Schwarz type lemmas and a Landau type theorem of functions satisfying the biharmonic equation (Q2317499)

This article discusses some Schwarz-type results for the biharmonic equation \(\Delta^2f=g\) in the open unit disk \(\mathbb{D}\) subject to boundary conditions \(\Delta f=\varphi\) and \(f=f^*\) on \(\mathbb{T}=\partial \mathbb{D}\), where \(g\in C(\overline{\mathbb{D}})\), \(\varphi, f^*\in C(\mathbb{T})\). A Landau-type theorem is also established.