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MiS Preprint
37/2015
Objectivity of Quantum Measurement in Many-Observer World
Chang-Pu Sun
Abstract
The objectivity of quantum measurement is treated as an emergent phenomenon with N observers who can agree to the same result of measurement, and meanwhile, they can identify their records with each other. In this many-observer world (MOW), an objective quantum measurement is dealt with as a multipartite [(N+1) -body] quantum correlation among the measured system and N observers when its bipartite reductions are the same classical correlations. With this conceptual clarification, we find that, an objective quantum measurement is implemented if and only if the MOW is initially factorized in a pure state and then the total system can evolve into a generalized GHZ state with respect to the orthogonal basis preferred by each observer. Especially, such objective quantum measurement is recast in ideal classical correlation when the observer world is macroscopic for $N\rightarrow\infty$
