Modified Newtonian dynamics (MOND) and its possible interpretations

Modified Newtonian dynamics (MOND) is intended for description of galaxy rotation curves and some other astrophysical phenomena without introduction of the dark matter hypothesis, which seems to encounter serious difficulties. Being rather simple and rich of its consequences, it leaves several questions concerning what physics underlies it. In particular, physical nature of the «fundamental acceleration» and its relation to Hubble constant still remain unclear. In present work, after brief discussion of the well-known versions of MOND, a new, relational version is proposed, which is based on a modification of classical conception of space-time at large scale of distances. In the framework of the proposed approach the effect of gravitational deflection of light is considered.