Knizhnik–Zamolodchikov equations

The Knizhnik–Zamolodchikov equations (KZ equations) are a set of linear partial differential equations that arise in the context of conformal field theory and quantum groups. They were introduced by Vladimir Knizhnik and Alexander Zamolodchikov in the late 1980s. These equations are particularly relevant in the study of vertex operators, conformal field theories, and the representation theory of quantum affine algebras.