@Article{CMR-31-89, author = {Xi , Cui and JI , Guoxing}, title = {Additive Maps Preserving the Star Partial Order on $\mathcal{B}(\mathcal{H})$}, journal = {Communications in Mathematical Research }, year = {2021}, volume = {31}, number = {1}, pages = {89--96}, abstract = {

Let $\mathcal{B}(\mathcal{H})$ be the $C^∗$-algebra of all bounded linear operators on a complex Hilbert space $\mathcal{H}$. It is proved that an additive surjective map $φ$ on $\mathcal{B}(\mathcal{H})$ preserving the star partial order in both directions if and only if one of the following assertions holds. (1) There exist a nonzero complex number $α$ and two unitary operators $\boldsymbol{U}$ and $\boldsymbol{V}$ on $\mathcal{H}$ such that $φ(\boldsymbol{X}) = α\boldsymbol{UXV}$ or $φ(\boldsymbol{X}) = α\boldsymbol{UX}^∗\boldsymbol{V}$ for all $X ∈ \mathcal{B}(\mathcal{H})$. (2) There exist a nonzero $α$ and two anti-unitary operators $\boldsymbol{U}$ and $\boldsymbol{V}$ on $\mathcal{H}$ such that $φ(\boldsymbol{X}) = α\boldsymbol{UXV}$ or $φ(\boldsymbol{X}) = α\boldsymbol{UX}^∗\boldsymbol{V}$ for all $X ∈ \mathcal{B}(\mathcal{H})$.

}, issn = {2707-8523}, doi = {https://doi.org/10.13447/j.1674-5647.2015.01.10}, url = {http://global-sci.org/intro/article_detail/cmr/18951.html} }