A Selection Theorem for the Carathéodory Kernel Convergence of Pointed Domains
Kang-Tae Kim, Thomas Pawlaschyk
TL;DR
The paper introduces a notion of Carathéodory kernel convergence for sequences of pointed domains in $\mathbb{C}^n$ and proves a selection theorem guaranteeing a subsequence converges to its kernel $Ker_{\hat p}\{(G_j,p_j)\}$. It then establishes a high-dimensional Carathéodory kernel theorem: when biholomorphic maps between tamed domain pairs converge, the limits between the kernels are biholomorphisms, with the subsequential limits preserving invertibility. The authors provide explicit kernel-computation tools, including monotone formulas, the pre-kernel construction, and a Psi-based framework for sublevel set kernels. Overall, the work furnishes a robust topological framework connecting kernel limits to normal-family phenomena and high-dimensional holomorphic mapping, enabling analysis of varying domains and their holomorphic images.
Abstract
We present a selection theorem for domains in $\mathbb{C}^n$, $n\ge 1$, which states that any tamed sequence of pointed connected open subsets admits a subsequence convergent to its own kernel in the sense of Carathéodory. Not only is this analogous to the well-known Blaschke selection theorem for compact convex sets, but it fits better in the study of normal families of holomorphic maps with varying domains and ranges.
