Solution to the measurement problem within linear, unitary, no collapse, no particle quantum mechanics

TL;DR

This paper proposes a solution to the quantum measurement problem by demonstrating that in linear, unitary, no-collapse quantum mechanics, different outcomes are isolated, leading observers to perceive only definite eigenstates.

Contribution

It shows that within a no-collapse quantum framework, the perception of definite outcomes arises naturally from the isolation of different reality branches.

Findings

Different versions of reality are completely isolated from each other.

Observers perceive only the eigenstates relevant to the measurement setup.

The approach explains the emergence of definite measurement outcomes without collapse.

Abstract

The measurement problem is to explain why a system which is in a linear combination of states appears, upon measurement, to be in just one of those states. The solution given here is to first show that if one assumes linear, unitary, no collapse, no particle quantum mechanics, the different versions of reality are completely isolated from each other. This then implies only the eigenstates appropriate to the measurement setup will be perceived. In a Stern-Gerlach experiment, for example, only spin up or spin down will be perceived, but never a combination of the two.