Non-planar ends are continuously unforgettable
Geometric Topology
2026-02-06 v2 Group Theory
Abstract
We show that continuous epimorphisms between a class of subgroups of mapping class groups of orientable infinite-genus 2-manifolds with no planar ends are always induced by homeomorphisms. This class of subgroups includes the pure mapping class group, the closure of the compactly supported mapping classes, and the full mapping class group in the case that the underlying manifold has a finite number of ends or is perfectly self-similar. As a corollary, these groups are Hopfian topological groups.
Cite
@article{arxiv.2409.05502,
title = {Non-planar ends are continuously unforgettable},
author = {Javier Aramayona and Rodrigo De Pool and Rachel Skipper and Jing Tao and Nicholas G. Vlamis and Xiaolei Wu},
journal= {arXiv preprint arXiv:2409.05502},
year = {2026}
}
Comments
v2: incorporates referee's comments, final version