When Greenberger, Horne and Zeilinger Meet Wigner’s Friend

Gijs Leegwater*

*Corresponding author for this work

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A general argument is presented against relativistic, unitary, single-outcome quantum mechanics. This is achieved by combining the Wigner’s Friend thought experiment with measurements on a Greenberger–Horne–Zeilinger (GHZ) state, and describing the evolution of the quantum state in various inertial frames. Assuming unitary quantum mechanics and single outcomes, the result is that the Born rule must be violated in some inertial frame: in that frame, outcomes are obtained for which no corresponding term exists in the pre-measurement wavefunction.

Original languageEnglish
Article number68
JournalFoundations of Physics
Issue number4
Publication statusPublished - 27 Jun 2022

Bibliographical note

I would like to thank F.A. Muller, Jeremy Butterfield, Renato Renner, Guido Bacciagaluppi and Richard Healey for valuable discussions and corrections. This work is part of the Research Programme ‘The Structure of Reality and the Reality of Structure’, which is financed by the Netherlands Organisation for Scientific Research (NWO).

Publisher Copyright: © 2022, The Author(s).


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