[en] The problem how to introduce an extended version of Heisenberg's closure hypothesis in the theory of cosmic turbulence is expounded. To be definite, the requirements are as follows: the hypothesis is applied only in the physically relevant frame; in this frame, the physical wave-number of the biggest eddy is identified with the reciprocal of the length specifying the event horizon; in the limit when the cosmic expansion disappears, the hypothesis is automatically reduced to the usual Heisenberg one. An isotropic big-bang universe is considered whose cosmic expansion is specified by an expansion parameter and whose inertial mass density is a definite cosmic time function. (Mori, K.)