English

Surfaces of infinite-type are non-Hopfian

Geometric Topology 2023-06-07 v2 Algebraic Topology

Abstract

We show that finite-type surfaces are characterized by a topological analog of the Hopf property. Namely, an oriented surface Σ\Sigma is of finite-type if and only if every proper map f ⁣:ΣΣf\colon\Sigma\to \Sigma of degree one is homotopic to a homeomorphism.

Keywords

Cite

@article{arxiv.2210.03395,
  title  = {Surfaces of infinite-type are non-Hopfian},
  author = {Sumanta Das and Siddhartha Gadgil},
  journal= {arXiv preprint arXiv:2210.03395},
  year   = {2023}
}

Comments

8 pages, 4 figures. v2: incorporates the referee's comments, accepted in the Comptes Rendus Math\'ematique