Collapse models and cosmology

TL;DR

This paper reviews how quantum collapse models, especially CSL, can address the measurement problem in cosmology and inflation, providing testable predictions and strong constraints from cosmological data.

Contribution

It demonstrates the application of collapse models to cosmology, deriving unprecedented constraints from observational data on CSL.

Findings

Collapse models can solve the quantum measurement problem in cosmology.

Cosmological data impose strong constraints on CSL parameters.

Collapse models are compatible with inflationary predictions.

Abstract

Attempts to apply quantum collapse theories to Cosmology and cosmic inflation are reviewed. These attempts are motivated by the fact that the theory of cosmological perturbations of quantum-mechanical origin suffers from the single outcome problem, which is a modern incarnation of the quantum measurement problem, and that collapse models can provide a solution to these issues. Since inflationary predictions can be very accurately tested by cosmological data, this also leads to constraints on collapse models. These constraints are derived in the case of Continuous Spontaneous Localization (CSL) and are shown to be of unprecedented efficiency.