Challenging theories of dark energy with levitated force sensor

TL;DR

This study uses a levitated force sensor to experimentally test the chameleon theory of dark energy, significantly narrowing the parameter space and ruling out the basic model as a viable explanation for dark energy.

Contribution

The paper introduces a highly sensitive laboratory experiment that extends previous tests of the chameleon dark energy model by nearly two orders of magnitude, providing decisive evidence against it.

Findings

No evidence for the chameleon fifth force was detected.

The results exclude the basic chameleon model as a candidate for dark energy.

The methodology can be applied to other fundamental physics tests.

Abstract

The nature of dark energy is one of the most outstanding problems in physical science, and various theories have been proposed. It is therefore essential to directly verify or rule out these theories experimentally. However, despite substantial efforts in astrophysical observations and laboratory experiments, previous tests have not yet acquired enough accuracy to provide decisive conclusions as to the validity of these theories. Here, using a diamagnetically levitated force sensor, we carry out a test on one of the most compelling explanations for dark energy to date, namely the Chameleon theory, an ultra-light scalar field with screening mechanisms, which couples to normal-matter fields and leaves a detectable fifth force. Our results extend previous results by nearly two orders of magnitude to the entire physical plausible parameter space of cosmologically viable chameleon models. We find no evidence for such a fifth force. Our results decisively rule out the basic chameleon model as a candidate for dark energy. Our work, thus, demonstrates the robustness of laboratory experiments in unveiling the nature of dark energy in the future. The methodology developed here can be further applied to study a broad range of fundamental physics.