New generalized inequalities using arbitrary operator means and their duals

Abstract

In this article, we present some operator inequalities via
arbitrary operator means and unital positive linear maps. For instance, we show
that if $A,B \in {\mathbb B}({\mathscr H}) $ are two positive invertible operators such that $0 < m \leq A,B \leq M$ and $\sigma$ is an arbitrary operator mean, then
\begin{align*}
\Phi^{p}(A\sigma B) \leq K^{p}(h) \Phi^{p}(B\sigma^{\perp} A),
\end{align*}
where $\sigma^{\perp}$ is dual $\sigma$, $p\geq0$ and
$K(h)=\frac{(M+m)^{2}}{4 Mm}$ is the classical Kantorovich constant. We also generalize the above inequality
for two arbitrary means $\sigma_{1},\sigma_{2}$ which lie between
$\sigma$ and $\sigma^{\perp}$.