文摘
We simplify and improve a recent result of Martin (Trans AMS 368:647–658, 2016). Then we prove that if f is an orientation preserving harmonic mapping of the unit disk onto a \(C^{3,\alpha }\) surface \(\Sigma \) bounded by a Jordan curve \(\gamma \in C^{3,\alpha }\), that belongs to the boundary of a convex domain in \(\mathbf {R}^3\), then f is a diffeomorphism.