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Relativistic quantum measurement

Donald Marolf·Carlo Rovelli
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Abstract

Does the measurement of a quantum system necessarily break Lorentz invariance? We present a simple model of a detector that measures the spacetime localization of a relativistic particle in a Lorentz invariant manner. The detector does not select a preferred Lorentz frame as a Newton-Wigner measurement would do. The result indicates that there exists a Lorentz invariant notion of quantum measurement and sheds light on the issue of the localization of a relativistic particle. The framework considered is that of single-particle mechanics as opposed to field theory. The result may be taken as support for the interpretation postulate of the spacetime-states formulation of single-particle quantum theory.

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Donald Marolf, Carlo Rovelli. 2002-03-22. Relativistic quantum measurement. https://doi.org/10.1103/physrevd.66.023510

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