Two-dimensional chiral models with infinite-dimensional symmetry algebras

Two-dimensional $G$-invariant chiral models of general form with torsion on Lie groups G are studied. A subclass of models that possess Kac–Moody (KM) symmetry is identified. The corresponding conserved currents are obtained. The geometrical part of the single-loop counterterm, which determines the renormalization of the coupling constants, is calculated. The renormalization-group properties of a class of two-charge models with KM symmetry are considered.