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On the notion of coexistence in quantum mechanics

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Mathematica Slovaca

Abstract

The notion of coexistence of quantum observables was introduced to describe the possibility of measuring two or more observables together. Here we survey the various different formalisations of this notion and their connections. We review examples illustrating the necessary degrees of unsharpness for two noncommuting observables to be jointly measurable (in one sense of the phrase). We demonstrate the possibility of measuring together (in another sense of the phrase) noncoexistent observables. This leads us to a reconsideration of the connection between joint measurability and noncommutativity of observables and of the statistical and individual aspects of quantum measurements.

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Correspondence to Paul Busch.

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Communicated by Anatolij Dvurečenskij

Dedicated to Professor Sylvia Pulmannová on the occasion of her 70th birthday

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Busch, P., Kiukas, J. & Lahti, P. On the notion of coexistence in quantum mechanics. Math. Slovaca 60, 665–680 (2010). https://doi.org/10.2478/s12175-010-0039-1

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  • DOI: https://doi.org/10.2478/s12175-010-0039-1

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