Uses of Sigma Models

Understand

This is a brief review of some of the uses of nonlinear sigma models.

• After a short general discussion touching on point particles, strings and condensed matter systems, focus is shifted to sigma models as probes of target space geometries.
• The relation of supersymmetric non-linear sigma models to K\"ahler, hyperk\"ahler, hyperk\"ahler with torsion and generalised K\"ahler geometries is described.