Single-world theory of the extended Wigner's world experiment

TL;DR

This paper presents a single-world interpretation of quantum mechanics using Bell-Bohmian theory, challenging claims that quantum theory cannot be self-consistent when only one world exists, especially in the context of Frauchiger and Renner's experiment.

Contribution

It introduces a Bell-Bohmian model that reproduces quantum predictions with a single-world perspective, critically analyzing Frauchiger and Renner's argument against such interpretations.

Findings

Bell-Bohmian theory models single-world quantum systems.

Frauchiger and Renner's standard quantum theory with collapse is inconsistent.

Single-world models can reproduce quantum predictions without contradiction.

Abstract

Frauchiger and Renner have recently claimed to prove that "Single-world interpretations of quantum theory cannot be self-consistent". This is contradicted by a construction due to Bell, inspired by Bohmian mechanics, which shows that any quantum system can be modelled in such a way that there is only one "world" at any time, but the predictions of quantum theory are reproduced. This Bell-Bohmian theory is applied to the experiment proposed by Frauchiger and Renner, and their argument is critically examined. It is concluded that it is their version of "standard quantum theory", incorporating state vector collapse upon measurement, that is not self-consistent.