CONTRIBUTIONS OF THE PLASMONS TO THE ENERGY DENSITY AND PRESSURE IN THE EARLY UNIVERSE

The contributions of the plasmons to the energy density and pressure o f the cosmic fluid in the early universe are calculated. It is found t hat the transverse and longitudinal plasmons make contributions to the energy density and pressure which amount to similar to 0.1% of the co ntributions of the ordinary photons. The present finding is expected n ot to influence the primordial nucleosynthesis in a drastic way. Never theless, the present investigation consolidates the conventional treat ment of the photons in the early universe that assumes the smallness o f the plasma effects.