Experimental bounds on collapse models from gravitational wave detectors

TL;DR

This paper uses gravitational wave detectors to set experimental bounds on collapse models, particularly the CSL model, excluding large parameter regions and testing quantum mechanics at macroscopic scales.

Contribution

It provides the first comprehensive bounds on collapse model parameters from gravitational wave experiments, especially highlighting LISA Pathfinder's strong constraints.

Findings

LIGO, LISA Pathfinder, and AURIGA set upper bounds on collapse parameters.

LISA Pathfinder provides the strongest constraint among the experiments.

The study rules out certain quantum-gravity-induced decoherence proposals.

Abstract

Wave function collapse models postulate a fundamental breakdown of the quantum superposition principle at the macroscale. Therefore, experimental tests of collapse models are also fundamental tests of quantum mechanics. Here, we compute the upper bounds on the collapse parameters, which can be inferred by the gravitational wave detectors LIGO, LISA Pathfinder, and AURIGA. We consider the most widely used collapse model, the continuous spontaneous localization (CSL) model. We show that these experiments exclude a huge portion of the CSL parameter space, the strongest bound being set by the recently launched space mission LISA Pathfinder. We also rule out a proposal for quantum-gravity-induced decoherence.