Wu-Yang ambiguity in connection space
  Two distinct gauge potentials can have the same field strength, in which case they are said to be ``copies'' of each other. The consequences of this possibility for the general space A of gauge potentials are examined. Any two potentials are connected by a straight line in A, but a straight line going through two copies either contains no other copy or is entirely formed by copies. 
R. Aldrovandi and A. L. Barbosa