Origin of probabilities and their application to the multiverse

TL;DR

This paper argues that all practical probabilities stem from quantum fluctuations, challenging classical probability's applicability in cosmology and suggesting new approaches to eternal inflation's measure problem.

Contribution

It introduces a quantum-based perspective on probabilities, questioning classical theories and proposing solutions to measure problems in eternal inflation.

Findings

Probabilities originate from quantum fluctuations.

Classical probability theory lacks physical verification.

Potential resolution to eternal inflation measure issues.

Abstract

We argue using simple models that all successful practical uses of probabilities originate in quantum fluctuations in the microscopic physical world around us, often propagated to macroscopic scales. Thus we claim there is no physically verified fully classical theory of probability. We comment on the general implications of this view, and specifically question the application of classical probability theory to cosmology in cases where key questions are known to have no quantum answer. We argue that the ideas developed here may offer a way out of the notorious measure problems of eternal inflation.