English

The \'{e}tale sectional number is either 1 or infinity

Algebraic Topology 2025-03-18 v1

Abstract

In this work, we show that the \'{e}tale sectional number (\text{\'{E}tale-sec()(-)}), i.e., the sectional number in the category of topological spaces with the \'{e}tale quasi Grothendieck topology (as defined in arXiv:2410.22515), is either 1 or infinity. Specifically, given a continuous map f:XYf:X\to Y, we demonstrate that Eˊtale-sec(f)={1, if f is locally sectionable,, if f is not locally sectionable.\text{\'{E}tale-sec$(f)$}=\begin{cases} 1,&\hbox{ if $f$ is locally sectionable,} \infty,&\hbox{ if $f$ is not locally sectionable.} \end{cases} Additionally, for a path-connected space XX, the \'{e}tale topological complexity satisfies TCeˊtale(X)={1, if X is locally contractible,, if X is not locally contractible.\text{TC}_{\text{\'{e}tale}}(X)=\begin{cases} 1,&\hbox{ if $X$ is locally contractible,} \infty,&\hbox{ if $X$ is not locally contractible.} \end{cases} These results provide a way to understand the \aspas{complexity} of maps and spaces within the context of the \'{e}tale quasi Grothendieck topology, a structure that considers local behavior of maps and spaces. The classification into values of 1 or infinity reflects a dichotomy in the local geometric structure of the map or space, with the presence or absence of local sections or contractibility significantly influencing the outcome.

Keywords

Cite

@article{arxiv.2503.11942,
  title  = {The \'{e}tale sectional number is either 1 or infinity},
  author = {Cesar A. Ipanaque Zapata},
  journal= {arXiv preprint arXiv:2503.11942},
  year   = {2025}
}

Comments

8 pages. Comments are welcome

R2 v1 2026-06-28T22:21:32.863Z