On the Ollivier-Poulin-Zurek definition of objectivity

TL;DR

This paper critically examines the Ollivier-Poulin-Zurek definition of objectivity within quantum decoherence and argues that it cannot adequately explain classicality emergence due to assumptions about Hilbert-space decomposition.

Contribution

The paper challenges the philosophical basis of quantum Darwinism by analyzing the reference issues in the definition of objectivity and its reliance on physical assumptions.

Findings

The definition leads to empty or circular references.

The assumption of physics laws being independent of Hilbert-space decomposition is crucial.

Decoherence alone cannot explain classicality emergence.

Abstract

The Ollivier-Poulin-Zurek definition of objectivity provides a philosophical basis for the environment as witness formulation of decoherence theory and hence for quantum Darwinism. It is shown that no account of the reference of the key terms in this definition can be given that does not render the definition either empty or circular. It is argued that this is not the fault of the language used, but of the assumption that the laws of physics are independent of Hilbert-space decomposition. All evidence suggests that this latter assumption is true. If it is, decoherence cannot explain the emergence of classicality.