Journal of Operator Theory, Vol. 64, No. 2 (Fall 2010), pp. 265-298 (34 pages) We prove some noncommutative analogues of a theorem proved by Plotkin and Rudin about isometries between subspaces of ...

We study the following question: suppose that A and ℬ are two algebras of complex n × n matrices such that the ring commutator [A, B] = AB – BA is "small" for each A ∈ A and B ∈ ℬ; does this imply ...