Isospectrality and matrices with concentric circular higher rank numerical ranges
نویسندگان
چکیده
We characterize under what conditions n×n Hermitian matrices A1 and A2 have the property that spectrum of costA1+sintA2 is independent t (thus, trigonometric pencil isospectral). One characterizations requires first ⌈n2⌉ higher rank numerical ranges matrix A1+iA2 to be circular disks with center 0. Finding unitary similarity between and, say, involves finding a solution Lax's equation.
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ژورنال
عنوان ژورنال: Linear Algebra and its Applications
سال: 2021
ISSN: ['1873-1856', '0024-3795']
DOI: https://doi.org/10.1016/j.laa.2021.08.025