Critical phenomena

Summary

Critical phenomena are the behaviours of a physical system near a critical point. Such a point is a point of a continuous phase transition, often the end point of a line of first-order transitions. There the correlation length diverges, thermodynamic quantities follow power laws with critical exponents, and the system looks the same at all scales. These exponents depend only on a few features, such as dimension and symmetry, which is called universality. The renormalization group explains these facts.