Algebraic Maximal Numerical Range and its preservers of Triple Products on $C^{\ast }$-Algebras

Yongqi Fan, Xiaofei Qi, Jinchuan Hou

Let $\mathcal{A}$ and $\mathcal{B}$ be unital $C^{\ast }$-algebras, and let $V_0(a)=\{f(a):f\in \mathcal{S}(\mathcal{A}),f(a^{\ast }a)=\Vert a{\Vert }^2\}$ be the algebraic maximal numerical range of $a\…