Preservers of Unitary Similarity Functions on Lie Products of Matrices

Jianlian Cui, Chi-Kwong Li, Yiu-Tung Poon

Denote by $M_n$ the set of $n\times n$ complex matrices. Let $f:M_n\to [0,\infty )$ be a continuous map such that $f(\mu UA{U}^{\ast })=f(A)$ for any complex unit $\mu$, $A\in M_n$ a…