1 Electromagnetic duality and monopoles

The electromagnetic duality of the Maxwell theory, exchanging electric and magnetic fields, plays a central role in this lecture note. It is therefore convenient to review it here, without the extra complication of supersymmetry. The basic features of magnetic monopoles will also be recalled.

 1.1 Electric and magnetic charges
 1.2 The S and the T transformations
 1.3 ’t Hooft-Polyakov monopoles
  1.3.1 Classical features
  1.3.2 Semiclassical features