Recall that a locally small category is total if its Yoneda embedding has a left adjoint .
A total category is totally distributive if has a further left adjoint .
If is totally distributive, then since is fully faithful, then, by the properties of adjoint triples, so is . Thus, is a coreflective subcategory of , which is cototal (or more precisely, pro-cototal?, since it is not locally small) β hence is also cototal.
Moreover this means that the induced adjoint pair of (co-)monads
is an adjoint modality.
Every totally distributive category is an example of a completely distributive category.
If is a small category, then its presheaf category is totally distributive.
If is totally distributive and is a full subcategory that is both reflective and coreflective, then is totally distributive.
For any total category, it is possible to define the functor which βwants to beβ the left adjoint of . The elements of are called waves from to (just because they are usually denoted by wavy arrows), and as in the case of continuous categories they form an idempotent comonad on in the bicategory of profunctors. A total category is totally distributive if and only if .
Totally distributive categories are βalmostβ an example of continuous algebras for a lax-idempotent 2-monad.
Robert Rosebrugh, Richard J. Wood, An adjoint characterization of the category of sets. PAMS 122 2 (1994) 409-413 [jstor:2161031]
Rory Lucyshyn-Wright, Totally distributive toposes. spnet.
Francisco Marmolejo, Bob Rosebrugh, and Richard Wood, Completely and totally distributive categories I, JPAA 216 no. 8-9 (2012). PDF
Richard J. Wood, βThe waves of a total category.β Theory and Applications of Categories 30.47 (2015): 1624-1646.
Last revised on January 7, 2025 at 16:07:21. See the history of this page for a list of all contributions to it.