Spectral geometric mean and trace characterizations

Airat Bikchentaev, Trung Hoa Dinh, Anh Vu Le +1

We use nearly parallel pure states to characterize positive linear functionals $\varphi$ on ${\mathbb{M}}_n$ as positive multiples of the trace if and only if $ϕ(A \natural B) \leq \sqrt{ϕ…