Cellular stratified spaces

TL;DR

This paper extends the theory of cellular stratified spaces by introducing topological acyclic categories, enhancing the understanding of their structure and applications in configuration spaces of graphs.

Contribution

It generalizes the correspondence between cellular stratified spaces and acyclic categories by replacing cells with stellar cells and categories with topological acyclic categories.

Findings

Extended the cellular stratified spaces framework.

Established a correspondence with topological acyclic categories.

Improved understanding of configuration spaces of graphs.

Abstract

The notion of cellular stratified spaces was introduced in a joint work of the author with Basabe, Gonz{\'a}lez, and Rudyak with the aim of constructing a cellular model of the configuration space of a sphere. Although the original aim was not achieved in the project, the notion of cellular stratified spaces turns out to be useful, at least, in the study of configuration spaces of graphs. In particular, the notion of totally normal cellular stratified spaces was used successfully in a joint work with the former students of the author arXiv:1312.7368 to study the homotopy type of configuration spaces of graphs with a small number of vertices. Roughly speaking, totally normal cellular stratified spaces correspond to acyclic categories in the same way regular cell complexes correspond to posets. In this paper, we extend this correspondence by replacing cells by stellar cells and acyclic categories by topological acyclic categories.