Comptes Rendus. Mathématique (Oct 2023)

Surfaces of infinite-type are non-Hopfian

  • Das, Sumanta,
  • Gadgil, Siddhartha

DOI
https://doi.org/10.5802/crmath.504
Journal volume & issue
Vol. 361, no. G8
pp. 1349 – 1356

Abstract

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