English

A note on proper asymptotic uniqueness for semifinite factors

Operator Algebras 2025-12-09 v1

Abstract

Let A\mathcal{A} be a separable nuclear C*-algebra, and let M\mathcal{M} be a semifinite von Neumann factor with separable predual. Let ϕ,ψ:AM\phi, \psi: \mathcal{A} \rightarrow \mathcal{M} be essential trivial extensions with ϕ(a)ψ(a)KM\phi(a) - \psi(a) \in \mathcal{K}_{\mathcal{M}} for all aAa \in \mathcal{A} such that either both ϕ\phi and ψ\psi (and hence A\mathcal{A}) are unital or both ϕ\phi and ψ\psi have large complement. Then ϕ\phi and ψ\psi are properly asymptotically unitarily equivalent if and only if [ϕ,ψ]CS=0[\phi, \psi]_{CS} = 0 in KK(A,C(SKM))KK(\mathcal{A}, \mathcal{C}(S \mathcal{K}_{\mathcal{M}})).

Keywords

Cite

@article{arxiv.2512.07587,
  title  = {A note on proper asymptotic uniqueness for semifinite factors},
  author = {Ping Wong Ng and Cangyuan Wang},
  journal= {arXiv preprint arXiv:2512.07587},
  year   = {2025}
}

Comments

22 pages

R2 v1 2026-07-01T08:14:54.621Z