SingleWorld Theory of the Extended Wigner's Friend Experiment
Abstract
Frauchiger and Renner have recently claimed to prove that "Singleworld interpretations of quantum theory cannot be selfconsistent". 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 BellBohmian 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 selfconsistent.
 Publication:

Foundations of Physics
 Pub Date:
 May 2017
 DOI:
 10.1007/s1070101700827
 arXiv:
 arXiv:1608.05873
 Bibcode:
 2017FoPh...47..658S
 Keywords:

 Wigner's friend;
 Single world;
 Quantum theory;
 Quantum Physics
 EPrint:
 14 pages. Version to be published in Foundations of Physics