SU(N) monopoles with and without SUSY

Abstract

These are expanded notes of lectures given at the Advanced Summer School on Modern Mathematical Physics (JINR Dubna, July 2005) and at the 8th International School-Seminar ``The actual problems of microworld physics 2005'' (Gomel-Dubna, August 2005). I review classical monopole solutions of the SU(N) Yang-Mills-Higgs theory. The first part is a pedagogical introduction into to the theory of non-Abelian SU(2) monopoles. In the second part I discuss a particular case of SU(3) theories containing different limits of symmetry breaking. It turns out that the multimonopole configurations are natural in a model with the gauge group of higher rank. Here I discuss fundamental and composite monopoles and consider the limiting situation of the massless states. In the last part I briefly discuss construction of the $N = 2$ SU(2) supersymmetric monopoles and some of the basic properties which are connected with the field theoretical aspects of these classical solutions.