Searching for Chameleon Dark Energy with Mechanical Systems

Understand

A light scalar field framework of dark energy, sometimes referred to as quintessence, introduces a fifth force between normal matter objects.

• Screening mechanisms, such as the chameleon model, allow the scalar field to be almost massless on cosmological scales while simultaneously evading laboratory constraints.
• We explore the ability of mechanical systems available in the near term to directly detect the fifth force associated with chameleon dark energy.
• We provide analytical expressions for the weakest accessible chameleon model parameters in terms of experimentally tunable variables and apply our analysis to two mechanical systems: levitated microspheres and torsion balances, showing that the current generation of these experiments have the sensitivity to rule out a significant portion of the proposed chameleon parameter space.