Toposes over which essential implies locally connected
Category Theory
2022-04-07 v1
Abstract
We introduce the notion of an EILC topos: a topos such that every essential geometric morphism with codomain is locally connected. We then show that the topos of sheaves on a topological space is EILC if is Hausdorff (or more generally, if is Jacobson). Further examples of Grothendieck toposes that are EILC are Boolean \'etendues and classifying toposes of compact groups. Next, we introduce the weaker notion of CILC topos: a topos such that any geometric morphism is locally connected, as soon as is cartesian closed. We give some examples of topological spaces and small categories such that resp. are CILC. Finally, we show that any Boolean elementary topos is CILC.
Cite
@article{arxiv.2204.02749,
title = {Toposes over which essential implies locally connected},
author = {Jens Hemelaer},
journal= {arXiv preprint arXiv:2204.02749},
year = {2022}
}
Comments
17 pages