摘要

Let C be a category with finite colimits, writing its coproduct +, and let (D, circle times) be a braided monoidal category. We describe a method of producing a symmetric monoidal category from a lax braided monoidal functor F: (C,+) (D, circle times), and of producing a strong monoidal functor between such categories from a monoidal natural transformation between such functors. The objects of these categories, our so-called 'decorated cospan categories', are simply the objects of C, while the morphisms are pairs comprising a cospan X -> N <- Y in C together with an element 1 -> FN in D. Moreover, decorated cospan categories are hypergraph categories-each object is equipped with a special commutative Frobenius monoid-and their functors preserve this structure.

  • 出版日期2015