English

Decomposability of bimodule maps

Operator Algebras 2014-04-07 v1

Abstract

Consider a unital C*-algebra A, a von Neumann algebra M, a unital sub-C*-algebra C of A and a unital *-homomorphism π\pi from C to M. Let u: A --> M be a decomposable map (i.e. a linear combination of completely positive maps) which is a C-bimodule map with respect to π\pi. We show that u is a linear combination of C-bimodule completely positive maps if and only if there exists a projection e in the commutant of π(C)\pi(C) such that u is valued in eMe and eπ(.)ee\pi(.)e has a completely positive extension A --> eMe.

Keywords

Cite

@article{arxiv.1404.1173,
  title  = {Decomposability of bimodule maps},
  author = {Christian Le Merdy and Lina Oliveira},
  journal= {arXiv preprint arXiv:1404.1173},
  year   = {2014}
}
R2 v1 2026-06-22T03:43:01.733Z