Abstract
We first review the fundamental ideas of the Dirac magnetic monopole and the 't Hooft-Polyakov topological monopole. The violation of the baryon number conservation law due to the monopole, which was recently discovered by Rubakov and Callan, is also reviewed. In the main part of this thesis we investigate the fermion condensation around the monopole at finite temperature. The condensate, which causes the baryon number non-conservation, is shown to evapolate as the temperature goes up. As a by-product of the investigation we find an unfamiliar non-monotonic temperature dependence of the static correlation function for bi-fermion operators.
