ALGEBRAICALLY COHERENT CATEGORIES

作者：Cigoli Alan S^*; Gray James R A; Van der Linden Tim

来源：Theory and Applications of Categories, 2015, 30: 1864-1905.

• Coherent functor
• Smith, Huq, Higgins commutator
• semi-abelian, locally algebraically cartesian closed category
• category of interest
• compact Hausdorff algebra

We call a finitely complete category algebraically coherent if 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.

• 出版日期2015