The hidden assumptions of Frauchiger and Renner

TL;DR

This paper critically examines Frauchiger and Renner's argument, revealing that additional assumptions are necessary for the contradiction and that these assumptions are invalid in some quantum mechanics frameworks.

Contribution

It clarifies the assumptions behind Frauchiger and Renner's claim and shows their invalidity in certain quantum theories.

Findings

Additional assumptions are required for the contradiction.

The key assumptions are invalid in some quantum mechanics models.

The original argument's conclusion depends on these questionable assumptions.

Abstract

This note is a critical examination of the argument of Frauchiger and Renner (Nature Communications 9:3711 (2018)), in which they claim to show that three reasonable assumptions about the use of quantum mechanics jointly lead to a contradiction. It is shown that further assumptions are needed to establish the contradiction, and that each of these assumptions is invalid in some version of quantum mechanics.