English

Internal categories, anafunctors and localisations

Category Theory 2013-02-25 v3

Abstract

In this article we review the theory of anafunctors introduced by Makkai and Bartels, and show that given a subcanonical site S, one can form a bicategorical localisation of various 2-categories of internal categories or groupoids at weak equivalences using anafunctors as 1-arrows. This unifies a number of proofs throughout the literature, using the fewest assumptions possible on S.

Keywords

Cite

@article{arxiv.1101.2363,
  title  = {Internal categories, anafunctors and localisations},
  author = {David M. Roberts},
  journal= {arXiv preprint arXiv:1101.2363},
  year   = {2013}
}

Comments

42 pages. Final version to appear in Theory and Applications of Categories. License is CC-BY

R2 v1 2026-06-21T17:11:00.805Z