An alternative to the dark matter paradigm: relativistic MOND gravitation

MOND, invented by Milgrom, is a phenomenological scheme whose basic premise is that the visible matter distribution in a galaxy or cluster of galaxies alone determines its dynamics. MOND fits many observations surprisingly well. Could it be that there is no dark matter in these systems and we witness rather a violation of Newton’s universal gravity law ? If so, Einstein’s general relativity would also be violated. For long conceptual problems have prevented construction of a consistent relativistic substitute which does not obviously run afoul of the facts. Here I sketch TeVe S, a tensor-vectorscalar field theory which seems to fit the bill: it has no obvious conceptual problems and has a MOND and Newtonian limits under the proper circumstances. It also passes the elementary solar system tests of gravity theory. Dedicated to Moti Milgrom who started it all Here I discuss a modified gravity theory. Modified gravity is often mentioned today in relation with dark energy in cosmology. But I concentrate on the first systematic modified gravity approach to the mass discrepancy in galaxies and clusters, Milgrom’s modified Newtonian dynamics (MOND) [1, 2, 3], and report on a relativistic implementation of it [4]. My approach is phenomenologically motivated, not theory motivated.