PreprintCC BY 4.0arXiv
Koebe uniformization, John domains, and transboundary modulus
Abstract
We prove Koebe's conjecture for John domains by showing that every planar John domain is conformally equivalent to a circle domain. Our proof is based on a geometric property of John domains, which we prove to be sufficient for uniformization by a circle domain. As a consequence, we obtain an alternative proof of Koebe's conjecture for inner uniform and Gromov hyperbolic domains, recovering results established in earlier work of the authors. Finally, we derive a necessary and sufficient condition for a domain to satisfy Koebe's conjecture by using Schramm's transboundary modulus and well-behaved exhaustions of circle domains constructed by the second author and Rajala.
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BibTeX
@misc{karafyllia2026koebe,
title = {{Koebe uniformization, John domains, and transboundary modulus}},
author = {Christina Karafyllia and Dimitrios Ntalampekos},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.31216},
eprint = {2609.31216},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.31216},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Koebe uniformization, John domains, and transboundary modulus
AU - Christina Karafyllia
AU - Dimitrios Ntalampekos
PY - 2026
DA - 2026/09/25
PB - arXiv
DO - 10.48550/arxiv.2609.31216
UR - https://arxiv.org/abs/2609.31216
AB - We prove Koebe's conjecture for John domains by showing that every planar John domain is conformally equivalent to a circle domain. Our proof is based on a geometric property of John domains, which we prove to be sufficient for uniformization by a circle domain. As a consequence, we obtain an alternative proof of Koebe's conjecture for inner uniform and Gromov hyperbolic domains, recovering results established in earlier work of the authors. Finally, we derive a necessary and sufficient condition for a domain to satisfy Koebe's conjecture by using Schramm's transboundary modulus and well-behaved exhaustions of circle domains constructed by the second author and Rajala.
ER -