AF -algebras from non AF groupoids
arXiv:2106.14032
Abstract
We construct ample groupoids from certain categories of paths, and prove that their -algebras coincide with the continued fraction AF algebras of Effros and Shen. The proof relies on recent classification results for simple nuclear -algebras. The groupoids are not principal. This provides examples of Cartan subalgebras in the continued fraction AF algebras that are isomorphic, but not conjugate, to the standard diagonal subalgebras.
version 4: final version, to appear in Transactions AMS; minor errors corrected