Intheoretical physics,statistical field theory (SFT) is a theoretical framework that describes systems with many degrees of freedom, particularly nearphase transitions.[1] It does not denote a single theory but encompasses many models, including formagnetism,superconductivity,superfluidity,[2]topological phase transition,wetting[3][4] as well as non-equilibrium phase transitions.[5] A SFT is any model instatistical mechanics where thedegrees of freedom comprise afield or fields. In other words, themicrostates of the system are expressed through field configurations. It is closely related toquantum field theory, which describes thequantum mechanics of fields, and shares with it many techniques, such as thepath integral formulation andrenormalization.If the system involves polymers, it is also known aspolymer field theory.
In fact, by performing aWick rotation fromMinkowski space toEuclidean space, many results of statistical field theory can be applied directly to its quantum equivalent.[citation needed] Thecorrelation functions of a statistical field theory are calledSchwinger functions, and their properties are described by theOsterwalder–Schrader axioms.
Statistical field theories are widely used to describe systems inpolymer physics orbiophysics, such aspolymer films, nanostructured blockcopolymers[6] orpolyelectrolytes.[7]