English

Computably strongly self-absorbing C*-algebras

Logic 2024-09-30 v1 Operator Algebras

Abstract

We introduce the notion of a computably strongly self-absorbing C*-algebra and show that the following C*-algebras are computably strongly self-absorbing: the Cuntz algebras O2\mathcal{O}_2 and O\mathcal{O}_\infty, the UHF algebra Mn(C)M_{\mathfrak{n}}(\mathbb{C}) and the tensor product Mn(C)OM_{\mathfrak{n}}(\mathbb{C})\otimes \mathcal{O}_\infty, where n\mathfrak{n} is a supernatural number of infinite type with computably enumerable support, and the Jiang-Su algebra Z\mathcal{Z}. In connection with the last example, we show that Z\mathcal{Z} has a computable presentation. The results above are a special instance of a computable version of the standard approximate intertwining argument due to Elliott.

Keywords

Cite

@article{arxiv.2409.18834,
  title  = {Computably strongly self-absorbing C*-algebras},
  author = {Isaac Goldbring},
  journal= {arXiv preprint arXiv:2409.18834},
  year   = {2024}
}

Comments

16 pages; first draft; comments welcome!

R2 v1 2026-06-28T18:59:39.607Z