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Entanglement, joint measurement, and state reduction

Alan Macdonald
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Abstract

Entanglement is perhaps the most important new feature of the quantum world. It is expressed in quantum theory by the joint measurement formula. We prove the formula for self-adjoint observables from a plausible assumption, which for spacelike separated measurements is an expression of relativistic causality. State reduction is simply a way to express the JMF after one measurement has been made, and its result known.

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Alan Macdonald. 2002-11-08. Entanglement, joint measurement, and state reduction. https://arxiv.org/abs/quant-ph/0108129

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