Positive linear maps on normal matrices
Affiliation auteurs | Affiliation ok |
Titre | Positive linear maps on normal matrices |
Type de publication | Journal Article |
Year of Publication | 2018 |
Auteurs | Bourin J-C, Lee E-Y |
Journal | INTERNATIONAL JOURNAL OF MATHEMATICS |
Volume | 29 |
Pagination | 1850088 |
Date Published | NOV |
Type of Article | Article |
ISSN | 0129-167X |
Mots-clés | Matrix geometric mean, matrix inequalities, Positive linear maps, Schur products, unitary orbits |
Résumé | For a positive linear map Phi and a normal matrix N, we show that vertical bar Phi(N)vertical bar is bounded by some simple linear combinations in the unitary orbit of Phi(vertical bar N vertical bar). Several elegant sharp inequalities are derived, for instance for the Schur product of two normal matrices A, B is an element of M-n, vertical bar A circle B vertical bar <= vertical bar A vertical bar circle vertical bar B vertical bar + 1/4V (vertical bar A vertical bar circle vertical bar B vertical bar)V* for some unitary V is an element of M-n, where the constant 1/4 is optimal. |
DOI | 10.1142/S0129167X1850088X |