Typical Worlds

TL;DR

This paper analyzes Hugh Everett III's many-worlds interpretation of quantum mechanics, focusing on the role of branch typicality and the assumptions needed to recover standard quantum probabilities.

Contribution

It critically examines Everett's argument and the concept of typicality, highlighting the auxiliary assumptions necessary for pure wave mechanics to align with quantum predictions.

Findings

Pure wave mechanics is deterministic with no inherent probabilities.

Recovering standard quantum predictions requires significant auxiliary assumptions.

The notion of branch typicality is crucial but complex in Everett's interpretation.

Abstract

Hugh Everett III presented pure wave mechanics, sometimes referred to as the many-worlds interpretation, as a solution to the quantum measurement problem. While pure wave mechanics is an objectively deterministic physical theory with no probabilities, Everett sought to show how the theory might be understood as making the standard quantum statistical predictions as appearances to observers who were themselves described by the theory. We will consider his argument and how it depends on a particular notion of branch typicality. We will also consider responses to Everett and the relationship between typicality and probability. The suggestion will be that pure wave mechanics requires a number of significant auxiliary assumptions in order to make anything like the standard quantum predictions.