Topogenous orders and related families of morphisms

Abstract

In a category C with a proper (E,M)-factorization system, we study the notions of strict, co-strict, initial and final morphisms with respect  to a topogenous order. Besides showing that they allow simultaneous study of four classes of morphisms obtained separately with  respect to closure, interior and neighbourhood operators, the initial and final morphisms lead us to the study of topogenous orders  induced by pointed and co-pointed endofunctors. We also lift the topogenous orders along an M-fibration. This permits one to obtain the  lifting of interior and neighbourhood operators along an M-fibration and includes the lifting of closure operators found in the literature.  A number of examples presented at the end of the paper demonstrates our results.