English

Some applications of two completely copositive maps

Functional Analysis 2020-01-09 v1 Operator Algebras

Abstract

A linear map Φ:MnMk\Phi :\mathbb{M}_n \to \mathbb{M}_k is called completely copositive if the resulting matrix [Φ(Aj,i)]i,j=1m[\Phi (A_{j,i})]_{i,j=1}^m is positive semidefinite for any integer mm and positive semidefinite matrix [Ai,j]i,j=1m[A_{i,j}]_{i,j=1}^m. In this paper, we present some applications of the completely copositive maps Φ(X)=(trX)I+X\Phi (X)=(\mathrm{tr} X)I+X and Ψ(X)=(trX)IX\Psi (X)= (\mathrm{tr} X)I-X. Some new extensions about traces inequalities of positive semidefinite 3×33\times 3 block matrices are included.

Keywords

Cite

@article{arxiv.2001.02343,
  title  = {Some applications of two completely copositive maps},
  author = {Yongtao Li and Yang Huang and Lihua Feng and Weijun Liu},
  journal= {arXiv preprint arXiv:2001.02343},
  year   = {2020}
}

Comments

8 pages

R2 v1 2026-06-23T13:05:35.134Z