The Calabi-Yau problem for minimal surfaces with Cantor ends
Franc Forstneric
TL;DR
This work resolves a Calabi--Yau-type problem for minimal surfaces by showing that every compact connected or bordered open Riemann surface $M$ contains a Cantor set $C$ whose complement $M\setminus C$ admits a complete conformal minimal immersion into $\mathbb{R}^3$ with a bounded image (and, in higher dimension, a bounded embedding into $\mathbb{R}^5$). The authors develop and combine tools from the Enneper--Weierstrass representation, Oka theory via the holomorphic null quadric $\mathbf{A}_*$, Runge--Mergelyan approximation on admissible sets, and an intrinsic-radius enlargement lemma to iteratively extend, approximate, and control the surface while driving completeness. The construction yields a Cantor-type end for the minimal surface, and the method extends to holomorphic immersions into complex manifolds ($\dim \ge 2$), holomorphic null immersions ($n\ge 3$), holomorphic Legendrian immersions, and oriented superminimal surfaces in (anti-)self-dual Einstein 4-manifolds through corresponding geometric correspondences. These results provide new, first-of-their-kind examples of complete bounded minimal surfaces with Cantor ends and reveal a broad axiomatic framework for Calabi--Yau-type properties across multiple geometric settings.
Abstract
We show that every connected compact or bordered Riemann surface contains a Cantor set whose complement admits a complete conformal minimal immersion in $\mathbb R^3$ with bounded image. The analogous result holds for holomorphic immersions into any complex manifold of dimension at least $2$, for holomorphic null immersions into $\mathbb C^n$ with $n\ge 3$, for holomorphic Legendrian immersions into an arbitrary complex contact manifold, and for superminimal immersions in any self-dual or anti-self-dual Einstein four-manifold.
