Entropic dynamics and the quantum measurement problem

Abstract

We explore the measurement problem in the entropic dynamics approach to quantum theory. The dual modes of quantum evolutioneither continuous unitary evolution or abrupt wave function collapse during measurement-are unified by virtue of both being special instances of entropic updating of probabilities. In entropic dynamics particles have definite but unknown positions; their values are not created by the act of measurement. Other types of observables are introduced as a convenient way to describe more complex position measurements; they are not attributes of the particles but of the probability distributions; their values are effectively created by the act of measurement. We discuss the Born statistical rule for position, which is trivially built into the formalism, and also for generic observables.

Trading drift and fluctuations in entropic dynamics: quantum dynamics as an emergent universality class

“…This immediately raises questions about the nature of other observables: are they beables or are they created in the act of measurement? The case of momentum and the Heisenberg uncertainty relation is discussed in [26]; other related matters in [1,31].…”

Quantum measurement and weak values in entropic dynamics

“…When, in a measurement, the information is in the form of discrete data the Bayesian update is discontinuous and the wavefunction collapses. Both forms of updating coexist harmoniously within the framework of ED [7].…”

“…In ED it is possible and convenient to introduce "observables" other than position (e.g., momentum, energy, and so on) but these are not attributes of the system, they are attributes of their probability distributions. While positions are "ontic" elements, these other observables are purely epistemic; they are properties of the wave function, not of the system [7]. These ideas can be pushed to an extreme when discussing the notion of the Weak Value [11]- [14] of an operator A in which the system is prepared in an initial state |Ψ and post-selected in state |Ψ ′ ,…”

“…It should be replaced by Bell's term 'beables' [15] for ontic elements such as particle positions, and perhaps 'inferables' for those epistemic elements associated to probability distributions. 2 After a brief review of ED and of the simplest or direct type of measurement [7], we discuss the less direct types of measurement -the von Neumann and weak measurements -in which information about the system is inferred by observation of another system, the pointer device, to which it has been suitably correlated. Finally we discuss Weak Values in the context of ED.…”

Entropic Dynamics

“…These include the quantum measurement problem [5,7,8]; momentum, angular momentum, their uncertainty relations, and spin [9,10]; relativistic scalar fields [11]; the Bohmian limit [12]; and the extension to curved spaces [13].…”