 Complex potential reduction of anti-self-dual Yang-Mills

Locally, the ASDYM equations permit a complex gauge with $A_w=A_z=0$. The trace equation then gives $A_{\bar{w}}=K_z$ and $A_{\bar{z}}=-K_w$. The remaining curvature equation is $K_{w\bar{w}}+K_{z\bar{z}}-[K_w,K_z]=0$. A complex gauge generally makes $K$ valued in the complexification of a Lie algebra; reconstructing a real connection requires its inherited reality condition. The gauge/potential construction is local and need not preserve prescribed behaviour at infinity.