Normal forms and joint numerical ranges of doubly commuting matrices
The authors call a finite set of square complex matrices doubly commuting if each matrix commutes with every other matrix and also with the adjoint of every other matrix. A normal form is derived for finite sets of doubly commuting matrices, under simultaneous unitary similarity. This normal form is further used to study joint numerical ranges of doubly commuting matrices.
scientific article; zbMATH DE number 1420055