Can Everett be Interpreted Without Extravaganza?

TL;DR

This paper critically examines the interpretative challenges of Everett's relative states theory, emphasizing the unresolved issues of multiplicity and the lack of a clear ontology in decoherence-based approaches.

Contribution

It highlights the persistent problems in Everettian interpretations, especially regarding the ontology of multiplicity, and critiques recent decoherence-based solutions for their lack of clarity.

Findings

Decoherence approaches have not clarified the ontology of multiplicity.

Problems of probability and the preferred basis remain unresolved.

Everett's interpretation faces fundamental conceptual challenges.

Abstract

Everett's relative states interpretation of quantum mechanics has met with problems related to probability, the preferred basis, and multiplicity. The third theme, I argue, is the most important one. It has led to developments of the original approach into many-worlds, many-minds, and decoherence-based approaches. The latter especially have been advocated in recent years, in an effort to understand multiplicity without resorting to what is often perceived as extravagant constructions. Drawing from and adding to arguments of others, I show that proponents of decoherence-based approaches have not yet succeeded in making their ontology clear.