English

Semisimplicity manifesting as categorical smallness

Functional Analysis 2023-11-23 v1 Category Theory Metric Geometry Operator Algebras Rings and Algebras

Abstract

For a compact group G\mathbb{G}, the functor from unital Banach algebras with contractive morphisms to metric spaces with 1-Lipschitz maps sending a Banach algebra AA to the space of G\mathbb{G}-representations in AA preserves filtered colimits. Along with this, we prove a number of analogues: one can substitute unitary representations in CC^*-algebras, as well as semisimple finite-dimensional Banach algebras (or finite-dimensional CC^*-algebras) for G\mathbb{G}. These all mimic results on the metric-enriched finite generation/presentability of finite-dimensional Banach spaces due to Ad{\'a}mek and Rosick{\'y}. We also give an alternative proof of that finite presentability result, along with parallel results on functors represented by compact metric, metric convex, or metric absolutely convex spaces.

Keywords

Cite

@article{arxiv.2311.13122,
  title  = {Semisimplicity manifesting as categorical smallness},
  author = {Alexandru Chirvasitu},
  journal= {arXiv preprint arXiv:2311.13122},
  year   = {2023}
}

Comments

15 pages + references

R2 v1 2026-06-28T13:28:09.513Z