Classical Yang-Mills fields with non-compact symmetry and an arbitrary compact gauge group

Classical Yang-Mills equations on Minkowski space are investigated. When the gauge group is SU(2), the authors have shown previously that the only solutions invariant under a non-compact maximal subgroup of the conformal group are Abelian Maxwell fields. In the present paper the analysis is extended to the case where the gauge group is an arbitrary semisimple compact group, with the same negative result. (author)