Generating all Ahlfors currents by a single entire curve
Yunling Chen, John Erik Fornæss, Song-Yan Xie
TL;DR
This work resolves Sibony's conjecture for weak Oka-1 manifolds by constructing an entire curve $F:\mathbb{C}\to X$ whose concentric discs generate all Ahlfors currents on $X$ under the Runge approximation on discs. The authors combine a holomorphic gluing technique, a novel ping-pong induction, and a careful inductive limiting process to amalgamate a countable family of discs into concentric discs from a single $F$, ensuring precise length-area and cohomology control. Central to the approach are a countable disc family generating all Ahlfors currents (via Xie24) and a shrinking-dumbbell lemma with Carathéodory kernel convergence that enables precise current convergence. The result highlights the extraordinary flexibility of entire curves in the weak Oka-1 setting and lays groundwork for potential extensions to Nevanlinna currents and broader Oka-type phenomena.
Abstract
Let \(X\) be a compact complex manifold possessing the \emph{Runge approximation property on discs}, meaning that every holomorphic map from a closed disc into \(X\) is approximable by a global holomorphic map from \(\mathbb{C}\). We construct an entire curve \(F : \mathbb{C} \to X\) such that the associated family of concentric holomorphic discs \(\{F|_{\overline{\mathbb{D}}_r}\}_{r>0}\) generates all Ahlfors currents on \(X\), thereby settling a conjecture of Sibony.
