$C^{\ast }$ exponential length of commutators unitaries in $AH$ algebras

Chun Guang Li, Liangqing Li, Iván Velázquez Ruiz

For each unital $C^{\ast }$-algebra $A$, we denote $ce{l}_{CU}(A)=\sup \{cel(u):u\in CU(A)\}$, where $cel(u)$ is the exponential length of $u$ and $CU(A)$ is the closure of the commutator s…