Searching for dark energy with the Sun

Understand

General extensions of General Relativity (GR) based on bona fide degrees of freedom predict a fifth force which operates within massive objects, opening up an exciting opportunity to perform precision tests of gravity at stellar scales.

• Here, focusing on general scalar-tensor theories for dark energy, we utilize the Sun as our laboratory and search for imprints of the fifth-force effect on the solar equilibrium structure.
• With analytic results and numerical simulations, we explain how the different solar regions offer powerful ways to test gravity.
• Accounting for the delicate interplay between fifth force and solar microphysics such as opacity, diffusion, equation of state and metallicity, we demonstrate that the fifth force still leaves a sharp signature on the solar sound speed, in a region where simple estimates of input physics uncertainties become negligible.