Measurements of Observables Replaced by "Detections" in Quantum Theory

TL;DR

This paper clarifies the distinction between measurements and detections in quantum physics, emphasizing that detections infer observable values without equating them to direct measurements, and explores their conceptual implications.

Contribution

It rigorously proves that detections are not equivalent to measurements in quantum theory and clarifies their conceptual role within the framework.

Findings

Detections are inferential, not direct measurements.

Measurements and detections have fundamentally different meanings in quantum physics.

The paper establishes the conceptual boundaries of detections in quantum theory.

Abstract

In Quantum Physics it is not always possible to directly perform the measurement of an obsevable; in some of these cases, however, its value can be {\sl detected}, i.e. it can be inferred by measuring {\sl another} observable characterized by perfect correlation with the observable of interest. Though a {\sl detection} is often interpreted as a {\sl measurement} of the detected observable, we prove that the two concepts cannot be identified in Quantum Physics. Furthermore, we establish what meaning and role can be ascribed to detections coherently with Quantum Theory.