Critical Slowing Down and Defect Formation

The formation of topological defects in a second order phase transition in the early universe is an out-of-equilibrium process. Condensed matter experiments seem to support Zurek's mechanism, in which the freezing of thermal fluctuations close to the critical point (critical slowing down) plays a crucial role. We discuss how this picture can be extrapolated to the early universe, pointing out that new scaling laws may emerge at very high temperatures and showing how critical slowing down emerges in the context of a relativistic quantum field theory.