English

2-positive almost order zero maps and decomposition rank

Operator Algebras 2020-10-13 v2 Quantum Algebra

Abstract

We consider 2-positive almost order zero (disjointness preserving) maps on C*-algebras. Generalizing the argument of M. Choi for multiplicative domains, we give an internal characterization of almost order zero for 2-positive maps. It is also shown that complete positivity can be reduced to 2-positivity in the definition of decomposition rank for unital separable C*-algebras.

Keywords

Cite

@article{arxiv.1908.03466,
  title  = {2-positive almost order zero maps and decomposition rank},
  author = {Yasuhiko Sato},
  journal= {arXiv preprint arXiv:1908.03466},
  year   = {2020}
}

Comments

21 pages, the first main theorem improved, minor corrections

R2 v1 2026-06-23T10:43:47.674Z