The magnetic charges of stable self-dual monopoles

Gauge theories, in which the Higgs field lies in the adjoint representation, has zero self-coupling (the BPS limit) and leads to an exact symmetry of the local form U(1) × K with K semisimple, are considered. The charges of potentially stable magnetic monopoles, arising as classical solutions, are analysed and it is found that they have a structure consistent with their interpretation as heavy gauge particles of an overall symmetry group dual to the original one, providing further circumstantial evidence for the duality between electric and magnetic fields in this type of theory.