English

The existence of UFO implies projectively universal morphisms

Functional Analysis 2022-08-10 v2 Category Theory Operator Algebras

Abstract

Let C\mathcal C be a concrete category. We prove that if C\mathcal{C} admits a universally free object F\mathsf F, then there is a projectively universal morphism u ⁣:FFu\colon \mathsf F\to \mathsf F, i.e., a morphism uu such that for any BCB\in \mathcal{C} and τMor(B)\tau\in {\rm Mor}(B) there exists an epimorphism πMor(F,B)\pi\in {\rm Mor}(\mathsf F, B) such that πτ=uπ\pi \tau = u \pi. This builds upon and extends various ideas by Darji and Matheron (Proc. Am. Math. Soc. 145 (2017)) who proved such a result for the category of separable Banach spaces with contractive operators as well as certain classes of dynamical systems on compact metric spaces. Specialising from our abstract setting, we conclude that the result applies to various categories of Banach spaces/lattices/algebras, C*-algebras, etc.

Cite

@article{arxiv.2208.03579,
  title  = {The existence of UFO implies projectively universal morphisms},
  author = {Marek Balcerzak and Tomasz Kania},
  journal= {arXiv preprint arXiv:2208.03579},
  year   = {2022}
}

Comments

7 pp

R2 v1 2026-06-25T01:32:25.037Z