RELATIVISTIC GAUGE-INVARIANT POTENTIALS

A global method characterizing the invariant connections on an abelian principal bundle under a group of transformations is applied in order to get gauge invariant electromagnetic (elm.) potentials in a systema tic way. So, we have classified all the elm. gauge invariant potential s under the Poincare subgroups of dimensions 4, 5, and 6, up to conjug ation. It is paid attention in particular to the situation where these subgroups do not act transitively on the space-time manifold. We have used the same procedure for some galilean subgroups to get nonrelativ istic potentials and study the way they are related to their relativis tic partners by means of contractions. Some conformal gauge invariant potentials have also been derived and considered when they are seen as consequence of an enlargement of the Poincare symmetries.