Algebras of diagonal operators of the form scalar-plus-compact are Calkin algebras

Pavlos Motakis, Daniele Puglisi, Andreas Tolias

For every Banach space $X$ with a Schauder basis consider the Banach algebra $\mathbb{R}I\oplus {\mathcal{K}}_{\mathrm{diag}}(X)$ of all diagonal operators that are of the form $λI + K…