Hilbert space operators with compatible off-diagonal corners

L. Livshits, G. MacDonald, L. W. Marcoux +1

Given a complex, separable Hilbert space $\mathcal{H}$, we characterize those operators for which $\Vert PT(I-P)\Vert =\Vert (I-P)TP\Vert$ for all orthogonal projections $P$ on $\mathca…