English

Gabriel-Ulmer duality for topoi and its relation with site presentations

Category Theory 2025-08-05 v2

Abstract

Let κ\kappa be a regular cardinal. We study Gabriel-Ulmer duality when one restricts the 2-category of locally κ\kappa-presentable categories with κ\kappa-accessible right adjoints to its locally full sub-2-category of κ\kappa-presentable Grothendieck topoi with geometric κ\kappa-accessible morphisms. In particular, we provide a full understanding of the locally full sub-2-category of the 2-category of κ\kappa-small cocomplete categories with κ\kappa-colimit preserving functors arising as the corresponding 2-category of presentations via the restriction. We analyse the relation of these presentations of Grothendieck topoi with site presentations and we show that the 2-category of locally κ\kappa-presentable Grothendieck topoi with geometric κ\kappa-accessible morphisms is a reflective sub-bicategory of the full sub-2-category of the 2-category of sites with morphisms of sites genearated by the weakly κ\kappa-ary sites in the sense of Shulman [37].

Keywords

Cite

@article{arxiv.1902.09391,
  title  = {Gabriel-Ulmer duality for topoi and its relation with site presentations},
  author = {Ivan Di Liberti and Julia Ramos González},
  journal= {arXiv preprint arXiv:1902.09391},
  year   = {2025}
}

Comments

25 pages

R2 v1 2026-06-23T07:50:16.263Z