Instanton-induced defects in gauge theories
The confinement of quarks in quantum chromodynamics is an unsolved problem within the standard model of elementary particles. The picture of the QCD vacuum as a dual superconductor relies on magnetic monopoles occuring in Abelian projections. The definition of the latter is discussed in detail, including the Gribov problem and the three most popular examples. Defects induced by instantons are presented both for special cases and in a general context. Results are obtained by analytical means and compared to lattice simulations.