English

Accessibility and presentability in 2-categories

Category Theory 2025-08-05 v6

Abstract

We outline a definition of accessible and presentable objects in a 2-category K\mathcal K endowed with a "KZ context", that is to say a pair of lax-idempotent monads interacting in a prescribed way; this perspective suggests a unified treatment of many "Gabriel-Ulmer like" theorems, asserting how presentable objects arise as reflections of generating ones. We outline the notion of "(Gabriel-Ulmer) envelope" for a KZ context, sufficient to concoct Gabriel-Ulmer duality. We end the paper with a roundup of examples, involving classical (set-based and enriched), low dimensional category theory, and a perspective for future work, rooted in higher category theory and homotopy theory.

Keywords

Cite

@article{arxiv.1804.08710,
  title  = {Accessibility and presentability in 2-categories},
  author = {Ivan Di Liberti and Fosco Loregian},
  journal= {arXiv preprint arXiv:1804.08710},
  year   = {2025}
}

Comments

Final version, accepted for publication on JPAA

R2 v1 2026-06-23T01:33:10.933Z