A Remark on Contractible Banach Algebras of Operators

Maysam Maysami Sadr

For a Banach algebra $A$, we say that an element $M$ in $A{\otimes }^{\gamma }A$ is a hyper-commutator if $(a\otimes 1)M=M(1\otimes a)$ for every $a\in A$. A diagonal for a Banach algebra is…