Flag Manifold Sigma Models and Nilpotent Orbits

We study flag manifold sigma models that admit a zero-curvature representation. We show that these models can be naturally viewed as interacting (holomorphic and antiholomorphic) $\beta \gamma $-systems. In addition, using the theory of nilpotent orbits of complex Lie groups, we establish a relation of flag manifold sigma models to the principal chiral model.