String Representation of Gauge Theories

In this talk, various approaches to the problem of evaluation of the field strength correlators in the SU(3)-gluodynamics, which play the major rôle in the Stochastic Vacuum Model, are reviewed. This is done in the framework of the effective Abelian-projected theories under the various assumptions implied on the properties of the ensemble of Abelian-projected monopoles. In particular, within the assumption on the condensation of the monopole Cooper pairs, the main method of investigation is the string representation of field strength correlators. The calculation of the bilocal field strength correlator in the 3D effective theory, where Abelian-projected monopoles are assumed to form a gas, is also presented.