Can the Quantum Measurement Problem be resolved within the framework of Schroedinger Dynamics and Quantum Probability?

Abstract

We provide an affirmative answer to the question posed in the title. Our argument is based on a treatment of the Schroedinger dynamics of the composite of a quantum microsystem, S, and a macroscopic measuring apparatus, I, consisting of N interacting particles. The pointer positions of this apparatus are represented by orthogonal subspaces of its representative Hilbert space that are simultaneous eigenspaces of coarse-grained macroscopic observables. By taking explicit account of their macroscopicality via a large deviation principle, we prove that, for a suitably designed apparatus I, the evolution of the composite (S+I) leads both to the reduction of the wave packet of S and to a one-to-one correspondence between the resultant state of this microsystem and the pointer position of I, up to utterly negligible corrections that decrease exponentially with N.