Atom-interferometry constraints on dark energy

Understand

If dark energy --- which drives the accelerated expansion of the universe --- consists of a light scalar field, it might be detectable as a "fifth force" between normal-matter objects, in potential conflict with precision tests of gravity.

• Chameleon fields and other theories with screening mechanisms, however, can evade these tests by suppressing the forces in regions of high density, such as the laboratory.
• Using a cesium matter-wave interferometer near a spherical mass in an ultra-high vacuum chamber, we reduce the screening mechanism by probing the field with individual atoms rather than bulk matter.
• Thus, we constrain a wide class of dark energy theories, including a range of chameleon and other theories that reproduce the observed cosmic acceleration.