English

On Krull-Schmidt bicategories

Category Theory 2022-01-31 v2 Representation Theory

Abstract

We study the existence and uniqueness of direct sum decompositions in additive bicategories. We find a simple definition of Krull-Schmidt bicategories, for which we prove the uniqueness of decompositions into indecomposable objects as well as a characterization in terms of splitting of idempotents and properties of 2-cell endomorphism rings. Examples of Krull-Schmidt bicategories abound, with many arising from the various flavors of 2-dimensional linear representation theory.

Keywords

Cite

@article{arxiv.2111.06965,
  title  = {On Krull-Schmidt bicategories},
  author = {Ivo Dell'Ambrogio},
  journal= {arXiv preprint arXiv:2111.06965},
  year   = {2022}
}

Comments

21 pages, final version. Several examples added

R2 v1 2026-06-24T07:36:53.962Z