Twistor Lifts and Factorization for Conformal Maps from a Surface to the Euclidean Four-space

Abstract

A conformal map from a Riemann surface to the Euclidean four-space is explained in terms of its twistor lift. A local factorization of a differential of a conformal map is obtained. As an application, the factorization of a differential provides an upper bound of the area of a super-conformal map around a branch point.