Open problems on compact constant mean curvature surfaces with boundary
Rafael López
TL;DR
This article aggregates easily stated open problems in the theory of compact cmc surfaces with boundary in $\mathbb{R}^3$ and surveys the current state of knowledge. It emphasizes circle-boundary problems, including conjectures that planar disks and spherical caps are the only compact embedded, disk-like, and stable cmc surfaces with boundary $\mathbb{S}^1$, and discusses related methods such as the Alexandrov reflection principle and rigidity via the Hopf differential. It then analyzes arbitrary boundary curves through the flux formula, clarifying how the mean curvature $H$ is constrained by boundary data and outlining existence questions for a range of $H$ values and boundary configurations. Finally, it reviews the Dirichlet problem for the cmc equation, summarizing solvability criteria under convexity and curvature hypotheses, known barrier-based estimates, and several open questions about convexity and graphicality of cmc graphs on convex domains.
Abstract
We present a collection of easily stated open problems in the theory of compact constant mean curvature surfaces with boundary. We also survey the current status of answering them.
