Copenhagen interpretation can survive the upgraded Schroedinger's cat Gedankenexperiment

TL;DR

This paper argues that the Copenhagen interpretation remains consistent with quantum mechanics even when analyzing the Frauchiger-Renner Gedankenexperiment, countering claims that quantum theory cannot self-describe.

Contribution

It demonstrates that the supposed inconsistency in quantum theory arises from an incorrect state description, reaffirming the Copenhagen interpretation's validity.

Findings

Incorrect state description led to false inconsistency claims

Copenhagen interpretation satisfies all assumptions of the Gedankenexperiment

Quantum theory remains self-consistent with proper state analysis

Abstract

Recently, Frauchiger and Renner proposed a Gedankenexperiment, which was claimed to be able to prove that quantum theory cannot consistently describe the use of itself. Here we show that the conclusions of Frauchiger and Renner actually came from their incorrect description of some quantum states. With the correct description there will be no inconsistent results, no matter which quantum interpretation theory is used. Especially, the Copenhagen interpretation can satisfy all the three assumptions (C), (Q), and (S) of Frauchiger and Renner simultaneously, thus it has no problem consistently describing the use of itself.