Dark Matter (DM) theories and mass-tracing-light theories like MOND are by construction nearly degenerate on galactic scales, but not when it comes to the predicted shapes of Roche Lobes of a two-body system (e.g., a globular cluster orbiting a host galaxy). We show that the flattening of the Roche lobe is sensitive to the function μ(g) in modification of the law of gravity. We generalise the a...

Since Bekenstein’s (2004) creation of his Tensor-Vector-Scalar theory (TeVe S), the Modified Newtonian dynamics (MOND) paradigm has been redeemed from the embarrassment of lacking a relativistic version. One primary success of TeVe S is that it provides an enhancement of gravitational lensing, which could not be achieved by other MONDian theories. Following Bekenstein’s work, we investigate the...

The phenomena customly called Dark Matter or Modified Newtonian Dynamics (MOND) have been argued by Bekenstein (2004) to be the consequences of a covariant scalar field, controlled by a free function (related to the MOND interpolating function μ̃(g/a0)) in its Lagrangian density. In the context of this relativistic MOND theory (TeVeS), we examine critically the interpolating function in the tran...

We look for observational signatures that could discriminate between Newtonian and modified Newtonian (MOND) dynamics in the Milky Way, in view of the advent of large astrometric and spectroscopic surveys. Indeed, a typical signature of MOND is an apparent disk of “phantom” dark matter, which is uniquely correlated with the visible disk-density distribution. Due to this phantom dark disk, Newto...

Modelling on the MOND proposal, we introduce an empirically motivated gravity law for galactic and sub-galactic scales. This, circumvents the need for the cumbersome and ill-defined transition regime which exists in MOND, when passing from the standard gravitational regime at high accelerations to the MOND regime at low accelerations. We show that the proposed force law does not violate dynamic...