depend on the electron density. A similar effect should exist in the general case of a quasineutral plasma.