Non-singular maps in toposes with a local state classifier
Abstract
Recent progress on the question of the size of the class of connected and hyperconnected geometric morphisms from a given topos has led to the definition of {\em local state classifier}. We discuss a historical precedent which leads to the notion of {\em non-singular map} and we show that, for a topos with a local state classifier, and each object therein, the domain of the full subcategory of consisting of non-singular maps over is a topos, and that the inclusion is the inverse image functor of a hyperconnected geometric morphism. The prospective geometric applications direct our attention to local state classifiers in toposes `of spaces'. We show that, at least in the pre-cohesive topos of reflexive graphs, the local state classifier, which is a colimit by definition, may be characterized as a limit; more specifically, as a variant of a subobject classifier.
Cite
@article{arxiv.2505.07131,
title = {Non-singular maps in toposes with a local state classifier},
author = {Matí as Menni},
journal= {arXiv preprint arXiv:2505.07131},
year = {2025}
}