Comment on Frauchiger and Renner paper (Nat. Commun. 9, 3711 (2018)): the problem of stopping times

TL;DR

This paper critiques a quantum thought experiment by highlighting the importance of proper synchronization in measurements, showing that previous paradoxes arise from an implicit assumption of complete entanglement.

Contribution

It identifies a key implicit assumption in Frauchiger and Renner's experiment and proposes a refined formulation that avoids measurement paradoxes without relying on wavefunction collapse.

Findings

Synchronization assumption implies complete entanglement

Refined postulate Q1 eliminates measurement paradoxes

Analysis is interpretation-agnostic

Abstract

The Gedankenexperiment advanced by Frauchiger and Renner in their "Nature" paper was based on an implicit assumption that one can synchronize stochastic measurement intervals between two non-interacting systems. This hypothesis, the author demonstrates, is equivalent to the complete entanglement of these systems. Consequently, Frauchiger and Renner's postulate Q is meaningless and needs to be narrowed. Accurate reformulation of the postulate Q1 does not entail any paradoxes with measurement. This paper is agnostic concerning particular interpretations of quantum mechanics. Nor does it refer to the "collapse of the wavefunction."