Title : ( Asymmetric Choi–Davis inequalities )
Authors: Mohsen Kian , Mohammad Sal Moslehian , R. Nakamoto ,Access to full-text not allowed by authors
Abstract
Let $\\\\\\\\\\\\\\\\Phi$ be a unital positive linear map and let $A$ be a positive invertible operator. We prove that there exist partial isometries $U$ and $V$ such that \\\\\\\\\\\\\\\\[ |\\\\\\\\\\\\\\\\Phi(f(A))\\\\\\\\\\\\\\\\Phi(A)\\\\\\\\\\\\\\\\Phi(g(A))|\\\\\\\\\\\\\\\\leq U^*\\\\\\\\\\\\\\\\Phi(f(A)Ag(A))U \\\\\\\\\\\\\\\\] and \\\\\\\\\\\\\\\\[\\\\\\\\\\\\\\\\left|\\\\\\\\\\\\\\\\Phi\\\\\\\\\\\\\\\\left(f(A)\\\\\\\\\\\\\\\\right)^{-r}\\\\\\\\\\\\\\\\Phi(A)^r\\\\\\\\\\\\\\\\Phi\\\\\\\\\\\\\\\\left(g(A)\\\\\\\\\\\\\\\\right)^{-r}\\\\\\\\\\\\\\\\right|\\\\\\\\\\\\\\\\leq V^*\\\\\\\\\\\\\\\\Phi\\\\\\\\\\\\\\\\left(f(A)^{-r}A^rg(A)^{-r}\\\\\\\\\\\\\\\\right)V\\\\\\\\\\\\\\\\] hold under some mild operator convex conditions and some positive numbers $r$. Further, we show that if $f^2$ is operator concave, then $$ |\\\\\\\\\\\\\\\\Phi(f(A))\\\\\\\\\\\\\\\\Phi(A)|\\\\\\\\\\\\\\\\leq \\\\\\\\\\\\\\\\Phi(Af(A)).$$ In addition, we give some counterparts to the asymmetric Choi--Davis inequality and asymmetric Kadison inequality. Our results extend some inequalities due to Bourin--Ricard and Furuta.
Keywords
, Choi--Davis inequality, positive linear map, Kadison inequality, Kantorovich constant@article{paperid:1082224,
author = {Mohsen Kian and Sal Moslehian, Mohammad and R. Nakamoto},
title = {Asymmetric Choi–Davis inequalities},
journal = {Linear and Multilinear Algebra},
year = {2020},
volume = {70},
number = {17},
month = {October},
issn = {0308-1087},
pages = {3287--3300},
numpages = {13},
keywords = {Choi--Davis inequality; positive linear map; Kadison inequality; Kantorovich constant},
}
%0 Journal Article
%T Asymmetric Choi–Davis inequalities
%A Mohsen Kian
%A Sal Moslehian, Mohammad
%A R. Nakamoto
%J Linear and Multilinear Algebra
%@ 0308-1087
%D 2020