4 papers
Morphisms and comorphisms of sites II -- Distributors of sites
Axel Osmond, Olivia Caramello
We introduce a notion of distributor of sites, involving suited analogs of flatness and cover-preservation, and show that this notion jointly generalizes those of morphism and como…
Morphisms and comorphisms of sites I -- Double categories of sites
Olivia Caramello, Axel Osmond
We arrange morphisms and comorphisms of sites as the horizontal and vertical cells of a double category of sites; using the formalism of extensions and restrictions of presheaves,…
On a (terminally connected, pro-etale) factorization of geometric morphisms
Olivia Caramello, Axel Osmond
We extend the classical (connected, etale) factorization of locally connected geometric morphisms into a (terminally connected, pro-etale) factorization for all geometric morphisms…
Bi-accessible and bipresentable 2-categories
Ivan Di Liberti, Axel Osmond
We develop a 2-dimensional version of accessibility and presentability compatible with the formalism of flat pseudofunctors. First we give prerequisites on the different notions of…