Reassessing the strength of a class of Wigner's friend no-go theorems

Abstract

Two recent, prominent theorems-the "no-go theorem for observer-independent facts" and the "Local Friendliness no-go theorem"-employ so-called extended Wigner's friend scenarios to try to impose novel, non-trivial constraints on the possible nature of physical reality. While the former is argued to entail that there can be no theory in which the results of Wigner and his friend can both be considered objective, the latter is said to place on reality stronger constraints than the Bell and Kochen-Specker theorems. Here, I conduct a thorough analysis of these theorems and show that they suffer from a list of shortcomings that question their validity and limit their strength. I conclude that the "no-go theorem for observer-independent facts" and the "Local Friendliness no-go theorem" fail to impose significant constraints on the nature of physical reality.