11 Novembro 1997, 15:30
Walter Tholen, York University
Weak factorization systems, pointed endofunctors, and separability

Analyzing the well-known correspondence between reflective subcategories and factorization systems, we are led to a functorial notion of weak factorization system and a correspondence with pointed endofunctors. A significant new technique is the "slicing" of pointed endofunctors, since notions like well-pointedness and idempotency become especially important when required for the slices of an endofunctor. We shall illustrate our results in terms of examples from general topology and module theory.