arXiv2018
We present some operator inequalities for positive linear maps that generalize and improve the derived results in some recent years. For instant, if $A$ and $B$ are positive operators and $m,m^{'},M,M^{'}$ are positive real numbers satisfying either one of the condition $ 0<m \leq B \leq m^{'} <M^{'} \leq A \leq M $ or $0<m \leq A \leq m^{'} <M^{'} \leq B \leq M$, then \begin{align*} Φ^{p} \big(A \nabla _{v} B+2 r Mm (A^{-1}\nabla B^{-1}- &A^{-1} \sharp B^{-1} )\big)\\ & \leq \left( \frac{K(h)}{ 4^{\frac{2}{p}-1} K^{r_{1}} \left( \sqrt {h^{'}}\right)} \right) ^{p} Φ^{p} (A \sharp_ν B) \end{align*} and \begin{align*} Φ^{p} \big(A \nabla _{v} B+2 r Mm (A^{-1}\nabla B^{-1}-& A^{-1} \sharp B^{-1} )\big) \\ &\leq \left( \frac{K(h)}{ 4^{\frac{2}{p}-1} K^{r_{1}}\left( \sqrt {h^{'}}\right)}\right) ^{p} (Φ(A) \sharp_ν Φ(B))^{p}, \end{align*} where $Φ$ is a positive unital linear map, $ 0 \leq ν\leq 1$, $p \geq 2,$ $r=\min\{ν,1-ν\},$ $h=\frac{M}{m},$ $h^{'}=\frac{M^{'}}{m^{'}}$, $K(h)=\frac{(1+h)^{2}}{4h}$ and $r_{1}=\min\{2r,1-2r\}.$ We also obtain a reverse of the Ando inequality for positive linear maps via the Kantorovich constant.