Subjectivistic interpretations of quantum probabilities

Journées d'étude le 13 et 14 mars à l'ENS organisées par Stefano Osnaghi et les Archives Husserl

Abstract

According to the “orthodox” interpretation of quantum mechanics, the probabilities delivered by the theory refer to the results that will be found if a suitable measurement is performed. Interpreting probabilities this way is supposed to put one in a position to account for the observed results without relying upon metaphysical assumptions, which are known to give rise to paradoxes in the quantum context. Once some essential realist features have been eliminated from the account of quantum observables, however, it becomes difficult to see on what grounds the theory may still be said to provide objective knowledge – a remark which puts the very consistency of the orthodox interpretation into question. Two problems in particular need to be addressed. First, the orthodox interpretation presupposesthe notion of measurement. This means that measurement itself cannot be analyzed as a quantum phenomenon (problem of measurement). Second, if the statistical distributions of the results are not constrained by the structure of an independent world, one might wonder why such distributions should follow certain reproducible patterns rather than others (problem of reconstruction). In a series of recent works, the proponents of QBism have argued that the subjectivist (de-Finettian) variety of the Bayesian view of probability may help deal with these issues. In particular, they have put forward a new approach to the longstanding problem of defining the role of the “observer” in quantum physics. The workshop aims to examine the insights provided by QBism, as well as its potential drawbacks, in light of a more general epistemological analysis of the subject’s contribution to the constitution of objectivity. The discussion will focus in particular on philosophical traditions – such as phenomenology and linguistic pragmatism – that have been largely neglected in the debate concerning the foundations of quantum mechanics.

Programme:
 
Mercredi 13 Mars 2019
 
14:30  S. Osnaghi (Ecole Normale Supérieure)
             Introduction
15:00 C. Fuchs (University of Massachusetts Boston)
            The day QBism shot itself in the foot <sarcasm>
15:45 Pause
16:00 M. Bitbol & L. de la Tremblaye (Ecole Normale Supérieure)
            Participatory probabilities
17:15 M. Müller (Austrian Academy of Sciences)
            QBism, beliefs, and the world: a reversal of perspective
 
Jeudi 14 Mars 2019
 
09:30 L. Henderson(University of Groningen)
            A road not traveled in pragmatist interpretation of quantum theory
10:15 V. Baumann & C. Brukner (University of Vienna)    
           Wigner's friend as a rational agent
11:30 Pause
11:45 R. Healey (University of Arizona)
           Objectivity without beables
12:30 Table ronde
 
Salle E 314 – ENS, 24 rue Lhomond, 75005 Paris