Constraining MOND Using the Vertical Motion of Stars in the Solar Neighborhood

Ben Margalit, Nir J. Shaviv

Published 2015-05-18Version 1

Stars with a different vertical motion relative to the galactic disk have a different average acceleration. According to Modified Newtonian Dynamics (MOND) theories they should therefore have a different average orbital velocity while revolving around the Milky Way. We show that this property can be used to constrain MOND theories by studying stars in the local neighborhood. With the Hipparcos dataset we can only place marginal constraints. However, the forthcoming GAIA catalogue with its significantly fainter cutoff should allow placing a stringent constraint. The method cannot be used to prove MOND, since halo stars can contribute a similar signal which would be hard to discern.