English

A note on \'etale endomorphisms of normal schemes

Algebraic Geometry 2024-09-24 v2

Abstract

We prove that under some extra hypothesis, given an \'etale endomorphism of a normal irreducible Noetherian and simply connected scheme, if the endomorphism is surjective then it is injective. The additional assumption concerns the possibility of constructing an \'etale cover out of a surjective \'etale morphism. We show that in some cases the surjectivity hypothesis can be removed if the intended \'etale cover is Galois.

Keywords

Cite

@article{arxiv.2409.12163,
  title  = {A note on \'etale endomorphisms of normal schemes},
  author = {Lázaro O. Rodríguez Díaz},
  journal= {arXiv preprint arXiv:2409.12163},
  year   = {2024}
}

Comments

Theorem 2 of the previous version is incorrect

R2 v1 2026-06-28T18:49:19.169Z