The Modified dynamics (MOND) has been propounded as an alternative to Dark matter. It imputes the mass discrepancy in galaxy systems to failure of standard dynamics in the limit of small accelerations. After a brief description of the MOND tenets, I discuss how its predictions now compare with the data. I put special emphasis on rotation-curve analysis– whence comes the most clear-cut support f...

Many past attempts to kill MOND have only strengthened the theory. Better data on galaxy velocity curves clearly favor MOND (without fine-tuning) over cold dark matter. The usual critism on the incompleteness of classical MOND has spurred a Modified Relativity (MR) by Bekenstein. After outlining cosmology and lensing in MOND, we review MOND on small scales. We point out some potential problems ...

A second-order dual for a nonlinear programming problem was introduced by Mangasarian ([1]). Later, Mond [2] proved duality theorems under a condition which is called “second-order convexity”. This condition is much simpler than that used by Mangasarian. Later, Mond and Weir [3] reformulated the second-order dual. In [4], Mond considered the class of nondifferentiable mathematical programming p...

To explain the appearance in MOND of a cosmological acceleration constant, a0, I suggest that MOND inertia–as embodied in the actions of free particles and fields–is due to effects of the vacuum. The same vacuum effects enter both MOND (through a0) and cosmology (e.g. through a cosmological constant Λ). For example, a constant-acceleration (a) observer in de Sitter universe sees Unruh radiation...

We examine two corollaries of MOND pertaining to properties of the equivalent darkmatter halo. MOND predicts for pure exponential discs a tight relation involving the halo and disc scale lengths and the mean acceleration in the disc, which we find to test favorably against the Verheijen sample of Ursa Major galaxies. A correlation between halo and disc length scales is also apparent when the “m...

The Modified Newtonian Dynamics (MOND) and the Universal Rotation Curve (URC) are two ways to describe the general properties of rotation curves, with very different approaches concerning dark matter and gravity. Phenomenological similarities between the two approaches are studied by looking for properties predicted in one framework that are also reproducible in the other one. First, we looked ...

We simultaneously integrate in a numerical way the equations of motion of both the Magellanic Clouds (MCs) in the MOdified Newtonian Dynamics (MOND), MOdified Gravity (MOG) and Cold Dark Matter (CDM) frameworks for −1 ≤ t ≤ 1 Gyr in order to see if, at least in principle, it is possible to discriminate between them. Since the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC) are...

Numerous astrophysical observations have shown that classical Newtonian dynamics fails on galactic scales and beyond, if only visible matter is taken into account. The two most popular theoretical concepts dealing with this problem are Dark Matter (DM) and Modified Newtonian Dynamics (MOND). In the first part of this paper it is demonstrated that a generalized MOND equation can be derived in th...

We examine the implications of Modified Newtonian Dynamics (MOND) on the large scale structure in a Friedmann-Robertson-Walker universe. We employ a “Jeans swindle” to write a MOND-type relationship between the fluctuations in the density and the gravitational force, g. In linear Newtonian theory, |g| decreases with time and eventually becomes < g0 , the threshold below which MOND is dominant. ...

We extend the MOND analysis to a sample of 17 high surface brightness, early-type disc galaxies with rotation curves derived from a combination of 21cm Hi line observations and optical spectroscopic data. A number of these galaxies have asymptotic rotation velocities between 250 and 350 km/s making them among the most massive systems (in terms of baryonic mass) considered in the context of MOND...