English

Classification of Certain C*-Algebras Generated by Two Partitions of Unity

Operator Algebras 2025-09-03 v1

Abstract

We study C*-algebras generated by two partitions of unity subject to orthogonality relations governed by a bipartite graph which we also call "bipartite graph C*-algebras". These algebras generalize at the same time the C*-algebra C(p,q)C^\ast(p,q) generated by two projections and the hypergraph C*-algebras of Trieb, Weber and Zenner. We describe alternative universal generators of bipartite graph C*-algebras and study partitions of unity in generic position associated to a bipartite graph. As a main result, we prove that bipartite graph C*-algebras are completely classified by their one- and two-dimensional irreducible representations which provides a first step towards a classification of the more general hypergraph C*-algebras.

Keywords

Cite

@article{arxiv.2509.01309,
  title  = {Classification of Certain C*-Algebras Generated by Two Partitions of Unity},
  author = {Björn Schäfer},
  journal= {arXiv preprint arXiv:2509.01309},
  year   = {2025}
}

Comments

28 pages