Charting the landscape of interpretation, theory rivalry, and underdetermination in quantum mechanics

Section: Egg On Underdetermination and Effective Ontologymentioning

confidence: 99%

(In)effective realism?

Saatsi

2022

“…Instead, the value of an "observable" measures only an incompletely predictable and controllable potentiality belonging just as much to the measuring apparatus as to the observed system itself" (Bohm 1952, 183). 19 That in deterministic HVTs the beables cannot be represented by Hermitian operators implies that Bohmian mechanics is not an interpretation of quantum mechanics but a rival theory, see Acuña (2019). 20 Notice that the continuity of the map ′ also holds in von Neumann's derivation of the trace rule (1), which in turn means that Bell's corollary to GT can also be derived from vNT.…”

Section: Bell and Gleasonmentioning

confidence: 99%

Must hidden variables theories be contextual? Kochen & Specker meet von Neumann and Gleason

Acuña

2021

Self Cite

It is a widespread belief that the Kochen-Specker theorem imposes a contextuality constraint on the ontology of beables in quantum hidden variables theories. On the other hand, after Bell's influential critique, the importance of von Neumann's wrongly called 'impossibility proof' has been severely questioned. However, Max Jammer, Jeffrey Bub and Dennis Dieks have proposed insightful reassessments of von Neumann's theorem: what it really shows is that hidden variable theories cannot represent their beables by means of Hermitian operators in Hilbert space. Hereby I show that i) the very same constraint can be derived from Gleason's theorem, and that ii) if we consider the import of von Neumann's and Gleason's theorems, the relevance of the Kochen-Specker theorem for hidden variables theories gets substantially weakened: it does not force them to be contextual in any interesting sense of the term.

“…The first layer is the underdetermination just described, obtaining between the different responses to the measurement problem. These are sometimes called different "interpretations of QM", but it is more appropriate to view them as predictively equivalent rival theories, which makes this an instance of the well-known problem of underdetermination of theory by evidence (Acuña 2019). The second layer of underdetermination is less well known, but it clearly appears in those recent debates on quantum ontology that are concerned with the question whether (and if so, how) quantum theories should be supplemented by a so-called primitive ontology (PO), that is, postulates about matter in ordinary space or space-time over and above what is contained in the standard formalism of QM (see Allori 2015 for an overview).…”

Section: Introductionmentioning

confidence: 99%

Quantum ontology without speculation

Egg

2021

Existing proposals concerning the ontology of quantum mechanics (QM) either involve speculation that goes beyond the scientific evidence or abandon realism about large parts of QM. This paper proposes a way out of this dilemma, by showing that QM as it is formulated in standard textbooks allows for a much more substantive ontological commitment than is usually acknowledged. For this purpose, I defend a non-fundamentalist approach to ontology, which is then applied to various aspects of QM. In particular, I will defend realism about spin, which has been viewed as a particularly hard case for the ontology of QM.