2004ApJ...604L..37D

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 Letter it is demonstrated that a generalized MOND equation can be derived in the framework of Newtonian DM theory. For systems satisfying a fixed relationship between the gravitational fields caused by DM and visible matter, this generalized MOND equation reduces to the traditional MOND law, first postulated by Milgrom. Therefore, we come to the conclusion that traditional MOND can be also interpreted as a special limit case of DM theory. In the second part of this Letter, a formal derivation of the Tully-Fisher relation is discussed.