Prof. T. P. Singh

The motion of stars in the outer regions of spiral galaxies disagrees with Kepler's third law, below a certain universal critical acceleration. The popular explanation is that there is additional invisible mass which resolves the discrepancy. An alternative explanation is that Newton's law of gravitation is being modified, as proposed in the phenomenological Modified Newtonian Dynamics (MOND). This MOND phenomenology is in need of an underlying fundamental theory. Our work on unification predicts a relativistic fifth force, dubbed dark electromagnetism (DEM), which couples to square root of mass, and which could be the origin of MOND. The experimental discovery of the corresponding massless gauge boson, the dark photon, could serve as evidence for DEM and for MOND.