Does the Vacuum Gravitate on Microscopic Scales? Rydberg Atoms Indicate Probably Not

TL;DR

This study tests whether vacuum energy gravitates at microscopic scales using Rydberg atoms and finds no evidence of such gravitation, setting new limits on the scale of vacuum energy effects.

Contribution

It introduces a novel experimental approach using Rydberg atoms to probe vacuum energy gravitation at microscopic distances, extending previous tests to smaller scales.

Findings

No evidence of vacuum energy gravitation at micron scales

Limits vacuum energy effects below 7 GeV scale

Extends the testing of vacuum gravitation to microscopic distances

Abstract

The cosmological constant presents one of the most fascinating and confounding problems in physics. A straightforward, seemingly robust prediction of quantum mechanics and general relativity is that the vacuum energy gravitates. Therefore, the cosmological constant should be enormous. It is minuscule. Since there is no understanding of why the cosmological constant is so small, it is important to test this idea in many different situations. In particular, given the span of distances in astronomy and particle physics, it is vital to test the gravitation of vacuum energy on as many distance scales as we can. Rydberg atoms open up a new set of distances for exploration. It is satisfying to measure the cosmological constant with an atom, but its main significance is extending measurements to microscopic distances. Here, too, there is no evidence of the gravitation of the vacuum. At scales of a micron and less, we place a limit of $7$ GeV on the scale of gravitating vacuum energy, well below the scale of $100$ GeV of the SM of particle physics.