THE STUCTURE OF THEORY ON ELECTROMAGNETISM FIELD
Li Changzhi ( Xi'an College of Geology )
The structure of electromagnetic field is discussed in this paper. we derive the Maxwell equations from variational principle, simultaneously We show two modern viewpoints that electromagnetic field is a gauge field and electromagnetic potential is the connection on U(1) bundle as well. We get a set of Lorentz covariant electromagnetic equations by means of expressing Maxwell equations into exterior differential forms. Sta'rting from the fact that over non-monoconnectivity base manifold there exist different connections on U ( 1 ) bundle, we get out Aharanov-Bohm effect. Finally taking account of symmetry of Maxwell equations carresponding to E and B , the magnetic monop-ole Problems are discussed.