Dark energy in the lab: searching for chameleons and symmetrons with atom interferometry

Theories of dark energy generically introduce new degrees of freedom to the gravitational sector. These degrees of freedom mediate a fifth force between matter particles, which can in principle be an O(1) correction to General Relativity. Compatibility with traditional tests of gravity requires that such forces be dynamically suppressed, or screened, in certain environments like the Solar System. I will discuss how a new generation of laboratory-based measurements of gravity, designed to be sensitive to screened forces, are playing a vital role in the search for dark energy. In particular, I will focus on two popular models of screened dark energy, the chameleon and the symmetron, and the strong new bounds on those theories coming from atom interferometers.