As is well known, a complex $m \times m$ matrix $A$ is a commutator (i.e., there are matrices $B$ and $C$ of the same dimensions as $A$ such that $A=[B,C]=BC-CB$) if and only if $A$ has zero trace. If $\|\cdot\|$ … Continue reading Colloquium: Tuesday, March 15, 2 pm. Speaker: Gideon Schechtman (Weizmann) . Title: “A quantitative version of the commutator theorem for zero trace matrices”.