English

Kan injectivity in order-enriched categories

Logic in Computer Science 2019-02-20 v1 Category Theory

Abstract

Continuous lattices were characterised by Martin Escardo as precisely the objects that are Kan-injective w.r.t. a certain class of morphisms. We study Kan-injectivity in general categories enriched in posets. For every class H of morphisms we study the subcategory of all objects Kan-injective w.r.t. H and all morphisms preserving Kan-extensions. For categories such as Top_0 and Pos we prove that whenever H is a set of morphisms, the above subcategory is monadic, and the monad it creates is a Kock-Zoeberlein monad. However, this does not generalise to proper classes: we present a class of continuous mappings in Top_0 for which Kan-injectivity does not yield a monadic category.

Cite

@article{arxiv.1311.1721,
  title  = {Kan injectivity in order-enriched categories},
  author = {Jiri Adamek and Lurdes Sousa and Jiri Velebil},
  journal= {arXiv preprint arXiv:1311.1721},
  year   = {2019}
}

Comments

23 pages

R2 v1 2026-06-22T02:03:06.288Z