Distinguishing modified gravity models

Understand

Modified gravity models with screening in local environments appear in three different guises: chameleon, K-mouflage and Vainshtein mechanisms.

• We propose to look for differences between these classes of models by considering cosmological observations at low redshift.
• In particular, we analyse the redshift dependence of the fine structure constant and the proton to electron mass ratio in each of these scenarios.
• When the absorption lines belong to unscreened regions of space such as dwarf galaxies, a time variation would be present for chameleons.