Wide binaries as a critical test for Gravity theories

Understand

Assuming Newton's gravity and GR to be valid at all scales leads to the dark matter hypothesis as a requirement demanded by the observed dynamics and measured baryonic content at galactic and extragalactic scales.

• Alternatively, modified gravity scenarios where a change of regime appears at acceleration scales $a<a_{0}$ have been proposed.
• This modified regime at $a<a_{0}$ will generically be characterised by equilibrium velocities which become independent of distance.
• Here we identify a critical test in this debate and we propose its application to samples of wide binary stars.