Related papers: A no-go theorem for observer-independent facts
Predictions of quantum theory have been confirmed experimentally in the microscopic domain with no known exceptions. This success motivates physicists to assume universal validity of the theory. To put the predictions of the quantum theory…
Recent no-go theorems on interpretations of quantum theory featuring an assumption of `Absoluteness of Observed Events' (AOE) are shown to have an unexpectedly strong corollary: one cannot reject AOE and at the same time assume that the…
An experiment by Proietti {\it et al} purporting to instantiate the `Wigner's Friend' thought experiment is discussed. It is pointed out that the stated implications of the experiment regarding the alleged irreconcilability of facts…
In April 2016, Daniela Frauchiger and Renato Renner published an article online in which they introduce a Gedankenexperiment that led them to conclude that single-world interpretation of quantum theory cannot be self-consistent. In a new…
Facts happen at every interaction, but they are not absolute: they are relative to the systems involved in the interaction. Stable facts are those whose relativity can effectively be ignored. In this work, we describe how stable facts…
Quantum theory in its conventional formulation is notoriously subject to various measurement-related paradoxes, as exemplified by the "Schrodinger's Cat" and "Wigner's Friend" thought experiments. It has been shown, for example by…
Relational Quantum Mechanics (RQM) treats quantum states as observer-dependent facts rather than absolute properties. While this relational stance is conceptually attractive, it raises concerns about empirical confirmation, particularly in…
Wigner's thought experiment illustrates quantum theory's measurement problem by considering an observer who measures a quantum system inside a sealed lab, modeled unitarily by an outsider. Recent extensions of this thought experiment,…
It is commonly thought that observers in distinct branches of an Everettian multiverse cannot communicate without violating the linearity of quantum theory. Here we show a counterexample, demonstrating that inter-branch communication is in…
We argue that Wigner's friend thought experiment does not support observer dependence of quantum states. An analysis in terms of history vectors suggests that quantum collapse is to be understood as collapse of histories rather than…
It is shown that the absence of an objective existence of the results of quantum measurements cannot be proved by known experiments. There are also general arguments confirming this conclusion.
Recent extended formulations of the Wigner's friend thought experiment throw the measurement problem of quantum mechanics into sharper relief. Here I respond to an invitation by Renner to provide a consistent and concrete set of rules for…
It is commonly expected that quantum theory is universal, in that it describes the world at all scales. Yet, quantum effects at the macroscopic scale continue to elude our experimental observation. This fact is commonly attributed to…
The famous Wigner's friend experiment considers an observer -- the friend -- and a superobserver -- Wigner -- who treats the friend as a quantum system and her interaction with other quantum systems as unitary dynamics. This is at odds with…
A recent paper by two of us and co-workers, based on an extended Wigner's friend scenario, demonstrated that certain empirical correlations predicted by quantum theory (QT) violate inequalities derived from a set of metaphysical assumptions…
In a recent paper, \.Zukowski and Markiewicz showed that Wigner's Friend (and, by extension, Schr\"odinger's Cat) can be eliminated as physical possibilities on purely logical grounds. I validate this result and demonstrate the source of…
We discuss the status of relative facts - the central concept of Relational Quantum Mechanics (RQM) - in the context of the new amendment to RQM called cross-perspective links postulate. The new axiom states that by a proper measurement one…
This is an analysis of the recently published article `Quantum theory cannot consistently describe the use of itself' by D. Frauchiger and R. Renner~\cite{1}. Here I decipher the paradox and analyze it from the point of view of de…
Wigner-friend scenarios -- in which external agents describe a closed laboratory containing a friend making a measurement -- highlight the difficulties inherent to quantum theory when accounting for measurements. In non-relativistic…
The original Wigner's friend paradox is a gedankenexperiment involving an observer described by an external agent. The paradox highlights the tension between unitary evolution and collapse in quantum theory, and is sometimes taken as…