English

A Gruss inequality for n-positive linear maps

Operator Algebras 2012-03-22 v1

Abstract

Let A\mathscr{A} be a unital CC^*-algebra and let Φ:AB(H)\Phi: \mathscr{A} \to {\mathbb B}({\mathscr H}) be a unital nn-positive linear map between CC^*-algebras for some n3n \geq 3. We show that Φ(AB)Φ(A)Φ(B)Δ(A,)Δ(B,)\|\Phi(AB)-\Phi(A)\Phi(B)\| \leq \Delta(A,||\cdot||)\,\Delta(B,||\cdot||) for all operators A,BAA, B \in \mathscr{A}, where Δ(C,)\Delta(C,\|\cdot\|) denotes the operator norm distance of CC from the scalar operators.

Keywords

Cite

@article{arxiv.1006.1021,
  title  = {A Gruss inequality for n-positive linear maps},
  author = {Mohammad Sal Moslehian and Rajna Rajic},
  journal= {arXiv preprint arXiv:1006.1021},
  year   = {2012}
}

Comments

7 pages; to appear in Linear Algebra Appl. (LAA)

R2 v1 2026-06-21T15:32:20.838Z