Non-linearities in the quantum multiverse

TL;DR

This paper discusses the challenges posed by non-linear evolution of observables in the quantum multiverse, questioning the viability of unifying eternal inflation and many-worlds interpretations.

Contribution

It highlights the potential issues non-linearities introduce to the quantum multiverse framework and argues these are expected from general theoretical considerations.

Findings

Non-linearities can obstruct the unification of multiverse and quantum interpretations.

Such non-linearities are expected based on general theoretical arguments.

They pose challenges for the measure and measurement problems in the quantum multiverse.

Abstract

It has been recently proposed that the multiverse of eternal inflation and the many-worlds interpretation of quantum mechanics can be identified, yielding a new view on the measure and measurement problems. In the present note, we argue that a non-linear evolution of observables in the quantum multiverse would be an obstacle for such a description and that these non-linearities are expected from quite general arguments.