Adlam's Frame: comment on "Wigner's Frame"

Abstract

Recent no-go theorems based on extended Wigner's Friend scenarios (EWFS) reveal a deep tension between the universal validity of quantum theory and local friendliness (LF), the conjunction of three natural assumptions: the absoluteness of observed events, locality, and no-superdeterminism. In a recent work, Adlam argues that this tension can be dissolved by appealing to quantum reference frames (QRFs). We present and critically assess her proposal. We show that her proposed resolution does not arise from QRFs, but instead relies on three independent modifications: certain degrees of freedom are always definite, observers can flip upon measuring spins, and the outcomes the superobservers record and use to test the inequalities are not their friends' observed results. The proposal and the arguments for the plausibility of these modifications rest on several misconceptions about QRFs and EWFS, which we rectify. We conclude that, within standard quantum theory, quantum reference frames do not evade the EWFS no-go theorems.