Understanding disk galaxy rotation velocities without dark matter
  contribution--a physical process for MOND?
  An impact model of gravity designed to emulate Newton's law of gravitation is
applied to the radial acceleration of disk galaxies. Based on this model
(Wilhelm et al. 2013), the rotation velocity curves can be understood without
the need to postulate any dark matter contribution. The increased acceleration
in the plane of the disk is a consequence of multiple interactions of gravitons
(called "quadrupoles" in the original paper) and the subsequent propagation in
this plane and not in three-dimensional space. The concept provides a physical
process that relates the fit parameter of the acceleration scale defined by
McGaugh et al. (2016) to the mean free path length of gravitons in the disks of
galaxies. It may also explain the modification of the gravitational interaction
at low acceleration levels in MOND (Milgrom 1983, 1994, 2015, 2016). Three
examples are discussed in some detail: The spiral galaxies NGC 7814, NGC 6503
and M 33.
