Unsharp Quantum Reality
Abstract
The positive operator (valued) measures (POMs) allow one to generalize the notion of observable beyond the traditional one based on projection valued measures (PVMs). Here, we argue that this generalized conception of observable enables a consistent notion of unsharp reality and with it an adequate concept of joint properties. A sharp or unsharp property manifests itself as an element of sharp or unsharp reality by its tendency to become actual or to actualize a specific measurement outcome. This actualization tendency - or potentiality - of a property is quantified by the associated quantum probability. The resulting single-case interpretation of probability as a degree of reality will be explained in detail and its role in addressing the tensions between quantum and classical accounts of the physical world will be elucidated. It will be shown that potentiality can be viewed as a causal agency that evolves in a well-defined way.
Cite
@article{arxiv.1005.0604,
title = {Unsharp Quantum Reality},
author = {Paul Busch and Gregg Jaeger},
journal= {arXiv preprint arXiv:1005.0604},
year = {2011}
}
Comments
Sections 2 and 4 of this Version 2 have been revised to increase clarity and reduce ambiguity. The terminology of unsharp properties, vagueness and fuzziness has been explained more explicitly. Main message has remained unchanged