A no-go result for QBism

TL;DR

This paper challenges QBism by demonstrating that its interpretation of the wave function as subjective belief conflicts with the concept of protective measurements, questioning the consistency of QBism's core assumptions.

Contribution

It provides a no-go result showing that QBism's subjective wave function cannot be reconciled with protective measurements without assuming psi-ontology.

Findings

QBism's wave function interpretation conflicts with protective measurements

The argument does not depend on psi-ontology assumptions

Highlights limitations of subjective probability views in quantum mechanics

Abstract

In QBism the wave function does not represent an element of physical reality external to the agent, but represent an agent's personal probability assignments, reflecting his subjective degrees of belief about the future content of his experience. In this paper, I argue that this view of the wave function is not consistent with protective measurements. The argument does not rely on the realist assumption of the psi-ontology theorems, namely the existence of the underlying ontic state of a quantum system.