Higher rank numerical ranges of Jordan-like matrices
Martín Argerami, Saleh Mustafa · Linear and Multilinear Algebra · 2019
We completely characterize the higher rank numerical range of the matrices of the form Jn(α)⊕βIm, where Jn(α) is the n×n Jordan block with eigenvalue α. Our characterization allows us to obtain concrete examples of several extreme properties of higher rank numerical ranges.