nLab
abstract circle

Contents

Idea

An abstract circle in the sense of (Moerdijk 96) is essentially a cellular structure of the form of a circle S 1S^1, in direct analogy to how a linear interval in the abstract sense is a cellular model of the actual topological interval [0,1][0,1].

Indeed, just as linear intervals have as classifying topos the category of simplicial sets, so abstract circles have as classifying topos the category of cyclic sets (Moerdijk 96).

References

Created on March 31, 2014 at 00:18:34. See the history of this page for a list of all contributions to it.