The Poincare group gauge approach which dominated gauge gravitation researches for a long time has not succeeded in providing a gravitational field with the status of a translation gauge potential. Therefore, the question on the physical meaning of this potential arises. At the same time, gauge potentials of spatial translations seem to possess the satisfactory physical utilization for description of dislocations in the theory of continuous media. Based on this result, we have suggested that gauge potentials of Poincare space-time translations can also describe sui generis dislocations of a space-time manifold.
The source of these potentials turns out to be the canonical energy-momentum tensor of matter, and they are inserted into the motion equations of a spinless matter via an effective metric. Therefore, translation gauge fields can contribute to standard gravitational effects. In particular, they may be responsible for an additional exponential (Yukawa) type term to the
gravitation potential, i.e., the so-called "fifth force". Newton
This is a hypothetic fifth fundamental interaction which is weaker than gravity. Its experimental verification attracted much attention in 80th, but nothing was found at least at laboratory distances. However, one discusses the fifth force as possible explanation of the “dark matter” phenomena on the astrophysical and cosmological level.