Stable Facts, Relative Facts

Abstract

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 emerge in a world of relative facts and discuss their respective roles in connecting quantum theory and the world. The distinction between relative and stable facts resolves the difficulties pointed out by the no-go theorem of Frauchiger and Renner, and is consistent with the experimental violation of the Local Friendliness inequalities of Bong et al.. Basing the ontology of the theory on relative facts clarifies the role of decoherence in bringing about the classical world and solves the apparent incompatibility between the ‘linear evolution’ and ‘projection’ postulates.

Wigner’s Friend Scenarios and the Internal Consistency of Standard Quantum Mechanics

“…In summary, quantum mechanics can be wrong in its predictions, but it is not inconsistent, at least as far as the Wigner’s Friend scenarios discussed here are concerned. It is, of course, still legitimate to question Feynman’s principle by anticipating situations in which they would fail, or where different interpretations, such as used in [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ] would make verifiable alternative predictions, one would need a stronger case to make further progress in this direction.…”

“…Such studies employed different variants of the de Broglie–Bohm interpretation [ 4 , 5 ], the consistent histories formalism [ 6 ], or the decoherence approach [ 7 , 8 ]. The Bayesian and relational approaches to quantum mechanics were used for the same purpose in [ 9 , 10 ]. Yet more elaborate methods included deriving theory-independent inequalities assuming a universal validity of all events to all agents [ 11 ], or adding non-invasive weak measurements in order to allow the external Observers to monitor the state of the Friends’ laboratories [ 12 ].…”

“…In [ 17 ], a coherent narrative was constructed by taking into account stable material records produced by each act of observation. In this paper, we extend the approach to more complex scenarios, in order to look for inconsistencies, similar to those discussed in [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. We will ask whether similar problems would also arise in the frame work proposed in [ 15 , 16 ] and, if they would, then in what particular form?…”

The Metaphysics of Decoherence

“…Such a characterization makes it crystal clear that participatory realism bears an essential perspectival component with it. Three important examples: Glick (2021) has recently argued that Qbism can be considered a perspectival normative realist stance; Di Biagio and Rovelli (2021) defend the view that quantum mechanics is fundamentally about relative facts, some of which become stable in light of decoherence; Auffèves and Grangier (2019) frame quantum measurements as the realization of a given definite value of the observable depending on the measurement context.…”

The gravitoelectrostatic nuclear energy

“…In the reference [7] the authors distinguish relative facts from stable facts, and conclude that the stable facts are only a subset of the more general category of relative facts.…”