"Theory of Measurement" in Differential-Space Quantum Theory

The "reduction of the wave packet" is an essential feature of the quantum description of measurement. Since it means an abrupt change in the wave function, it therefore also implies an abrupt change in the statistical description of the system. If the differential-space theory of quantum systems rests on a description of reality more detailed than quantum mechanics, it must contain an account of this change which is consistent with the strictly probabilistic point of view of the theory. It is here shown that the theory does satisfy this necessary condition. The need of a special postulate for the measurement process is eliminated in this formulation, and a new explicitness is introduced into the description.