English

Internal geometry and functors between sites

Category Theory 2024-08-12 v1 Differential Geometry

Abstract

Locality is implemented in an arbitrary category using Grothendieck topologies. We explore how different Grothendieck topologies on one category can be related, and, more general, how functors between categories can preserve them. As applications of locality, we review geometric objects such as sheaves, groupoids, functors, bibundles, and anafunctors internal to an arbitrary Grothendieck site. We give definitions such that all these objects are invariant under equivalences of Grothendieck topologies and certain functors between sites. As examples of sites, we look at categories of smooth manifolds, diffeological spaces, topological spaces, and sheaves, and we study properties of various functors between those.

Keywords

Cite

@article{arxiv.2408.04989,
  title  = {Internal geometry and functors between sites},
  author = {Konrad Waldorf},
  journal= {arXiv preprint arXiv:2408.04989},
  year   = {2024}
}
R2 v1 2026-06-28T18:08:31.430Z