Measurement, Interpretation and Information

Abstract

During many years since the birth of quantum mechanics, instrumentalist interpretations prevailed: the meaning of the theory was expressed in terms of measurements results. However, in the last decades, several attempts to interpret it from a realist viewpoint have been proposed. Among them, modal interpretations supply a realist non-collapse account, according to which the system always has definite properties and the quantum state represents possibilities, not actualities. But the traditional modal interpretations faced some conceptual problems when addressing imperfect measurements. The modal-Hamiltonian interpretation, on the contrary, proved to be able to supply an adequate account of the measurement problem, both in its ideal and its non-ideal versions. Moreover, in the non-ideal case, it gives a precise criterion to distinguish between reliable and non-reliable measurements. Nevertheless, that criterion depends on the particular state of the measured system, and this might be considered as a shortcoming of the proposal. In fact, one could ask for a criterion of reliability that does not depend on the features of what is measured but only on the properties of the measurement device. The aim of this article is precisely to supply such a criterion: we will adopt an informational perspective for this purpose.

Relational Event-Time in Quantum Mechanics

“…In particular, it was applied to the Stern-Gerlach experiment taking into account the possibility of infinite "tails" (Elby 1993). Moreover, in the non-ideal case it gives a criterion to distinguish between reliable and non-reliable measurements (Lombardi and Castagnino 2008: Section 6), a criterion that can be generalized when expressed in informational terms (Lombardi, Fortin, and López 2015).…”

A new application of the modal-Hamiltonian interpretation of quantum mechanics: The problem of optical isomerism

“…The modal-Hamiltonian interpretation (MHI) endows the Hamiltonian of a system with the role of selecting the subset of the definitevalued observables of the system. This makes the MHI immune to the non-ideal measurement's "silver bullet", since it not only accounts for ideal and non-ideal measurements, but it also supplies a criterion to distinguish between reliable and non-reliable measurements in the non-ideal case , Ardenghi, Lombardi and Narvaja 2013, Lombardi, Fortin and López 2015. Moreover, the MHI rule of definitevalue ascription has been reformulated in an explicitly invariant form, in terms of the Casimir operators of the Galilean group Lombardi 2009, Lombardi, Castagnino andArdenghi 2010), and the compatibility of the MHI with the theory of decoherence has been proved (Lombardi 2010, Lombardi, Fortin, Castagnino andArdenghi 2012).…”