Turbulence in the Hot Universe

Abstract

THE development of von Weizsäcker's cosmogonical hypothesis¹ has led to work² on the combined hydrodynamical motions of the photon gas and the cosmic plasma in the early hot universe, when the radiation density ρr greatly exceeds the density of matter ρ. In the case of vortex motions, the initial stage of cosmological expansion is non-Friedmannian with anisotropic and inhomogeneous geometry². But there is some speculation in favour of the motion having a potential character, and in this case the departures from the Friedmann model are small at all epochs, from the general theory³. Here I consider hydrodynamical aspects of the evolution of the cosmic fluid at the matter-dominated stage, assuming cosmological expansion to be described by an open Friedmann model because of a number of observational and theoretical arguments^4–6.