English

Non-amenable simple C*-algebras with tracial approximation

Operator Algebras 2021-01-21 v1

Abstract

We construct two types of unital separable simple CC^*-alebras AzC1A_z^{C_1} and AzC2,A_z^{C_2}, one is exact but not amenable, and the other is non-exact. Both have the same Elliott invariant as the Jiang-Su algebra, namely, AzCiA_z^{C_i} has a unique tracial state, (K0(AzCi),K0(AzCi)+,[1AzCi])=(Z,Z+,1)(K_0(A_z^{C_i}), K_0(A_z^{C_i})_+, [1_{A_z^{C_i}} ])=(\mathbb Z, \mathbb Z_+,1) and K1(AzCi)={0}K_{1}(A_z^{C_i})=\{0\} (i=1,2i=1,2). We show that AzCiA_z^{C_i} (i=1,2i=1,2) is essentially tracially in the class of separable Z{\cal Z}-stable CC^*-alebras of nuclear dimension 1. AzCiA_z^{C_i} has stable rank one, strict comparison for positive elements and no 2-quasitrace other than the unique tracial state. We also produce models of unital separable simple non-exact CC^*-alebras which are essentially tracially in the class of simple separable nuclear Z{\cal Z}-stable CC^*-alebras and the models exhaust all possible weakly unperforated Elliott invariants. We also discuss some basic properties of essential tracial approximation.

Keywords

Cite

@article{arxiv.2101.07900,
  title  = {Non-amenable simple C*-algebras with tracial approximation},
  author = {Xuanlong Fu and Huaxin Lin},
  journal= {arXiv preprint arXiv:2101.07900},
  year   = {2021}
}
R2 v1 2026-06-23T22:20:07.646Z