Quantum realism: axiomatization and quantification

TL;DR

This paper develops an axiomatic framework for quantum realism using information-theoretic measures, aiming to quantify the degree of reality of observables in quantum systems.

Contribution

It introduces a set of principles and entropic measures to formalize and quantify quantum realism within a metric-independent framework.

Findings

Constructed entropic quantifiers satisfying proposed axioms

Identified measures as faithful estimates of observable reality

Provided a foundation for further foundational quantum discussions

Abstract

The emergence of an objective reality in line with the laws of the microscopic world has been the focus of longstanding debates. Recent approaches seem to have reached a consensus at least with respect to one aspect, namely, that the encoding of information about a given observable in a physical degree of freedom is a necessary condition for such observable to become an element of the physical reality. Taking this as a fundamental premise and inspired by quantum information theory, here we build an axiomatization for quantum realism -- a notion of realism compatible with quantum theory. Our strategy consists of listing some physically-motivated principles able to characterize quantum realism in a ``metric'' independent manner. We introduce some criteria defining monotones and measures of realism and then search for potential candidates within some celebrated information theories -- those induced by the von Neumann, R\'enyi, and Tsallis entropies. We explicitly construct some classes of entropic quantifiers that are shown to satisfy (almost all of) the proposed axioms and hence can be taken as faithful estimates for the degree of reality (or definiteness) of a given physical observable. Hopefully, our framework may offer a formal ground for further discussions on foundational aspects of quantum mechanics.