English

Algebraically coherent categories

Category Theory 2015-12-10 v3

Abstract

We call a finitely complete category algebraically coherent when the change-of-base functors of its fibration of points are coherent, which means that they preserve finite limits and jointly strongly epimorphic pairs of arrows. We give examples of categories satisfying this condition; for instance, coherent categories, categories of interest in the sense of Orzech, and (compact) Hausdorff algebras over a semi-abelian algebraically coherent theory. We study equivalent conditions in the context of semi-abelian categories, as well as some of its consequences: including amongst others, strong protomodularity, and normality of Higgins commutators for normal subobjects, and in the varietal case, fibre-wise algebraic cartesian closedness.

Keywords

Cite

@article{arxiv.1409.4219,
  title  = {Algebraically coherent categories},
  author = {Alan S. Cigoli and James R. A. Gray and Tim Van der Linden},
  journal= {arXiv preprint arXiv:1409.4219},
  year   = {2015}
}

Comments

33 pages; changes throughout the text

R2 v1 2026-06-22T05:56:43.818Z