English

Perturbations of completely positive maps and strong NF algebras

Operator Algebras 2014-02-26 v1 Functional Analysis

Abstract

Let ϕ:MnB(H)\phi:M_n\to B(H) be an injective, completely positive contraction with \Vϕ1:ϕ(Mn)Mn\Vcb1+δ(ϵ).\V\phi^{-1}:\phi(M_n)\to M_n\V_{cb}\leq1+\delta(\epsilon). We show that if either (i) ϕ(Mn)\phi(M_n) is faithful modulo the compact operators or (ii) ϕ(Mn)\phi(M_n) approximately contains a rank 1 projection, then there is a complete order embedding ψ:MnB(H)\psi:M_n\to B(H) with \Vϕψ\Vcb<ϵ.\V\phi-\psi\V_{cb}<\epsilon. We also give examples showing that such a perturbation does not exist in general. As an application, we show that every CC^*-algebra AA with OL(A)=1\mathcal{OL}_\infty(A)=1 and a finite separating family of primitive ideals is a strong NF algebra, providing a partial answer to a question of Junge, Ozawa and Ruan.

Keywords

Cite

@article{arxiv.0906.3510,
  title  = {Perturbations of completely positive maps and strong NF algebras},
  author = {Caleb Eckhardt},
  journal= {arXiv preprint arXiv:0906.3510},
  year   = {2014}
}

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26 pages